Technical field
[0001]
　The present invention relates to a process for the preparation of quasi-crystalline-containing plated steel sheet and quasicrystal-containing plated steel sheet.
Background technique
[0002]
　Typically, the outer skin of automobiles, plated steel sheets from the viewpoint of rust is used, it is mainly applied alloyed galvanized steel sheet. Galvannealed steel sheet performs alloying treatment after galvanized steel sheet, improved by diffusing the Fe from the steel sheet as the base material (base steel) in the plating layer, the weldability and corrosion resistance after painting is a plated steel sheet was. On the other hand, in the case of galvannealed steel sheet, easily peeled off the plating layer since the plating layer becomes hard by diffusion of Fe from the base steel, such as powdering or flaking, not seen in the hot-dip galvanized steel sheet softer specific there is also a problem.
[0003]
　Plated steel sheet having a plating layer of rigid, fragile plating layer by external pressure, once cracking occurs, cracks propagated to the interface between the base steel, plating layer falls off by peeling from the interface. For example, when using the galvannealed steel outer panel of an automobile, peeling paint and the plating layer at the same time by chipping by stone recoil vehicle, base steel is likely to be exposed, plated steel sheet of soft without alloying corrosion than may become severely (decrease in chipping resistance).
[0004]
　Here, in order to improve the chipping resistance of the automobile outer plate it is sufficiently provided with a sacrificial protection ability, using plated steel sheet with high plating layer sufficiently suppressing corrosion corrosion from chipping portions as outer plate it is preferable to. Simply, in order to improve the chipping properties, plating layer of soft, or molten Zn-plated steel sheet, but easy to use electrical Zn-plated steel sheets, these plated steel sheets could coating peeling part by chipping case, since the rapid corrosion will progress, not a fundamental resolution of the chipping portion. When corrosion of the plated steel sheet progresses, pitting portion becomes too large, red rust occurs from the center.
[0005]
　For example, as an excellent plated steel sheet corrosion resistance, Patent Document 1 discloses a Zn-Al-Mg-Si-plated steel sheets, fused Zn-Mg alloy plated steel sheet is disclosed in Patent Document 2. Al in the plating layer as described in Patent Document 1, Mg, plated steel sheets with increased corrosion resistance by adding various alloying elements such as Si is Zn-plated steel sheet, a relatively soft plating layer, chipping although portions is small, and chipping portion, if the coating film peeling unit has occurred, again pitting-like corrosion would proceed quickly. Progress in progress of corrosion, also for red rust from the center occurs, there is not sufficient sacrificial protection property. Therefore, the plated steel sheets with improved corrosion resistance under the Patent Document 1, the chipping resistance is not sufficient.
[0006]
　As means for solving the above problems, there is a Zn-Mg alloy coated steel sheet as described in Patent Document 2. Since contain more Mg in the plating layer has a sacrificial protection ability sufficiently, even it progressed pitting, a valid plated steel sheet which does not long to generate red rust. However, plated steel sheet described in Patent Document 2, the first place Zn in the plating layer 3 Mg 7 is formed increase in hardness is intensified, too many pitting point, chipping resistance is remarkably lowered.
[0007]
　Here, in order to achieve both corrosion resistance and chipping resistance, along with constituting the plating layer of a plurality of layers, it means for compounding the plurality of layers have been devised. For example, on the surface of the soft, low alloy plating layer formed on the steel sheet (alloyed galvanized layer), a method of forming a high hard Mg-Al alloy plating layer having corrosion resistance by ion plating method, Patent Document 3 which is incorporated herein by reference. If multi-layered plating layer by laminating a high corrosion resistance Mg-Al alloy plating layer of a soft, low alloy plating layer and the hard, it may be possible to achieve both corrosion resistance and chipping resistance. However, in practice, since the mother layer of the plated layer low alloy plating layer is a simple galvannealing, corrosion resistance of the plated steel sheet is inferior to alloy plated steel sheet disclosed in Patent Document 1 and Patent Document 2. Further, in the plated steel sheet obtained by multilayer the plating layer as disclosed in Patent Document 3, in order to obtain the same corrosion resistance and corrosion resistance disclosed in Patent Document 1 and 2, the upper layer is formed by ion plating the thickness of the mg-Al alloy plating layer, it is necessary to considerably thicker. However, it is difficult to produce a plated steel sheet excellent high corrosion, chipping resistance in a way that increasing the thickness by the ion plating method. Moreover, since it requires a two step process that galvannealed and ion plating, there are also problems such as the cost is increased.
[0008]
　As described above, heretofore, in a relatively large amount of alloy added with alloy-plated steel sheet to improve the corrosion resistance, approach to both chipping resistance is not disclosed.
[0009]
　By the way, quasi-crystals, is the first discovered the crystal structure by Mr. Daniel Shuhitoman in 1982, has an atomic arrangement of the icosahedron (icosahedron). The sintered product structure is aperiodic crystal structure having ordinary metal, are not specific rotational symmetry resulting in alloy (e.g. 5-fold symmetry), a non-periodic typified by 3-dimensional Penrose pattern it is known as the structure and the equivalent crystal structure.
[0010]
　The arrangement of new metal atoms (i.e., the new crystal structure) and later discovery, attention is paid to the quasi-crystals having a specific rotation symmetry having a quasi-periodic structure. Recently, quasicrystals, which can be obtained by the crystal growth is known, heretofore, generally, quasicrystals preparation was a liquid quenching method. Therefore, the shape of the quasicrystals, powder, foil, from being restricted to small pieces, practical examples of products using quasicrystals was very small.
[0011]
　Patent Document 4 and Patent Document 5, high-strength Mg based alloy, and a manufacturing method thereof are disclosed. These Mg-based alloy, a quasi-crystal phase of hard having a particle size of about several tens of nm ~ several hundred nm in the metal structure are dispersed precipitation is an excellent alloy strength and elongation. In these Patent Documents 4 and 5, it utilizes the characteristic that quasicrystals are rigid.
[0012]
　In Patent Document 6, the thermoelectric material is disclosed using the Al reference crystal. In Patent Document 6, utilizing the characteristic that quasicrystals has excellent thermoelectric properties. Patent Document 7 discloses a heat catalyst and a manufacturing method thereof in which a precursor quasicrystalline Al alloy (Al reference crystal) is disclosed. In Patent Document 7, quasicrystals no periodic crystal structure takes advantage of the characteristics of easy brittle fracture. Thus, In the previous inventions, or by dispersing a quasicrystalline as fine particles, or often or solidified molded quasicrystals are fine particles.
[0013]
　To these inventions as another type of usage mode, Patent Document 8 discloses a cooking utensil metal coating comprising a quasicrystal. In Patent Document 8, Al, by plasma spraying the alloy powder containing semi sintered product excellent in corrosion resistance of Fe and Cr, the wear resistance and, by applying a coating having excellent corrosion resistance to salt cookware there.
[0014]
　As mentioned above, Mg reference crystal is used as a material excellent in strength, Al reference crystal member excellent in strength, heat conductive material, and is utilized as cookware coatings. However, their use is intended to be limiting, it can not be said that the use of quasi-crystals are necessarily many areas.
[0015]
　The quasicrystal, there are excellent performance due to the unique crystal structure. However, its properties has not been elucidated only partially, the current can not be said to have been widely industrially used materials. The present inventor has applied a quasicrystal that is not yet industrially most utilized in the plating layer of the plated steel sheet, an attempt was made to improve both the corrosion sacrifice and chipping resistance.
CITATION
Patent Document
[0016]
Patent Document 1: Laid-Open Patent Publication No. 2001-355055
Patent Document 2: Laid-Open Patent Publication No. 2008-255464
Patent Document 3: Japanese Patent Publication No. 4-52284
Patent Document 4: Laid-Open Patent Publication No. 2005-113235
Patent Document 5: Laid-Open Publication No. 2008-69438
Patent Document 6: Japanese Patent Publication No. 8-176762
Patent Document 7: JP Laid-open No. 2004-267878
Patent Document 8: Japanese Patent Publication No. 2007-525596
Summary of the Invention
Problems that the Invention is to Solve
[0017]
　The present invention has been made in view of the above circumstances, it is an object of the present invention achieve both corrosion resistance and chipping resistance, provides a method for producing a quasi-crystalline-containing plated steel sheet and quasicrystal-containing plated steel sheet It is to.
Means for Solving the Problems
[0018]
　The present inventors, in the Zn-Mg alloy plated steel sheet, as a means of obtaining a good chipping resistance, and the plurality of layers having different properties a plating layer considering that the laminated structure. As a result, in the plating layer having a laminated structure, and the surface side of the layer, if the nature of the plating layer inside the layers are significantly different, the plating layer surface cracks caused by external pressure from the plating layer surface is less likely to progress therein, chipping resistance was found to be greatly improved.
[0019]
　Also, with the inclusion of Al in the plating layer, by growing a quasicrystalline phase, the corrosion resistance is improved, and further, in addition to the plurality of layers, the alloy layer at the interface between the plating layer and the base steel sheet by forming, and found to be able to realize a quasi-crystal-containing plated steel sheet that can achieve both with higher dimensions corrosion resistance and chipping resistance.
[0020]
　Further, as a method for producing a quasi-crystalline-containing plated steel sheet, using a Zn-Mg alloy plating in a molten state to form a plating layer, then, it was found to retain heat a predetermined time at a predetermined temperature range . By the production method, the plating layer at a relatively soft and, and, a layer comprising the fine grains, can be separated into two phases of dendritic hard layer located inside the plating layer, quasi having the above characteristics the crystal-containing plated steel sheet becomes possible to manufacture at low cost.
[0021]
　The present invention has been made based on the above findings, and its gist is as follows.
[0022]
(1) and the plating layer located on at least one surface of the steel sheet, is located in the interface between the between the plated layer steel sheet, comprising an alloy layer consisting of Al-Fe intermetallic compound, a, of the plating layer chemical composition, in atomic%, Zn: 28.5% ~ 50 %, Al: 0.3% ~ 12%, La: 0% ~ 3.5%, Ce: 0% ~ 3.5%, Y: 0% ~ 3.5%, Ca: 0% ~ 3.5%, Sr: 0% ~ 0.5%, Si: 0% ~ 0.5%, Ti: 0% ~ 0.5%, Cr: 0% ~ 0.5%, Fe: 0% ~ 2%, Co: 0% ~ 0.5%, Ni: 0% ~ 0.5%, V: 0% ~ 0.5%, Nb: 0% ~ 0.5%, Cu: 0% ~ 0.5%, Sn: 0% ~ 0.5%, Mn: 0% ~ 0.2%, Sb: 0% ~ 0.5%, Pb: 0% containing ~ 0.5%, and the balance of Mg and impurities, wherein Me Is come layer, in order from the steel sheet side, MgZn phases, a first plating layer made of tissue containing Mg phase and quasi-crystalline phase, is located on the first plating layer, Mg 51 Zn 20 phase, Zn a second plating layer comprising a tissue containing phase and quasi-crystalline phase, a semi-crystalline-containing plated steel sheet.
(2) chemical composition of the plating layer, in atomic%, Zn: 32% ~ 40 %, Al: 2% ~ 5%, Ca: containing 1% to 2.5%, the balance being Mg and impurities becomes, the chemical composition satisfies the Zn / Al = 7.5 ~ 18, Ca / Al = 0.4 ~ 1.1, the maximum grain size of the second plating layer, 1 [mu] m or less in circle equivalent diameter in a quasi-crystal-containing plated steel sheet according to (1).
(3) If the thickness direction and the cutting direction viewed the plating layer in a section made parallel, the MgZn phase of the first plating layer, the circle equivalent diameter is composed of more crystal grains 1 [mu] m, the the quasicrystalline phase of the first plating layer is composed of grown tissue along the thickness direction, the quasi-crystal-containing plated steel sheet according to (1) or (2).
(4) when viewed thickness direction and the plating layer and the cutting direction is in a section made parallel, the area of tissue the maximum crystal grain size of the second plating layer is 1μm or less in circle equivalent diameter, wherein 90% or more with respect to the cross-sectional area of the entire second plating layer, (1) quasicrystal-containing plated steel sheet according to any one of - (3).
(5) When the plate thickness direction and cutting direction saw the plating layer in a section made parallel, the area of the MgZn phases of the first plating layer, with respect to the cross-sectional area of the entire first plating layer 10% to 70%, (1) quasicrystal-containing plated steel sheet according to any one of - (4).
(6) the second plating layer does not contain Mg phase, (1) quasicrystal-containing plated steel sheet according to any one of - (5).
(7) the mean value of Vickers hardness of the second plating layer is 250 - 350 Hv, (1) quasicrystal-containing plated steel sheet according to any one of - (6).
(8) the alloy layer, as the Al-Fe intermetallic compound, Fe 5 Al 2 or Al 3.2 comprises at least one of Fe, the thickness of the alloy layer is 10 nm ~ 200 nm, (1) quasicrystal-containing plated steel sheet according to any one of (1) to (7).
(9) Chemical component, in atomic%, Zn: 28.5% ~ 50 %, Al: 0.3% ~ 12%, La: 0% ~ 3.5%, Ce: 0% ~ 3.5% , Y: 0% ~ 3.5% , Ca: 0% ~ 3.5%, Sr: 0% ~ 0.5%, Si: 0% ~ 0.5%, Ti: 0% ~ 0.5% , Cr: 0% ~ 0.5% , Fe: 0% ~ 2%, Co: 0% ~ 0.5%, Ni: 0% ~ 0.5%, V: 0% ~ 0.5%, Nb : 0% ~ 0.5%, Cu : 0% ~ 0.5%, Sn: 0% ~ 0.5%, Mn: 0% ~ 0.2%, Sb: 0% ~ 0.5%, Pb : containing 0% to 0.5%, the balance being Mg and impurities, the plating alloy in a molten state, a plating step of disposed on at least one surface of the steel sheet, the plating alloy of the molten, average It cooled to a temperature range of 330 ° C. or less at a cooling rate of 10 ° C. / sec Te, a first cooling step of forming a plating layer on the surface of the steel sheet, the rear first cooling step, the plating layer, a temperature of 350 ° C. ~ 400 ° C. at a speed range of heating rate 10 ~ 50 ° C. / sec while heated to the range, including a heating holding step of holding 5 to 30 seconds, after the heating holding step, and a second cooling step of cooling the plated layer at 20 ° C. / sec or more cooling rate, the method of quasi-crystal-containing plated steel sheet.
(10) The plating process is performed by hot dipping, after pulled out the steel sheet from the molten coating bath, continuously carrying out the first cooling step, the quasi-crystals contained plated steel sheet according to (9) Production method.
(11) chemical composition of the plating alloy of the molten state, in atomic%, Zn: 32% ~ 40 %, Al: 2% ~ 5%, Ca: containing 1% to 2.5%, the balance being Mg and consists impurities, the chemical composition satisfies the Zn / Al = 7.5 ~ 18, Ca / Al = 0.4 ~ 1.1, according to any one of (8) - (10) method for producing a quasi-crystal-containing plated steel sheet.
Effect of the Invention
[0023]
　According to the present invention described above, as compared with the conventional melting Zn-Mg alloy plated steel sheet, it is possible to provide a quasicrystal-containing plated steel sheet excellent in both corrosion resistance and chipping resistance.
[0024]
　Further, the quasicrystal-containing plated steel sheet according to the present invention, can be excellent chipping properties in addition to automobile parts required, building materials, home appliances member, suitably used to members and the like related to the energy field, long life of these members can contribute to the maintenance effort reduction of, the development of industry to reduce costs and the like.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025]
[1] is an example of a photograph of a sectional structure of the plating layer according to the embodiment of the present invention (TEM images).
[Figure 2A] Mg contained in the second plating layer of the plated layer according to the embodiment of the present invention 51 Z 20 is an example of an electron beam diffraction image of phase.
[FIG 2B] is an example of the quasi-crystal phase electron diffraction image of the contained in the second plating layer of the plated layer according to the embodiment of the present invention.
[FIG 3A] is an example of an electron beam diffraction image of MgZn phases contained in the first plating layer of the plated layer according to the embodiment of the present invention.
[FIG 3B] is an example of the quasi-crystal phase electron diffraction image of the contained in the first plating layer of the plated layer according to the embodiment of the present invention.
[Figure 4] A cross-sectional TEM image of the plating layer shown in FIG. 1, it shows how the crack of the plating layer after the chipping test (chipping cracking) 4 progresses along the interface of the fine layer 1 and the compound layer 2 TEM which is an image.
DESCRIPTION OF THE INVENTION
[0026]
　Reference will now be described in detail preferred embodiments of the present invention. In the specification and the drawings, components having substantially the same function and structure are a repeated explanation thereof by referring to the figures.
[0027]
(Quasicrystal-containing the plated steel sheet)
　One of the characteristics of the quasi-crystal-containing plated steel sheet according to the present invention, as a specific organizational structure of the plating layer having a specific chemical composition, the plated layer base steel (hereinafter, simply " also called steel sheet ".) is to form on the surface of the.
[0028]
　Hereinafter, firstly relates quasicrystal-containing plated steel sheet according to the embodiment of the present invention will be described in detail chemical composition and organization structure of the plating layer.
[0029]
　Quasicrystal-containing plated steel sheet according to the present embodiment, a plating layer located on at least one surface of the steel sheet, is located at the interface between the plated layer and the steel sheet, an alloy layer consisting of Al-Fe intermetallic compounds , comprising a. Here, the chemical components of the plated layer in atomic%, Zn: 28.5% ~ 50%, Al: 0.3% ~ 12%, La: 0% ~ 3.5%, Ce: 0% ~ 3 .5%, Y: 0% ~ 3.5%, Ca: 0% ~ 3.5%, Sr: 0% ~ 0.5%, Si: 0% ~ 0.5%, Ti: 0% ~ 0 .5%, Cr: 0% ~ 0.5%, Fe: 0% ~ 2%, Co: 0% ~ 0.5%, Ni: 0% ~ 0.5%, V: 0% ~ 0.5 %, Nb: 0% ~ 0.5%, Cu: 0% ~ 0.5%, Sn: 0% ~ 0.5%, Mn: 0% ~ 0.2%, Sb: 0% ~ 0.5 % Pb: it contains 0% to 0.5%, the balance being Mg and impurities.
[0030]
　The plating layer of quasi-crystalline-containing plated steel sheet according to the present embodiment, in order from the steel sheet side, MgZn phases, a first plating layer made of tissue containing Mg phase and quasi-crystalline phase, to the first plating layer located, Mg 51 Zn 20 has phase, and a second plating layer comprising a tissue containing Zn phase and quasi-crystalline phase, a.
[0031]
　Incidentally, the steel sheet as a base material of the quasicrystal-containing plated steel sheet according to the present embodiment is not limited in particular. An example of such a steel sheet, for example, can be mentioned Al-killed steel, very low carbon steel, high carbon steel, various high strength steels, Ni, various steel sheets such as Cr-containing steel. Further, steelmaking method and of the base material steel plate, the strength of the steel, hot rolling method, the pickling method, the manufacturing conditions of the steel cold rolled method such as is not particularly limited. That is, the manufacturing conditions and material of the steel sheet to be subjected as a base material of the quasicrystal-containing plated steel sheet is not particularly limited.
[0032]

　First, the chemical components of the plating layer will be described below.
　Incidentally, the plating layer according to the present embodiment, as described below, form, crystal structure, various phases having different compositions becomes layered, it has a characteristic tissue structure. Although for the embodiment and the crystal structure of the plated layer can be observed, since it is difficult to define the chemical composition of the individual layers constituting the plating layer, the chemical composition of the plating layer of the present invention , and to define the chemical composition of the entire plating layer. In the following description,% indicating the chemical components are unless otherwise stated, it means an atomic%. Normally, when displaying the constitutive equation of the metallic phase and the intermetallic compound is not a mass ratio, is because the use of the atomic ratio.
[0033]
: [Zn (zinc) 28.5% to 50%]
　Basically, Mg is poor wettability and reactivity with the steel sheet, the plating layer containing only Mg is very difficult to form on the steel plate . This is not Fe diffusion of the steel sheet in the plating layer, is because the plated layer and the steel plate are not in close contact. Therefore, by incorporating the Zn in the plating layer during a certain concentration or more, can be reactive with the base steel sheet (adhesion) is improved, formed on stable steel plating layer mainly composed of Mg to become.
[0034]
　Further, Zn is an element Al and atomic radii are close a chemical component to be described later. Usually, when Al is added to the plating layer, the Al is replaced with Zn position than Mg and Ca position. This embodiment discloses the multilayer structure formed of a brittle by defining the Mg-Zn composition in the plating layer intermetallic compound avoided, excellent further chipping resistance is formed as described above there. Therefore, as in this embodiment, if the Al is added as chemical components, in order to change substitution behavior of Zn position, it is necessary to define the chemical composition of Zn depending on the amount of Al added. Suitable Zn content satisfies this condition plated layer is 28.5% to 50%.
[0035]
　The Zn content by 28.5% to 60% as metallic structure of the plating layer, it is possible to obtain a quasi-crystalline phase. When Zn content is less than 28.5%, it is impossible to generate a quasi-crystal phase in the plating layer. Further, Zn content is in the case of more than 50%, in the method disclosed in the present invention, it is impossible to preferably generate and distribute the quasicrystalline phase in the plating layer. To control preferably the generation of the quasi-crystal phase, a Zn content may be 30% to 50%. Zn content is more preferably from 35% to 45%. Further, Zn content is more preferably from 36% to 40%. Zn content to be to 36 to 40%, to produce a predetermined position of the preferred plating layer quasicrystalline phase, and it is possible to further improve the corrosion resistance.
[0036]
[Al (aluminum): 0.3% ~
　12%] Al is an element to improve the performance of the plating layer. Specifically, by containing Al in the plating layer, it is possible to improve the plane corrosion resistance of the plating layer. Further, by incorporating the Al, a part of Zn present in phase or intermetallic compound in the coating layer is replaced with Al, to form a substitutional solid solution. As a result, insulating properties with increasing the plating layer, the corrosion resistance is suppressed plating dissolution during ion reaction by increasing, the corrosion loss is reduced.
[0037]
　In particular, the substitution effect, Mg 51 Zn 20 tends to occur with respect to Zn contained in, when the component ratio of Zn is constant, Mg 51 Zn 20 crystal grains are easily further decreased, the planar corrosion resistance there tends to be further improved. The present inventors have found that the composition range of Zn and Al, to meet the Zn / Al = 7.5 ~ 18 are presumed to be important. In order to obtain a further improvement of such a plane corrosion resistance, at the same time, it is important to meet also the component ratio of Ca, the composition range of Ca and Al, a Ca / Al = 0.4 ~ 1.1 it is estimated that it is important to satisfy.
[0038]
　That is, normally, although the effect of improving certain corrosion resistance only when the content is quasicrystalline phase is expected, and further limiting the component composition, by producing a plated steel sheet in the process of the present invention, further improvement in the planar portion corrosion resistance effect can be expected.
[0039]
　Further, Al is the generation of quasi-crystalline, is also the element which exerts a certain effect on the growth, further suitably control the thermal history during manufacture of the plating layer as described later, the interface between the plated layer and the base steel, Al 3 Fe (more specifically, Al 3.2 Fe) or Fe 5 Al 2 like Al-Fe intermetallic compound layer that is formed of, further improves the adhesion of the plating layer, further chipping resistance improvement it is possible to.
[0040]
　For the advantages described above more reliably, the Al content is 0.3% to 12%. If Al content is less than 0.3% can not sufficiently enjoy the insulation increase effect of substituting Zn, and there is a possibility that the formation of the intermetallic compound layer becomes insufficient. Further, without also observed multilayer structure hardly formed quasicrystalline phase.
[0041]
　On the other hand, when the Al content is 12% exceeded, microstructure of the second plating layer to be described below are, coarse primary crystal Al phase is changed to the tissue structure to be dispersed in the tissue, multilayer results structure is not formed, there is a possibility that chipping resistance is lowered. Further, the quasi-crystal phase is also hardly observed for Al phase grows.
[0042]
　Quasicrystals and, in view of the Al-Fe intermetallic compounds formed, a suitable Al content is more preferably 2% to 5%. The Al content by 2% to 5% quasicrystals, so a dendritic form in the first layer, the first layer is kept to a suitable hardness. As a result, corrosion resistance can be produced excellent plated steel sheet in adhesiveness, for example, it is confirmed to improve the impact resistance of the ball impact test or the like.
[0043]
[Mg (magnesium)]
　Mg (magnesium), as well as the Zn and Al, a major element constituting the plating layer is an element to further improve the sacrificial protection property. Moreover, Mg is an important element for promoting the formation of the quasi-crystal phase. In the present embodiment, in particular there is no need to define the Mg content of the plating layer may be the content excluding the content of impurities among the balance described above.
[0044]
　Here, if the Mg content is less than 45%, the balance of the ratio of Zn and Mg in the plating layer is broken, brittle intermetallic compounds in the plating layer is likely to form. When such intermetallic compounds are formed, the adhesion of the plating layer becomes extremely poor, it is difficult to form a plating layer on the steel plate. Therefore, the lower limit of the Mg content in the plating layer is 45%. Incidentally, Mg content is preferably not less than 50%, more preferably at least 55%.
[0045]
　On the other hand, Mg content exceeds 67%, the Zn content in the microstructure of the second plating layer is lowered to be described below, the number of generation of Mg phase, corrosion resistance decreases. Therefore, the upper limit of the Mg content in the plating layer is set to 67%. Incidentally, Mg content is preferably not more than 62%, more preferably not more than 57%.
[0046]
　In addition to the basic components described above, the plating layer of the quasi-crystal-containing plating copper plate according to the present embodiment contains impurities. Here, the impurities, in producing a quasi-crystal-containing plated steel sheet according to the present embodiment industrial raw materials of the steel and plating alloy, or mixed from the manufacturing environment, for example, C (carbon), N (nitrogen), O (oxygen), P (phosphorus), S (sulfur), means the elements such as Cd (cadmium). As these elements impurities be contained respectively 0.1% the effect is not impaired.
[0047]
　Metallization layer of the plated steel sheet according to the present embodiment, instead of a part of the Mg the balance, Ca, Y, La, Ce, Si, Ti, Cr, Fe, Co, Ni, V, Nb, Cu , Sn, Mn, Sr, at least one or more selected components selected from Sb and Pb, may be further included. For either the inclusion of any component of these selected components may be determined as appropriate depending on the purpose. Therefore, it is not necessary to limit the lower limit of these selected components may lower even 0%. Moreover, even if these optional components are contained as an impurity, the effect is not impaired.
[0048]
[Ca (calcium): 0% ~ 3.5%] Ca
　is the case of applying the hot dipping method to form a plating layer, in order to improve the workability of hot dipping, it is contained as necessary it may be. When producing a quasi-crystal-containing plated steel sheet according to the present embodiment in melt plating method, a highly oxidizing molten Mg alloy held in the air as a plating bath. Therefore, it is preferable to take oxidation prevention means some Mg. Ca is easily oxidized than Mg, by forming a stable oxide film on the plating bath surface in the molten state, to prevent oxidation of Mg in the bath. Therefore, the Ca content of the plating layer may be from 0% to 3.5%.
[0049]
　Further, when Ca is contained in the plating bath, the formation of brittle Mg-Zn-based intermetallic compounds contained in the plating layer is suppressed, as a result, the preferred plating layer from the viewpoint of adhesion of the plating layer it is possible to obtain a tissue. Further, since the Ca is contained in the plating bath, it is possible to suppress the generation of dross, the viscosity of the plating bath is decreased, it is possible to improve the operability of the high Mg-containing plating bath . Effect on these Ca is, Ca content was confirmed by 0.3% or more, by 1.0% or more, it is possible to more reliably expression. Therefore, if the inclusion of Ca in the plating bath, Ca content is more preferably 1.0% or more. On the other hand, when the Ca content is 2.5% excess, or brittle intermetallic compound in the plating layer out of balance in the ratio of Zn and Mg is formed, the corrosion resistance is intermetallic compound containing Ca is formed possibility or decrease is high. Therefore, Ca content is preferably set to 2.5% or less. When Ca concentration is high, in the test for evaluating the adhesion of such ball impact, uneven edge tends to be easily peeled off at the top portion or the like.
[0050]
Further,　Mg 51 Zn 20 from the viewpoint of the crystal grains of the control, Ca content preferably satisfies the 1-2%. Further, as described above, it is more preferable to satisfy the component ratio Ca / Al = 0.4 ~ 1.1 with Al. At this time, Mg 51 Zn 20 occur substitution effect of Mg and Ca in, Mg 51 Zn 20 tends to crystal grains is reduced.
[0051]
[Y (yttrium): 0% ~
3.5%] [La (lanthanum): 0% ~
3.5%] [Ce (cerium): 0% ~
　3.5%] Y, La, Ce is, Ca similar to the case of applying the hot dipping method to form a plating layer, may be contained as necessary to improve the operation sacrifice of hot dipping. Y, La, Ce is easily oxidized than Mg, by forming a stable oxide film on the plating bath surface in the molten state, to prevent oxidation of Mg in the bath. Thus, the Y content of the plating layer was 0% to 3.5% of La content is set to 0% to 3.5%, the Ce content may be 0% to 3.5%. More preferably, Y content, La content, with respect to Ce content, respectively, the lower limit was made 0.3%, the upper limit may be 2.0%.
[0052]
　Incidentally, Ca, Y, La, the inclusion of 0.3% or more in total of at least one element selected from Ce, since the Mg content is high plating bath can be maintained without being oxidized in the atmosphere, preferably. On the other hand, Ca, Y, La, Ce is easily oxidized because it may adversely affect the corrosion resistance, Ca, Y, La, the upper limit of the content of Ce, in total, it is preferably set to 3.5% . That is, a Ca content of chemical components in the Y content and the content of La and Ce content in the plating layer, in atomic%, it is preferable to satisfy the 0.3% ≦ Ca + Y + La + Ce ≦ 3.5%.
[0053]
　Further, in order to further be preferably generates a quasi-crystal phase in the plating layer, Ca, Y, La, the content of Ce, in total, is preferably set to 2.0% or less than 0.3%. These elements are believed to replace the Mg constituting the quasi-crystal phase, a large amount when containing these elements, it is conceivable that the generation of the quasi-crystal phase is inhibited. When these elements are contained in a suitable amount, thereby improving the rust inhibiting effect of the quasi-crystal phase and other phases. This effect, the timing of the dissolution of the quasi-crystal phase is presumed to be due to affecting the holding power of the white rust. That is, after elution of the quasi-crystal phase in the coating layer, these elements are incorporated into the formation to white rust, improved rust prevention of white rust and long period until red rust due to corrosion of base steel a is estimated.
[0054]
　Further, among these elements, the effect (oxidation, formation of quasicrystalline phase), Ca, La, obtained relatively large by the inclusion of Ce. On the other hand, the effect obtained by the inclusion of Y is, Ca, La, when compared with Ce, has proven to be small. Ca, La, Ce, compared to Y, easily oxidized, it is estimated to be related is an element rich in reactivity. Analysis of the chemical composition of the quasi-crystal phase in EDX (Energy Dispersive X-ray Spectroscopy), because in many cases Y is not detected, Y is estimated to be not readily taken up into the quasicrystals. On the other hand, Ca, La, Ce tends to be detected with respect to content, the quasi-crystals above its content. Therefore, it is not necessarily contain a Y in the plating layer. If the plating layer Y is not contained, and 0.3% ≦ Ca + La + Ce ≦ 3.5%, may be 0.3% ≦ Ca + La + Ce ≦ 2.0%.
[0055]
[Si (silicon): 0% ~
0.5%] [Ti (titanium): 0% ~
0.5%] [Cr (chromium): 0%
　~ 0.5%] Si, Ti, Cr is plated to preferably generates a quasi-crystal phase in the layer, it may be contained if necessary. Si traces, Ti, when Cr is contained in the plating layer, tends to generate the quasi-crystalline phase, the structure of quasi-crystal phase is stabilized. Si combines with Mg fine Mg 2 by forming a Si, Also, Ti and Cr is poor reactivity with Mg, by which a fine metal phase is considered to be a starting point (nucleus) of the generation of the quasi-crystal phase. Generation of the quasi-crystalline phase generally affected by the cooling rate during manufacturing. However, Si, Ti, when Cr is contained in the plating layer, the tendency of dependence of the cooling rate is reduced for generation of the quasi-crystal phase. Therefore, the Si content of the plating layer was 0% to 0.5% of Ti content is set to 0% to 0.5%, the Cr content may be 0% to 0.5%. More preferably, Si content, Ti content, with respect to the Cr content, respectively, the lower limit was made 0.005%, the upper limit may be 0.1%.
[0056]
　Furthermore, Si, Ti, at least one element selected from Cr, in total, the inclusion 0.005% to 0.5%, the structure of quasi-crystal is preferable to further stabilize. That is, the sum of the Si content of chemical components in the Ti content and the Cr content of the plating layer is, in atomic%, it is preferable to satisfy the 0.005% ≦ Si + Ti + Cr ≦ 0.5%. Further, these elements that are contained in a suitable amount, for quasi-crystals form large amounts Preferably, to improve the corrosion resistance of the plating layer surface. As a result, further improved corrosion resistance in a wet environment, the generation of white rust can be suppressed.
[0057]
[Co (cobalt): 0% ~
0.5%] [Ni (nickel): 0% ~
0.5%] [V (Vanadium): 0% ~
0.5%] [Nb (niobium): 0%
　0.5% ~] To obtain the above effects, the Co content is set to 0% to 0.5%, the Ni content is set to 0% to 0.5%, the V content is set to 0% to 0.5%, the Nb content it may be 0% to 0.5%. More preferably, Co content, Ni content, V content, with respect to the Nb content, respectively, the lower limit was made 0.05%, the upper limit may be 0.1%. However, these elements, Si, Ti, when compared with Cr, the effect of improving the corrosion resistance is small.
[0058]
: [Fe (iron) 0% to 2%
　in the plating layer, the steel sheet as the base material, sometimes elements constituting the steel sheet is mixed. In particular, in the hot dipping method, a solid-liquid reaction element interdiffusion due between the steel sheet and the plating layer, adhesiveness is improved. Therefore, the plating layer, which may contain a certain amount of Fe. For example, as a chemical component of the entire plating layer, there is a case where Fe is contained before and after 2%. However, Fe that have diffused into the plated layer is reacted with Al and Zn in the vicinity of the interface between the steel sheet and the plating layer often generates an intermetallic compound. Therefore, Fe which is contained in, the possibility of an effect on corrosion resistance and chipping resistance of the plating layer is small. Therefore, the Fe content of the plating layer may be 0% to 2%. Likewise, the elements constituting the steel sheet has been diffused into the plated layer (in other than the elements described in the present embodiment, elements have been Kochi from steel to the plating layer), can affect relative corrosion resistance of the plating layer It is small.
[0059]
[Cu (copper): 0% to
0.5%] [Sn (tin): 0% to 0.5%
　in order to improve the adhesion between the steel sheet and the plated layer, with respect to steel, Ni, Cu , there is a case of applying a pre-plating of Sn or the like. Use steel sheet has been subjected to pre-plating, if you produce a quasi-crystal-containing plated steel sheet, the plating layer, these elements may be contained up to about 0.5%. Ni is a component of the pre-plating, Cu, among Sn, Cu, Sn does not have the above-mentioned effect Ni has. However, the less likely to provide about 0.5% Cu, even Sn is contained in the plating layer, with respect to corrosion resistance and chipping resistance of formation behavior and the plated layer of semi-crystalline, Cu, Sn is an effect . Therefore, the Cu content of the plating layer was 0% to 0.5% the Sn content may be 0% to 0.5%. More preferably, Cu content, with respect to Sn content, respectively, and the lower limit is 0.005%, the upper limit may be 0.4%.
[0060]
: [Mn (manganese) 0% to 0.2%
　as a steel sheet as the base material of the quasicrystal-containing plated steel sheet, in recent years, high-tensile steel (high-strength steel) have come to be used. When produced quasicrystals containing plated steel sheet using a high-tensile steel, Si contained in the high-tensile steel, an element such as Mn and may spread in the plating layer. Si, Mn of Mn does not have the above-mentioned effect Si has. However, even on the order of 0.2% Mn is contained in the plating layer, with respect to corrosion resistance and chipping resistance of formation behavior and the plating layer of quasi-crystalline, possibly Mn affects small. Therefore, the Mn content of the plating layer may be from 0% to 0.2%. More preferably, with respect to the Mn content, the lower limit was made 0.005%, the upper limit may be 0.1%.
[0061]
[Sr (strontium): 0% ~
0.5%] [Sb (antimony): 0% ~
0.5%] [Pb (lead): 0%
　~ 0.5%] Sr, Sb, Pb is plated an element for improving the appearance, is effective in improving the antiglare. To obtain this effect, the Sr content of the plating layer was 0% to 0.5% of Sb content is set to 0% to 0.5%, the Pb content may be 0% to 0.5% . Sr content, Sb content and Pb content if within the above range, there is little effect on the corrosion resistance and chipping resistance. More preferably, Sr content, with respect to Sb content and Pb content, respectively, and the lower limit is 0.005%, the upper limit may be 0.4%.
[0062]
　Sr, Sb, Pb is processability, but hardly affect the plating properties such as corrosion resistance, affecting the coating appearance. Plating layer disclosed in this invention there are metallic gloss surface, metallic luster is lost by these elements be contained in the above composition range, it is possible to obtain an antiglare effect.
[0063]
[Measurement method of chemical components]
　chemical composition of the plating layer, using the ICP-AES (Inductively Coupled Plasma Atomic Emission Spectrometry) or ICP-MS (lnductively Coupled Plasma Mass Spectrometry) a known analytical method such as measurement it is possible to. Quasicrystals containing plated steel, crushed immersion for about 1 minute with respect to 10% hydrochloric acid was added to the inhibitor, the plated layer part was peeled off, to prepare a solution of the plating layer. The resulting solution was analyzed by ICP-AES or ICP-MS, etc., can be obtained chemical components of the overall average of the plating layer.
[0064]
　Further, in the hot-dip plating method, a plating layer is formed to have substantially the same chemical components and chemical composition of the molten coating bath. As for an element which can be ignored mutual diffusion between the steel sheet and the plated layer, by measuring the chemical composition of the plating bath used it may be substituted by measurements taken as a chemical component of plating layer. From the plating bath, a small piece ingot was collected, the drill powder was collected to prepare a solution of an acid dissolving the drill dust. The resulting solution was analyzed by like ICP, obtain chemical components of the plating bath. The measurements of the chemical composition of the resulting plating bath may be used as a chemical component of plating layer.
[0065]
　Although the chemical components of the quasicrystal-containing plated steel sheet according to the present embodiment has been described in detail.
[0066]

　Next, the plating organizational structure of the quasicrystal-containing plated steel sheet according to the present embodiment will be described in detail.
　Plating layer having a quasi-crystal-containing plated steel sheet according to the present invention, the multiple layers of different tissue together are stacked in the thickness direction of the plating layer, and a composite layer of a multilayer structure. Specifically, the plating layer according to the present embodiment, in order from the steel sheet side, MgZn phases, a first plating layer made of tissue containing Mg phase and quasi-crystalline phase, is located on the first plating layer , Mg 51 Zn 20 has phase, and a second plating layer comprising a tissue containing Zn phase and quasi-crystalline phase, a. Further, according the second plating layer is preferably a maximum grain size and a circle equivalent diameter 1μm or less is tissue.
[0067]
　Quasicrystal-containing plated steel sheet according to the present embodiment, as described in detail below, the plating layer, as a metal structure, and one comprising a quasi-crystalline phase. In the following, for such quasi-crystalline phase, first it is described.
[0068]
　Quasicrystalline phase, Mg content to be included within the grains of the quasi-crystal phase and Zn content and Al content, in atomic%, the quasi-crystal phase satisfies 0.5 ≦ Mg / (Zn + Al ) ≦ 0.83 It is defined as. That is, the Mg atoms, the sum of Zn atoms and Al atoms, Mg is the ratio of: is (Zn + Al), 3: 6 ~ 5: is defined as 6 to become quasi-crystal phase. Theoretical ratio of the quasi-crystal phase, Mg: (Zn + Al) = 4: believed to be 6. Chemical components of the quasi-crystalline phase, quantitative analysis and by TEM-EDX (Transmission Electron Microscope- Energy Dispersive X-ray Spectroscopy), it is preferable to calculate a quantitative analysis due EPMA (Electron Probe Micro-Analyzer) mapping. Incidentally, it is not easy to define the quasi-crystals in the correct chemical formula as intermetallic compounds. Quasicrystalline phase can not be defined a grid unit of repeating such a unit cell of the crystal, and further, Zn, because also difficult to identify the atomic positions of Mg. For reference, when measuring the quasi-crystal layer in TEM-EDX, quasicrystalline phase, Mg 51 Zn 20 higher Zn ratio than phase, and, Mg ratio is detected in the low state. Further, Al and, for the elements Ca or the like if it is contained in the quasi-crystalline phase, Mg 51 Zn 20 tends to ratio is detected higher than phase. Here, also for the chemical components of the quasi-crystal phase other than the metallic phase contained in the plating layer, the quantitative analysis and by TEM-EDX, quantitative analysis or the like by EPMA mapping it can be identified.
[0069]
　Further, to determine the metal phase of interest with quasicrystalline phase, and the electron diffraction image by TEM, necessary to check whether the crystal structure of the pentagonal electron beam diffraction image is observed there is. The crystal structure of pentagonal can be determined by obtaining an electron beam diffraction image called Penrose pattern (Penrose pattern). Because the difficulty to observe the range of more than 10μm with TEM, as described in detail below, when estimating the phase contained in the tissue from the representative fields of the plating layer, similar organizations were obtained in some cases, determining the quasi-crystal phase of the metal phase of interest from the measurement results of EPMA or EDX.
[0070]
　Presence of quasicrystals, basic performance of the coated steel sheet, acts on rust inhibiting effect. If the quasi-crystal phase is present, generally the plating surface to red rust occurs, with respect to the plating thickness (μm), × 150 hours of red rust is found that can be secured.
[0071]
　Hereinafter, the organizational structure of the plating layer according to the present embodiment will be described in detail.
[0072]
　Figure 1 is an electron micrograph of the plating layer of the quasi-crystal-containing plated steel sheet according to the present embodiment, in which the cutting direction is obtained by observing the cut surface is parallel to the thickness direction of the quasicrystal-containing plated steel sheet is there. The cross-sectional structure photograph is a bright-field image obtained by observing a cut surface in TEM. More specific organizational structure of the plating layer, as shown in FIG. 1, the second plating layer 1 made of microstructure which is located on the surface side of the plating layer (the opposite side of the steel plate), the second plating layer internal (i.e., the steel sheet side of the plating layer) located in a first plating layer 2 containing the grown tissue in the thickness direction of the plating layer, made of. Further, the interface between the plated layer and the base steel having such a multilayer structure, an alloy layer consisting of Al-Fe metal compound (interfacial alloy layer) 3 is formed.
[0073]
　Thereafter, the second plating layer comprising a microstructure located on the surface side of the plating layer, simply described as "fine layer", located on the steel sheet side of the plating layer includes growing tissue in the thickness direction of the plated layer a first plating layer, simply referred to as "compound layer". Further, the Fe-Al intermetallic compound layer positioned on base steel interface, simply referred to as "interfacial alloy layer".
[0074]
○ second plating layer (fine layers)
　among the plurality of layers constituting the plating layer, the fine layer (second plating layer) located on the outermost surface layer of the plating layer 1, 1 [mu] m or less in maximum crystal grain size equivalent circular diameter which is the organization. By fine layer 1 in such a fine structure is configured, which is one of the features of the present invention, the control effect of the plating layer crack propagation described below (i.e., chipping resistance) is not exhibited. That is, by the grain size of the tissue constituting the fine layer 1 as fine, it is possible to suppress the propagation of cracks in the inner plating layer.
[0075]
　Here, the circle equivalent diameter of the largest grain size contained in the fine layer 1 is more preferably preferably at 500nm or less, and 200nm or less. In the example shown in FIG. 1, the crystal grain size of the phases constituting the fine layer 1, most were 100nm or less in circle equivalent diameter (1 [mu] m or more crystalline phases are not observed.). The lower limit of the circle equivalent diameter of the largest grain size contained in the fine layer 1 is not particularly limited. However, if necessary, the lower limit may be 10 nm.
[0076]
　In fine layer 1, the area of ​​the following tissues 1μm maximum crystal grain size in equivalent circle diameter, the cut surface of any of the plating layer is preferably 90% or more with respect to the cross-sectional area of ​​the entire fine layer 1. In other words, the fine layer 1, the area ratio of 1μm or less of tissue maximum crystal grain size in equivalent circle diameter, preferably 90% or more. Maximum crystal grain size by area ratio of 1μm or less of tissue equivalent circle diameter is 90% or more, with the expression of inhibitory effect of crack propagation inside reliably plating layer, it is possible to further improve the corrosion resistance. Area ratio of 1μm or less of tissue maximum crystal grain size in the circle equivalent diameter is more preferably 95% or more, more preferably 100%.
[0077]
　Fine phase 1, the large crystal phase (or quasi-crystalline phase) is present, at the time Gurabero test, the plated layer tends frequency of delamination is increased. Also, generally, it tended to increase the corrosion resistance and fine crystal grains of the fine layer 1, in the plating hardness tends to increase.
[0078]
　Metal phase constituting the fine layer 1 organization, at least, Zn phase, semi-crystalline phase and Mg 51 Zn 20 is phase, phase containing both Zn and Mg crystal structure is not clear, it may be present . Further, Zn phase which mainly constituting the fine layer 1, the quasi-crystal phase and Mg 51 Zn 20 of phase, main metal phase, Mg 51 Zn 20 is phase. Further, the fine layer 1 according to this embodiment, Mg phase is hardly present in the fine layer 1.
[0079]
　Mg plating surface layer, when present in moisture environment blackened, because it may impair the appearance, especially in the fine layer 1, it is preferable that Mg is not contained.
[0080]
　Figure 2A is an electron beam diffraction image obtained from the black portion occupying most of the fine layer 1 shown in FIG. 1, FIG. 2B, was obtained from the white portion in a fine layer 1 shown in FIG. 1 electronic is a line diffraction image. Electron beam diffraction image shown in FIG. 2A, which accounts for most of the fine layer 1, Mg 51 Zn 20 is an electron beam diffraction image derived from phase. By electron beam diffraction image shown in FIG. 2A, Mg fine layer 1 51 Zn 20 can be confirmed that phase is contained. Further, in FIG. 2B, the intensity although weak, it is possible to check the electron beam diffraction image of the radial regular decagonal caused by icosahedral structure. The electron beam diffraction image shown in FIG. 2B is an image obtained from fine quasicrystalline phase contained in the fine layer 1. By electron beam diffraction image shown in this Figure 2B, it can be confirmed that the fine quasicrystals phase fine layer 1 is contained.
[0081]
　Although not shown, by analyzing the electron beam diffraction image obtained from the gray area in a fine layer 1, Zn phase was confirmed to be contained in the fine layer 1. Incidentally, Mg contained in the fine layer 1 51 Zn 20 or intermetallic compounds of equality, the presence of a metal phase of Zn equality is, it is also possible to check the electron beam diffraction image by TEM as described above, XRD ( it is also possible to be confirmed by X-Ray Diffractometer).
[0082]
　Mg 51 Zn 20 phase, JCPDS card: PDF # 00-008-0269, or # 00-065-4290, or, non-patent literature Higashira (Journal of solid state chemistry 36,225-233 ( 1981)) in defining the structure phase can be identified.
[0083]
　Further, Mg 51 Zn 20 phase, according to non-patent literature above Higashira has a unit cell is close to a cubic, it is reported to have an atomic structure forming a regular icosahedron in the unit cell It is. The Mg 51 Zn 20 unit cell is different with icosahedral structure of quasicrystals, strictly, Mg 51 Zn 20 is different phases from the quasi-crystals. However, Mg 51 Zn 20 the crystal structure of and quasicrystals are similar, Mg 51 Zn 20 considered phase is affecting the generation of the quasi-crystal phase.
[0084]
　Zn phase contained in the fine layer 1, the quasi-crystal phase and chemical composition and crystal structure is different. The Zn phase may result element diffusion at high temperature during preparation of the quasi-crystal-containing plated steel sheet occurs sufficiently, it can be determined that stable phase is generated.
[0085]
　The determination of the presence or absence of Mg phase, TEM-EDX, or may be confirmed by SEM-EDX or the like, may be confirmed by XRD. For example, in XRD diffraction patterns obtained by measuring the fine layer 1, the diffraction intensity from the (110) plane of Mg phase, Mg 51 Zn 20 diffraction angles of phase: 1% or less of the diffraction intensity at 2 [Theta] = 36.496 ° If, it can be said that does not contain Mg phase metallographic fine layer 1. Similarly, in the TEM diffraction image of the fine layer 1, if the crystal grains of the even fraction of Mg phase when sampling any grain at 100 or more than 3%, Mg phase metallographic fine layer 1 it can be said that does not contain. Grain even number fraction of Mg phase, more preferably is less than 2%, most preferably less than 1%.
[0086]
　Here, the abundance ratio of the aforementioned phases of the fine layer 1 may not particularly defined. Although existence ratio of each phase varies with chemical composition, factors affecting the chipping resistance, than existing ratio of each phase, a fineness of a tissue which depends on the grain size.
[0087]
　In this plating composition range, even if the existing ratio of the above-mentioned phases of the fine layer 1 is changed, it reduced effect on the plane corrosion resistance, not occur corrosion resistance deteriorates in question.
[0088]
　Although not particularly limited also the thickness of the fine layer 1, a typical thickness of the plating layer of the molten coated steel sheet tends to basis weight is increased is generally about 3 [mu] m ~ 30 [mu] m, fine according to the present embodiment since the layer 1 is often occupies 1 / 4-1 2/3 of the entire plating layer can be a 0.75 ~ 20 [mu] m as the thickness of the fine layer 1.
[0089]
　Fine layer (second plating layer) 1 consisting of tissue, such as described above, as compared with 2 described later compound layer (first plating layer), it has a relatively hard plating layer. Specifically, Vickers hardness of the fine layer 1 measured with reference to JIS Z2244 is at any 30-point average value of the fine layer 1 becomes 250 ~ 350 Hv. Fine layer 1, the maximum crystal grain size becomes a 1μm following fine structure in circle equivalent diameter, that has a rigid layer than the first plating layer, the crack propagation in the plating layer inside as described below inhibiting effect (i.e., chipping resistance) can be expressed. Hardness distribution of the fine layer 1 depends on the cooling rate during plating production. When plating hardness is increased, other chipping resistance, 耐疵 with resistance, is effective in improving such wear.
[0090]
○ first plating layer (compound layer)
　of the plurality of layers constituting the plating layer, the inside of the plated layer (steel side), located between the in other words the fine layer 1 and the steel plate as a second plating layer cages, the compounds were grown in the thickness direction of the plating layer layer (first plating layer) 2 is composed of tissue containing MgZn phase, Mg phase and quasi crystalline phase. DESCRIPTION OF THE PREFERRED EMBODIMENTS Exemplary compound layer, described in detail.
[0091]
　Tissue compound layer 2, first, a tissue gray portion located at the bottom of the compound layer 2 in FIG. 1, contains a MgZn phases. The MgZn phase, as is clear from FIG. 1, the crystal grain diameter and the circle equivalent diameter 1μm or more is relatively large hard tissue. Also, compound layers 2, such upper side of the MgZn phases of rigid (plating layer surface), a small than MgZn phases rigid and contains a grown tissue in the thickness direction of the plating layer. This was grown to a thickness direction of the plating layer tissue is composed of fine MgZn phase and quasi crystal phase, so as to satisfy the clearance of tissue according MgZn phases and quasicrystal phase, Mg phase soft exists there.
[0092]
　Here, the crystal grain size of the hard MgZn phases contained in the compound layer 2 is preferably 500nm or more in circle equivalent diameter, and more preferably 1μm or more. The upper limit of the crystal grain of the circle equivalent diameter of hard MgZn phases contained in the compound layer 2 is not particularly limited. However, if necessary, the upper limit may be 5 [mu] m. The size of the MgZn phases is related to the thickness of the compound layer 2, small as compound layer 2 becomes smaller, as large as the compound layer 2 is also increased. From the determination of the appropriate thickness of the compound layer, 500 nm ~ 5 [mu] m is considered appropriate thickness of MgZn. When equivalent circular diameter of MgZn layer is as large as 1 [mu] m, the thickness of the compound layer 2 becomes thicker, for example, during chipping, the portion base steel is exposed decreases. That is, immediately after the chipping, since the plating layer of the compound layer 2 remains, rust is not generated, will be covered with white rust.
[0093]
　Also, small MgZn phases and fine quasicrystals phase of MgZn phases, the thickness direction of the plating layer as described above, it is often grown in dendritic cooling direction. Therefore compound layer 2 is observed with a SEM or an optical microscope or the like, it may look like a fan to spread as shown in FIG. Furthermore, dendritic relevant part of the grown tissue dendritic, rather than MgZn phases are often predominantly quasicrystalline phase. That is, the out arborescence that portion of the grown tissue dendritic, there also to fine MgZn phase mainly of quasicrystalline phase, the portion corresponding to the leaves of the dendritic and Mg phase is present it can be likened. The dendritic structure in any cross-section, refers to a tissue that does not have a distinct separator, a tissue forms present impossible state replaced by equivalent circle like, spherical, flat circle, specified as polygonal different from the morphology of aggregated area. Respect chipping properties, spheres, in a distributed organization polygonal crack propagation suppressing effect can not be obtained, the presence of the dendritic structure, it is possible to obtain such crack propagation suppressing effect.
[0094]
　Figure 3A, of the compound layer 2 shown in FIG. 1, an electron beam diffraction image obtained from coarse MgZn phase, FIG. 3B, among the compound layer 2 shown in FIG. 1, the grown tissue dendritic obtained is an electron beam diffraction image. Electron beam diffraction image shown in FIG. 3A is an electron beam diffraction image from a coarse MgZn phases. By electron beam diffraction image shown in FIG. 3A, it can be confirmed that MgZn phase compound layer 2 is contained. Further, in FIG. 3B, it is possible to confirm the radial positive decagonal electron beam diffraction image due to the icosahedral structure. Electron beam diffraction image shown in FIG. 3B is an image obtained from the quasi-crystalline phase contained in the compound layer 2. By electron beam diffraction image shown in FIG. 3B, it can be confirmed that the quasi-crystalline phase compound layer 2 is contained. Although not shown, of the dendritic structure in the compound layer 2, by analyzing the electron beam diffraction image obtained from the portion corresponding to the leaves of the dendrite, the Mg phase is contained in the compound layer 2 There has been confirmed. Incidentally, or a compound layer between MgZn equality of metal contained in the second compound, the presence of a metal phase of Mg equality is, it is also possible to check the electron beam diffraction image by the above-described TEM, it is confirmed by XRD it is also possible.
[0095]
　In the compound layer 2, the area of ​​MgZn phases massive, in the cut surface of any of the plating layer is preferably 10% to 70% with respect to the cross-sectional area of ​​the entire compound layer 2. In other words, in the compound layer 2, the area ratio of the MgZn phase is preferably 10% to 70%. By area ratio of MgZn phases massive becomes 10% to 70%, certainly with the expression of chipping resistance, it is possible to further improve the corrosion resistance. Area ratio of MgZn phases of massive, more preferably from 20% to 40%.
[0096]
　Here, the aforementioned proportions and form of the respective phases in the compound layer 2 may be considered a variety of situations. However, the presence ratio and the form of the aforementioned layers in the compound layer 2 may not particularly defined. In this plating composition range, even as the existence ratio or the form of the above-mentioned respective phases in the compound layer 2 changes, reduced effect on the plane corrosion resistance, not occur corrosion resistance deteriorates in question.
[0097]
　Although not particularly limited also the thickness of the compound layer 2, a typical thickness of the plating layer of the molten coated steel sheet tends to basis weight is increased is generally about 3 [mu] m ~ 30 [mu] m, the compounds according to the present embodiment since the layer 2 is often occupies 1/3 to 3/4 of the entire plating layer can be a 1 [mu] m ~ 23 .mu.m as the thickness of the compound layer 2.
[0098]
　In the compound layer 2, operating on, oxides of MgO, Fe oxide, or Zn oxide and the like as an inevitable impurity in the manufacturing process of the plating layer is sometimes mixed. However, if these impurities traces without any problem, the compound layer 2 be composed by the above phases, the good chipping resistance and corrosion resistance, which is the effect of the present invention can be sufficiently enjoyed. Further, in the compound layer 2, the MgZn phases, addition of Mg phase and quasicrystal phase, a small amount of "Mg 51 Zn 20 there is a case where" is rarely observed, even in this case the "Mg 51 Zn 20 " There no problem if a minor, compound layer 2 be composed by the above phases, the good chipping resistance and corrosion resistance, which is the effect of the present invention can be sufficiently enjoyed.
[0099]
　Compound layer (first plating layer) 2 consisting of tissue, such as described above, as compared to 1 minute layer described above (second plating layer), has a relatively soft plating layer. Specifically, Vickers hardness of the compound layer 2 measured with reference to JIS Z2244 is the average value, and has a 80 ~ 200 Hv. Compound layer 2, the above MgZn phase consists tissue containing quasicrystalline phase and Mg phase, that has a second plating layer softer layer than, the crack propagation in the plating layer inside as described below inhibiting effect (i.e., chipping resistance) can be expressed.
[0100]
　In the present invention, it is characterized in a heat treatment process after plating alloying described later, by the heat treatment method, it is possible to form the plating layer composed of the fine layer 1 and the compound layer 2.
[0101]
　While the plating layer quasicrystal-containing plated steel sheet according to the present embodiment comprises, as described in detail.
[0102]

　Next, the interfacial alloy layer is an alloy layer comprising the quasicrystal-containing plated steel sheet according to the present embodiment will be described in detail.
　In the present embodiment, as shown in FIG. 1, the interface between the plated layer and the base steel with a fine layer 1 and the compound layer 2, the interface alloy layer 3 made of Al-Fe intermetallic compound is formed.
[0103]
　Plating the alloy Al are contained in appropriate concentration range as described above, and by performing appropriate heat treatment after the plating alloying, and further the steel sheet side of the compound layer 2 (i.e., the plating layer and the base steel the interface), it is possible to form the interfacial alloy layer 3 made of Al-Fe intermetallic compound. The interfacial alloy layer 3, as an intermetallic compound, Al 3 (in more detail, Al Fe 3.2 Fe) or Fe 5 Al 2 preferably includes at least one of such. Al-Fe intermetallic compound containing the above intermetallic compounds have a needle-like complex form, the adhesion by increasing the coupling force between the upper layer of the compound layer 2 and the base steel by the anchor effect improve the chipping resistance can be further improved. Also, Al-Fe intermetallic compound layer, in addition to the chipping resistance has been found that also affect the adhesion of the plating layer.
[0104]
　The thickness of the interfacial alloy layer 3 is not particularly limited, preferably in the 10 ~ 200 nm. Since the thickness of the interfacial alloy layer 3 is less than 1μm as described above, the presence or absence of interfacial alloy layer 3 is preferably confirmed by TEM observation or the like.
[0105]
　Note that the outermost surface of the plating layer, the thickness is that the oxide film of the order of less than 200nm is formed. Such oxide film, since the chipping resistance of the quasicrystal-containing plated steel sheet according to the present embodiment does not influence, not particularly defined in the present invention.
[0106]

　Next, the confirmation method of various metal tissue in the plating layer quasicrystal-containing plated steel sheet according to the present embodiment.
　Organizational structure of the plating layer, either polished specimen, CP (Cross Section Polisher) processing, FIB (Focused lon Beam) processing, the plating layer cross-section of the tissue by ion milling, and observed with an optical microscope, SEM, TEM or the like, various by performing the analysis processing, it can be confirmed. The measurement, the crystal grain size of the metallic structure, if 1μm or more tissue can be measured by SEM observation, the fine structure and the quasicrystal phase than 1μm, as described above, by TEM observation or the like can do.
[0107]
　The type of phases in fine layer 1 and the compound layer 2 by a known method such as electron beam diffraction pattern of EPMA and TEM, can be confirmed.
[0108]
　Furthermore, in order to define the ratio of the respective phases in the tissues constituting the plating layer, based on the observations at a plurality of visual field, it is necessary to calculate the area of ​​the phase of interest. Observation for determining the area ratio is preferably, for example, be implemented in any of at least 10 or more visual fields. Any entire plating layer cross-section, taken at 1000 times by SEM or the like, to create a region surrounded by the tissue in a known image processing and binarization processing, etc. on the image, measuring the area ratio.
[0109]
　More specifically, it can be, for example, as follows, confirming the metallic structure of the plating layer. First, as the cut surface of the thickness direction and the cutting direction is parallel becomes observation surface, by cutting the quasicrystal-containing plated steel sheet, a sample is taken. The cut surface of the obtained sample, polishing, or CP processing. When polishing the cross section after polishing, to nital etching. Then, observing the resulting cross-section with an optical microscope or SEM, etc., taking a metal structure photograph. The chemical components of the constituent phases, as described above, can be determined by analysis by EDX or EPMA. From the chemical analysis, it is possible to identify the configuration phase in a simplified manner. The resulting metallic structure photograph, for example, binarized by the image analysis, by measuring the area ratio of each portion of the plating layer, it is possible to measure the area ratio of the constituent phases. Also, from the area of ​​individual regions obtained (configuration phase), it is possible to calculate the average circle equivalent diameter. Or, by observing the metallic structure of the plating layer by EBSD (Electron Back Scattering Diffraction Pattern) method, to identify the configuration phase may be obtained area ratio and average circle equivalent diameter of constituent phases.
[0110]
　To identify further detail configuration phase, observing the metallic structure of the plating layer as follows. That is, as the cut surface of the thickness direction and the cutting direction is parallel becomes observation surface, by cutting the quasicrystal-containing plated steel sheet, collecting a thin sample. The resulting thin sample subjected to ion milling. Or, as the cut surface of the thickness direction and the cutting direction is parallel becomes the observation plane, and FIB processing quasicrystals containing plated steel sheet, collecting a thin sample. Observing the thin sample obtained by utilizing TEM, the shooting metal structure photograph. Configuration phase can be identified accurately by the electron beam diffraction image. Moreover, the resulting metal structure photograph by image analysis, it is possible to determine the area ratio and average circle equivalent diameter of constituent phases.
[0111]
　Incidentally, although not known spatial present state, and most simply, on the basis of the diffraction peak of XRD of the plating layer, it is possible to confirm the presence of the constituent phases.
[0112]
　It has been described how to check various metal tissue in the plating layer quasicrystal-containing plated steel sheet according to the present embodiment. The above confirmation method, it is also to check the tissue of the interface alloy layer is applicable, of course.
[0113]
　Incidentally, on the plating layer of the quasi-crystal-containing plated steel sheet according to the present embodiment, further, performing organic chemical conversion treatment or an inorganic chemical conversion treatment, it is also possible to form a chemical conversion film layer. Plating layer according to the present embodiment, because it contains Zn more than a certain concentration in the plating layer, it is possible to carry out Zn-based plated steel sheet similar to phosphate conversion treatment and chromate treatment and chromate-free treatment. Furthermore, for the paint for the chemical conversion coating formed by such a chemical conversion treatment, it can be implemented similarly to the Zn-plated steel sheet. Further, the quasicrystal-containing plated steel sheet according to the present embodiment can also be used as the original plate of the laminated steel sheet.
[0114]

　As described above, in the quasicrystal-containing plated steel sheet according to the present invention, the structure of the plating layer, a fine layer 1 positioned on the surface side of the plating layer (surface layer side), a fine with a compound layer 2 located further base steel side of the layer 1, and a multilayer structure composed of. By providing the plated layer of such a multilayer structure, cracks in the plating layer surface generated by external pressure due to chipping is less likely to reach the interface between the plated layer and the base steel. Specifically, the external pressure will be relatively hard fine layer 1 is finely crushed located plated layer surface, resulting crack reaches the interface between the fine layer 1 and the compound layer 2, such surface it propagates along the. That is, cracks generated in the plating layer surface, the relatively soft compound layer 2 is not propagate, therefore, not reach the interface between the plated layer and the base steel. Therefore, even if the fine layer 1 was finely crushed by the generation and crack propagation of cracks is peeled off, the compound layer 2 has excellent adhesion to the base steel is not easily peeled off, it is possible to avoid the exposure of the base steel .
[0115]
　Here, cracking of the plating layer after the chipping test (chipping cracking) 4, an example of progress along the interface of the fine layer 1 and the compound layer 2, shown in FIG. As can be seen from Figure 4, when the plated layer and the multilayer structure as comprising a fine layer 1 and the compound layer 2, the plating layer surface at the interface that is cracking generated in the fine layer 1 and the compound layer 2 along propagates, it can be seen that does not reach the base steel without propagating inside the compound layer 2. Propagation of such a special crack (crack) is one in which the plating layer as in the present invention can be realized by a multi-layer tissue structure. For example, even a plating layer were present invention the same components as described above, when the plating layer is such that a single layer structure leaves a large chipping trace cracks linked one after another in the organization, the exposed portion of the base steel is increased.
[0116]
　Further, the quasicrystal-containing plated steel sheet, the addition of Al in the plating layer, by forming the interface between the interfacial alloy layer 3 and the steel sheet and the plating layer by suitable heat treatment to be described later, the anchoring effect of the compound layer 2 produced. Thus is further improved adhesion between the plated layer and the base steel.
[0117]
　Thus, quasicrystal-containing plated steel sheet according to the present invention is not conspicuous chipping marks even in a situation where a part of the breakdown has occurred in the plating layer, since the remaining compound layer 2 to exhibit anti-corrosion function, red rust not a, it is also suppressed progression of corrosion.
[0118]
　Although the quasicrystal-containing plated steel sheet according to the present embodiment has been described in detail.
[0119]
(Method for producing a quasi-crystalline-containing plated steel sheet)
　Next, a method of manufacturing a quasicrystal-containing plated steel sheet according to the present invention, a method for forming a particular coating layer, will be described in detail.
[0120]
　The formation of the plating layer, other hot dipping method, applying a thermal spraying method, a sputtering method, an evaporation method, an electroplating method, or the like. However, to form a plating layer of a degree that is generally used in an automobile or the like thickness, melt plating is most preferred in terms of cost.
[0121]
　In order to control the plating layer to the phase tissue and layer structures specified in the present invention may be carried out in different conditions a plurality of times of the plating process. However, in the present embodiment, after first forming a plating layer of uniform components, by performing a heat treatment to be described later to the plating layer to form a multilayer structure by controlling the phase structure and the layered structure in the coating layer it can also be advantageous in cost preferable. In this respect, the molten plating method, it is possible to utilize the cooling process of the molten coating alloy as the heat treatment, it is advantageous.
[0122]
　Note that previously formed the metal film layer having a specific composition on the surface of the steel sheet by vapor deposition or the like, then heated, such as by charging the steel sheet in a heating furnace to melt only the metal coating layer of the surface, followed by also by performing heat treatment in the cooling process, it is possible to form a plating layer similar to the plating layer by hot dipping. In this way, the plating layer only (metallization layer) be remelted, since quite different from the melting point of the steel sheet, which is the melting point and the base material of the metal coating layer mainly composed of Mg and Zn, those skilled in the art by optimizing the temperature and time if is to be done easily. For example, the metal coating layer mainly composed of Mg and Zn by heating at 500 ° C. was completely melted, the base material does not melt. In particular, rapid heating by high-temperature atmosphere is, since heating the steel sheet surface in contact with the atmosphere preferentially, it is advantageous to heat only the coating layer on the surface.
[0123]
　Hereinafter, by heat treatment, the phase structure of the plating layer on a method for the construction of the present invention will be described in detail.
[0124]
　To the phase organizational structure of the present invention, first, having the chemical components described above, the plating alloy in a molten state, it is disposed on the base steel (plating step). Plating available plating process is as described above, it is preferable to employ a hot dipping. Subsequently, the plating alloy in a molten state located on the base steel, cooled to 330 ~ 200 ° C. at a cooling rate of 10 ° C. / sec (first cooling step). Incidentally, in the case of employing a hot dipping in the plating step, the first cooling step is carried out immediately after leaving the plating bath. When the cooling rate in the first cooling step is high, cracks in the plating layer by internal stress due to the rapid solidification is often occur, chipping resistance is extremely lowered. Further, if the cooling rate is too fast, will be deposited a large amount of the quasi-crystal phase in the plating layer, in the subsequent thermal process, it can not be maintained and the precipitated form or plating layer structure of the quasi-crystal phase.
[0125]
　Such cracks and coarse precipitates generated, unless re-melted plating layer is heated above the melting point of the plating alloy to not disappear, it is unsuitable for forming a plating layer of the multilayer structure. In particular, cracks, since hindering the uniformity of subsequent heat treatment when the plating layer inside the tissue, there is also the formation of the composite layer can not occur. Formation of cracks, since it exacerbates the corrosion resistance with respect to the present invention extremely, it is preferable to suppress as much as possible formation.
[0126]
　Incidentally, the occurrence of cracks more from the viewpoint of suppressing the plating layer surface, the cooling rate of the plating alloy in a molten state is preferably set to 8 ° C. / sec or less.
[0127]
　Here, the lower limit of the cooling rate of the plating alloy, not particularly limited, and may suppress the occurrence of cracks in the slow enough plated layer surface as late, in consideration of operability of the cost, the lower limit value appropriately it may be determined.
[0128]
　In the first cooling step, the cooling temperature reached is 330 ° C. or less, the plating layer is once completely solidified. After fully clotted the plating layer, to re-heating step at a heating holding step of the plating layer as described below. However, without going through the process of fully solidify the plating layer (i.e., in a state where the plating layer is not completely solidified) Doing heating holding step, in the plating layer, coarse quasicrystals and spherical, MgZn phase is dispersed, and the remainder Mg 51 Zn 20 becomes organizations meeting, the above compound layer 2 is less likely to very form. In addition, there is also a crack many occur trend in the plating layer. Therefore, the ultimate cooling temperature when cooling the plating alloy in a molten state, it is important to 330 ° C. or less.
[0129]
　Incidentally, from the viewpoint of forming a compound layer 2 stably, the ultimate cooling temperature is preferably 300 ° C. or less, more preferably it is 250 ° C. or less. On the other hand, when cooling the cooling achieving temperature as less than 200 ° C., in a subsequent heating holding step, rough surface texture of the plating layer, since the surface appearance tends to be deteriorated, that the ultimate cooling temperature 200 ° C. or higher preferable. Further, when cooling the cooling achieving temperature as less than 200 ° C., will be deposited and grow quasicrystalline phase in the plating layer more than necessary, coarse quasicrystalline phase tends to mix into a fine layer. Since the control of the subsequent tissue structure sometimes becomes somewhat difficult, also from this point of view, it is preferable that the cooling achieving temperature and 200 ° C. or higher.
[0130]
　However, even less than 200 ° C. cooling temperature reached in the first cooling step, without affecting the plating capability itself, further, the rough surface texture of the foregoing, there is a means of somewhat eliminated by skin pass rolling , it is possible to solve problems of the appearance of the plating layer after cooling as described above. Accordingly, the lower limit of ultimate cooling temperature in the first cooling step is not necessary to limit as severely limited the ultimate cooling temperature. For example, those cooling the plated layer is melted down to room temperature, satisfy the following heat treatment conditions, it is possible to obtain the organizational structure of the present invention.
[0131]
　Then, the plated steel sheet cooling is performed in the first cooling step, at an average heating rate of 10 ° C. / sec ~ 50 ° C. / sec (average heating rate), up to the Atsushi Nobori range of 350 ° C. ~ 400 ° C. reheated and held at this temperature range 5 seconds to 30 seconds (heating holding step). By reheated held until temperature range according to the plating layer becomes a semi-molten state from the solidification state in the interior of the plating layer, tissue deposited in the first cooling step is substantially reset (although, in some cases, the quasicrystalline phase formed in one cooling step may remain slightly). Temperature range of 350 ° C. ~ 400 ° C. is no specific precipitation phase, the tissue state nearly liquid phase. Also, a certain amount of recovery crack generated in the first cooling step.
[0132]
　The temperature range of this 350 ° C. ~ 400 ° C., initially precipitates is MgZn phase from the base steel surface, followed by Mg phase, growing quasicrystalline phases are successively compound layer 2 with these composite phase is formed that. Most tissue growth material susceptible at this temperature range, a MgZn, component segregation by MgZn precipitation, a result of the separation, dendritic quasicrystals are subsequently deposited, comprising a gap of dendritic and organizational structure Mg satisfies.
[0133]
　Incidentally, if the average heating rate is too low and below 10 ° C. / sec, too MgZn phases coarsening deposited from base steel interface compound layer 2 is not a composite phase. Furthermore, cracks formed in the first cooling step also tends to remain intact. Further, when the average heating temperature is 50 ° C. / sec exceeded and too large, since the heating temperature range is narrow, it is technically difficult in terms of temperature control.
[0134]
　On the other hand, if the holding time is less than 5 seconds, the generation of composite phase becomes insufficient in the compound layer 2, it is impossible to sufficiently improve the chipping resistance. Further, when the retention time is 30 seconds exceeded, the proportion of the compound layer 2 is too large in plating layer, it is difficult to sufficiently produce a fine layer 1 in a second cooling step to be described later, in this case even without forming composite layer, it is impossible to sufficiently improve the chipping resistance.
[0135]
　Controlling the crystal grain size of MgZn, i.e., to control the thickness of the compound layer, the time held in a range of 350 ° C.-400 ° C. is preferably about 10 seconds to 20 seconds. As time becomes longer, MgZn 2 tends to grow.
[0136]
　Thus, Atsushi Nobori in the range of 350 ° C. ~ 400 ° C., and, if the holding time in such Atsushi Nobori is not both satisfy the above are not composite phase is not sufficiently generated in the compound layer 2, chipping sex is not sufficiently improved. In addition, when the temperature of temperature and holding time the temperature is not both satisfy the above, the surface texture of the plating layer is roughened, there is a tendency that the surface appearance is deteriorated. Thus by controlling the heating temperature and retention time in the reheating is very important.
[0137]
　In the temperature of 350 ° C., it is present Mg-MgZn eutectic composition, the liquid phase appears in the plating layer and a 350 ° C. exceeded. However, when the temperature is 400 ° C. exceeded, the plating layer becomes completely molten state, and further is concerned impact on the material of the base steel. In addition, MgZn extremely grow, longer composite layer structure will not be formed. In addition, when rapidly cooled in a subsequent process, the temperature is too high, occur many cracks. Also, when it exceeds 400 ° C., in the subsequent temperature processing process, to become poor appearance with rough plated surface, the upper limit temperature is preferably 400 ° C. or less. Further, when the temperature is 400 ° C. exceeded, Al and Fe, or an alloy of the reaction of Zn and Fe, which may lead to deterioration due to component change of the plating tissue. Therefore, in order to make the plated layer and the semi-molten state, to control the Atsushi Nobori range in the range of 350 ° C. ~ 400 ° C. is a very important condition.
[0138]
　In the Atsushi Nobori holding step shall start counting retention time from the time of reaching 350 ° C..
[0139]
　After the heating holding step, the plated steel sheet at an average cooling rate of more than 20 ° C. / sec is cooled (quenched) (second cooling step). Thereby, the plating layer surface region was a semi-molten state at the Atsushi Nobori holding step, solidifies from the liquid phase, without precipitating Mg phase equilibrium phase, the maximum grain size (circle equivalent diameter) of 1μm fine layer 1 is formed consisting of microstructure. When the average cooling rate is less than 20 ° C. / sec, Mg phase precipitates in large amounts in the plating layer surface, the corrosion resistance becomes extremely poor.
[0140]
　Here, the upper limit of the average cooling rate in the second cooling step is not particularly limitation, for example, may be set to 2000 ° C. / sec approximately. Cooling rate in the plated surface when submerged is the approximately 2000 ° C. / sec, whereby the formation of a complex phase disclosed in the present invention has been confirmed. As the cooling rate is high, the hardness of the fine layer increases. Intentionally abrasion resistance, if you want to improve the scratch resistance, it is sufficient to increase as much as possible during this period of cooling rate. Generally, although the coarse quasicrystals is the partially hardness increases mixed trend, increase in the hardness of the average value is a little, scratch resistance does not change much.
[0141]
　As measured process temperature of the plating layer in the production of quasi-crystal-containing plated steel sheet according to the present embodiment, for example, it may be used a contact type thermocouple of (K-type). The thermocouple contact type by attaching to the base steel, can always be monitored average temperature of the entire plating layer. Also, mechanically, and controls the various speed and thickness, if unify various operating conditions such as temperature or the like of the pre-heating temperature and hot-dip plating bath of a steel sheet, the temperature of the entire plating layer at that point in such production conditions, it is possible to almost exactly monitoring. Therefore, it is possible to heat treatment in the first cooling step and the second cooling process or heating holding step in the cooling step, to precisely control. Incidentally, as the contact type, but not exactly, the surface temperature of the plating layer may be measured by a radiation thermometer of the non-contact type.
[0142]
　Further, by simulation for heat conduction analysis, it may be previously obtained relation between the surface temperature of the plating layer and the average temperature of the entire plating layer. Specifically, the preheating temperature and the temperature of the hot-dip plating bath of the steel sheet, the pulling speed of the steel sheet from the plating bath, the plate thickness of the steel sheet, the thickness of the plating layer, the heat exchange heat between the plated layer and the production facilities, the plating layer based on various manufacturing conditions such as heat dissipation, etc., determine the surface temperature and the average temperature of the whole plating layer of the plated layer. Then, by using the results obtained, it may be obtained a relationship between the surface temperature of the plating layer and the average temperature of the entire plating layer. Thus, by measuring the surface temperature of the plating layer during the production of quasi-crystal-containing plated steel sheet, it is possible to estimate the average temperature of the whole plated layer at that point in its manufacturing conditions. As a result, the cooling process and in the first cooling step and a second cooling step, the heat treatment at a Atsushi Nobori holding step, it is possible to precisely control.
[0143]
　In the case of adopting the hot dipping in the plating step, in order to melt plating, the temperature of the plating bath, (in the plating composition of the present invention, 440 ~ 540 ° C.) melting point of the plating alloy to + 40 ℃ longitudinal it is a common practice. Therefore, in the present invention Al is contained in the plating alloy, at the first immersing be plated in the plating bath, Al moves instantly at the interface between the plated layer and the base steel, Al-Fe intermetallic compounds interfacial alloy layer is formed consisting of. Once Such surface alloy layer is formed, the higher the melting point of the Al-Fe intermetallic compound constituting the interface alloy layer, interfacial alloy layer will not be extinguished by the heat treatment to be subsequently performed.
[0144]
　Hereinafter, in the plating step of the method for manufacturing coated steel sheet of the present invention, it describes a case of adopting the hot dipping.
[0145]
　The time of the material produced in the plating alloy, it is preferable to formulate with pure metal (purity 99%) as an alloy material. First, by mixing the predetermined amounts of alloying metal so that the plating layer composition, using a high-frequency induction furnace or arc furnace in a vacuum or inert gas substitution conditions, completely dissolved in the alloy. Furthermore, a predetermined component the alloys were mixed in (the plating layer composition) was dissolved in air, using a melt obtained as a plating bath.
[0146]
　Here, bath temperature of the plating bath, as described above, from the viewpoint of the normal plating operation to the 40 ° C. approximately range above the melting point of the plating alloy, for example, a 480 ℃ ~ 520 ℃, 550 ℃ it is preferable to be less than or equal to.
[0147]
　Incidentally, in the production of the plating alloy as described above, no limitation to particular use of pure metals, existing Zn alloy, Mg alloy, may be used to dissolve the Al alloy. At this time, by using even less impurities predetermined alloy composition, there is no problem.
[0148]
　Further, when applying a hot dipping method, Zenjimia method, pre-plating method, two-step plating method, known methods flux method or the like can be applied. Prior to plating step of forming a plating layer according to the present invention, as a pretreatment, Ni pre-plating, it is also possible to apply a pre-plating treatment such as Cu pre plating. Incidentally, deposition, when applying the plating means such as sputtering plating step, pretreatment as described above is not necessary, a plating layer having a predetermined alloy composition, may be formed on the steel plate.
[0149]
　Furthermore, when applying a hot dipping in the plating step, except to note the heat treatment described above, it may be applied to general plating operating conditions, in particular special facilities and conditions not required. For example, when employing a hot dipping in a plating process, after immersion in the plating bath, N 2 by adjusting the basis weight in wiping using gas, then, N 2 by gas cooling or spontaneous cooling, the first cooling the process may be performed.
[0150]
　Further, even if the heating and cooling equipment for the heat treatment, in particular special facilities and conditions not required. For example, in a heat treatment or reheat treatment, by using known equipment such as IH (Induction Heating) furnace or infrared heating furnace or the like, so as to satisfy the above-mentioned heat treatment conditions, by setting the operating conditions of appropriate facilities good. Further, in the cooling process, N 2 gas cooling, mist cooling, can be applied the method generally known such as submersion like. The cooling gas, N 2 in addition to gas, may be used, He gas, high heat removal effect such as hydrogen gas gas.
[0151]
　Although the method for producing a quasi-crystalline-containing plated steel sheet according to the present embodiment has been described in detail.
[0152]
(Evaluation method of characteristics of the quasi-crystal-containing plated steel sheet)
　Next, the excellent corrosion resistance and chipping resistance of the evaluation method indicated quasicrystal-containing plated steel sheet according to the present embodiment will be briefly described.
[0153]

　In order to evaluate the corrosion resistance of the quasicrystal-containing plated steel sheet is most preferable to perform evaluable exposure test the corrosion resistance of the plating layer in a real environment. To assess the corrosion weight loss of the plating layer during inter periodically, it is possible to evaluate the relative merits of the corrosion resistance.
[0154]
　Plating layers having high corrosion resistance, when comparing the corrosion resistance, it is preferred to carry out the long-term corrosion resistance test. The magnitude of the period of red rust to occur, to evaluate the corrosion resistance. Furthermore, when assessing the corrosion resistance, it is important to also consider corrosion protection period of the steel sheet.
[0155]
　To evaluate the corrosion resistance more easily, it is possible to use accelerated corrosion test, such combined cycle corrosion test and the hot water spray test and the like. To evaluate the corrosion weight loss and rust rust period, it can determine the relative merits of the corrosion resistance. Note that the plating layer having high corrosion resistance, when comparing the corrosion resistance, it is preferred to carry out the accelerated corrosion test using NaCl aqueous solution of a high concentration (e.g., around 5%). With concentrations of thin (e.g. less than 1%) NaCl solution, it is often difficult sticks superiority of corrosion resistance.
[0156]

　In order to evaluate the chipping resistance of the quasicrystal-containing plated steel sheet, for example, it is preferable to carry out the method of using the Gurabero tester visually evaluate the peeling area of the plating layer. Test conditions can be appropriately set, but for example, "using Gurabero tester, 3.0 kg / cm No. 7 crushed stone 100g from a distance of 30 cm 2 at an air pressure of, with respect to the plating layer was cooled to -20 ° C. Te may be employed conditions such collisions is to "like at an angle of 90 degrees.
[0157]
　The evaluation of the chipping resistance, than the evaluation of the steel plate remains plating, after phosphate conversion treatment, electrodeposition coating, intermediate coating, be carried out in plated steel sheet top coating, close to the actual use conditions, more preferably .
[0158]

　The area ratio of MgZn contained in each of the plating layer, from the TEM electron diffraction, replaced by SEM field of view after the phase of interest was identified as MgZn, the following method it may be evaluated by. That binarizes the image obtained from the SEM field to monochrome image, on the entire plating layer, the area occupied by the MgZn phases, may be calculated by computer image processing.
[0159]

　The evaluation method of hardness of the plating layer, to prepare a plating layer having a thickness of more than 10 [mu] m, it is easy to measure the Vickers hardness of the surface. However, in this method, without the degree of plating thickness, and base steel, interfacial alloy layer, for susceptible hardness effect of the compound layer, care must be taken. If there is a certain thickness in the plating layer, it will measure the hardness of the outermost layer of the plating layer. The higher the plating layer hardness, it can be determined that generally excellent wear resistance. More preferably, the cross section of the plating layer was collected, it is preferable to evaluate the hardness for each phase in a nano indenter like.
[0160]

　When evaluating the adhesion of the plating layer after the ball impact test, it is common to evaluate the tape peeling at the uneven portion. More peeling amount is small, excellent in adhesion. Other, V bending test, T bend test after Erichsen test, be evaluated tape peeling in the processing unit, it can be evaluated similarly adhesion.
[0161]
　Although the evaluation method of characteristics indicated by the quasicrystal-containing plated steel sheet according to the present embodiment it has been briefly described.
Example
[0162]
　Hereinafter will be described the effects of the present invention through examples, the present invention is not limited to the conditions used in the following examples.
[0163]
　First, as a material of the plating alloy, to produce an ingot having the chemical compositions shown in Tables 1 to 8, to prepare a plating bath. Further, as the original plate (be plated) of the plated steel sheet was used cold rolled steel sheet (thickness 0.6 mm). Such cold-rolled steel sheet after cutting into 10 cm × 17cm, were plated in a batch hot dip plating test apparatus of-house. As the cold-rolled steel sheet, generally low carbon steel (C: 0.1% or less, Si: 0.01% or less, Mn: 0.2% or less, P and S: 0.03% or less, Fe: balance ) was adopted.
[0164]
　Also, blank in the chemical composition of the plating alloy, it indicates that no intentionally added to the appropriate chemical composition.
[0165]
　Hereinafter, a method for forming a plating layer of the present embodiment will be specifically described.
[0166]
　First, be plated, 5% H 2 -N 2 800 ° C. in an atmosphere, after reduction annealing for 1 minute, then dipped be plated in the plating bath of the original plate melting point + 40 ° C., after pulling, N 2 was used gas wiping in was adjusted coating weight (plating step).
[0167]
　And temperature specific plating bath for temperature history of the subsequent plating production, shown in detail in Tables 9 to 12.
[0168]
[Table 1]

[0169]
[Table 2]

[0170]
[table 3]

[0171]
[Table 4]

[0172]
[table 5]

[0173]
[Table 6]

[0174]
[Table 7]

[0175]
[Table 8]

[0176]
[Table 9]

[0177]
[Table 10]

[0178]
[Table 11]

[0179]
[Table 12]

[0180]
　In order to confirm the structure of the plating layer, implement CP machining in the cross-sectional direction of the resulting coated steel sheet was subjected to FE-SEM observation. As the evaluation criteria, in the obtained FE-SEM image, as a plating layer, a compound layer 2, which multi-layer structure made of a compound layer fine layer 1 formed above the 2 were observed "+", It was - only one or fine layer 1, such as one made of other tissue "". For those multilayer structure was confirmed, it was measured the ratio of thickness to the total fine layer (second plating layer) 1 of the plated layer.
[0181]
　The crack of the plating layer, the plating layer surface observed by SEM for 5 field select any 1cm square field of view. 1 field, is divided in 100 grid area of ​​1 mm @ 2, observing the respective regions, those cracks were observed in 50% or more in average is "+", those not observed " - it was ".
[0182]
　Furthermore, in cross-sectional observation of the plating layer obtained by electron beam diffraction image of TEM, for those multilayer structure was confirmed and the fine layer 1 a compound layer 2 and the second plating layer is a first plating layer It was confirmed plated organization. Here, in the compound layer 2, MgZn, against observed plated tissue of Mg and quasicrystal were appended to "+", respectively. Similarly, in a fine layer 1, Mg 51 Zn 20 against, Zn and quasicrystal observed plated tissues of, and are indicated by the "+", respectively. Moreover, those interfacial alloy layer consisting of Al-Fe intermetallic compounds was observed and as "+", while measuring the thickness of the interfacial alloy layer, those that did not exist - and as "".
[0183]
　Furthermore, in cross-sectional observation of the plating layer obtained by electron beam diffraction image of TEM, for those multilayer structure has been confirmed, MgZn phases in the compound layer 2, and the Zn phase and quasicrystal consisting phase structure area ratio of , Mg in the fine layer 1 51 Zn 20 phase were measured and the area of the tissue consisting of Zn phase and semi crystalline phase, respectively. The measurement of the area ratio in each layer was carried out by image processing by a computer.
[0184]
Further, the plated steel sheet obtained, JASO in cycle accelerated corrosion test according to M609-91 (Japan Automobile Technology Standards), brine concentration only and 0.5% NaCl, bare corrosion resistance of the plated steel sheet (flat corrosion resistance) evaluated. Specifically, the corrosion weight loss after 60 cycles elapsed, 30 g / m 2 of which exceeds the "Poor", 30 ~ 10 g / m 2 was used as a "Good", 10 g / m 2 less than the "Excellent" did. Removal of corrosion products of the plating layer was performed by the method of "using chromium oxide (VI) 200g / l, is immersed for 1 minute at room temperature."
[0185]
　To confirm the rust inhibiting effect of the plating layer was to salt spray test defined in JIS Z2371. Beyond the × 150 hours to the plating thickness (μm), that red rust was not seen, as "Good", that red rust has been confirmed it was "Poor". Especially for those beyond × 200 hours with respect to the plating thickness ([mu] m), was evaluated as "Excellent".
[0186]
　Plating adhesion was evaluated by a ball impact test. The ball impact test, place the impact core having a hemispherical convex surface on the back side of the sample surface, on the sample surface side of arranging the saucer hemispherical concave, steel 1/2 inch diameter (heavy hit the impact core by dropping a weight of 2kg) from a height of 70cm. Peeled from the paste the Nichiban cellophane adhesive tape sample surface protruded by impact core was observed peeling from the surface of the plated steel sheet. Is that peeling was not observed, and "Excellent", the edge peeling slightly plating layer at the convex portion (less than 1% by area%) which was observed as "Good", and peel least 1% what was "Poor".
[0187]
　White rust is, JIS Z2371: salt spray test according to 2000 were evaluated by (SST Salt Spray Test). Specifically, it performs salt spray test according aqueous 5% NaCl solution (SST) with the plated steel sheet produced, white rust of more than 5% by area% was investigated test elapsed time occurring in the plane of the plated steel sheet . As white rust evaluation, the coated steel sheet in which the white rust is not confirmed after a lapse of 120 hours as "Excellent", a plated steel sheet which the white rust is not confirmed after 24 hours and "Good", the above white rust in less than 24 hours the confirmed plated steel sheet was evaluated as "Poor". It should be noted, indicating that "Excellent" is excellent in most white rust evaluation.
[0188]
　Further, in the obtained plated steel sheet, Zn phosphate treated, electrodeposition paint (Nippon Paint Co., Ltd. POWERTOP U-30) painted coated board and intermediate coating (Nippon Paint Co., Ltd. Orga P- 2) after application wet-on-wet and baked 30 minutes at 140 ° C.. The top coat paint, metallic-based paint after the dry film thickness (Nippon Paint Co., Ltd., trade name "Super rack M-155 Silver") was painted in such a way as to provide about 15μm, in the wet-on-wet, clear paint (Nippon paint Co., Ltd., the trade name of "super-rack O-150 clear") dry film thickness was painted in such a way as to provide about 40μm. After setting for about 7 minutes to obtain a multilayer coating film by baking at 140 ° C. 25 min. This was coated with Nippon Paint Co., Ltd. solvent type metallic base paint "Super rack M-90", was baked for 30 minutes in the coating to 140 ℃ a clear paint in the wet-on-wet.
[0189]
　Then, the coating film coated plated steel sheet a series of painted is performed described above, was evaluated for chipping resistance. Specifically, using Gurabero tester (manufactured by Suga Test Instruments Co., Ltd.), No. 7 crushed stones 100g from a distance of 30 cm 3.0 kg / cm 2 in the air, 90 ° to the coating film was cooled to -20 ° C. collide at angles, visually observed the degree of peeling (delamination) was evaluated by determining the following criteria. In the present embodiment, as a temporary assess 3, and "Good", the 4 or more "Excellent", and the 2 or less as "Poor".
[0190]
　5 completely without exfoliation
　4 peeled-off area is small, the frequency is small
　but 3 peeled area is small, somewhat more frequently
　but two peeling area larger, less frequently
　large 1 peeling area, often many
[0191]
　Further, after Gurabero test was to salt spray test defined in JIS Z2371. After 720 hours, what only confirmed white rust as "Excellent", those red rust area ratio white rust is less 0-10% in the frequency, and "Very Good", those 10-20% less and "Good", was the one that more than 20% as "Poor".
[0192]
　Anti-glare effect was evaluated by spectrophotometry. Although preferred visual evaluation originally, L visual and colorimeter * after confirming that there is a correlation value previously, SCI (specular reflection using a spectrophotometer (D65 light source, 10 ° viewing) It was evaluated in light inclusive) scheme. Specifically, the plated steel sheet produced by using a spectrocolorimeter CM2500d of Konica Minolta, measured diameter 8φ, 10 ° field of view, under conditions of D65 light source, L * were investigated value.
[0193]
　As anti-glare effect, L * a plated steel sheet value is less than 75 and "Excellent", L * was a plated steel sheet value is not less than 75 and "Poor". It should be noted, indicating that "Excellent" is an excellent anti-glare effect.
[0194]
　For indicators for evaluating the scratch resistance was measured plating layer hardness (Vickers hardness). The samples were cut into 50 × 50 mm, lateral 2mm spacing, longitudinal 7.5mm intervals, load 10 gf, MITUTOYO made AAV-504, MSDF test No. According H-05TK225, it was measured Hv value on average 30 points. Average Hv value is more than 250 as "Excellent", more than 200 as "Good", and less than 200 as "Poor". Incidentally, 1 gf is about 9.8 × 10 -3 is N.
[0195]
　Appearance of the plated steel sheet was evaluated by storage test at constant temperature and humidity chamber. Specifically, the plated steel sheets manufactured, stored at a temperature 40 ° C. and 95% humidity in a constant temperature and humidity bath for 120 hours to investigate the area% of blackening portions of the plane portion of the storage after plating steel sheet.
[0196]
　As appearance evaluation, the evaluation area 45 mm × 70 mm, in area%, blackened portion is a plated steel sheet of less than 1% as "Excellent", the plated steel sheet blackening portion is less than 1% to 3% "Good" and then, and the plated steel sheet of black strange part is more than 3% as "Poor". It should be noted, indicating that "Excellent" is excellent in most appearance evaluation.
[0197]
　As a comparative material, as Zn-plated steel sheet, Zn-22% Al-7% Mg-0.2% Si, was also similarly evaluated commercially available material molten Zn-plated steel sheet.
[0198]
　These evaluation results are shown in conjunction with the following table 13-20.
[0199]
[Table 13]

[0200]
[Table 14]

[0201]
[Table 15]

[0202]
[Table 16]

[0203]
[Table 17]

[0204]
[Table 18]

[0205]
[Table 19]

[0206]
[Table 20]

[0207]
　Having described in detail preferred embodiments of the present invention with reference to the accompanying drawings, the present invention is not limited to such an example. It would be appreciated by those skilled in the relevant field of technology of the present invention, within the scope of the technical idea described in the claims, it is intended to cover various changes in form , also such modifications are intended to fall within the technical scope of the present invention.
DESCRIPTION OF SYMBOLS
[0208]
　1 second plating layer (fine
　layers) 2 first plating layer (compound
　layer) 3 alloy layer (interfacial alloy
　layer) 4 cracking (chipping cracking)

The scope of the claims
[Claim 1]
　A plating layer located on at least one surface of the steel sheet,
　is located in the interface between the between the plated layer steel sheet, an alloy layer consisting of Al-Fe intermetallic compound,
comprising a
　chemical composition of the plating layer is , in
　　atomic%,
　　Zn:
　　28.5% ~ 50% Al:
　　0.3% ~ 12% La: 0% ~ 3.5% Ce:
　　0% ~ 3.5% Y: 0% ~ 3.5% 　　Ca:
　　　　0% ~ 3.5% 　　Sr: 0% ~ 0.5% Si: 0% ~ 　　0.5% Ti: 0% ~ 0.5% Cr: 0% 　　~ 0.5% Fe: 0% ~ 　　% 2 　　Co:　　0% ~ 0.5% 　　Ni: 0% ~ 0.5% V: 0% ~ 　　0.5% Nb: 0% ~ 0.5% Cu: 0% ~ 　　0.5% Sn: 0 　　~ 0.5%%　　Mn: 0% ~ 0.2% 　　Sb: 0% ~ 0.5% Pb: 0% ~ 0.5% contained, and the balance of Mg and impurities, 　said plating layer, in order from the steel sheet side, 　gZn phase, a first plating layer made of tissue containing Mg phase and quasi-crystalline phase, 　is located on the first plating layer, Mg 51 Zn 20 phase, the tissue containing the Zn phase and quasi-crystalline phases comprising a second plating layer, having a quasi-crystal-containing plated steel sheet.

[Claim 2]
　Chemical components of the plated layer in atomic%
　　Zn:
　　32% ~ 40%
　　Al: 2% ~ 5% Ca: 1% ~ 2.5%
contained, and the balance of Mg and impurities,
　the chemical composition ,
　　Zn
　　/ Al = 7.5 ~ 18 Ca / Al = 0.4 ~ 1.1
satisfied,
　the maximum grain size of the second plating layer is 1μm or less in circle equivalent diameter, in claim 1 quasi-crystal-containing plated steel sheet according.
[Claim 3]
　When the plate thickness direction and cutting direction saw the plating layer in a section made parallel,
　the said MgZn phases of the first plating layer, the circle equivalent diameter is composed of more crystal grains 1 [mu] m,
　the first plating the quasicrystalline phase of the layer is composed of tissue grown along the thickness direction, the quasi-crystal-containing plated steel sheet according to claim 1 or 2.
[Claim 4]
　When the plate thickness direction and cutting direction saw the plating layer in a section made parallel,
　the area of tissue the maximum crystal grain size of the second plating layer is 1μm or less in circle equivalent diameter, the second it is 90% or more with respect to the cross-sectional area of the entire plating layer, quasi-crystal-containing plated steel sheet according to any one of claims 1 to 3.
[Claim 5]
　When the plate thickness direction and cutting direction saw the plating layer in a section made parallel,
　the area of the MgZn phases of the first plating layer is 10% to with respect to the cross-sectional area of the entire first plating layer 70%, quasicrystals containing plated steel sheet according to any one of claims 1 to 4.
[Claim 6]
　The second plating layer does not contain Mg phase, quasicrystal-containing plated steel sheet according to any one of claims 1 to 5.
[Claim 7]
　The average value of Vickers hardness of the second plating layer is 250 ~ 350 Hv, quasicrystals containing plated steel sheet according to any one of claims 1 to 6.
[8.]
　The alloy layer, as the Al-Fe intermetallic compound, Fe 5 Al 2 or Al 3.2 comprises at least one of Fe,
　the thickness of the alloy layer is 10 nm ~ 200 nm, of claims 1 to 7, quasicrystal-containing plated steel sheet according to any one.
[Claim 9]
　Chemical composition, in
　　atomic%,
　　Zn:
　　28.5% ~ 50% Al: 0.3% ~
　　12% La: 0% ~ 3.5% Ce: 0% ~
　　3.5% Y: 0% ~ 3
　　% .5
　　Ca:
　　0% ~ 3.5% Sr:
　　0% ~ 0.5% Si: 0% ~ 0.5% Ti:
　　0% ~ 0.5% Cr: 0% ~
　　0.5% Fe:
　　%
　　~
　　2 0% Co: 0% ~ 0.5% Ni:
　　0% ~ 0.5% V: 0% ~ 0.5%
　　Nb: 0% ~ 0.5% Cu: 0% ~ 0.5%
　　sn:
　　
　　0% ~ 0.5% Mn: 0% ~ 0.2%
　　Sb: 0% ~ 0.5% Pb: 0% ~ 0.5%
containing, the balance being Mg and impurities, a molten state of the plating alloy, the plating step of disposed on at least one surface of the steel sheet,
　the plating alloy of the molten state is cooled to a temperature range of 330 ° C. or less at an average cooling rate 10 ° C. / sec or less, the steel sheet plating layer on the surface A first cooling step of forming,
　after the first cooling step, the plating layer, while heated to the temperature range of 350 ° C.-400 ° C. at a speed range of heating rate 10 ~ 50 ° C. / sec, 5 ~ and heating holding step of holding for 30 seconds,
　after the heating holding step, and a second cooling step of cooling the plating layer at a cooling rate higher than 20 ° C. / sec
including method of quasi-crystal-containing plated steel sheet.
[Claim 10]
　The plating step is performed by hot dipping,
　the steel sheet after pulled out from the molten coating bath, continuously carrying out the first cooling step, the manufacturing method of the quasicrystal-containing plated steel sheet according to claim 9.
[Claim 11]
　Chemical composition of the plating alloy of the molten state, in atomic%
　　Zn:
　　32% ~ 40%
　　Al: 2% ~ 5% Ca: 1% ~ 2.5%
contained, and the balance of Mg and impurities,
　wherein chemical
　　components,
　　Zn / Al = 7.5 ~ 18 Ca / Al = 0.4 ~ 1.1
satisfies the method for producing a quasi-crystal-containing plated steel sheet according to any one of claims 8-10.