Technical field
[0001]
　The present disclosure relates to a plated steel.
Background technique
[0002]
　Conventionally, the surface of the steel material by coating a metal such as Zn to improve the corrosion resistance of the steel have been made. Still Zn, Zn-Al, Zn-Al-Mg, steel is plated with such Al-Si is produced. It the coating of steel material which is required after adhesion abrasion resistance and processability in addition to corrosion resistance is large. As a method of coating steel, suitable for mass production molten plating is the most widely used.
[0003]
　Corrosion resistance required for the coating of steel becomes higher every year, therefore in recent years has also been proposed plated with an increased Mg content more than ever as shown in Patent Documents 1 and 2 below. However, an attempt to increase the Mg than ever, without dissolving metal during the production of hot-dip plating bath, there is a possibility such as dross generated under the heating conditions with the bath composition.
　Further, the molten plating film processability after adhesion of the coating by the formation of interfacial alloy layer is lowered by plating composition, it may be subject to constraints on processing methods. In particular, non-equilibrium phase, with a film obtained by precipitating an intermetallic compound has a strong tendency, proposed in Patent Document 1 and Patent Document 2 may be subject to constraints on likewise processing method.
　Against them, immersion plating (groove pickled), spraying, techniques such as vapor deposition from the viewpoint can also coated products after processing, has been known as a method capable of coating and less workability of the alloy. Among them, a vapor deposition method because it does not dipped steel into molten metal, thermal influence on the steel is small, coatable metals, there is an advantage such as wider melting tolerance of the alloy system.
[0004]
　To increase the corrosion resistance of the steel, as well as the formation of the plating layer, but the addition of Zn in the plating layer becomes basic, corrosion resistance becomes insufficient coating with a film of only Zn addition for many applications in many cases.
　Therefore, deposition of Mg-containing coating as described in Patent Document 3 have been proposed. This up 5% ~ 30% Mg, 0.5 ~ 5% of Al, Cr, Co, Mn, Ti, and comprises one or more selected from Ni, an alloy film balance being Zn It intended to deposit a plating film having excellent corrosion resistance. Further, as shown in Patent Document 4, technology for producing the Zn-Mg plating heat treatment after lamination has been proposed by evaporation plating monolayer.
[0005]
　Other, Patent Document 5, "Al: 5 ~ 70% (mean of% by weight, hereinafter the same), as well
as, Cr, Co, Ti, Ni, 1 kind selected from Mg, or two or more in total 0. 5 contains 1-5% (however, Ti, Mg is less than 5%), corrosion resistance and workability balance deposition plating layer consisting essentially of Zn, and characterized in that formed on the surface of the metal gear it has been proposed excellent zinc alloy plated metal material "to.
[0006]
Patent Document 1: Japanese Patent 2008-255464 JP
Patent Document 2: Japanese Patent 2011-190507 JP
Patent Document 3: Japanese Patent Laid-Open 1-021066 discloses
Patent Document 4: Japanese Patent 7-268604 JP
Patent Document 5: Japanese Patent Laid-Open 1-21064 discloses
Summary of the Invention
Problems that the Invention is to Solve
[0007]
　In the prior art, various alloy deposition plating coated as they are proposed, in any of the prior art, the corrosion resistance of the product can be plated film (especially corrosion resistance after processing), alkali corrosion, abrasion resistance, after processing adhesion is a problem that not be said to be sufficient.
[0008]
　One aspect of the present disclosure has been made in view of the background described above, corrosion resistance (in particular, corrosion resistance after processing), excellent alkali corrosion resistance and abrasion resistance, having a plating layer is also allowed excellent coating adhesion after processing and an object thereof is to provide a plated steel.
Means for Solving the Problems
[0009]
　The present disclosure has been made based on the above background, including the following aspects.
[1] and a steel, a plated layer coated on the surface of the steel product, the a steel material and the plated layer surface alloy layers formed on the boundary,
　composition of the plating layer, Zn mass%: 20 to 83%, and Al: 2.5 contains ~ 46.5%, and the balance of Mg and impurities, and has a Mg content of 10% or more,
　the organization of the plating layer, quasi-crystalline phase and MgZn 2 consists of a phase and remaining structure, the quasi-crystalline phase area fraction of 30-60%, 90% by number or more of the quasicrystalline phase 0.05 ~ 1.0 .mu.m particle size of the major axis direction and a quasi-crystalline phase, and
　the thickness of the plating layer is not 0.1μm or more, the thickness of the interfacial alloy layer plated steel is 500nm or less.
[2] plating steel according to the remaining structure area fraction of 40% or less [1].
[3] Plating steel according to the thickness of the plating layer is 0.1 ~ 10 [mu] m [1] or [2].
[4] plating steel according to any one of the plating layer is deposited plating layer [1] to [3].
[5] plated steel material according to any one of the interfacial alloy layer is Al-Fe alloy layer [1] to [4].
[6] The plated layer, C, Ca, Si, Ti , Cr, Fe, Co, Ni, V, Nb, Cu, Sn, Mn, Sr, Sb, Pb, Y, Cd, and one of La or comprise two or more selected elements, and plating steel according to any one of the total content of the selected element is from 0 to 0.5% by mass% [1] to [5].
Effect of the invention
[0010]
　According to one aspect of the present disclosure, the plating layer to have a quasi-crystalline phase, the corrosion resistance than the conventional Mg-containing plating steel (especially corrosion resistance after processing) and excellent alkali corrosion resistance, fine quasicrystals high hardness can provide a plating steel is excellent in abrasion resistance by distributed in uniformly plated layer. Furthermore, since the thin interfacial alloy layer of the plating layer and the steel material, it can provide excellent plating steel to the plating adhesiveness after processing.
　Also, embossing be rinsed processed into steel has been performed by the one aspect of the present disclosure it is possible to impart the function, it is possible to contribute to the development of industry to realize a long life of the member .
BRIEF DESCRIPTION OF THE DRAWINGS
[0011]
Side sectional view of a plating steel according to the embodiment of FIG. 1 the present disclosure.
Graph showing FIG. 2 of the temperature and the metal vapor pressure relationship.
[Figure 3] quasicrystalline phase TEM electron beam diffraction image of.
DESCRIPTION OF THE INVENTION
[0012]
　Studies of the present inventors, plating layer containing quasicrystalline phase Zn-Mg-Al-based high-Mg has found to exhibit high corrosion resistance. At the same time, steel forming the Zn-Mg-Al-based plating layer containing the quasi-crystal phase is also found to have had a very high hardness, excellent wear resistance.
　However, there is sparingly is to stabilize the plating bath composition of the foregoing, it is not easy to operate by using the plating bath of the composition range.
　Thus, as a result of the aforementioned high Mg-containing Zn-Mg-Al-based plating without using a plating bath having the composition described above was studied applying the steel, thereby achieving the present disclosure.
[0013]
　The following describes the plating steel according to the embodiment of the present disclosure.
　In the present specification, the numerical range expressed using "to" means a range including numerical values described before and after "to" as the lower and upper limits.
　In this specification, "%" indicating the content of the component (element) means "% by mass".
[0014]
　Plating steel 1 coated with the Mg-containing Zn alloy plating layer according to the embodiment, as shown in the cross-sectional structure of FIG. 1 (sectional structure taken along the plating layer thickness direction), the steel plate, steel pipe, civil engineering materials (guardrail, stop waterwall, corrugated tube or the like), the housing of consumer electronics member (air conditioner outdoor unit, etc.), automotive parts (suspension member or the like) steel 2 and plating layer formed by vapor deposition on the surface of the steel material 2, such as (deposition plating layer ) consisting of 3. Also, the interface of the steel product 2 and the plating layer 3 is a thin interfacial alloy layer (Fe-Al alloy layer) 4 is formed.
[0015]
　There is no particular limitation on the material of the steel 2 underlying the plating. Steel 2, e.g., generally steel, Ni pre-plating steel, Al-killed steel, it is possible to apply a portion of the high alloy steel. There is no particular limitation on the shape of the steel 2, molding may be subjected.
　Steel 2 is not limited to the flat of Figure 1, or the like may be used molding steel is bent in an L shape. Also, pressing, roll forming, the steel 2 processed into a desired shape by a variety of plastic working techniques such as bending, there is no obstacle to the free form a plating layer 3.
[0016]
　Hereinafter, structure of the plating layer 3 and the interfacial alloy layer 4, the composition, etc. is described.
　The boundary portion of the plating layer 3 and the steel material 2, for example, thickness of less than 500nm interfacial alloy layer 4 is formed. Plated layer 3 is formed from a Zn-Mg-Al alloy layer having a thickness of 0.1 ~ 10 [mu] m. Interfacial alloy layer 4 is composed of Al-Fe alloy layer. Incidentally, there are cases where interfacial alloy layer 4 becomes thin layer of a degree that can not be confirmed almost by the manufacturing conditions of the plating layer 3.
　Because the thickness of the interfacial alloy layer 4 depends on the deposition conditions of the plating layer 3, there is no particular limitation on the lower limit of the thickness of the interfacial alloy layer 4, for example, 300 nm from the viewpoint of the adhesiveness of the plating layer 3 more than is desirable. If the thickness of the interfacial alloy layer 4 is exceeds 500 nm, it reduces the adhesion of the plating layer 3, when the plastic working steel 2, the plating layer 3 is easily peeled off from the surface of the steel material 2.
　The thickness of the plating layer 3 may be difficult to obtain sufficient corrosion resistance is less than 0.1 [mu] m. Further, although the plating layer 3 of 10μm or more thick is possible to produce, it may be inferior in productivity in the case of performing production with continuous passage plate. Therefore, the thickness of the plating layer 3 is 0.1μm or more, preferably from 0.1 ~ 10 [mu] m, more preferably 0.5 ~ 5 [mu] m. In particular, when the thickness of the plating layer 3 to 0.5 ~ 5 [mu] m, are compatible adhesion corrosion resistance and plating after plating.
[0017]
　The thickness of the plating layer 3 and the interfacial alloy layer 4 is measured as follows. SEM parallel by (scanning electron microscope), the plating layer 3 and the interfacial alloy layer 4 of cross-sectional observation (plating layer 3 and is cut in the cross section in the thickness direction of the surface alloy layer 4, and the plating layer 3 and the interfacial alloy layer 4 to observe the area) corresponding to 2.5mm length fraction in such direction. In this region, determining at least three field of view the thickness of the average value of the plating layer 3 and the optional five locations of each interface alloy layer 4 is observed (magnification 10,000 times) (at least the total of 15 points). And the average value is set as the thickness of the plating layer 3 and the interfacial alloy layer 4.
　Incidentally, sample preparation methods for cross-sectional observation may be carried out by known resin embedding or cross-section polishing method.
[0018]
　Plating layer 3, quasicrystalline phase is precipitated therein. That is, in the plating layer 3 comprises a plurality of multiple quasicrystalline phase. Then, among the plurality of quasicrystalline phases which are precipitated in the plating layer 3 is the quasicrystalline phase 90% by number or more quasi-crystalline phases were a particle size of the major axis direction and 0.05 ~ 1.0 .mu.m it is desirable. Further, it may be very thin oxide film is formed on the surface of the plating layer 3.
[0019]
　Interfacial alloy layer 4 is formed on the surface of the steel material 2, for example, a layer range of Fe concentration of 10% to 90%. That is, the interfacial alloy layer 4 Fe 3 Al, FeAl 3 , Fe 2 Al 5 , FeAl 3 , and a part of Fe and Al include any one or more of the intermetallic compounds substituted on Zn there.
　Incidentally, the interface alloy layer 4 is, for example, average composition Fe: 30 ~ 50%, Al : 50 ~ 70%, Zn: 2 ~ 10 wt%, and the balance: made of impurities.
[0020]
　Al in the plating layer 3, and contain a large amount of Zn, Al in the plating layer 3 is Al reacts with Fe of the steel material 2 to the surface of the steel material 2 3 form a Fe phase. Further, Zn component of the plating layer 3 is taken inevitably becomes a shape incorporating some Zn, Al 3 Fe phase and the nature of the slightly differing interfacial alloy layer 4 is formed.
　Al 3 because the interfacial alloy layer 4 made of Al-Fe alloy mainly comprising Fe phase, inevitably, for example, the average value of the Fe concentration of the alloy layer is 30 to 50 percent. The average value of the Al concentration is 50% to 70%.
[0021]
　If to produce a plating layer 3 by a vapor deposition method, the plating layer 3 of composition of Zn-Mg-Al alloy, the component composition ratio is maintained even plating layer 3 is determined by the deposition rate of approximately deposition source metal. Al component of Zn-Mg-Al alloy layer due to the production of the interfacial alloy layer 4, a decrease in the Zn component is usually slight. This formation of an interface alloy layer 4 is for very thin.
[0022]
　The present inventors have, as a result of examining the composition range quasicrystalline phase is obtained by vapor plating method, that the quasi-crystal phase in the following composition ranges are contained in an area fraction required Zn-Mg alloy layer heading was.
[0023]
　In other words, the composition of the plating layer 3, Zn in wt% 20 to 83% and Al: 2.5 ~ containing 46.5%, the balance being Mg and impurities, and Mg content of more than 10% it is.
[0024]
　The composition of the plating layer 3, will be described why the desired range.
: "Zn (zinc) from 20 to 83%"
　to obtain a quasi-crystal phase as a plating layer 3 of metal structure, it is essential to contain the Zn within the above range. Therefore, the Zn content of the plating layer and 20 to 83%. If Zn content is less than 20%, to generate a quasi-crystal phase in the plating layer 3 becomes difficult. Similarly, if the Zn content is 83 percent, to generate a quasi-crystal phase in the plating layer 3 it becomes difficult.
　In order to further improve the corrosion resistance by generating preferably quasicrystals, and more preferably to the Zn content less than 60% (i.e. 60-83%). When 60% or more, quasicrystalline phase becomes grow easily composition range as primary crystal, Mg phase is less likely to grow as a primary crystal. That is, it is possible to increase the phase volume of the quasi-crystal phase (area fraction) of the plating layer 3, it is possible to reduce Mg phase deteriorate the corrosion resistance as much as possible.
[0025]
　"Al (aluminum): 2.5 to 46.5%"
　Al is an element that improves the corrosion resistance of the flat portion of the plating layer 3. Further, Al is an element promoting the formation of the quasi-crystal phase. To obtain these effects, the Al content of the plating layer 3 is 2.5% or more. To control the average circle equivalent diameter of the quasi-crystal phase within a preferred range is preferably to the Al content of 3% or more, and more preferably 5% or more.
　On the other hand, if a large amount of Al is contained, it reduces the alkali corrosion resistance, corrosion resistance becomes more difficult to generate the quasi-crystalline phase is reduced. Therefore, the Al content is set to less 46.5%, preferably 20% or less.
　Therefore, Al content of the plating layer 3, and 2.5 to 46.5%, preferably 3-20%, more preferably 5 to 20%.
[0026]
　"Mg (magnesium): balance"
　Mg, as well as the Zn and Al, a major element constituting the plating layer 3, and further, is an element that improves the sacrificial protection property. Moreover, Mg is an important element for promoting the formation of the quasi-crystal phase. Therefore, Mg content of the balance is set to 10% or more, preferably in the range of 10 to 43%, and more preferably in the range 15-35%. When the Mg content to 10% or more, to form a stable semi-crystalline phase, it does not require heat treatment as long as only the only generation of a quasi-crystalline phase than for the purpose. Although inclusion of Mg is essential, Mg contained is possible to suppress the precipitate as Mg phase in the plating layer 3 is preferred for improving corrosion resistance.
[0027]
　The plating layer 3, C, Ca, Si, Ti , Cr, Fe, Co, Ni, V, Nb, Cu, Sn, Mn, Sr, Sb, Pb, Y, Cd, and one of La or 2 it may contain the seeds or more selected elements. However, the total content of these selected elements to 0 to 0.5%.
　These elements are possible to be contained in the plating layer 3, the range of the total content, without inhibiting the formation of the quasi-crystal phase, the composition range can be added without deteriorating the performance of the plating layer it is. Exceeds the range of the total content, quasicrystalline phase becomes difficult to form.
[0028]
　Here, the composition of the plating layer 3, and the measurement method of the thickness of the plating layer 3 and the interfacial alloy layer 4 is as follows.
　First, peel only plating layer 3 of the upper surface alloy layer 4 by fuming nitric acid (Fe-Al layer) was passivated, the solution ICP-AES (Inductively Coupled Plasma Atomic Emission Spectrometry) or ICP-MS ( at Inductively Coupled Plasma Mass Spectrometry), for measuring the composition of the plating layer 3.
[0029]
　Next, a description will be given tissue of the plating layer.
　Organization of the plating layer 3, quasicrystalline phase and MgZn 2 consists of a phase and remaining structure, the area fraction of the quasi-crystal phase is 30-60%, of the plurality of quasi-crystalline phases, more than 90% by number quasicrystalline phase quasicrystalline phase has a particle size of the major axis direction and 0.05 ~ 1.0 .mu.m (hereinafter, the particle size of the quasi-crystal phase having a particle size of 0.05 ~ 1.0 .mu.m of "quasi-crystalline phase 90 also referred to as% or more of particle size ".) a.
[0030]
　In the plating layer 3 of tissue, that has 30% or more in area fraction of quasicrystalline phase is a hard, wear resistance is improved. In addition, the effect can be seen also in corrosion resistance by having a quasi-crystalline phase. However, since the quasi-crystal phase is harder, the area fraction of quasicrystalline phase exceeds 60%, cracking occurs at the time of machining, reduces the coating adhesion after processing. Therefore, the area fraction of the quasi-crystal phase is more preferably preferably 30 to 60%, more preferably 35 to 50%.
　MgZn 2 also phase quasicrystal as well as wear resistance, corrosion resistance, improve alkali corrosion resistance. MgZn 2 although also phase improve the performance, the degree is more quasicrystalline phase effect is significant. Meanwhile, with respect to coating adhesion after working is small degree of reduction than quasicrystalline phase. Therefore while ensuring the adhesion of the plating layer 3 after processing, corrosion resistance, alkali corrosion resistance, and it is possible to enhance the abrasion resistance. In this respect, the quasi-crystal phase and MgZn 2 total area fraction of the phase, 60% ≦ quasicrystalline phase + MgZn 2 preferably a phase ≦ 90%, 70% ≦ quasicrystalline phase + MgZn 2 in phase ≦ 85% there it is more preferable.
[0031]
　The area fraction of the remaining structure is preferably 40% or less, more preferably 30% or less. Reducing the area fraction of the remaining structure, the quasi-crystal phase and MgZn 2 to increase the total area fraction of the phase area fraction plating phase, while ensuring the adhesiveness of the plating layer 3 after processing corrosion resistance, This is because the enhanced alkali corrosion, wear resistance. However, the area fraction of the remaining structure is bur even 0%, it is 10% or more from the viewpoint of plating adhesion after processing.
[0032]
　Here, in the plating layer 3, the quasi-crystalline phase, Mg content in the quasicrystalline phase, Zn content and Al content, in atomic%, 0.5 ≦ Mg / (Zn + Al) ≦ 0.83 It is defined as a quasi-crystal phase satisfying. That is, the Mg atoms, Mg is the ratio of the sum of Zn atoms and Al atoms: the (Zn + Al), 3: 6 ~ 5: is defined as 6 to become quasi-crystal phase. The theoretical ratio, Mg: (Zn + Al) of 4: believed to be 6.
　Chemical components of the quasi-crystalline phase, quantitative analysis and by TEM-EDX (Transmission Electron Microscope- EnergyDispersive X-ray Spectroscopy), it is preferable to calculate in quantitative analysis by 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.
　The plating layer 3, MgZn besides quasicrystalline phase 2 including the phase and remaining structure, the remaining structure is the quasi-crystal phase and MgZn 2 a phase other tissues, Mg 51 Zn 20 phase, Mg 32 (Zn , Al) 49 phase, MgZn phase, Mg 2 Zn 3 phase, Zn phase include Al phase.
[0033]
　Quasicrystalline phase is the first discovered crystalline structure by Daniel Shuhitoman in 1982, and has an atomic arrangement in the icosahedron (icosahedron). The crystal structure, usually of metal, specific rotational symmetry which can not be obtained in the alloy, in a non-periodic crystal structure having, for example, 5-fold symmetry, aperiodic structure equivalent represented by 3-dimensional Penrose pattern It is known as Do not crystal structure. This in order to identify the metal material, typically by electron beam observation by TEM observation, the phase is confirmed by obtaining a radial positive decagonal electron beam diffraction image due to the icosahedral structure. For example, an electron beam diffraction image shown in FIG. 3 to be described later is obtained only from the quasicrystals, not be obtained from any other crystal structure.
[0034]
　Further, the quasi-crystalline phase obtained by the composition of the plating layer 3 is the simplified, Mg 32 (Zn, Al) 49 by X-ray diffraction as a phase, JCPDS card: PDF # 00-019-0029, or # 00 It shows diffraction peaks that can be identified by -039-0951.
　Quasicrystalline phase is a material excellent in a very corrosion resistance, when contained corrosion resistance is improved in the plating layer 3 (Zn-Mg-Al layer). Especially in an area fraction of 5% or more, tends to white rust is suppressed in corrosion initial stage are contained in the deposited plating layer. For example a higher area fraction, increasing its effectiveness when it is contained 30% or more. That quasicrystalline phase formed on the surface of the plating layer 3 (Zn-Mg-Al layer) has a high barrier effect against corrosion factor.
[0035]
　Then, the quasi-crystal phase of the plating layer 3, MgZn 2 phase, and the measuring method of the area fraction of the remaining structure will be described.
　Any cross-section of the plating layer 3 at least 3 or more visual fields of (cross section cut in the plating layer thickness direction) (at least 3 or more visual fields at a magnification of 5,000 times the area corresponding to 500μm length min in a direction parallel to the plating layer 3) the SEM- shooting in reflected electron image. From experimental results obtained by separately TEM observation, quasicrystalline phase in SEM- reflected electron image, MgZn 2 identifies phase, and the remaining structure. In certain field, grasps the component mapping image, quasicrystalline phase in the plating layer 3, MgZn 2 phase, and to identify the same component composition places the remaining structure, the image processing, the quasi-crystal phase in the plating layer 3, MgZn 2 phases, and identifies the remaining structure. By image analysis apparatus, quasicrystalline phase, MgZn 2 phase, and providing a range selected image of each region of the remaining structure, the quasi-crystal phase occupied in the plating layer 3, MgZn 2 phase, and measuring the ratio of the remaining structure to. The average value of from similarly treated 3 field, the quasi-crystal phase in the plating layer 3, MgZn 2 phase, and an area fraction of the remaining structure.
[0036]
　Phase identification of the plating layer 3, after the cross section of the plating layer 3 (cross section cut in the plating layer thickness direction) was subjected to FIB (focused ion beam) processing, by electron diffraction image of a TEM (transmission electron microscope) do.
[0037]
　Further, when the quasi-crystalline phase in accelerated corrosion test or the like is corroded, highly corrosion products form a barrier effect and anti-corrosion of the base steel for a long time. High corrosion products Accessible effect, Zn-Mg-Al component ratio contained in the quasi-crystal phase is concerned. In the component composition of the plating layer 3 (Zn-Mg-Al alloy layer), Zn> Mg + Al case (where the element symbols indicating content of the element (mass%)) is satisfied, the barrier of corrosion products effect is high. In general, corrosion resistance, higher is the area fraction of quasicrystalline phase. The effect when an area fraction of the quasi-crystal phase is 80% or more is particularly large. These effects, in combined cycle corrosion test including the salt spray cycle (SST), the effect is largely appears.
[0038]
　MgZn 2 phase and Mg 2 Zn 3 phase is corrosion resistance improving effect by containing as compared with quasi-crystal phase is small, has a constant corrosion resistance, and, since it contains a large amount of Mg, excellent alkali corrosion resistance. Alkali corrosion by being contained in the plating layer 3 in these single intermetallic compound is obtained, quasicrystalline phase to the quasi-crystal phase of highly alkaline environment (pH 13 ~ 14) surface of the plating layer 3 in comorbid oxide film is stabilized, so that particularly shows a high corrosion resistance. For this purpose, the quasi-crystal phase is preferably contained 30% or more in area fraction in the plating layer 3.
[0039]
　On the other hand, in the plating layer 3 tissues, the particle size of more than 90% by number of quasicrystalline phases crack propagates from the grain boundary by the machining and larger than 1.0 .mu.m, the adhesion of the plating layer 3 after processing is reduced . That is, the particle size of 90% or more of the plurality of quasicrystalline phase becomes 1.0μm or less, to improve the adhesion of the plating layer 3 after processing, also the wear resistance by the grain is finely dispersed improves. Particle size of more than 90% by number of the quasi-crystal phase is not sufficiently exhibited abrasion resistance is less than 0.05 .mu.m. Therefore, it is preferable that 90% number or more of the particle size of the quasi-crystal phase is 0.1 ~ 0.5 [mu] m, and more preferably 0.1 ~ 0.3 [mu] m.
[0040]
　The ratio of the quasi-crystal phase having a particle size of 0.05 ~ 1.0 .mu.m is preferably 90% by number or more, more preferably 95% by number or more.
[0041]
　The particle size of the quasi-crystal phase (the long axis direction of the grain size of the quasi-crystal phase), the proportion of quasicrystalline phase having a particle size of 0.05 ~ 1.0 .mu.m is measured by the following methods.
　(At least 3 or more viewing at a magnification of 5,000 times the area corresponding to 500μm length min in a direction parallel to the plating layer 3) at least three field of view of any cross-section of the plating layer 3 (cross section cut in the plating layer thickness direction) the captured by the measurement method similar to method area fraction of the quasi-crystalline phase, count the number of particles quasicrystalline phase in the plating layer 3. Also measures the length of the long axis of the quasi-crystal phase (ie the length of a straight line diameter of quasicrystalline phase becomes longest) as the particle size. Then, to the total number of particles counted was quasicrystalline phases, to calculate the ratio of the quasi-crystal phase having a particle size of 0.05 ~ 1.0 .mu.m.
[0042]
　It will be described in detail a method for manufacturing the plated steel material of the present embodiment.
　Steel 2 is desirably surface cleaning prior to depositing the plating layer 3 (hydrochloric acid pickling, water washing, drying) is subjected to. Strong oxide film generated on the surface of the steel material 2, for example, peeled by immersing 10% hydrochloric acid over 10 minutes. Pickled, and washed with water to remove surface moisture using dryer or drying oven.
[0043]
　To form a plating layer 3 on the surface of the steel material 2 uses a deposition method using a vacuum chamber as an example. Incidentally, in the following description will be described the case of forming the plating layer 3 in a closed system, similar results can be obtained with continuous passing sheet to the system.
[0044]
　Vacuum deposition is usually 10 -2 to 10 -5 conducted under a pressure of Pa, the mean free path at this time is several tens of cm ~ several tens m. Therefore, to reach the surface of the steel material 2 without colliding little material vaporized from the deposition metal source. Further, since the energy of evaporated particles is very small, it provides little damage to the surface of the steel material 2. The other hand, the plating layer 3 tends to be porous, low density, it will tend to be insufficient strength. This is due to the inability moving particles from a position reaching the steel surface for the energy of the vaporized particles are small.
　Therefore, the incident frequency of the steel 2 of the deposition (plating) in the evaporating particles by vapor deposition, to be sufficiently larger than the incident frequency to the substrate of the residual gas in the chamber, the residual gas is taken into the plating layer 3 put away. The most common components of the residual gas is H 2 is O. H in the plating layer 3 2 When O is taken, will be capable of voids in the plating layer 3, the brittle plating layer porous.
　It is effective to deposit plating by heating the steel material 2 in order to improve this. The higher the temperature of the steel material 2, reduces the probability of adhesion to steel 2 of residual gases, the amount incorporated into the plating layer 3 is reduced. Also, vapor-deposited metal adsorbed on steel 2 becomes easy to move by thermal energy, become those adhering to the unstable surface can be moved to a stable place, also increases the density of the plating layer 3.
[0045]
　A plating layer 3 a quasicrystalline phase and ZnMg phase, in order yet to secure the post-process adhesion of the plating layer 3, it is desirable to heat the steel material during deposition. Temperature of the steel material 2 is preferably 50 ~ 400 ° C.. 50 often plated layer 3 next to the metal atoms deposited on the surface of the steel material 2 is void unable form sufficiently crystalline phase at temperatures below ° C., it can not be sufficiently obtained corrosion resistance. The temperature of the steel material 2 is set more than 400 ° C., when the deposited plating over a long time, the interface alloy layer 4 will grow thick, a factor of the post-process adhesion deterioration of the plating layer 3. Therefore, preferably 0.99 ~ 350 ° C., more preferably 200 ~ 300 ° C., it is desirable to deposit while heating the surface of the steel material 2 (film formation).
[0046]
　Deposition rate when depositing the plating layer 3 is determined by the contents of the following.
It is determined by the temperature and vapor pressure of the metal source at that time the "1" deposition metal source.
Surface area of the "2" deposited metal source, is determined by the capacitance.
Distance from "3" deposited metal source to steel 2 is determined by the size of the chamber.
　The heating method in a method for depositing a plating layer 3 may select one of the methods exemplified below.
(1) resistance heating. (2) electron beam heating. (3) high-frequency induction heating. (4) laser heating.
[0047]
　It is preferable to selectively use a deposition method by the characteristics of the metal to be deposited.
　The resistance heating to generate Joule heat flowing electric added a voltage across the high melting point metal and various heating materials. The resistance heated can be dissolved by installing a vapor-deposited metal source on the sample stage is.
　In wire heating thermal electrons generated by resistive heating filament such as tungsten are accelerated by a high voltage to irradiate the metal evaporation source. By the electron kinetic energy is converted collision to heat, it is capable of dissolving the metal evaporation source.

claim.
　Comprising a steel, a plated layer coated on the surface of the steel material, the interfacial alloy layer formed at the boundary of the steel and the plating layer,
　the composition of the plating layer, Zn mass%: 20 to 83% , and Al: 2.5 contains ~ 46.5%, and the balance of Mg and impurities, and has a Mg content of 10% or more,
　the organization of the plating layer, quasi-crystalline phase and MgZn 2 and phase consists of a remaining structure, the quasi-crystalline phase area fraction of a 30-60% level of the at least 90% by number quasicrystalline phase has a particle size of the major axis direction and 0.05 ~ 1.0 .mu.m a crystalline phase,
　the thickness of the plating layer is not 0.1μm or more, the plating steel thickness of the interfacial alloy layer is 500nm or less.
[Claim 2]
　Plated steel according to claim 1 area fraction of the remaining structure is 40% or less.
[Claim 3]
　Plated steel according to claim 1 or claim 2 the thickness of the plating layer is 0.1 ~ 10 [mu] m.
[Claim 4]
　Plated steel according to any one of claims 1 to 3 wherein the plating layer is deposited plating layer.
[Claim 5]
　Plated steel according to any one of the interfacial alloy layer claims 1 to 4 is a Al-Fe alloy layer.
[Claim 6]
　The plating layer, C, Ca, Si, Ti, Cr, Fe, Co, Ni, V, Nb, Cu, Sn, Mn, Sr, Sb, Pb, Y, Cd, and one or more La plated steel of containing the selection element, and according to any one of claims 1 to 5 the total amount of the selected element is from 0 to 0.5% by mass%.