[0001]The present invention, grain-oriented electrical steel sheet having an insulation coating containing no chromate, and a method for producing the grain-oriented electrical steel sheet.
　The present application, on September 29, 2015, claiming priority based on Japanese Patent Application No. 2015-191155, filed in Japan, the contents of which are incorporated here.
Background technique
[0002]
　Oriented electrical steel sheet is a steel sheet that is mainly used as an iron core, such as transformers. Typically, such a grain-oriented electromagnetic steel sheet, forsterite layer formed during the high temperature finish annealing and (also primary coating referred to), after applying the treatment solution mainly composed of such phosphates, of steel surface coating of the two layers of the phosphate coating formed baking during heat flattening is formed.
[0003]
　Phosphate coating is an electrically insulating impart oriented electrical steel sheet is required in order to improve the iron loss by reducing the eddy current loss. In addition, the phosphate coating, corrosion resistance in addition to insulation, heat resistance, slip properties, various properties such as adhesion are required. This means that when the iron core of the transformer or by processing the oriented electrical steel sheet, in order to facilitate the various manufacturing steps. For example, the heat resistance of the phosphate coating, slipperiness, adhesiveness is inferior, that the phosphate coating is peeled off when the strain relief annealing iron core production, the original insulating phosphate coating is exhibited or not be, workability can not smoothly laminated steel sheet is sometimes deteriorated.
[0004]
　Further, as an important characteristic of the insulating coating of the grain-oriented electrical steel sheet, and to impart tension to the steel sheet. If you apply tension to the steel sheet, it is possible to improve the iron loss oriented electrical steel sheet by facilitating domain wall motion. It is also possible to oriented electrical steel sheet to reduce the magnetostriction is one of the main causes of noise generated trans prepared using the iron core by applying tension.
[0005]
　In order to improve the properties of grain-oriented electrical steel sheet as described above, specifically, techniques such as disclosed in Patent Documents 1 to 7 below are being researched and developed.
[0006]
　For example, Patent Document 1, on the forsterite film formed on the surface of the steel sheet after finish annealing, phosphates having a specific composition, chromates, and an insulating film treatment solution mainly composed of colloidal silica coated after, it is disclosed that burn. According to disclosed in Patent Document 1 technology, an insulating film having a high tension to form on the surface of the steel sheet, it is possible to reduce the iron loss of grain-oriented electrical steel sheet and magnetostriction.
[0007]
　Further, Patent Document 2, after the particle diameter was coated 8μm following ultrafine colloidal silica, primary phosphates, and a treatment liquid containing at specific proportion of chromate steel sheet, a method of baking is disclosed It is. According to the technique disclosed in Patent Document 2, with retention of high tension insulating film, it is possible to further improve the lubricity of the coating.
[0008]
　Further, Patent Document 3, phosphate, chromate, and an insulating film having a glass transition point as a main component 950 ° C. ~ 1200 ° C. of colloidal silica that is a specific amount deposited, the high tension insulating film a technique of forming on the surface of grain-oriented electrical steel sheet is disclosed.
[0009]
　According to the above disclosed in Patent Documents 1-3 art, various film properties are much better, it was possible to form an insulation coating film tension was also improved. However, the technique disclosed in Patent Documents 1 to 3 are all contained chromate chromium compound in an insulating film. In recent years, with the environmental problems have been highlighted, lead, chromium, that prohibit or limit the use of compounds such as cadmium have been socially demanded.
[0010]
　Therefore, without containing the chromium compound capable of forming a good insulating film technology it has been studied. For example, Patent Document 4, a colloidal silica SiO 2 20 parts by mass content, 10 to 120 parts by mass of aluminum phosphate, 2 to 10 parts by weight of boric acid, Mg, Al, Fe, Co, Ni, one or insulating coating treatment method of the grain-oriented electrical steel sheet for baking with a treatment liquid containing 300 ° C. or higher at a total of 4 to 40 parts by weight of sulfuric acid salt of 2 or more kinds of metal elements and selected from among Zn is It has been disclosed.
[0011]
　Further, Patent Document 5, a mixture of boric acid and alumina sol, and a organic solvent having compatibility with water, technology disclosed relates to film-forming coating agent having a tensioning effect on the grain-oriented electrical steel sheet It is.
[0012]
　Further, Patent Document 6, in the grain oriented electrical steel sheet for surface-treating agent containing the phosphate and colloidal silica, one selected Ca, Mn, Fe, Zn, Co, Ni, Cu, B and Al or technique of adding an organic acid salt of two or more metal elements is disclosed. In Patent Document 6, as organic acid salts, formate, acetate, oxalate, tartrate, lactate, citrate, succinate and salicylate are exemplified.
[0013]
　Further, Patent Document 7, the insulating film treatment agent for grain-oriented electrical steel sheet containing phosphate and a colloidal silica, a divalent metal element of the metal components in the phosphate, trivalent metal elements , and techniques that a combination of certain proportions of 4 or more valent metal element is disclosed.
[0014]
　However, the insulating film disclosed in Patent Document 4, the sulfate ions in sulfates, corrosion resistance of the steel sheet was sometimes lowered. In the technique disclosed in Patent Document 5, since corrosion resistance and the baking temperature of the insulating coating is too high, defects is likely per steel sheet. In the technique disclosed in Patent Document 6, an organic acid in an organic acid salt, a solution of the surface treatment agent was discolored, liquid stability was low. Further, in the technique disclosed in Patent Document 7, the preparation of the coating solution is complex, and can not increase the concentration of the coating solution, a uniform coating is difficult.
[0015]
　In addition, an insulating film not containing chromate as disclosed in Patent Documents 4-7, it fails to impart sufficient tension to the steel sheet, thus possible to sufficiently improve the iron loss of the grain-oriented electrical steel sheet It could not be. Therefore, techniques relating to the insulating coating of these oriented electrical steel sheet, further improvement was required.
[0016]
　Insulation coating of oriented electrical steel sheet, by utilizing the difference between the thermal expansion coefficient of the insulating coating and the thermal expansion coefficient of the steel sheet, to apply tension to the steel sheet. If the thermal expansion coefficient of the insulating coating is less than the steel plate, the amount of shrinkage of the steel sheet occurring during baking of the insulating coating, becomes larger than the amount of shrinkage of the insulating film, a tensile stress is applied to the steel sheet, the compressive stress in the insulating film There are granted. Thus, in the prior art, for the tension increase in the insulation coating of the grain-oriented electrical steel sheet, reduction in the thermal expansion coefficient of the main insulating film, and increased adhesion strength of the insulating coating it has been attempted. However, the present inventors have been studying on the insulating film that does not contain a conventional chromate found that insulation coating is the cause of even tension reducing to have a porous structure. If the insulation coating has a porous structure, baked fine destruction starting from the porous when the insulating coating occurs, insulation coating was estimated to be unable to impart sufficient tensile stress to the steel sheet.
　However, the denseness of the insulating coating of the grain-oriented electrical steel sheet, the insulating film is the relationship between the tension capable of imparting a grain-oriented electrical steel sheet, and grain oriented electrical steel sheet prior how the densification of the insulating film that does not contain chromates enough to have not been considered in technology.
CITATION
Patent Literature
[0017]
Patent Document 1: Japanese Patent Publication 53-28375 Patent Publication
Patent Document 2: Japanese Sho 61-41778 Patent Publication
Patent Document 3: Japanese Unexamined Japanese Patent Application Laid-Open No. 11-071683
Patent Document 4: Japanese Patent Publication 57- 9631 JP
Patent Document 5: Japanese Unexamined Japanese Patent Application Laid-Open No. 7-278828
Patent Document 6: Japanese Patent 2000-178760 JP
Patent Document 7: Japanese Patent 2010-13692 JP
Summary of the Invention
Problems that the Invention is to Solve
[0018]
　Insulation coating of oriented electrical steel sheet, shall allow impart significant tension to the surface of the steel sheet. For this purpose, the insulating coating of the oriented electrical steel sheet, the thermal expansion coefficient is small, high adhesion, is required to be more dense. In addition, the insulating coating of oriented electrical steel sheet, it corrosion resistance is good, it is the productivity is good, and the like is also required to be free of chromate.
[0019]
　The present invention has been made in view of the above problems, it is an object of the present invention can impart significant tension to the surface of the steel sheet, adhesion and corrosion resistance is also good, good further productivity do, an insulating film containing no chromate, and to provide good grain-oriented electrical steel sheet also magnetic properties, and a manufacturing method of the grain-oriented electrical steel sheet.
Means for Solving the Problems
[0020]
　The gist of the present invention is as follows.
(1) grain-oriented electrical steel sheet according to an embodiment of the present invention is an oriented electrical steel sheet and a steel sheet and the insulating film, the insulating film is, in the Al, Fe, Mg, Mn, Ni, and Zn one or more metal phosphates metal salt of a first metal phosphate of selected from; Co, Mo, V, W and one or more metals selected from among Zr, secondary phosphate metal salt of a phosphoric acid metal salt and; colloidal silica; contains, the insulating film does not contain a chromate, in pure water boiled the oriented electrical steel sheet boiled for 10 minutes, the amount of phosphoric acid eluted in pure water was measured, it is measured by dividing the area of the insulating film of the grain-oriented electrical steel sheet amount is boiled in the phosphoric acid, the insulating phosphate elution of coating 30 mg / m 2 or less.
(2) oriented electrical steel sheet according to the above (1), the first phosphoric acid metal salt is, Al, Mg, Ni, and said one or more of the metals selected from Zn it may be a phosphoric acid metal salt.
(3) above (1) or oriented electrical steel sheet according to (2), said second metal phosphate is, V, W, and one or more of the metals selected from among Zr it may be of the metal phosphate.
(4) oriented electrical steel sheet according to any one of the above (1) to (3), the content of the second metal phosphate, 0.5 with respect to the total weight of the insulation coating it may be 10.0 wt%.
(5) oriented electrical steel sheet according to any one of the above (1) to (4), the content of the colloidal silica, based on the total weight of the insulating coating 25 to in terms of solid content it may be 55 mass%.
(6) oriented electrical steel sheet according to any one of the above (1) to (5) has an average primary particle diameter of the colloidal silica may be 7 ~ 30 nm.
(7) oriented electrical steel sheet according to any one of the above (1) to (6), the coating amount of said insulating coating is 2.0 ~ 7.0 g / m 2 may be.
(8) oriented electrical steel sheet according to any one of the above (1) to (7), the insulating coating is further boric acid, sodium borate, titanium oxide, molybdenum oxide, pigments, and titanate it may contain one or more kinds selected from the group consisting of barium.
(9) above (1) oriented electrical steel sheet according to any one of - (8), the steel sheet, at unit mass%, C: 0.005% or less, Si: 2.5 ~ 7. 0%, Mn: 0 ~ 1.0 %, Al: 0 ~ 0.03%, N: 0.01% or less, P: 0.01% or less, and S: to 0.01% or less, the balance there Fe and impurities, the average crystal grain size of the steel sheet is 1 ~ 10 mm, the angle between the crystal orientation and the rolling direction (110) [001] of the steel sheet, there an average 8 ° or less it may be.
(10) The method of producing grain-oriented electrical steel sheet according to another aspect of the present invention includes the steps of applying an insulating coating treatment liquid to the surface of the steel sheet; and a step of forming an insulating film by baking the insulation coating treatment solution; wherein the insulation coating treatment liquid of 100 parts by weight in terms of solid content, Al, Fe, Mg, Mn, at least one metal phosphate metal salt selected from among Ni, and Zn in the terms of the solid content of 3 to 20 parts by weight, Co, Mo, V, W 1 or two or more metals metal phosphate of which are selected from, and Zr; there first and phosphoric acid metal salt there a second metal phosphate of; colloidal silica 35-125 parts by weight in terms of solid content; and 0.3 to 6.0 parts by weight of the polymerization aids; contains, in the baking, 100-200 800 heating rate 30 in the temperature range ° C. ° C. / sec or higher, baking soaking temperature 80 ~ 1000 ° C., and it is soaking time of 10 to 60 seconds.
(11) The method of producing grain-oriented electrical steel sheet according to (10), said first metal phosphate of, Al, Mg, Ni, and one selected from among Zn, or two or more of the a said phosphoric acid metal salt of the metal may be.
(12) The method of producing grain-oriented electrical steel sheet according to (10) or (11), said second metal phosphate of, V, W, and Zr 1 or more species selected from among it may be of the metal the metal phosphate of.
(13) (10) - (12) The method for producing oriented electrical steel sheet according to any one, the polymerization adjuvant, nitrite, sodium nitrite, potassium nitrite, nitrate, sodium nitrate, potassium nitrate , chlorite, sodium chlorite, phosphonate, sodium phosphonate, triphosphate, sodium triphosphate, polyphosphate, and may be at least one selected from the group consisting of sodium polyphosphate.
(14) The method of producing the (10) oriented electrical steel sheet according to any one of - (13) has an average primary particle diameter of the colloidal silica may be 7 ~ 30 nm.
(15) the production method of the above (10) oriented electrical steel sheet according to any one of - (14), the insulating film treatment solution is further boric acid, sodium borate, titanium oxide, molybdenum oxide, pigments, and it may contain one or more kinds selected from the group consisting of barium titanate.
(16) (10) The method of producing grain-oriented electrical steel sheet according to any one of - (15), the steel sheet, at unit mass%, C: 0.005% or less, Si: 2.5 ~ 7.0%, Mn: 0 ~ 1.0%, Al: 0 ~ 0.03%, N: 0.01% or less, P: 0.01% or less, and S: 0.01% or less and the balance being Fe and impurities, the average crystal grain size of the steel sheet is 1 ~ 10 mm, the angle between the crystal orientation and the rolling direction of the steel sheet (110) [001] is on average at 8 ° it may be less than or equal to.
Effect of the invention
[0021]
　According to the present invention described above, low thermal expansion, high adhesion, a further compact and since it is possible to impart a large tension to the surface of the steel sheet, further contains no chromate insulating coating a. Accordingly, the present invention does not use a chromate, grain-oriented electrical steel sheet magnetic characteristics are greatly improved is obtained. Further, according to the present invention, it is possible to obtain corrosion resistance, sliding properties, and productivity is also good oriented electrical steel sheet.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022]
Relative [1] phosphate elution volume is a graph plotting the tensile force of the insulating coating.
Is a flowchart illustrating a method of manufacturing a grain-oriented electrical steel sheet according to an embodiment of the present invention; FIG.
DESCRIPTION OF THE INVENTION
[0023]
　Reference will now be described in detail preferred embodiments of the present invention.
[0024]
　For insulating coating on grain oriented electrical steel sheet to impart tension to the steel sheet, a thermal expansion coefficient of the steel sheet, it is necessary that there is a difference between the thermal expansion coefficient of the insulating coating. Specifically, if the thermal expansion coefficient of the insulating coating is less than the steel plate, the amount of shrinkage of the steel sheet occurring during baking of the insulating coating, to become larger than the amount of shrinkage of the insulating coating, the steel sheet tensile stress is applied, so that the compressive stress is applied to the insulation coating. Therefore, in order to further increase the tensile stress applied to the steel sheet, it is important to further reduce the thermal expansion coefficient of the insulating coating. Further, in order to be given tension to the steel sheet so as not to peel the insulation coating on grain oriented electrical steel sheet is required to have excellent adhesion.
[0025]
　As the insulating film treatment agent for forming an insulating film having the above characteristics, in general, phosphate, colloidal silica, and mixtures chromate is used. However, the increasing awareness of environmental problems in recent years, to prohibit or restrict the use of chromium compounds such as chromic acid salts are socially demanded. However, the insulating film containing no chromate are unable to impart sufficient tension to the steel sheet, thus the iron loss of the grain-oriented electrical steel sheet can not be sufficiently improved.
[0026]
　Therefore, the present inventors have component system containing no chromate, and conducted intensive studies to obtain an insulating film for retaining the high tension required to oriented electrical steel sheet. As a result, the present inventors have found that the insulation coating containing no chromate is causing even tension reducing to have a porous structure.
[0027]
　Conventionally, in the insulating coating composed mainly of phosphate and colloidal silica, colloidal silica reduces the thermal expansion coefficient of the insulating coating, the phosphate has been thought to play a role of binder. However, does not contain chromate, the insulation coating contains a phosphate was found that the coating becomes porous structure. If the insulation coating has a porous structure, fine destruction starting from the porous occurs, insulation coating was estimated to be unable to impart sufficient tensile stress to the steel sheet. The present investigators, the results of extensive studies on how to densify the insulating coating, insulating phosphate obtained by combining the first phosphoric acid metal salt of a second metal phosphate that are described later coated of used as the material for further this, by adding a polymerization adjuvant, to increase the bond between the phosphoric acid metal salt, the dense insulating film to prevent the pore formation of the insulating film can be formed heading was. Note that when densifying the insulating film, the friction coefficient of the insulating coating is reduced, it was found that is also obtained a secondary effect of improving the sliding property of the grain-oriented electrical steel sheet.
[0028]
　Incidentally, the polymerization degree of phosphate, and it is extremely difficult to quantitatively measure the fineness itself of the insulating coating. In the prior art, by observing the electron micrograph of the insulating coating, to qualitatively determine the degree of polymerization and denseness of the insulating coating of phosphate it has been carried out. However, the present inventors have found that low insulating coating is phosphate elution has been found that there is a high tendency polymerization degree and compactness of phosphate. The term "phosphate elution amount" in the present embodiment, the insulating film for a predetermined time boiled in pure water boiled oriented electrical steel sheet having, thereby measuring the amount of phosphoric acid eluted in pure water, It is defined as the value measured by dividing the area of ​​the insulating coating of the amount of boiled-oriented electrical steel sheet of phosphoric acid. Note that the area of ​​the insulating film of the grain-oriented electrical steel sheet, the area of ​​the insulation coating as seen from the rolled surface of the grain-oriented electrical steel sheet, if both the rolling surfaces oriented electrical steel sheet insulating coating is formed, the area of ​​the insulating film of the two rolling surfaces are those summed. Phosphate elution amount, the degree of polymerization of the phosphate in the insulating film, and is available denseness of the insulating coating as quantitatively evaluating index. If a low phosphate elution amount in the insulating film, a high polymerization degree of the phosphate in the insulating film, is determined to be high denseness of the insulating coating.
[0029]
　Furthermore, the present inventors have mainly of phosphate and colloidal silica, the phosphate, Al, Fe, Mg, Mn, Ni, and one or two or more selected among Zn , relatively high solubility metal phosphate metal salt (hereinafter, referred to as a first metal phosphate) and Co, Mo, V, W, and one or more selected from among Zr, comparison solubility is low metal phosphate metal salt of the insulating coating is a combination of (hereinafter, the second referred to as phosphoric acid metal salt), the tension applied to the phosphate elution and the steel sheet insulating coating it has been found that there is a strong correlation between.
[0030]
　1, a first metal phosphate, and a second metal phosphate of, containing colloidal silica, the various steel sheets having an insulation coating containing no chromate, 10 in pure water minutes boiling phosphoric acid elution amount of time was (mg / m 2 and), the insulating film 1 g / m 2 in terms the insulating coating tension (N / mm per 2 is a graph showing a relationship between). Phosphate elution amount was measured according to the above definition. Coating the tension of the insulating coating was measured from the warpage of the steel sheet caused by the removal of one surface of the insulating coating. In preparing various insulating film serving as a sample, the first and second metal phosphate, and the composition of the colloidal silica, as well as varying the degree of polymerization by varying the amount of the polymerization aid.
[0031]
　As shown in FIG. 1, a first metal phosphate, and a second metal phosphate of, containing colloidal silica, the insulating film containing no chromate, phosphate elution amount (mg / m 2 and), the insulating film 1 g / m 2 was found that a good linear relationship is observed between the insulating film tension as converted per (N). To improve the iron loss oriented electrical steel sheet, since the film tension is desirably greater than 1.5 N, in view of the experimental results shown in Figure 1, the phosphate elution amount 30 mg / m 2 limited to it is judged to be necessary to. In the experiments shown in Figure 1, almost all of the samples, phosphate elution amount is 0 mg / m 2 Ultra 25 mg / m 2 group and phosphoric acid elution of less than the 30 mg / m 2 , either with a group of more than belongs to, phosphate elution amount is 25 ~ 30 mg / m 2 there was little of the sample. The cause is not clear, phosphate elution 25 ~ 30 mg / m 2 to the range of the threshold, it is estimated that the change in the structure of the insulating film occurs.
[0032]
　Based on the above experimental results, the present inventors have found that a first metal phosphate, and a second metal phosphate of, containing colloidal silica, the insulating film containing no chromate, phosphate the acid elution amount 30 mg / m 2 was limited to, by inhibiting the generation of free phosphate, an insulating film having a dense structure on the surface of the steel sheet, that a high tension to the steel sheet can be imparted it has been found.
[0033]
　For phosphate elution amount of measurement, as described above, oriented magnetic steel sheet having an insulation coating was boiled for 10 minutes in pure water in the boiling, thereby the amount of phosphoric acid eluted in pure water it is necessary to measure. For the measurement of the amount of phosphoric acid eluted in pure water, but a variety of methods exist, for example, ICP-AES method (inductively coupled plasma emission spectroscopy), are known, such as hydrazine sulfate coloring method, in particular but it is not limited to, for example, can be used to analyze quantitatively by ICP-AES method.
[0034]
　Next, description reasons for limiting oriented electrical steel sheet according to the present embodiment.
[0035]
　Oriented electrical steel sheet according to the present embodiment includes a steel plate and an insulating film. Insulation coating of a grain-oriented electrical steel sheet according to the present embodiment, Al, Fe, Mg, Mn , first phosphorus is one or more metal phosphates metal salts selected from among Ni, and Zn containing an acid metal salt, Co, Mo, V, W , and a second metal phosphate of a and one or more metal phosphates metal salts selected from among Zr, and a colloidal silica and, and it is one which does not contain chromate, and is formed on the surface of the steel sheet. Further, the insulating coating of the grain-oriented electrical steel sheet according to the present embodiment, the phosphate elution amount measured in the manner described above 30 mg / m 2 or less.
[0036]
　Phosphate elution amount is 30 mg / m 2 if it is greater, the film tension is insufficient. This compactness of the insulating coating is considered to be because impaired. Further, when the phosphate elution amount is too large, not only the film tension is decreased, by which the insulating coating is hygroscopic, there is a possibility that the corrosion resistance is deteriorated. For the above reasons, phosphate elution amount in the insulating film of grain-oriented electrical steel sheet according to the present embodiment is 30 mg / m 2 is less. Phosphate elution amount in the insulating film is preferably, 27 mg / m 2 or less, 20 mg / m 2 or less, or 12 mg / m 2 or less.
[0037]
　Incidentally, when the insulating film is a porous structure, the surface area of the insulating film is increased, since the phosphoric acid to elute from the interior coating, with increasing coating weight of the insulation coating is also increased phosphate elution. However, the grain-oriented electrical steel sheet according to the present embodiment, since the insulating film is a dense structure, phosphoric acid elutes only from the surface of the insulating coating, the phosphoric acid elution from the interior coating, negligibly small. Accordingly, in the oriented electrical steel sheet according to the present embodiment, the upper limit of the phosphate elution amount in the insulating coating, irrespective of the coating weight of the insulation coating, 30 mg / m 2 a.
[0038]
　Phosphate elution amount in the insulating film, since better the less, the lower limit is 0 mg / m 2 is. However, considering the production cost, the lower limit of the phosphate elution amount in the insulating film, for example, 3 mg / m 2 or 8 mg / m 2 is.
[0039]
　Phosphoric acid metal salt of the insulating coating of the grain-oriented electrical steel sheet according to the present embodiment, Al, Fe, Mg, Mn, Ni, and one or more selected from among Zn, relatively high solubility metal metal phosphate (hereinafter, the first referred to as phosphoric acid metal salt), Co, Mo, V, W, and one or more selected from among Zr, relatively solubility of the low metal phosphoric acid metal salt is a combination of (hereinafter, the second referred to as phosphoric acid metal salt). The present inventors have found that the only relatively high solubility primary phosphate metal salt was found that it is difficult to suppress the phosphate elution amount in the insulating film. On the other hand, a relatively low solubility in the second metal phosphate of, can not be dissolved at a high concentration in the material at which the treatment liquid of the insulating coating, it only with adequate thickness, uniformity, and density, etc. it is difficult to produce an insulating film having a. By combining both the first phosphoric acid metal salt and the second metal phosphate, to suppress the phosphate elution amount in the insulating film, it is possible to improve the denseness of the insulating coating.
[0040]
　Incidentally, the first metal phosphate Al, Mg, it is preferable that the one or more metal phosphates metal salt selected from among Ni and Zn. Because the first metal phosphate Al, Mg, when the one or more metal phosphates metal salt selected from Ni and Zn, is flat and uniform appearance in a wide range of baking conditions it is because it is obtained. Further, it is preferable that the one or more metal phosphates metal salt selected the second metal phosphate from among V, W, and Zr. Because it a second metal phosphate of V, W, and when the one or more metal phosphates metal salt selected from the group consisting of Zr, from uniform color tone of the coating is obtained . In the case where the second metal phosphate of including Co is liable color tone of the film becomes uneven, it is necessary to strictly manage the coating and drying conditions occur.
[0041]
　The metal phosphate metal salts, such as non-Na, K, Ca, Sr, and Ba above are preferably not used in the insulating film of a grain-oriented electrical steel sheet according to the embodiment. For example, alkali metal salts of phosphoric acid, such as Na salt, K salt, is not preferable to reduce the corrosion resistance of the insulating coating. Ca salt of phosphoric acid, tend to produce a hydrous minerals apatite, likewise undesirable to reduce the corrosion resistance of the insulating coating. Further, Sr salts of phosphoric acid, Ba salt, the solubility is very low, relatively even when mixed with high solubility metal phosphate poor liquid stability of the insulating coating treatment solution, a uniform insulating film is formed is not preferable because you can not.
[0042]
　Aspect of the colloidal silica of the insulating coating of the grain-oriented electrical steel sheet according to the present embodiment (silica particles) is not particularly limited, it is preferable that the average particle size (average primary particle diameter) is 7 ~ 30 nm. When the average particle size of the colloidal silica is less than 7 nm, the stability of the insulating coating treatment solution becomes poor, and an insulating film becomes large porous coating gap, because it may adhesiveness of the insulating film is reduced unfavorable. On the other hand, when the average particle diameter of the colloidal silica is 30nm greater becomes poor reactivity of the colloidal silica, when mixed with the phosphoric acid salt and colloidal silica as a binder is not sufficient, and cracking in the insulating film there is not preferable because it may decrease the adhesion occurs. The lower limit of the average particle diameter of colloidal silica is more preferably set to 8nm or 10 nm,. The upper limit of the average particle diameter of colloidal silica, 25nm, 20nm, 15nm, or even more preferably to a 12 nm. Further, more preferably the surface of the colloidal silica is chemically treated with aluminum. The average particle diameter of colloidal silica (average primary particle diameter), for example, can be obtained by conversion from the specific surface area measured by the BET adsorption method (in accordance with JIS Z8830).
[0043]
　In the insulating film of grain-oriented electrical steel sheet according to the present embodiment, first metal phosphate, secondary phosphate metal salts, and colloidal silica respective ratios are not particularly limited. Phosphate elution amount is 30 mg / m 2 as long as it is less, the insulating film of the grain-oriented electrical steel sheet according to the present embodiment is capable of exhibiting excellent characteristics. However, it illustrates preferred values below.
[0044]
　The content of the colloidal silica of the insulating coating, based on the total weight of the insulating coating, it is preferable that 25 to 55% by weight in terms of solid content. When the content of the colloidal silica of the insulating coating is less than 25 mass% is not preferable because it may coat the tension of the insulating coating is sufficient, the content of colloidal silica insulation coating is more than 55 wt% is not preferable because it may adhesiveness of the insulating coating is reduced. The lower limit of the content of colloidal silica insulation coating is more preferably based on the total weight of the insulating coating, 27 wt% in terms of solid content, 30 wt%, 32 wt%, or 35 wt% is there. The upper limit of the amount of the colloidal silica of the insulating coating is more preferably based on the total weight of the insulating coating, 50 wt% in terms of solid content, 49 wt%, 45 wt%, or 40 wt%.
[0045]
　The content of the second metal phosphate of the insulating film is preferably 0.5 to 10.0 mass% relative to the total weight of the insulating coating. If the content of the second metal phosphate of the insulating coating is less than 0.5 wt%, to densify the insulating coating, it may not be possible to suppress the phosphate elution amount in the insulating film. If the content of the second metal phosphate of the insulating coating is more than 10.0 mass%, there is a case where uniform film formation becomes difficult. In is because, if the amount of the low solubility second metal phosphate is excessive, it may not completely dissolve the phosphate dibasic metal salt in an insulating film treatment solution in which the material of the insulating coating This is because there. A further preferred upper limit of the content of the second metal phosphate of the insulating coating is 9.0 wt%, 7.0 wt%, or 4.0% by mass. A further preferred lower limit of the content of the second metal phosphate of the insulating coating is 0.8 wt%, 1.0 wt%, or 1.5 wt%.
[0046]
　Of the insulating coating of the grain-oriented electrical steel sheet according to the present embodiment, balance other than colloidal silica, and the second metal phosphate of the above is mainly a first metal phosphate.
[0047]
　Insulation coating of a grain-oriented electrical steel sheet according to the present embodiment further include boric acid, sodium borate, and titanium oxide, various oxides such as molybdenum oxide, may also contain pigments, and inorganic compounds such as barium titanate. The insulating film of the grain-oriented electrical steel sheet according to the present embodiment further may include a variety of compounds derived from the polymerization adjuvant later contained in the insulating film treatment solution in which the material of the insulating coating. The first metal phosphate, the amount of the second metal phosphate, and these compounds other than colloidal silica, as long as the phosphoric acid elution amount in the insulating film is within the specified range, adverse effects on the properties of the insulating coating It is not particularly limited so remain at a level that does not adversely. Meanwhile, the first phosphoric acid metal salt in an insulating film, a second metal phosphate, and the upper limit of the amount of these compounds other than colloidal silica, 10 wt% based on the total weight of the insulating film, 9 mass %, or as an 8 wt%. The first phosphoric acid metal salt in an insulating film, a second metal phosphate, and the lower limit of the amount of these compounds other than colloidal silica, may be 0 mass%.
[0048]
　Coating amount in the insulating film of grain-oriented electrical steel sheet according to the present embodiment is not particularly limited, 2.0 ~ 7.0 g / m 2 are suitable. Amount coating 2.0 g / m 2 is less than, it is difficult to impart a high tension to the grain-oriented electrical steel sheet, and insulating properties of a grain-oriented electrical steel sheet, and undesirably drops corrosion resistance. On the other hand, the amount of coating 7.0 g / m 2 if it exceeds, not preferable because the transformer characteristics deteriorate decreased space factor of the grain-oriented electrical steel sheet. The lower limit of the coating amount of the insulating coating is more preferably 3.0 g / m 2 or 4.0 g / m 2 is. The upper limit of the coating amount of the insulating coating is more preferably 6.0 g / m 2 or 5.0 g / m 2 is.
[0049]
　In the insulating coating of oriented electrical steel sheet according to the present embodiment, the content of the second metal phosphate can be determined from measuring the amount of metal elements and elemental analysis as ICP-AES. In the insulating coating of oriented electrical steel sheet according to the present embodiment, the content of the colloidal silica, which can also be measured by measuring the amount of Si using an ICP-AES. In the insulating coating of oriented electrical steel sheet according to the present embodiment, first metal phosphate, secondary phosphate metal salts, and colloidal silica other than the substances (e.g. boric acid, sodium borate, titanium oxide, molybdenum, pigments, and the content of barium titanate) can be measured by elemental analysis methods such as ICP-AES or atomic absorption spectrometry. In the insulating coating of oriented electrical steel sheet according to the present embodiment, the content of the first metal phosphate is obtained by subtracting the total content of the material from 100% by weight other than the first metal phosphate .
[0050]
　Method for measuring phosphoric acid elution of oriented electrical steel sheet according to the present embodiment is as described above. Oriented electrical steel sheet according to the present embodiment, the average primary particle diameter of colloidal silica may be measured by electron microscopy. The average primary particle size of the colloidal silica used as a material of the insulating coating is substantially the same as the average primary particle size of the colloidal silica of the insulating coating. Oriented electrical steel sheet according to the present embodiment, the coating amount of the insulating coating can be measured by measuring the weight difference before and after coating delamination.
[0051]
　Next, a method for manufacturing a grain-oriented electrical steel sheet according to the present embodiment. 2, the method for producing a grain-oriented electrical steel sheet according to the present embodiment (insulating film treatment method) includes a step S1 for applying an insulating coating treatment liquid to the surface of the steel sheet, the step S2 of baking an insulating film treatment solution including. Insulating coating is deposited by baking. Insulation coating treatment solution, a first metal phosphate in 100 parts by weight in terms of solid content, a second metal phosphate of from 3 to 20 parts by weight in terms of solid content, 35 to 125 mass in terms of solid content colloidal silica parts, 0.3 contains a ~ 6.0 parts by weight of polymerization adjuvants, wherein in the baking, heating rate in the temperature range of 100 ~ 800 ℃ 30 ℃ / sec or higher, baking Hitoshi heat temperature 800 ~ 1000 ° C., and it is soaking time of 10 to 60 seconds.
[0052]
　First, in the method of manufacturing the oriented electrical steel sheet according to the present embodiment will be described insulation coating treatment solution.
[0053]
　Insulation coating treatment liquid contains a first metal phosphate, and a second metal phosphate of the colloidal silica, and a polymerization auxiliary agent. The first phosphoric acid metal salt of the insulation coating treatment solution is Al, Fe, Mg, Mn, 1 or two or more metals metal phosphate of which are selected from Ni, and Zn, the insulating film treatment secondary phosphate metal salt of the liquid is Co, Mo, V, W, and one or more metal phosphates metal salts selected from among Zr. The first phosphoric acid metal salt of the insulation coating treatment liquid, Al, Mg, is preferably one or more metal phosphates metal salts selected from among Ni, and Zn, the insulating film secondary phosphate metal salt of processing solutions, V, W, and is preferably one or more metal phosphates metal salts selected from among Zr. Reason these metal phosphate is selected as the material of the insulating coating treatment solution is the same as the selection reasons of the phosphoric acid metal salt in an insulating film.
[0054]
　The amount in terms of solid content of the second metal phosphate in the insulating coating treatment solution to the first phosphoric acid metal salt to 100 parts by mass of the solid basis, is suitably from 3 to 20 parts by weight. When the amount in terms of solid content of the second metal phosphate in the insulating film treatment solution is less than 3 parts by mass with respect to the first metal phosphate 100 parts by weight of the solid basis, dense insulating coatings However, it is impossible to suppress the phosphate elution amount in the insulating film. On the other hand, if the amount in terms of solid content of the second metal phosphate in the insulating coating treatment liquid is 20 parts by mass with respect to the first 100 parts by weight of phosphoric acid metal salt in terms of solid content, solubility lower the second metal phosphate of it is difficult to completely dissolve the insulating film treatment solution, it is impaired uniformity of the insulating coating. The lower limit of the amount in terms of solid content of the second metal phosphate in the insulating coating treatment solution to the first phosphoric acid metal salt to 100 parts by mass of the solid basis, 5 parts by mass, or 7 wt part is preferred. The upper limit of the amount in terms of solid content of the second metal phosphate in the insulating coating treatment solution to the first phosphoric acid metal salt to 100 parts by mass of the solid basis, 15 parts by mass, or 10 parts by weight is preferred.
[0055]
　The polymerization auxiliary agent contained in the insulating film treatment solution is intended to promote the dehydration polymerization reaction of phosphoric acid metal salts, nitrite, nitrate, chlorate and their salts that functions as a dehydrating agent, and, condensed phosphoric acid , and a condensed phosphoric acid compound of low molecules such as condensed phosphates.
[0056]
　Specifically, polymerization adjuvants, nitrite, sodium nitrite, potassium nitrite, nitrate, sodium nitrate, potassium nitrate, chlorite, sodium chlorite, phosphonate, sodium phosphonate, triphosphate, sodium triphosphate, polyphosphoric acid, and it may be at least one selected from the group consisting of sodium polyphosphate and the like. It is used singly, or may be used in combination. The polymerization adjuvants, in particular sodium nitrite, nitrous acid, and the use of more than one selected from the group consisting of phosphonic acid.
[0057]
　The amount of the polymerization aid in the insulation coating treatment solution to the first phosphoric acid metal salt to 100 parts by mass of the solid basis, is suitably from 0.3 to 6.0 parts by weight. When the amount of the polymerization aid in the insulating film treatment solution is less than 0.3 parts by mass with respect to the first metal phosphate 100 parts by weight of the solid basis, the polymerization reaction of the phosphoric acid metal salt is not sufficiently proceed not, it is difficult to the insulating film to obtain a high tensile strength. On the other hand, if the amount of the polymerization aid in the insulating film treatment solution exceeds 6.0 parts by mass with respect to the first metal phosphate 100 parts by weight of the solid basis, it may corrosion resistance of the insulating coating is reduced is there. In the method of manufacturing the oriented electrical steel sheet according to the present embodiment, by adding a predetermined amount of the polymerization aid in an insulating film treatment solution, suppressing the phosphate elution amount of the insulating coating, achieve a high tensile of insulating coating it is intended to. The amount of the polymerization aid in the insulating film treatment solution is preferably to the first phosphoric acid metal salt to 100 parts by mass of the solid basis, 0.8-2.0 parts by weight. Component of the polymerization aids, there is a case that remains in the insulation film after baking, as long as the type and amount of the polymerization auxiliary in the range described above, the residual is acceptable.
[0058]
　The amount of colloidal silica in the insulating film treatment solution for the first metal phosphate 100 parts by weight of the solid basis, from 35 to 125 parts by mass in terms of solid content is appropriate. When the amount in terms of solid content of colloidal silica in an insulating film treatment solution is less than 35 parts by weight with respect to the first metal phosphate 100 parts by weight of the solid content basis, the effect of tensioning by colloidal silica It can not be sufficiently exhibited. On the other hand, if the amount in terms of solid content of colloidal silica in an insulating film treatment solution is 125 parts by mass relative to the first 100 parts by weight of phosphoric acid metal salt of the solid basis, the formed insulating coating film-forming property is lowered, the adhesion property may deteriorate. The lower limit of the amount in terms of solid content of the colloidal silica is preferably relative to the first metal phosphate 100 parts by weight of the solid basis, 45 parts by weight, or 50 parts by weight. The upper limit of the amount in terms of solid content of colloidal silica in the insulating film treatment solution is preferably to the first 100 parts by weight of phosphoric acid metal salt in terms of solid content, 100 parts by weight, or 75 parts by weight it is. When the amount of the colloidal silica is in such a range, it is possible to obtain a more beautiful insulation coating surface appearance.
[0059]
　While aspects of the colloidal silica in the insulating film treatment solution is not particularly limited, it is preferable that the average particle size (average primary particle diameter) is 7 ~ 30 nm. The lower limit of the average particle diameter of colloidal silica is more preferably set to 8nm or 10 nm,. The upper limit of the average particle diameter of colloidal silica, 20 nm, or 15 nm, or even more preferably to a 12 nm. Why these particle size preferably is the same as the selection reasons of the particle size of the colloidal silica in the insulating film.
[0060]
　Incidentally, the colloidal silica or the insulating treatment solution used in oriented electrical steel sheet according to the present embodiment, boric acid, sodium borate, and titanium oxide, various oxides such as molybdenum oxide, pigments, and barium titanate inorganic compounds may be added an equal. In particular, inorganic compounds such as pigments, not only color the insulating coating, for improve the coating hardness, the effect of With less scratches on the insulating film, preferred.
[0061]
　However, first metal phosphate, it is not essential in the production method of the second metal phosphate, colloidal silica, and the polymerization of these materials other than adjuvant oriented electrical steel sheet according to the present embodiment the insulating coating . Therefore, the lower limit of the amount of these substances in the insulating coating treatment solution is 0 parts by mass with respect to the first metal phosphate 100 parts by weight on solid basis. Further, the first phosphoric acid metal salt in an insulating film treatment solution, a second metal phosphate of, colloidal silica, and also the upper limit of the amount of substances other than the polymerization adjuvant is not particularly limited. However, first metal phosphate, secondary phosphate metal salts, colloidal silica, and the upper limit of the amount in terms of solid content of substances other than the polymerization auxiliaries, the first terms of the solid content per 100 parts by mass of phosphoric acid metal salts, 15 parts by weight, it may be defined with 12 parts by weight, or 10 parts by weight.
[0062]
　Insulating treatment solution in the method of manufacturing the oriented electrical steel sheet according to the present embodiment, since there is no need to include an organic acid salt, liquid stability is high, discoloration of the solution is less likely to occur. The insulating treatment solution in the method of manufacturing the oriented electrical steel sheet according to the present embodiment, since the amount of the low solubility second metal phosphate is limited to within a specified range, easily and uniformly to the steel sheet coated it can be subjected.
[0063]
　Next, in the method of manufacturing the oriented electrical steel sheet according to the present embodiment describes a method of forming the insulating coating.
[0064]
　In the manufacturing method of the grain-oriented electrical steel sheet according to the present embodiment, the steel sheet an insulating film is formed may be oriented electrical steel sheet having a usual forsterite film, no directional electromagnetic the forsterite film it may be a steel plate. Even when using any of the steel sheet, the grain-oriented electrical steel sheet after finish annealing, after the excess annealing separator is removed by washing with water, pickling due sulfuric acid bath, and rinsing process is performed. Thus, cleaning and activation of surfaces of the steel sheet is performed, then, an insulating film treatment solution is applied to the steel sheet. Insulating film treatment solution oriented electrical steel sheets coated is, by baking step is performed at later-described condition, the insulating film is formed on the surface.
[0065]
　The baking process, grain-oriented electrical steel sheet insulating coating treatment liquid has been applied is heated to a baking soaking temperature is held at baking soaking temperature and then cooled. Here, in order to the polymerized state of the metal phosphate ideal ones, heating rate in the temperature range of 100 ~ 800 ° C. in the applied insulation coating treatment solution of baking steps (° C. / sec) , baking soaking temperature (° C.), it is important to appropriately control the soaking time (in seconds).
[0066]
　Heating rate in the temperature range of 100 ~ 800 ℃ (℃ / sec) is required at least 30 ° C. / sec, preferably at least 50 ° C. / sec, and more preferably from 70 ° C. / sec or more. When heating rate is 50 ° C. / sec or more, easy insulation coatings were obtained to impart a high tension, when heating rate is 70 ° C. / sec or more, preferably liable obtained a uniform insulating film. On the other hand, if the heating rate is less than 30 ° C. / sec, since the non-uniformity of the insulating coating proceeds, sufficient film tension is obtained. The upper limit of the heating rate is not particularly limited, considering the capabilities of the manufacturing cost, and manufacturing facilities of a grain-oriented electrical steel sheet, for example, 100 ° C. / sec. Incidentally, the provisions of the heating rate in this embodiment needs to be satisfied in the temperature range within the entire region of 100 ~ 800 ° C.. That is, heating rate of the steel sheet to insulating coating treatment liquid has been applied, within a temperature range of 100 ~ 800 ° C., it should always be a 30 ° C. / sec or more.
[0067]
　The baking soaking temperature (° C.), represents the peak metal temperature (highest metal temperature) in the baking step, it must be at 800 ° C. or higher 1000 ° C. or less, more preferably 850 ° C. or higher 950 ° C. or less. When baking the soaking temperature is lower than 800 ° C., the insulating film can not impart sufficient tension to the steel sheet, if the baking soaking temperature exceeds 1000 ° C., cracks occur in the insulating film, the film tension is lowered , there is a case where an insulating property is lowered. Further, if the baking soaking temperature exceeds 1000 ° C., there is a case where flaws in the steel sheet occurs.
[0068]
　Soaking time (in seconds) shows the isothermal holding time at baking soaking temperature. Soaking time is required more than 10 seconds, more preferably 20 seconds or more. If soaking time is less than 10 seconds, there is a possibility that seizure of the insulating coating is insufficient, moisture deteriorates. On the other hand, soaking time is 60 seconds or less. If soaking time becomes greater than 60 seconds, since the excessive crystallization of the insulating film occurs, tension is impaired insulation coating becomes porous.
[0069]
　Incidentally, the steel sheet which the insulating coating treatment is performed is not particularly limited. The main characteristic of a grain-oriented electrical steel sheet according to the present embodiment, in the configuration of the insulating coating, insulating coating of the effect of grain-oriented electrical steel sheet according to the present embodiment is capable imparting a large tensile force that is the surface of the steel sheet, the adhesion It has good sex and corrosion resistance, has good productivity, an effect that further do not contain chromates, because exerted regardless of the type of steel.
[0070]
　Preferably, for example, by performing the above-described insulation coating process to the grain-oriented electrical steel sheet as produced using the technique disclosed in Japanese Patent Laid-Open No. 7-268567, to obtain the effect of further reducing the iron loss be able to. Specifically, the unit mass percent, at least C of 0.005% or less, and contains Si 2.5 ~ 7.0%, optionally, other alloying elements within the range that does not impair the properties (e.g., Mn: 0 ~ 1.0%, Al: 0 ~ 0.03%, N: 0.01% or less, P: 0.01% or less, and S: 0.01% or less) a further possible containing and balance includes Fe and impurities, the average crystal grain size is the 1 ~ 10 mm, with respect to (110) [001] crystal orientation and, oriented electrical steel sheet angle and the rolling direction is not more than 8 ° on average, by applying the insulating coating treatment, it is possible to obtain the effect of further reducing the iron loss.
Example
[0071]
　It will now be described embodiments of the present invention. However, the following examples are examples for describing the present invention, but the present invention is not limited to the following examples.
[0072]
　By mass%, C: 0.082%, Si: 3.25%, Mn: 0.084%, sol. Al: 0.026%, N: 0.0088%, P: 0.008%, S: comprises 0.023% the balance being cast slabs Fe and impurities, after heating the slab, hot It performed rolled to a 2.3mm hot rolled sheet of. Next, after annealing for 5 minutes at 1100 ° C., and cold rolled to 0.23mm thick, was decarburization annealed at 850 ° C.. Subsequently, an annealing separator composed mainly of MgO to the cold-rolled sheet after decarburization annealing was coated, was finished annealed for 10 hours at 1200 ° C..
[0073]
　A coil of steel sheet after finish annealing, cut out a sample having a width 7 cm × length 30 cm, to remove the annealing separator remaining on the surface by washing and silicate washing, after leaving the glass film, stress relief annealing It was carried out. Next, to prepare an insulating film treatment solution at the mixing ratio shown in Table 1. Table 1 in "silica content (in terms of solid content)" and, first metal phosphate (phosphate 1), a second metal phosphate (phosphate 2), colloidal silica (silica ) is the ratio of the amount in terms of the solid colloidal silica to the total amount in terms of the solid. The adjusted insulating film treatment solution, the coating amount of the grain-oriented electrical steel sheet after firing 4.3 ~ 4.7 g / m 2 by adjusting the coating amount to be in the range of, was applied to the steel sheet. The steel sheet insulating coating treatment liquid has been applied and baked in the condition shown in Table 2. By "Atsushi Nobori" in Table 2, a heating rate in the temperature range of 100 ~ 800 ° C.. However, for Comparative Examples 4 and 10 were heated to 800 ° C., the "heating temperature" is the heating rate in the temperature range of 100 ° C. ~ soaking temperature. The "soaking temperature" in Table 2, a baking soaking temperature, the "soak time" is the soaking time.
[0074]
　In oriented electrical steel sheet after baking, the content of the first metal phosphate, the content of the second metal phosphate, and the content of colloidal silica (solid content), as well as these other materials ( the content of other substances) were measured. Further, in the grain-oriented electrical steel sheet after baking was measured phosphate elution. The results are shown in Table 3. Phosphate elution amount, boiled for 10 minutes in pure water boiled oriented electrical steel sheet, the phosphate eluted in pure water amount was measured, and the phosphoric acid amount of boiled-oriented electrical steel sheet It was determined by dividing the area of ​​the insulating coating. Measurement of the amount of phosphoric acid eluted in pure water, the measurement of pure water in which phosphoric acid was eluted (solution) was cooled, the phosphate concentration of the sample diluted solution after cooling with pure water at ICP-AES It was calculated by. Content of the first metal phosphate in the insulating coating (phosphate 1) is to quantify the amount of each metal element in ICP-AES, a value obtained by this, phosphoric acid metal salts according to the respective metal elements It was measured by the method to convert the mass equivalent. The second content of the phosphoric acid metal salt (phosphate 2) of, likewise to quantify the amount of each metal element in ICP-AES, a value obtained by this, the mass of the metal phosphate according to the respective metal elements It was measured by the method of converting considerably. The content of colloidal silica (silica) measures the amount of Si in the ICP-AES, was measured by the method of conversion. The content of other substances, were measured by ICP-AES or atomic absorption spectrometry.
[0075]
[Table 1]

[0076]
[Table 2]

[0077]
　In Table 1, symbol "-" represents that no blending the appropriate components. The polymerization adjuvant "A" represents a nitrite, polymerization adjuvants "B" represents a phosphonic acid, a polymerization adjuvant "C" represents a triphosphate, polymerization adjuvant "D", nitrous represents sodium nitrate, and other substances "J" represents the titanium oxide, other materials "K" represents a sodium borate. In Table 3, the symbols given as the amount of "other materials", "-" indicates that the amount of other materials was below the detection limit. Incidentally, the first phosphoric acid metal salt of the insulating coating in some instances, the second metal phosphate of, colloidal silica, and others although the total value of the content of a substance does not become exactly 100% by weight, which is it is due to the difference in the measurement accuracy of the content of each substance. In Table 3, "other substance" value is "-" Examples of the insulating film is described as consists substantially only the first metal phosphate, secondary phosphate metal salts and colloidal silica, It was those.
[0078]
[table 3]

[0079]
　Respect oriented electrical steel sheet forming an insulating film in the above, the film tension, adhesion was evaluated corrosion resistance and magnetic properties. The evaluation results are shown in Table 4.
[0080]
　Coating the tension of the insulating coating was measured from the amount of warp of the steel plate when peeled off one side of the insulating coating. Film tension is 1.5 N / mm 2 or more samples were determined to be acceptable for coating tension.
　The adhesion after sticking a cellophane tape to the steel plate, each steel sheet 10 mm, 20 mm, when the wrapped rod of each diameter of 30 mm, was evaluated in diameter insulation coating is peeled off. In Table 3, "0" indicates the case where the diameter of the round bar winding the steel plate was not peeled insulating coating in 10mm diameter. Samples peeling the insulation coating did not occur when the wrapped rod of each diameter of 20mm or 30mm was judged to be acceptable for adhesion.
　Various magnetic properties, veneer magnetic properties test specified in JIS C2556: measured by (Single Sheet Tester SST test). B 8 is at 1.91 or more, and W 17/50 samples was 0.83 or less was judged to be acceptable for the magnetic properties.
　Corrosion resistance was evaluated by the 5% salt spray test. Exposure time was 10 hours. Evaluate rust situation 10 steps, the sample without rust regarded as corrosion resistance 10 were considered area ratio of 50% of the samples of rusting portion as corrosion resistance 1. The corrosion resistance of 7 or more of the sample, was passed with respect to corrosion resistance.
[0081]
[Table 4]

[0082]
　Referring to the results in Table 4, was formed using a combination of phosphoric acid metal salt specified in the present invention as a polymerization adjuvant, phosphate elution amount 30 mg / m 2 insulating film was controlled below, Comparative Examples compared to have a high tensile, and was found to be excellent in adhesion. Further, grain-oriented electrical steel sheet such insulating coatings have been deposited has been found that the magnetic properties are improved. On the other hand, comparative examples out of the provisions of the present invention did not have excellent properties.
[0083]
　Specifically, Comparative Example 1, since the first metal phosphate is a Ca salt, adhesion is deteriorated by cracking the insulating coating occurs. Comparative Example 2, since using the colloidal silica of particle size smaller than the range of the present invention as a material, the insulating film becomes large porous coating gap, adhesion was reduced. Comparative Example 3, since using the colloidal silica of particle size greater than the range of the present invention as a material, the adhesion is lowered by cracking occurs in the insulating film.
[0084]
　In Comparative Example 4, since the compounding ratio of the colloidal silica is less than the range of the present invention, the crystallization of the insulating coating adhesion advances is lowered. Comparative Example 5, since the blending ratio of the colloidal silica is greater than the range of the present invention, swelling the insulating coating occurs. Comparative Example 6, since using an insulating film treatment solution of a combination of different metal phosphate from the present invention as a material, swelling was coated tension deteriorated occurs. Comparative Example 7, an insulating film treatment solution of a combination of different metal phosphate from the present invention as a material, and does not use a polymerization aid, adhesion insulating coating becomes more porous coating gaps There was deterioration. Comparative Examples 8 to 12, heating rate, soaking temperature, and since one of the soaking time is outside the specified range of the present invention, the flow advances crystallization of the insulating film, the adhesiveness becomes porous film There was deterioration. Comparative Example 13, since the polymerization aid is insufficient, the adhesion is deteriorated insulating film becomes a more porous coating gaps. Comparative Example 14, since using an insulating film treatment solution of a combination of different metal phosphate from the present invention as a material, the film tension is deteriorated.
[0085]
　Therefore, according to the present invention, to improve the properties of the insulating coating containing no chromium compound is deposited on the surface of grain-oriented electrical steel sheet, and improving the film tension and adhesion of the insulating film, oriented electrical steel sheet it is possible to improve the magnetic properties.
[0086]
　Further, grain-oriented electrical steel sheet according to the present invention can be suitably used as an iron core material in the transformer manufacturing.
[0087]
　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 and modifications , also such modifications are intended to fall within the technical scope of the present invention.
Industrial Applicability
[0088]
　According to the present invention, small thermal expansion coefficient, high adhesion, denser and since it is possible to impart a large tension to the surface of the steel sheet, an insulating film containing no further chromate. Accordingly, the present invention does not use a chromate, grain-oriented electrical steel sheet magnetic characteristics are greatly improved is obtained. Further, according to the present invention, it is possible to obtain corrosion resistance, sliding properties, and productivity is also good oriented electrical steel sheet.

claims

[Claim 1]A grain-oriented electrical steel sheet and a steel sheet and the insulating film,
　the insulating film is,
　Al, Fe, Mg, Mn, Ni, and one or more metal phosphates metal salts selected from among Zn first and phosphoric acid metal salt is;
　Co, Mo, V, second and phosphoric acid metal salt is one or more metal phosphates metal salts selected from among W, and Zr;
　colloidal silica;
contains,
　the insulating film does not contain a chromate,
　the amount of the boiled directional 10 minutes in pure water of magnetic steel sheets was boiled, phosphoric acid eluted the pure water was measured, wherein the grain-oriented electrical steel sheet amount is boiled in the phosphoric acid is measured by dividing the area of the insulating coating, phosphoric acid dissolution amount of the insulation coating is 30 mg / m 2 or less
that oriented electrical steel sheet characterized.
[Claim 2]
　According to claim 1, wherein the first metal phosphate of, for Al, Mg, characterized in that one or more of the metal the metal phosphate of which are selected from Ni, and Zn of grain-oriented electrical steel sheet.
[Claim 3]
　Said second metal phosphate of, V, W according to claim 1 or 2, characterized in that, and one or more of the metal the metal phosphate of which are selected from Zr of grain-oriented electrical steel sheet.
[Claim 4]
　The content of the second metal phosphate, according to any one of claims 1 to 3, wherein from 0.5 to 10.0 mass% relative to the total weight of the insulating coating of grain-oriented electrical steel sheet.
[Claim 5]
　The content of the colloidal silica, the with respect to the total weight of the insulating coating, the direction of any one of claims 1 to 4, characterized in that 25 to 55% by weight in terms of solid content electromagnetic steel sheet.
[Claim 6]
　Oriented electrical steel sheet according to any one of claims 1 to 5, wherein the average primary particle diameter of the colloidal silica is 7 ~ 30 nm.
[Claim 7]
　Coating amount in the insulating film is 2.0 ~ 7.0 g / m 2 oriented electrical steel sheet according to any one of claims 1 to 6, characterized in that a.
[8.]
　Wherein the insulating film is further boric acid, sodium borate, titanium oxide, molybdenum oxide, any one of claims 1 to 7, characterized in that it comprises pigments, and one or more selected from the group consisting of barium titanate oriented electrical steel sheet according to an item.
[Claim 9]
　The steel sheet is a unit
　mass%, C: 0.005% or
　less,
　Si: 2.5 ~
　7.0%, Mn: 0 ~ 1.0%, Al: 0 ~
　0.03%, N: 0. 0.1% or
　less, P: 0.01% or less, and
　S: 0.01% or less
contained, and the balance Fe and impurities,
　the average crystal grain size of the steel sheet is 1 ~ 10 mm,
　the steel plate (110) the angle between the crystal orientation and the rolling direction of the [001] is on average at at 8 ° or less
oriented electrical steel sheet according to any one of claims 1 to 8, characterized in that.
[Claim 10]
　A step of applying an insulating coating treatment liquid to the surface of the steel sheet;
　a step of forming the insulating film treatment solution by baking the insulating coating;
equipped with,
　the insulation coating treatment liquid
　of 100 parts by weight in terms of solid content, al, Fe, Mg, Mn, Ni, and one or more metal metal phosphate of the first phosphoric acid metal salt of the selected from among Zn;
　in terms of solid content of 3 to 20 parts by weight of, Co, Mo, V, W , and one or more metal metal phosphate of the second metal phosphate of the selected from among Zr;
　35 ~ 125 parts by weight in terms of solid content
　; colloidal silica and a 0.3 to 6.0 parts by weight of the polymerization aids;
contain,
　and in the baking, 100-heating rate 30 in the temperature range of 800 ° C. ° C. / sec or higher, baking soaking temperature 800 ~ 1000 ° C., and are soaking time of 10 to 60 seconds
that Method for producing a grain-oriented electrical steel sheet characterized.
[Claim 11]
　According to claim 10, wherein the first metal phosphate of, Al, Mg, characterized in that one or more of the metal the metal phosphate of which are selected from Ni, and Zn the method for producing oriented electrical steel sheet.
[Claim 12]
　Said second metal phosphate of, V, W claim 10 or 11, characterized in that, and one or more of the metal the metal phosphate of which are selected from Zr the method for producing oriented electrical steel sheet.
[Claim 13]
　The polymerization adjuvant, nitrite, sodium nitrite, potassium nitrite, nitrate, sodium nitrate, potassium nitrate, chlorite, sodium chlorite, phosphonate, sodium phosphonate, triphosphate, sodium triphosphate, polyphosphate and, method for producing a grain-oriented electrical steel sheet according to any one of claims 10 to 12, characterized in that at least one selected from the group consisting of sodium polyphosphate.
[Claim 14]
　Method for producing a grain-oriented electrical steel sheet according to any one of claims 10 to 13, wherein the average primary particle diameter of the colloidal silica is 7 ~ 30 nm.
[Claim 15]
　The insulating film treatment solution is further boric acid, sodium borate, titanium oxide, molybdenum oxide, pigments, and claims 10 to 14, characterized in that it comprises one or more selected from the group consisting of barium titanate method for producing a grain-oriented electrical steel sheet according to any one.
[Claim 16]
　The steel sheet is a unit
　mass%, C: 0.005% or
　less,
　Si: 2.5 ~
　7.0%, Mn: 0 ~ 1.0%, Al: 0 ~
　0.03%, N: 0. 0.1% or
　less, P: 0.01% or less, and
　S: 0.01% or less
contained, and the balance Fe and impurities,
　the average crystal grain size of the steel sheet is 1 ~ 10 mm,
　the steel plate (110) the angle between the crystal orientation and the rolling direction of the [001] is on average at at 8 ° or less
manufacturing method of the grain-oriented electrical steel sheet according to any one of claims 10 to 15, wherein the .