WO2005054523A1 - Method for annealing grain oriented magnetic steel sheet and method for producing grain oriented magnetic steel sheet - Google Patents

Abstract

A method for annealing a grain oriented magnetic steel sheet, wherein a treating fluid containing an Al compound in the form of a solution or a colloidal solution and further a compound stable at a high temperature and having a viscosity of 25 mPa s or less is used as an separation agent for annealing. The separating agent exhibits good separation effect for annealing without the occurrence of powdery dust problems and of the staining of a production line. A method for producing a grain oriented magnetic steel sheet, wherein the above separation agent for annealing is applied to a finish annealing step and the like. The method allows the production of a grain oriented magnetic steel sheet which has no forsterite-like coating film or is excellent in characteristics of a forsterite-like coating film.

Description

 Method of annealing grain-oriented electrical steel sheet and method of manufacturing grain-oriented electrical steel sheet

 The present invention relates to an annealing separator for preventing seizure of grain-oriented electrical steel sheets during annealing, and an annealing method using the same for IJ.

 The present invention also relates to a method for producing a grain-oriented electrical steel sheet utilizing the annealing separator. Here, a forsterite coating is applied to the grain-oriented electric steel sheet.

Some have and some do not. This statement is about each manufacturing method. Background art

 Electrical steel sheets are widely used as core materials for transformers and rotating machines. Among them, grain-oriented electrical steel sheet is a steel sheet that achieves particularly excellent low iron loss by highly accumulating the crystal orientation in the {110} and 001> orientations called the Goss orientation. Of the properties required for electrical steel sheets, iron loss properties, in particular, are regarded as important because they directly lead to the energy consumption of products.

 In electrical steel sheets, punchability and bendability are also important properties. That is, when manufacturing an iron core for a transformer or a rotating machine, the electromagnetic steel sheet is formed into a predetermined shape through processing such as punching and shear bending. Also, when a steel strip passes through a processing line for performing these processing, the steel sheet may be bent. Therefore, the above characteristics are important. Generally, grain-oriented electrical steel sheets are manufactured by processes disclosed in, for example, paragraph [0005] of JP-A-2003-41323. That is, the steel sheet obtained by rolling is subjected to recrystallization annealing, and then to one batch annealing called finish annealing. This batch annealing promotes secondary recrystallization, and accumulates Goss-directional crystal grains.

By the way, in the notch annealing, the steel sheet is heated in a coil shape. Finish annealing for producing electrical steel sheets generally requires a high temperature, S, so that the steel sheets are seized in the coil. In order to prevent this burning, a technique of applying an annealing separator containing MgO as a main component and forming a funal stellite coating at the time of annealing is widely used. Fuorusuteti DOO quality coating and MgO in the annealing separating agent, during S i 0 ₂ and is believed to be formed by the reaction (although the coating film of the oxide formed on the surface of the steel sheet Fe Are also included).

 This forsterite coating has good annealing separation performance and also has an advantage in the properties of directional magnetic steel sheets. For example, a hard coating (tensile coating) can be applied on the forsterite coating with good adhesion, and low iron loss can be achieved by applying tension to the steel sheet.

 On the other hand, since the forsterite coating is a hard glass coating, the grain-oriented electrical steel sheet having the forsterite coating is inferior in both punching properties and bending properties. In other words, there is a problem that the die for punching is worn out quickly and burrs are generated on the O-sheared surface of the steel sheet. In addition, since peeling is likely to occur even when bending and bending, good bending and peeling resistance that does not peel even when bending and the like are applied after strain relief annealing, for example, is required. To resolve these issues,

 (1) As a means of producing a grain-oriented electrical steel sheet with good workability (emphasizing workability), a method of manufacturing a grain-oriented electrical steel sheet without forming a forsterite coating that is disadvantageous to workability,

 (2) A method of forming a forsterite coating film having good bending and peeling resistance, which does not peel even when subjected to processing such as bending after strain relief annealing, with emphasis on low iron loss and the like,

 And so on.

As the method of (1) a method of changing the component of the annealing separating agent, i.e., an annealing separator containing no MgO which reacts with Si0 ₂ steel plate surface, recrystallization; applied after ¾ blunt, the finish annealing Application methods have been attempted. Here, examples of the annealing separating agent containing as a main component other than MgO include alumina disclosed in JP-A-6-136448, JP-A-7-118750 and JP-A-5-156362. (Powder) as a main component, and those containing alumina and / or silicium as a main component disclosed in JP-A-11-61261 and JP-A-8-134542. ing. These annealing separators are applied electrostatically or as a suspension in water slurry or alcohols to the steel sheet. However, since these annealing separators have poor adhesion to steel sheets, they tend to peel off during the production line after application of the annealing separator. As a result, 1) it is difficult to control the amount of coating. 2) The yield of the annealing separator is poor. 3) There were problems such as the generation of dust and concerns about line contamination. As an annealing separator having excellent adhesiveness to a steel sheet, an annealing separator mainly composed of an aggregate of colloidal alumina in a feather form is disclosed in Japanese Patent Application Laid-Open No. 10-121142. ing. However, there was a problem in that it was difficult to apply the annealing separator uniformly to the steel sheet. In addition, this annealing separator requires a removal step by pickling or cleaning before further forming an insulating film, which is inconvenient in operation. After all, conventionally, the most practical method is to form the forsterite coating once and then remove the forsterite coating by means of pickling, chemical polishing or electrolytic polishing, etc. It has been done as an effective method. Attempts have been made to produce grain-oriented electrical steel sheets with good workability without using an annealing separator. For example, Japanese Patent Application Laid-Open No. 2000-129356 proposes a technique for secondary recrystallization of Goss-oriented crystal grains in a component system not containing an inhibitor-forming component. The agent is no longer needed. However, even at low temperatures, the finish of grain-oriented electrical steel sheets is not at a level that can completely prevent seizure of the steel sheets, and there is a problem from the viewpoint of stable production. On the other hand, as the method (2), JP-A-2003-41323 discloses a technique for achieving both the magnetic properties and the film properties by performing two patch annealing steps after continuous re-annealing after recrystallization annealing. Is disclosed. That is, in the conventional technology, both the progress of the secondary recrystallization and the formation of the forsterite coating are achieved in the finish annealing. However, since the optimum annealing conditions do not match each other, the coating properties deteriorate when trying to improve the magnetic properties, and conversely, the magnetic properties deteriorate when trying to improve the coating properties. On the other hand, the technology disclosed in JP-A-2003-41323 achieves the function of finish annealing by performing two patch annealings, promotes secondary recrystallization by the first patch annealing, and performs the second patch annealing. It is intended to form a phonoresterite coating by annealing.

 This publication states that if there is a concern that the steel sheets may adhere to each other during the first batch annealing, an annealing separator may be applied. However, if an annealing separator containing MgO as a main component is used in the first batch annealing after recrystallization annealing, the formation of a forsterite film in the second patch annealing is adversely affected, and the favorable film properties are improved. Is very difficult to obtain. In the method of JP-A-2003-41323, it is preferable to perform decarburization after the first batch annealing, but there is also a disadvantage that a coating such as a forsterite coating hinders decarburization. is there.

 On the other hand, if the first notch annealing is performed without using an annealing separator mainly composed of MgO, the same problems as in (1) occur. Disclosure of the invention

 [Problems to be solved by the invention]

 The present invention has been made to solve the above-mentioned problems, and does not contain MgO, has excellent coatability to a steel sheet and excellent adhesion after coating, and causes a dust problem and a resulting line contamination. It proposes an annealing separator that can produce grain-oriented electrical steel sheets without any problem, and an annealing method using it.

The present invention also relates to a method for producing a grain-oriented electrical steel sheet suitable for an iron core material of a transformer or a rotating machine, using the annealing separator. In particular, it proposes a method of manufacturing a grain-oriented electrical steel sheet with excellent coating properties of forsterite coating and a method of producing a grain-oriented electrical steel sheet with excellent workability without a phono-resterite coating. It is.

[Means for solving the problem]

 The embodiments of the present invention include (1) a method of annealing a grain-oriented electrical steel sheet, (2) a use as an annealing separator, (3) a method of producing a grain-oriented electrical steel sheet having a forsterite coating, and (4) It is classified as a method of manufacturing grain-oriented electrical steel sheets without forsterite coating.

(1) Steel sheet annealing method.

 The present invention

A method for annealing a grain-oriented electrical steel sheet, comprising applying an annealing separator to a steel sheet and annealing the coated steel sheet, wherein the annealing separator contains an A1 compound in the form of a solution or a colloid solution, and A method for annealing _a grain-oriented electrical steel sheet, comprising _a compound stable at high temperatures and having _a viscosity of 25 mPa's or less.

After the application of the annealing separator, it is preferable to perform a baking process of baking the annealing separator. Here, a compound that is stable at high temperatures means that the compound does not react with or hardly reacts with the steel sheet surface or oxides on the steel sheet surface during the target annealing, and that the compound itself does not react or reacts. It is hard to wake up. Specifically, at least one selected from the group consisting of Si compounds, Sr compounds, Ca compounds, Zr compounds, Ti compounds and Ba compounds is exemplified. Although MgO alone is stable at high temperatures, it does not fall under “high-temperature stability” as it reacts with oxides on the steel sheet surface. Here, since the A1 compound is in a solution state or a colloid solution state, a substance having a structural part (functional group or the like) having an affinity for a solution or a liquid forming the colloid solution (collectively referred to as a solvent for convenience). It is. Therefore, it is a substance that is chemically different from, for example, general slurry and alumina particles used in suspensions. Needless to say, even in the form of existence, it is different from slurry or suspension To do.

 Preferably, the solvent is water-based. Further, the A1 compound is at least one of an A1 compound having a hydroxyl group and an organic acid group, and a dehydration reaction product (including a partial dehydration reaction product) of the A1 compound having a hydroxyl group and an organic acid group. Preferably, there is. More preferably, the A1 compound is a basic acetic acid Al, a basic formic acid Al, a basic hydrochloric acid Al, a basic nitric acid Al, a basic oxalic acid, a basic sulfamic acid Al, a basic lactic acid A1 and a basic quinone One or a mixture of two or more selected from the acids A1. The annealing separator may contain the compound stable at a high temperature in the form of a solution or a colloid solution. Further, the content of the A1 compound is 40 to 95 mass ° / in terms of a solid content ratio represented by the following formula (1). It is preferable that

 Solid content ratio of A1 compound = (Solid content of A1 compound) / {(Solid content of A1 compound) + (Solid content (sum) of compound stable at high temperature)} Formula (1)

However, the solid content of the A1 compound is converted to A1 ₂ 0 _3, a stable compound wherein the elevated temperature is assumed to be converted into the primary compounds produced when baked after applying the annealing separator . The present invention preferably comprises

 A method for annealing a grain-oriented electrical steel sheet, comprising applying an annealing separator to a steel sheet and annealing the coated steel sheet,

The annealing separator contains the A1 compound in the form of a solution or a colloid solution, and at least one selected from the group consisting of Si compound, Sr compound, Ca compound, Zr compound, Ti compound and Ba compound. One type of compound is further contained, and the content of the A1 compound is 40 to 95 mass / ° in a solid content ratio represented by the following formula (2). And _a viscosity of the annealing separating agent is 25 niPa · s or less. here,

Solid content ratio of A1 compound = (solid content of A1 compound) / {(solid content of A1 compound) + (previously described solid content of at least one compound (sum))} Formula (2) Wherein the solids content of the compound is converted value to the weight of each compound of the following A1 compound _{· · · Α1 2 0 3,} Si compound · · 'Si0 _2,

Sr compound '' '' 31 ~ 0, Ca compound

Zr compound · · -Zr0 _2, Ti compound · · 'Τί0 _2,

Ba compound · · · 3θ. In this case, the annealing separating agent may include at least one compound selected from the group consisting of the Si compound, the Sr compound, the Ca compound, the compound, the Ti compound and the Ba compound, in the form of a solution or a colloid solution. It may be contained in a state. A particularly preferred embodiment of the invention is a method for annealing a grain-oriented electrical steel sheet, comprising applying an annealing separator to a steel sheet and annealing the coated steel sheet, wherein the annealing separator is an A1 compound and a Si compound. as a main component, 40～95Mass a value ratio in terms of _{Al 2 0 3 / (A1 2} 0 3 + Si0 2) of the A1 compound and Si compound. /. And a viscosity of 25 mPa's or less and in a solution or colloid solution state. In the above invention, the annealed separating agent further has a solid content ratio of 25 ma _SS // which is required when the annealed product containing S or S is baked after applying the annealed separating agent. The following may be contained. The “S or S-containing compound” is preferably at least one selected from Sr sulfate, Mg sulfate and Mg sulfide.

(2) Use as an annealing separator

The present invention provides an A1 compound in the form of a solution or a colloid solution, and at least one compound selected from the group consisting of a Si compound, an Sr compound, a Ca compound, a Zr compound, a Ti compound and a Ba compound. The liquid further contains: the content of the compound A1 is 40 to 95 mass ° / in terms of a solid content ratio represented by the above formula (2). And a liquid having a viscosity of 25 mPa's or less is used as an annealing separator. Here, the annealing separator contains at least one compound selected from the group consisting of the Si compound, the Sr compound, the compound, the Zr compound, the Ti compound, and the Ba compound in the form of a solution or a colloid solution. May be. The present invention also includes a main component A1 compound Contact Yopi Si compound, 40～95Mass% in value ratio in terms of _{Al 2 0 3 / (A1 2} 0 3 + Si0 2) of the A1 compound and Si compound And a liquid having a viscosity of 25 mPa's or less and being in the form of a solution or a coid solution is used as an annealing separator. In addition, it goes without saying that the preferred annealing separator used in the method for annealing a steel sheet according to (1) is applicable to all the inventions of (2).

(3) A method for producing a grain-oriented electrical steel sheet having a forsterite coating

C: 0. 08mas s _^0/0 or ^{less, Si: 2. 0~8 Omass 0 /} Mn:. 0. 005 · ~: including L Omass _^0/0 slab that was created from the soluble steel containing (thin slab or the like. The same shall apply hereinafter) to the final sheet thickness to form a steel sheet, a step of subjecting the steel sheet to recrystallization annealing, and a first batch of applying the patch annealing to the steel sheet by the annealing method according to (1). An annealing step, wherein the annealing separator applied before annealing in the first batch annealing step is referred to as a first annealing separator.

 The recrystallization annealing is performed either before the application of the first annealing separator or after the application of the first annealing separator and before the batch annealing. And the amount of application of the first annealing separator on one side is 0.005 to

And 5g / m ^2,

 Thereafter, a step of subjecting the steel sheet to continuous annealing, and a second patch annealing step of applying a second annealing separator containing MgO to the steel sheet and thereafter performing batch annealing, the production of grain-oriented electrical steel sheet. Is the way.

The grain-oriented electrical steel sheet has excellent magnetic properties and forsterite coating properties. (4) A method for producing a grain-oriented electrical steel sheet having no forsterite coating

C: 0. 08mass ^{_0/0 less, Si: 2. 0~ 8. Omass 0} / Mn: 0. 005~: a steel plate by rolling a slab made from soluble steel containing L. Omass% to a final sheet thickness A step of performing recrystallization annealing on the steel sheet; and a finish annealing step of performing batch annealing on the steel sheet by the annealing method according to (1).

Here, the recrystallization annealing is performed before the application of the annealing separating agent in the finish annealing step, or is performed after the application of the annealing separating agent according to (1) and before the patch annealing. A method for producing a grain-oriented electrical steel sheet, wherein the coated amount of the annealing separator is 0.005 to 5 g / m ² per side. This grain-oriented electrical steel sheet has excellent magnetic properties and workability. In any of the above inventions (3) and (4), the invention can be applied to a grain-oriented electrical steel sheet that does not use an inhibitor-forming component. In this case, it is preferable that the slab is a slab made of molten steel having a composition in which A1 is 150 ppm or less and N, S, and Se are each reduced to 50 ppm or less. Further, in any of the above inventions (3) and (4), the step of rolling the slab to a final thickness to form a steel sheet includes: a step of hot-rolling the A1 slab to form a hot-rolled steel sheet; A step of performing hot-rolled sheet annealing to anneal the hot-rolled steel sheet as necessary, and a step of performing one or more cold-rolling operations including one or more intermediate-annealing processes to obtain a final thickness. And preferably

A further preferred form of the invention of (4) is:

C: 0. 08mass% or less, Si: 2. 0 ~ 8. 0mass %, Mn: 0. 005~: 1. a step of a slab made from molten steel containing 0mass _^0/0 hot rolling, then 1 Cold rolling or intermediate annealing two or more times of cold rolling to obtain the final thickness, followed by recrystallization annealing, and then the annealing method described in (1). and a step of subjecting the finish annealing, and the the coating amount of the annealing fraction eluant to applied before annealing in the finishing annealing and per side 0. 005~5g / m ^2, a manufacturing method of the grain-oriented electrical steel sheet, Or

C: 0. 08mas s _^0/0 less, Si: 2. 0 ~ 8. Omass ° / o N Mn: 0. 005~ 1. 0mass 0/0 includes and 150ppm or less of Al Oyopi N, S Hot rolling of a slab made of molten steel having a composition of 50 _ppm m or less, and then two or more cold rollings with one cold re-rolling or intermediate annealing An annealing separator applied to the final sheet thickness, followed by recrystallization annealing, and then subjected to finish annealing by the annealing method described in (1), and is applied before the annealing in the finish annealing. This is a method for producing a grain-oriented electrical steel sheet, wherein the coating amount is 0.005 to 5 g / m ² per side.

In the form of the preferred invention, the annealing separator is mainly composed of A1 compound and S i compound, the _{Al 2 0 3 / (A1 2} 0 3 + Si0 2) the ratio of the A1 compound and Si compound The converted value is 40 to 95 mass. /. It is preferable that the viscosity is 25 mPa's or less and that the solution is in the form of a solution or a colloid solution. BEST MODE FOR CARRYING OUT THE INVENTION

 The inventors of the present invention have conducted intensive studies on an annealing separator having excellent coatability and adhesion after coating.As a result, the inventors first found that the A1 compound and the compound stable at high temperatures were the main components, and at least the A1 compound was It has been found that the above-mentioned problems can be solved by using a solution state or a colloid solution state. The present inventors have also found a suitable viscosity of the annealing separator, a solid content ratio of the A1 compound, and a suitable coating amount when applied to a steel sheet. The present invention will be described below based on experiments that have succeeded.

<Experiment 1>

^{C:. 0 020mass 0 / o} , Si: 3. 30mass¾, Mn: 0. 070mass 0/0 Oyopi Sb: 400massppm only including, Al: 38massppm, N: 33massppm , S: 18ppm, Se: less than 10ppm ( A steel slab with a composition controlled to the analytical limit ^: full) was manufactured by continuous production. Thereafter, the copper slab was subjected to one cold rolling or two or more cold rollings with intermediate annealing to obtain a final sheet thickness. Next, the cold-rolled steel sheet was subjected to recrystallization annealing and finish annealing. Here, before the final annealing, an aqueous colloid solution (solid content: 3.0 ma _SS %) of silica sol (colloidal silicic power) was used as an annealing separating agent, and the surface of the steel sheet (both sides) was 0.1 ... 3. Coating was performed using a roll coater in the range of Og / m ² . After the application, the steel sheet was baked at the ultimate temperature of 250 ° C and then allowed to cool. The applied amount of the annealing separator was determined from the difference in the weight of the steel sheet before and after the baking treatment, and this was used as the applied amount of the annealing separator. In the final annealing, the specimen was kept at 850 ° C for 30 hours in a nitrogen atmosphere, and then kept at 1000 ° C for 5 hours in an Ar atmosphere.

 The obtained steel sheet was tested for three items: the applicability of the annealing separator, the adhesion of the annealing separator after drying, and the annealing separation effect during finish annealing. The details of each performance evaluation method are as follows. The same applies to the evaluation methods in Experiments 2 and 3 described later and the examples.

• Applicability

 The steel sheet after the application of the annealing separator was visually evaluated.

 〇: The entire steel sheet is uniformly applied

 Δ: applied to the whole but uneven

 X: Some parts are applied and some are not

• Adhesion after drying

 After baking the annealing separator, the steel plate was washed with running water at a flow rate of about 1. Om / s for 10 seconds while brushing the steel sheet. Then, it was drained with a ringer roll and dried under the condition of 200 ^ X10Os. Then, the weight of the steel sheet was re-measured, and the adhesion amount of the annealing separator was calculated again. Then, the difference between the amounts of the adhesion of the annealing separator before and after the water washing was determined, and this was defined as the amount of peeling. Based on the obtained peeling amount, the following evaluation was made.

 〇: Separation amount of separating agent is 10% or less of applied amount

 △: Separation amount of separating agent is more than 10 to less than 80% of applied amount

X: The separation amount of the separating agent is 80% or more of the applied amount • Annealing separation effect

 A separating agent was applied, and finish annealing was performed while applying a pressing load of 0.74 MPa. Thereafter, the baked steel sheet was peeled off with a tensile tester, and the strength required for peeling (peeling strength) was measured to evaluate as follows.

 〇: No seizure of steel sheet (peel strength 10N or less)

 △: Seizure of the steel sheet is partially observed (peel strength of more than 10N to less than 60N) X: Steel sheet is completely seized (peel strength of 60N or more) Table 1 shows the test results. The annealing separator used in Experiment 1 had good applicability and annealing. The separation effect was good, but the adhesion of the separating agent to the steel sheet was insufficient under all conditions.

table 1

From the above Experiment 1, it was found that silica sol had an annealing separation effect at the time of finish annealing, but had a problem in adhesion to a steel sheet as an annealing separating agent. Therefore, the present inventors examined the effectiveness of using alumina sol as a film-forming component in order to use silica sol as an annealing separating agent and to improve adhesion to a steel sheet.

<Experiment 2>

In the same manufacturing process as in Experiment 1, the surface (both sides) of the steel sheet before Ruminazoru (colloids like alumina) and silica force sol annealing separator consisting of an aqueous co Roy de solution mainly containing (solid concentration 2. 0mas _S%), and the per side 0. 5 _g / m ² coating amount The coating was performed using a roll coater. Next, the steel sheet was baked at the ultimate temperature of 250 ° C and allowed to cool. After that, as in Experiment 1, finish annealing was performed at 850 ° C for 30 hours in a nitrogen atmosphere and then at 1000 ° C for 5 hours in an Ar atmosphere.

 The same evaluation method as in Experiment 1 was used to evaluate the three properties of the obtained steel sheet: the applicability of the annealing separator, the adhesion of the annealing separator after drying, and the annealing separation effect during finish annealing.

The ratio of the alumina sol and silica sol, in the range of. 20 to 100 mass% with A1 ₂ 0 ₃ Pas Al ₂ 0 ₃ + Si0 ₂₎ in terms of the viscosity of the annealing separator is in the range of 3. 5~ 100 mPa 's, respectively change I let it. Note that the viscosity of the annealing separator was changed by using alumina sols having different viscosities. The viscosity of the alumina sol can be controlled by, for example, the shape of the sol particles and the solid content concentration. For example, if the outer shape of the sol particles is feather-like, the viscosity will be high, and if it is close to spherical (or granular) or elliptical (or rod-like), the viscosity will be low. Table 2 shows the experimental results when the ratio between the alumina sol and the silica sol was changed. When the ratio of alumina sol was low, the adhesion of the annealing separator was insufficient. On the other hand, if the ratio of the alumina sol was too large, the film-forming effect was too strong, and it was difficult to apply uniformly to the steel sheet, resulting in poor appearance of the product. The effect of annealing separation was good under all conditions.

Table 3 shows the experimental results when the viscosity of the annealing separator was changed. When the viscosity was increased, the applicability to the steel sheet was significantly deteriorated, and some portions were applied and some were not. Since the steel sheet seized in the area where the coating was not performed, it was found that the viscosity had to be controlled in order to secure good coating properties and to have an annealing separation effect. Table 2

Table 3

<Experiment 3>

Next, in the same manufacturing process as in Experiment 1, using a roll coater on the steel sheet surface (both sides) before finish annealing, an annealing separator (solid content concentration) consisting of an aqueous colloid solution containing alumina sol and silicic acid sol as main components was used. 2.5 m _ass %) was applied under each condition that the application amount was in the range of 0.001 to 6 _g / m ² per one side. The viscosity of the annealing separator was set to 2.5 mPa's, the ratio of the alumina sol and silica sol was 75 mass% in the _{A1 2 0 3 / (Al 2} 0 3 + Si0 2) terms. Next, the steel sheet was baked at the ultimate temperature of 250 ° C and allowed to cool. Then, as in Experiment 1, finish annealing was performed at 850 ° C for 30 hours in a nitrogen atmosphere and then at 1000 ° C for 5 hours in an Ar atmosphere.

 Using the same evaluation method as in Experiment 1, the obtained steel sheet was examined for three items: the coatability of the annealing separator, the adhesion of the annealing separator after drying, and the annealing separation effect during finish annealing. Table 4 shows the experimental results when the coating amount was changed. When the coating amount was extremely small, the annealing separation effect was insufficient and the steel sheet was seized. On the other hand, when the amount of coating increases, the adhesion of the annealing separator to the steel sheet decreases. From the above, it is preferable to control the application amount of the annealing separator in order to ensure good adhesion to the steel sheet and to have an annealing separation effect. Table 4

From the above experimental results, it was found that a compound such as silica, which has excellent stability during high-temperature annealing, as an annealing separating agent, and a solution-forming or colloid-solution-forming film-forming component.

By adopting the A1 compound as the main component and defining the solid content ratio and viscosity of the A1 compound, it is newly possible to obtain excellent coating properties and adhesion after coating. Heading, the present invention has been completed. Next, the annealing separator of the present invention, the method for annealing a grain-oriented electrical steel sheet, and the method for producing a grain-oriented electrical steel sheet will be described in detail. First, the reason for limiting the annealing separator will be described. Limitations are generally specified at the time of application to the steel sheet.

 A1 compound in the form of a solution or colloid solution as the main component of the annealing separator, and a compound that is stable at high temperatures, that is, it has excellent high-temperature stability and does not react or hardly react during patch annealing. One or more compounds are used as the main components. The high-temperature stable compound may be in a solution state or a colloid solution state together with the A1 compound. That is, the annealing separator may be a solution or a colloid solution.

Here, being in a solution state means a state in which the compound is dissolved in water or an organic solvent as a medium. Further, being in a colloid solution state means that particles of the compound having a size of about 100 nm or less are stably dispersed in the medium via a structural part such as a functional group having an affinity for the medium. Say state. In any case, the liquid serving as the medium is generically called a solvent. The colloid solution is similar to the solution because it is transparent without apparent suspension, but the presence of colloid particles is confirmed by light scattering measurements. Here, the main component refers to a composition component other than the below-described auxiliary agent and additive. Therefore, the main component accounts for about 65 mass% or more, preferably 75 ma _SS % or more, based on the whole of the annealed separator component after drying (that is, the substance forming a solute or colloid). There is no particular limitation on the liquid serving as the solvent, and water or an organic solvent can be used. As the organic solvent, methanol, isopropanol, ethylene dalicol and the like are generally used, but not limited thereto. The use of water as a solvent is preferred from the viewpoint of cost and diversity of selection of the compound. This In this case, water may be mixed with an organic solvent of about 50 ma _Ss % or less for the purpose of adjusting the liquid properties. In the above case where water is the main solvent, it is referred to as an aqueous annealing separator.

The A1 compound and the compounds stable at high temperatures described above hardly react with the base iron unlike MgO used in conventional annealing separators, and thus significantly degrade punching workability such as forsterite coating. Does not form a coating. For this reason, it is very effective when supplying grain-oriented electrical steel sheets with excellent punching workability.

 The use of two or more compounds as the main components of the annealing separator is due to both the large annealing separation effect of a stable compound at high temperature and the good film-forming effect of a solution or colloidal A1 compound. In order to get For the first time, the combination of the two functions effectively as an annealing separator for steel sheets with excellent applicability and adhesion to steel sheets after coating, and is particularly required for annealing separators for grain-oriented electrical steel sheets. Satisfies the characteristics.

The A1 compound is limited to a compound that forms a colloid in a solvent such as water in order to secure a film forming function. That is, the A1 compound does not exhibit a film-forming effect unless it is in a colloidal state, so that adhesion cannot be obtained. For example, when alumina is applied as a slurry / suspension, no film is formed. The particle size of the A1 compound colloid is preferably about 50 mn or less. As for the lower limit, there is no suitable particle size limit, and the effect is sufficiently exhibited even near the analysis limit.

In the case of the aqueous annealing separating agent, the A1 compound is preferably an aluminum compound having a hydroxyl group and an organic acid group and / or a dehydration reaction product thereof (partially dehydration may be performed. The same applies hereinafter). More preferably, it is an aluminum compound comprising Al, a hydroxyl group and an organic acid group, and / or a dehydration product thereof. Specifically, for example, basic aluminum acetate, basic aluminum formate, basic aluminum hydrochloride, basic aluminum nitrate, basic aluminum oxalate, basic aluminum sulfamate, base Examples include one selected from basic aluminum lactate and basic aluminum citrate, or a mixture of two or more selected from these. Among them, basic aluminum acetate is represented by the molecular formula of Al _x (0H) _y (CH ₃ C00) _z , where x, y, and z are 1 or more, and in particular, Al ₂ (OH) ₅ (CH ₃ COO) is preferred. It can exist from a dissolved state at the molecular level to a colloidal state of about several nm, and can be suitably used as a coating liquid material. Thermal analysis shows a large peak of the dehydration reaction at about 200 to 230 ° C, and heating forms a network between molecules by dehydration condensation to form a film. Part or all of the basic aluminum acetate and the like may have caused a dehydration reaction.

When an organic solvent is used as the solvent, the same A1 compound as that used in the case of the aqueous annealing separator can be used as a suitable A1 compound. High temperature stability, as the compound except the M _g 0, can be used known ones, is not particularly limited, for example, Si compounds, Sr compounds, Ca compounds, Zr compounds, Ti compounds, Ba compounds No. Specific compounds, Si0 _2, SrO,

Oxides such as TiO ₂ , BaO, and CaO are mentioned.

 In order to include the above-mentioned compound stable at high temperature as a solution or a colloid solution, for example, in the case of an aqueous annealing separating agent, it is necessary to use a chemical conversion to a form having a hydrophilic group such as a hydroxyl group. preferable. However, in the case of a compound that is stable at a high temperature, as another method, a state in which the surface is covered with a known hydrophilic substance in a solvent may be created. When an organic solvent is used as a solvent, it may be designed based on a similar concept using a lipophilic group or the like.

The high temperature when referring to a compound that is stable at high temperature refers to the annealing temperature, but for oriented magnetic steel sheets, 1200 ° C is sufficient if it is stable, and more preferably 1300 ° C. . At these temperatures, the compound, it themselves, steel, or an oxide such as a steel sheet surface _{(Si0 2, Fe0, Fe 3} 0 4, Fe 2 Si0 4 , etc.) and may be substantially react. All of the above compounds have the effect of improving the applicability of the annealing separator in coexistence with the A1 compound. Among them, Si compounds are particularly preferable from the viewpoint of applicability, annealing separation performance, and the like. As a Si compound, colloidal silicon force, The so-called colloidal silicide is particularly suitable because it has high stability with alumina sol and relatively low cost. Colloidal silica is an inorganic colloids which mainly components Si0 _2, it is often amorphous. A1 compounds that are not a solution or colloid solution (referred to as non-colloidal A1 compounds), such as alumina particles, are stable at high temperatures, but improve the applicability of the solution “colloid solution A1 compounds”. The effect is small. Therefore, although the addition of the non-colloidal A1 compound itself as a part of the main component is not prohibited, it is preferable to include a compound which is stable at a high temperature other than the non-colloidal A1 compound. Non-colloidal A1 compounds shall not be considered in the calculation of the solid content ratio described below.

The solid content ratio of the A1 compound is preferably 40 to 95 ma _SS % in terms of the solid content ratio represented by the following formula (1).

 Solid content ratio of A1 compound = (solid content of A1 compound) / {(solid content of A1 compound) + (solid content of high-temperature stable compound (sum))} Formula (1)

However, the solid content of the A1 compounds in terms of A1 ₂ 0 _3, a stable compound wherein the elevated temperature is assumed to be converted to the main compound after baking. If for example a silica sol, silica i.e. Si0 ₂ is the main compound, Wachi Ti0 ₂ such to titania is the main compound if titania sol. Even if the baking step is not particularly provided, it is converted to the main compound generated when the baking treatment is performed.

 If the solids consist essentially of only these compounds, formula (1) is replaced by formula (3).

 Solid content ratio of A1 compound = (solid content of A1 compound) / (total solid content) Formula (3) Here, solid content refers to the amount contained in the annealing separator after drying.

The solid content ratio of the A1 compound is 40 mass ° /. If the ratio is less than the above, the amount of the A1 compound as a film forming component becomes insufficient, and the adhesion of the annealing separator becomes insufficient. The solid content ratio is ⁹⁵ ma _SS /. When the amount exceeds the limit, the amount of the highly reactive A1 compound becomes too large, Not determined. For this reason, a uniform film cannot be formed, and the appearance of the product becomes poor. Solid content of A1 compound is preferably, 50 mA _SS%, more preferably, 60 mass%, more preferably at least 70 mass%. When at least one compound selected from the group of Si compound, Sr compound, compound, Zr compound, Ti compound and Ba compound is used as the compound stable at high temperature, the solid content of A1 compound is as follows. Replaced by equation (2).

 Solid content ratio of A1 compound = (solid content of A1 compound) / {(solid content of A1 compound) + (the solid content of at least one compound (sum))} formula (2)

 However, the solid content of each compound is preferably a value converted to the weight of each compound described below.

A1 Compound _{· · · Α1 2 0 3,} Si compounds' ·· 5Ϊ0 _2,

Sr compound · 330, Ca compound 化合物 3ϋ,

Zr compounds ',' Zr0 _2, Ti compound · · · 0 _2,

Ba compound-. 'Ba0. When employing a Si compound as a stable compound at a high temperature, that is, when the solids mainly composed of the A1 compound and the Si compound, the ratio of the A1 compound and Si compound A1 ₂ 0 ₃ bar Al ₂ 0 ₃ + Si0 ₂₎ 40 to at the exchange value to ⁹⁵ mass ° /. It is preferable that The viscosity of the annealing separator is specified to be 25 (mPa's) or less. If the viscosity exceeds 25 (mPa's), the applicability will be significantly degraded, hindering the uniform application of the annealing separator to the steel sheet. In addition, as a result, a portion that is not applied is generated, which causes the steel sheets to adhere to each other during the finish annealing. Note that. The viscosity in the present invention is a value obtained by measuring the viscosity of the annealing separator at the liquid temperature with an Ostwald viscometer.

In addition, when using a colloid slurry instead of a colloid solution, uniformity of coating cannot be obtained. This is thought to be due to the inconsistency in viscosity and large fluctuations in viscosity due to aggregation of colloid in the slurry. Further, S (simple) or S is contained as an auxiliary agent in the above-mentioned annealing separator By adding a compound (both are hereinafter collectively referred to as an S-containing compound), it becomes possible to stably impart good magnetic properties to the grain-oriented electrical steel sheet. Although the reason for this is not clear, it is considered that the S-containing compound was decomposed during batch annealing, and S entered the steel and segregated at the grain boundaries. That is, it is considered that grain growth is suppressed by segregated S, and as a result, secondary recrystallization is stabilized.

If the amount of S to be segregated is excessive, secondary recrystallization failure may occur. When avoiding such a situation is important, the amount of the S-containing compound to be added is about 25 ma _SS ° / in solid content ratio to the annealing separator component after baking. It is preferable that: Even when the baking step is not particularly provided, the evaluation is made based on the solid content ratio of the S-containing compound generated when the baking treatment is performed.

The S-containing compound is not particularly limited, but is preferably an inorganic S compound such as a sulfate (including a sulfite) and a metal sulfide. Specific examples include stotium sulfate, magnesium sulfate, and magnesium sulfide. Various methods, such as a roll coater, a flow coater, a spray, and a knife coater, which are generally used in industry, can be applied as a method of applying the annealing separating agent. It is preferable that the annealing separator of the present invention be heated and baked after application. As for the baking method, a method such as a hot air method, an infrared method, or an induction heating method, which is usually performed, can be applied. The conditions of the baking treatment may be set according to various circumstances, but usually, a preferable temperature is about 150 to 400 ° C and a preferable time is about 1 to 300 seconds. In order to further improve the performance such as the applicability of the annealing separator and the adhesion to the steel sheet, additives such as a surfactant and a heat-resistant agent may be blended. The content of the additive is preferably about _iomass % or less based on the annealed separating agent component after drying in order to maintain a sufficient annealing separating effect as the annealing separating agent.

Surfactants can be any of commercially available nonionic, anionic or cationic surfactants. These are also applicable.

 Like the surfactant, the type of the protective agent is not particularly limited, and a commercially available one can be used. The annealing separator of the present invention is particularly suitable for application to grain-oriented electrical steel sheets. The application to other steel sheets is not prohibited.

 Further, the annealing separator of the present invention is particularly effective when the steel strip is heated in a furnace while being wound in a coil shape, but can also be applied to a case where a steel sheet is stacked and subjected to a heat treatment. Next, preferred conditions for producing a grain-oriented electrical steel sheet according to the present invention will be described below.

 Regarding the composition of the starting material of the product sheet (molten steel or steel slab), any composition known to be suitable for grain-oriented electrical steel sheets can be applied. Hereinafter, the reasons for limiting the respective components of the preferred molten steel components in the typical component system will be described.

C: 0.08 mass% or less

If the content of C exceeds 0.08 mass%, it is difficult to reduce C to 50 mass _PP or less, at which magnetic aging does not occur, during the manufacturing process.Therefore, the content of C is set to 0.08 mass% or less. Is preferred. In particular, a lower limit is not required. Industrially, about 5 massppm is the limit of reduction.

Si: 2.0-8.0 mass%

Si is an element effective in increasing the electrical resistance of steel and improving iron loss. To obtain the effect, it is preferable to contain 2.0 mass% or more. On the other hand, if it exceeds 8.0 mass%, the workability and the magnetic flux density decrease, so the upper limit is preferably set to 8.0 mass%. Therefore, a preferable Si content is 2.0 to 8.0 mass%. Mn: 0.005 to 1.0 mass%

 Mn is an element effective for improving hot workability, and is preferably added at 0.005 mass% or more. On the other hand, excess Mn lowers the magnetic flux density of the product plate. From this viewpoint, the preferable content of Mn is 1. Omass. /. It is as follows. Therefore, the preferable content of Mn is 0.005 to 1.0 mass. /. It is. In the production of grain-oriented electrical steel sheets, it is common to add an element that forms an inhibitor (inhibitor-forming component) in order to develop the Goss orientation during secondary recrystallization. However, it has recently become known that it is also possible to develop the Goss orientation without using inhibitors by reducing the impurity elements in steel.

To obtain a Goss orientation crystal grains by secondary recrystallization without using an inhibitor, 150Massppm the A1 below, N, S, it is preferable to lower reduced below 50massp _P m for Se. It is desirable that such components be reduced as much as possible from the viewpoint of magnetic properties. For example, A1 is more preferably 100 ppm or less. However, there is a case where the cost is high in order to reduce such components, so that it is not a problem to leave them within the above range. At present, the lower limit of the content, which is limited by the reduction cost, is about lOmassppm for all elements.

Conversely, when an inhibitor is used, these elements are added according to the inhibitor to be applied. For example, when A1N is used as the inhibitor, A1: 0.015 to 0.4 mass. /. And N: 0.005 to 0.00 OlSmass. /. The, when using BN B:. 0. 001~0 006mas s % and N:. 0. 005~0 the 015mass ⁰ / o, any MnSe and / or Se in the case of using the MnS, and least of S also It is common to add only one of them at 0.005 to 0.06 mass%.

 It is preferable to add Sb and / or Sn to the grain-oriented electrical steel sheet in a total amount of about 0.005 to 0.1 mass%, since the magnetic properties can be further improved.

In addition, Ge, Mo, Te, and Bi are each 0.1 lmass ° /. ^{Hereinafter, P, Cu, Cr 2 mass} % , respectively 0.5 or less, Ni is 0. 5mas s. /. There is no particular problem even if it is contained below. In addition, the balance is preferably iron and inevitable impurities. From the molten steel having the above components, slabs of normal dimensions may be manufactured by a normal ingot-making method or a continuous sintering method, or a thin slab piece of ioo _mm or less (a so-called thin slab). May be directly manufactured by a manufacturing method. The slab is re-heated and hot-rolled by an ordinary method, but may be immediately hot-rolled without heating after fabrication. In the case of a thin piece, hot rolling may be performed, or hot rolling may be omitted and the process may proceed to the subsequent steps. The hot-rolled steel sheet is then subjected to annealing (hot-rolled sheet annealing) as necessary. In particular, in the case where a band structure is formed in hot rolling, it is preferable to perform hot-rolled sheet annealing in order to realize a primary recrystallized structure of sized particles and thus promote the development of secondary recrystallization. .

 In order to eliminate the band structure, the hot-rolled sheet annealing temperature is preferably set to 800 ° C. or higher. On the other hand, it is not preferable that the grain size is excessively coarsened by the hot-rolled sheet annealing in order to realize the primary recrystallized grain structure, and therefore the hot-rolled sheet annealing temperature is preferably 1100 ° C or less. Therefore, in order to highly develop the Goss structure in the product sheet, it is preferable that the hot-rolled sheet annealing temperature be 800 ° C or higher and 1100 ° C or lower. The preferred annealing time for hot-rolled sheet annealing is 1 to 300 seconds. Next, after performing cold rolling at least once to obtain a cold rolled steel sheet, recrystallization annealing is performed. When cold rolling is performed twice or more, intermediate annealing is interposed between each cold rolling. The intermediate annealing is preferably performed at 900 to 1200 ° C. for about 1 to 300 seconds.

 In order to further develop the Goss structure, the cold rolling temperature may be increased by 100 to 250. This is treated as a type of cold rolling, called S, which is sometimes called warm rolling. For the same purpose, the aging treatment in the range of 100 to 250 ° C may be performed once or plural times during the cold rolling.

Recrystallization annealing is preferably performed by continuous annealing for the purpose of mainly forming a primary recrystallization structure. The recrystallization annealing may be performed in a dry atmosphere if decarburization is not required and the dehumidification is not required. Preferred recrystallization annealing conditions are 750 to 1100 ° C. for about 1 to 300 seconds. Adjusting the C content in the steel sheet to 100 to 250 massppm in the secondary recrystallization annealing (finish annealing or the first patch annealing when the final annealing is divided into two patch annealings) is particularly effective in containing inhibitors. This is suitable for improving the magnetic flux density in a non-oriented electrical steel sheet. The adjustment of the C content may be performed by recrystallization annealing or may be performed separately thereafter.

 The technique of increasing the amount of Si by the siliconizing method may be applied to, for example, a steel sheet after recrystallization annealing. The application of the annealing separator of the present invention is performed before or after recrystallization annealing.

Conventional annealing separators have poor adhesion to steel sheets, so applying an annealing separator before recrystallization annealing was not possible from the viewpoint of line contamination due to peeling during recrystallization annealing. The same applies to the case of an annealing separator containing MgO as a main component, which requires a long heating time to form a film. However, the annealing separator of the present invention has good adhesion to a steel sheet, and there is no fear of line contamination due to peeling, so that it can be applied before or after recrystallization annealing. In this step, the application amount of the annealing separator of the present invention is preferably 0.005 g / m ² or more in order to exert the effect of preventing adhesion of the steel sheet. On the other hand, in order to ensure the adhesiveness of the annealing separator, the amount of adhesion is preferably 5 g / m ² or less. Therefore, it is preferable that the application amount of the annealing separator be in the range of 0.005 to 5 g / m ² . A more preferred lower limit is 0.05 g / m ² and a more preferred upper limit is 2 g / m ² . The preferable application amount in the production of the grain-oriented electrical steel sheet is as described above. Depending on the heat treatment conditions and required quality of each force, it can be used outside the above-mentioned preferred range.

The annealing separator may be applied to only one side or both sides of the steel sheet, but is preferably applied to both sides in order to surely obtain the effect. It is not prohibited to change the composition of the annealing separator on the front and back of the steel sheet, but it is preferable to apply the same annealing separator on both sides in the process. Magnetic properties without forsterite coating In the case of manufacturing a magnetic steel sheet, after the recrystallization annealing and the application of the annealing separator of the present invention, the finish annealing is performed by patch annealing. The purpose of finish annealing is to reduce (purify) impurities during the secondary recrystallization. Known annealing conditions can be applied as the annealing conditions. The preferred finish annealing temperature is about 750-1300 ° C, but the first half may be about 750-1000 ° C and the second half may be about 900-1300 ° C. Here, secondary recrystallization is mainly promoted in the first half, and purification is mainly promoted in the second half. A preferable finish annealing time is about 1 to 300 hours as a holding time in the above temperature range.

 In the case of the conventional technology in which an annealing separator containing MgO as a main component is applied, a thicker film is formed, so that the time required for purification is longer than when no separator is used. However, an effect was observed in which the annealing separator of the present invention did not hinder purification even though the A1 compound formed a film. When the finish annealing is performed with the C content of about 100 to 250 mass ppm for the purpose of improving the magnetic properties, it is preferable to reduce the C to 50 ppm or less at which the magnetic aging does not occur after the completion of the secondary recrystallization. Methods for reducing C include a method of decarburizing during finish annealing and a method of adding a decarburization step after finish annealing. In order to decarburize during the finish annealing, it is recommended to perform high-temperature annealing at 1000 ° C or more during finish annealing, especially in the atmosphere containing hydrogen in the latter half.

 On the other hand, decarburization processes added after finish annealing include (1) annealing in an oxidizing atmosphere (decarburizing annealing), (2) surface grinding to mechanically remove surface graphite, and (3) surface grinding of Electrolytic cleaning to remove the graphite chemically, chemical polishing, plasma irradiation, etc. are effective. The reason why decarburization by means (2) or (3) is possible is that C precipitates as graphite on the surface of the steel sheet by the end of finish annealing, and decarburization in the steel has been completed. It is.

Regarding the phenomenon in which graphite is precipitated on the surface of a steel sheet, for example, the following mechanism can be considered. C forms a metastable cementite in steel, S, and forms graphite in an activated state with high surface energy. Therefore, during cooling, C precipitates as graphite on the surface layer before it precipitates as cementite in the base iron. By the way, guessing from the phase diagram of pure iron, The solubility of graphite is slightly lower than that of cementite. Therefore, the concentration of solid solution C in the surface layer decreases to a concentration that is in equilibrium with the graphite, causing a concentration gradient between solid solution C in the surface layer and solid solution C in the ground iron, and decarbonization from the ground iron. It is speculated that this will progress.

 However, if a dense or strong coating layer is formed on the surface during finish annealing (for example, when a conventional annealing separator containing MgO as a main component is applied), surface activation is hindered, and Precipitation of the steel sheet surface layer is also inhibited. However, although the film formed by the annealing separator of the present invention is excellent in adhesion, it does not adversely affect the precipitation of the graphite steel sheet surface for any unknown reason, and the above decarburization method can be suitably used. . After finish annealing, it is effective to correct the shape by applying tension by flattening annealing to reduce iron loss. By performing the flattening annealing in a humid atmosphere, decarburization may be performed at the same time (a type of the method (1)).

 Note that a technique of increasing the amount of Si by the siliconizing method after the finish annealing may be further applied. This technology is effective for further reducing iron loss. When a steel sheet is laminated and used for an iron core or the like, it is effective to improve the core loss of the laminated body by applying an insulating coating to the surface of the steel sheet after flattening annealing. In order to ensure particularly good punchability, an organic coating containing a resin is desired as the insulating coating. On the other hand, when weldability is important, it is desirable to apply an inorganic coating as an insulating coating.

 It should be noted that a step of simply removing the annealing separator is unnecessary. When manufacturing a grain-oriented electrical steel sheet having excellent forsterite coating film properties and magnetic properties, the first recrystallization after the recrystallization annealing and the application of the annealing separator of the present invention are required to develop secondary recrystallization. Perform patch annealing. As annealing conditions at this time, known annealing conditions under which secondary recrystallization proceeds can be applied. Preferred conditions are about 750 to 1100 ° C for about 1 to 300 hours.

After that, a forsterite coating is formed by the second patch annealing. As a preparation stage, first, a subscale is formed by continuous annealing. When the first batch annealing is performed with a predetermined amount of C contained for the purpose of improving the magnetic properties, it is preferable that decarburization is simultaneously performed in the continuous annealing for forming the subscale. Known annealing conditions can be applied to the annealing conditions (time, temperature, atmosphere, etc.) of the continuous annealing so that the forsterite coating can be easily and stably formed in the subsequent batch annealing. The preferred annealing temperature is about 750 to 1000 ° C., the preferred annealing time is about 1 to 300 seconds, and the preferred atmosphere is an oxidizing atmosphere consisting of hydrogen gas and nitrogen gas.

The step of removing the annealing separator of the present invention before the continuous annealing is unnecessary. That is, even if a forsterite coating is applied over the annealing separator of the present invention, not only the adhesion of the forsterite coating is good, but also the purification due to the presence of the annealing separator of the present invention. There is no hindrance. Next, an annealing separator mainly composed of MgO is applied to the steel sheet surface, and a second batch annealing is performed. Since the second batch annealing is performed for the purpose of forming a forsterite coating and purifying impurities, known annealing conditions that can achieve the two purposes can be applied. The preferred annealing temperature is about 900-1300 ° C., and the preferred annealing time is about 1-300 hours. It should be noted that known annealing separators containing MgO as a main component can be used. For example, as a solid content, rather preferably the MgO: about ⁸ 0 to ⁹⁹ mass%, the remainder optionally used Ti0 _2, SRS0 _4, MgSO be preferably those with one or more selected ₄ and the like or al Can be

After the second patch annealing, a technique to increase the amount of Si by the siliconizing method may be further applied. Finally, if necessary, a tension coating is applied and baked. In addition, the shape can be adjusted by flattening annealing, and further, flattening annealing that also serves as baking of a tension film can be performed. The grain-oriented electrical steel sheet in the present invention means an electrical steel sheet in which secondary recrystallization has developed. Therefore, not only the Goss direction but also the Cube direction ({100} The present invention also covers the case where (100) (011) orientation is secondary recrystallized. A known method can be applied to the accumulation in the Cube orientation, for example, it can be performed by controlling the rolling texture.However, the steps after recrystallization annealing are the same as the case where secondary recrystallization in which the Goss orientation is accumulated The same is true in the outline.

〔Example〕

 (Example 1)

 A grain-oriented electrical steel sheet with excellent forsterite coating properties and magnetic properties was prepared by the following method.

C: 0. 020mass%, Si: 3. 35mass 0 / o, Mn: 0. 050mass% Oyopi Sb: 380 comprises massppm, Al as a is et to Inhi Bitter forming component: 320 massppm Oyopi N : A steel slab containing 80 massppm, the balance being iron and unavoidable impurities was produced by a continuous production method. After the steel slab was heated to 1200 ° C, it was hot-rolled to finish a hot-rolled sheet having a thickness of 2.0 mm, and annealed at 1050 ° C for 60 seconds. Then, it was finished into a cold-rolled sheet having a thickness of 0.30 mm by cold rolling, and was subjected to recrystallization annealing in a dry atmosphere having a dew point of -45 ° C at 900 ° C for 10 seconds.

 After recrystallization annealing, the first batch annealing was performed. The annealing separator was applied before or after recrystallization annealing according to Table 5. The annealing separator was applied using a roll coater, and then subjected to a baking treatment at an ultimate temperature of the steel sheet (sheet temperature) of 250 ° C and allowed to cool. The baking was performed by propane gas baking. The first patch annealing was carried out in a nitrogen atmosphere at 850 ° C for 40 hours to complete the secondary recrystallization.

 After that, the applicability of the annealing separator, the adhesion of the annealing separator after drying, and the annealing separation effect after the first batch annealing were investigated, respectively. Was further applied to obtain a product plate.

In the subsequent steps, first, continuous annealing was performed to form a good subscale, and then an annealing separator containing MgO as a main component was applied. The first batch anneal was performed with 100 to 150 mass ppm of C remaining. Therefore, in the continuous anneal performed to form this subscale, decarburization was performed simultaneously. The continuous annealing was performed at 835 ° C for 120 seconds in an oxidizing atmosphere with a dew point of 55 ° C. Annealing separating agent for batch annealing of the second time with a solid content of _{MgO: 95as s%, Ti0 2} : 5nias s. /. Used was used. Next, a second patch annealing was performed in a dry hydrogen atmosphere at 1200 ° C for 5 hours. Finally, a tension coating was applied and baked and a strain relief annealing was performed. Tensile coatings containing phosphoric acid, coumic acid, and cinnamate were used and baked at a temperature of 800 ° C. The strain relief annealing was performed in a nitrogen atmosphere at 800 ° C for 3 hours. Table 5 shows the components of the annealing separator and the application conditions. S i0 _2, the annealing separator composed A1 ₂ 0 ₃ powder the main components was applied by the exception water slurry scratch No. 26, No. 26 is to be a solid 5 mas s% in alcohol And applied by spraying. The ratio of the main component other than powder was different depending on the amount of application, but was diluted with water and applied as a colloid solution. 3 wt% each of sodium sulfate, magnesium sulfate and magnesium sulfide added as adjuncts. /. Added. Solid contents other than those described in Table 5 were not added, but a surfactant (non-ion type) or the like was appropriately added at 0.5 mass% or less. Table 6 shows the order of the annealing separator application process (before or after recrystallization annealing), the coating properties of the annealing separator, and the annealing separator after drying. 5 shows the adhesion and the effect of annealing separation after the first patch annealing.

 In Nos. 14 and 19, since the viscosity of the annealing separator was out of the range of the present invention, the applicability was extremely poor, and adhesion of the steel sheet occurred in portions where the application was not possible. In Nos. 12 and 15, the ratio of the A1 compound to the Si compound is out of the preferred range of the present invention, and in No. 12, the adhesion of the annealing separator to the steel sheet is inferior because the amount of the A1 compound which is a film forming component is small. On the other hand, in No. 15, since the amount of the highly reactive A1 compound was large, the coating liquid was not stable and a uniform film could not be formed. As a result, the appearance was poor.

Nos. 1 to 4 had insufficient adhesion to the steel sheet because the main component of the annealing separator was outside the present invention. In No. 5, adhesion of the steel sheet occurred at the time of finish annealing because the amount of the applied annealing separator was insufficient. No. 17 had too much applied amount of annealing separator Therefore, peeling occurred due to insufficient adhesion to the steel sheet.

 In Nos. 3, 4, 6, 7, 12 and 26, the annealing separator was applied in two different order, before and after recrystallization annealing. Regardless of the sequence of the annealing separator application step, the annealing separator of the present invention has good applicability of the annealing separator, adhesion of the annealing separator after drying, and annealing separation effect after the first batch annealing. Obtained. In Comparative Examples Nos. 3, 4, and 26, the annealing separation effect was different depending on the application sequence of the annealing separating agent. This is because, when applied before recrystallization annealing, these annealing separation agents, which have poor adhesion to steel sheets, peel off during recrystallization annealing, and as a result, the annealing separation agent that adheres to steel sheets during the first batch annealing It is probable that the adhesion of the steel sheets occurred because the amount of the agent was reduced. On the other hand, it is probable that the steel sheet applied after recrystallization annealing did not adhere to the steel sheet because the amount of peeling was small and the amount required to prevent the steel sheet from adhering remained on the steel sheet.

Table 7 shows the magnetic properties, forsterite coating properties, and 1, (, 3) after the second batch annealing when the sample to which the annealing separator of the present invention was applied was subjected to subsequent steps to obtain a product plate. , 36 content (results of analysis after removing the coating in the base steel, that is, the surface of the steel sheet) Forsterite coating characteristics are as follows: the sample after strain relief annealing was wound around a cylinder to remove the coating. was evaluated by the minimum bend radius not occurred. magnetic properties, using Epusutain specimen 30 X 300 mm, was measured in accordance with JIS C ²⁵ 50. B ₈ is magnetic flux density at a magnetizing force _{800A / m (T), W} 17 / ₅₀ is the iron loss value (W / kg) at a frequency of 50 Hz and a maximum magnetic flux density of 1.7 T.

When the annealing separator of the present invention was applied, both the magnetic properties and the properties of the forsterite coating were achieved, and the purification of impurities was performed without any problem. Further, when a compound containing S was added to the annealing separator as a secondary agent (Nos. 8, 10 and 11), further improvement in magnetic properties was observed. Table 5

*: Suspended in alcohol with a viscosity of 1.6, spray applied 6

Annealing separator coating

 Annealing

Cloth process sequence Peeling amount Annealing Separation Peeling strength

 Applicability Separating agent Remarks ((g / rr.2) effect of recrystallization annealing (N)

 Adhesion

 Before / after)

 After OX 1.10 0 0 Comparative example After OX 1.05 0 0 Comparative example Before o X 1.05 X 65 Comparative example After o X 1.10 o 0 Comparative example 刖 o X 1.10 Δ50 Comparative example After o X 1.00 O 0 Comparative example After o 〇 0 X 90 Comparative Example Before o O 0 O 5 Invention Example After O O 0 O 5 Invention Example Before o 〇 0 〇 2 Invention Example After o O 0 〇 3 Invention Example After o O 0 〇 2 Invention Example After o 〇 0 〇 0 Invented example after o 〇 0 〇 0 Invented example after o 〇 0 〇 0 Invented example Before o Δ 0.80 O 0 Invented example after o △ 075 〇 0 Invented example after o O 0 o 0 Invented example after X 〇 0 m 20 Comparative example After Δ O 0 〇 0 Comparative Example After o O 0.15 〇 0 Invention Example After o Δ1.5 1.5 0 Comparative Example After o O 0 〇 0 Invention Example After XO 0 Δ 40 Comparative Example After o O 0 0 0 Invention Example After O O 0 〇 0 invention example after o O 0 O 0 invention example after o O 0 O 0 invention example after o O 0 O 0 invention example after oo 0 O 0 invention example

o X 1.0 X 70 Comparative example After o X 1.0 O 0 Comparative example Table Ί

(Example 2)

 A grain-oriented electrical steel sheet having excellent forsterite coating properties and magnetic properties was prepared by the following method.

C: 0. 019mass%, Si: 3. 28mass%, Mn: 0. 073mass 0/0 Oyopi Sb: 330 comprises massppm, further Al: 38 massppm, N: 30 massppm, S: 18 massppm Oyohi Se: Steel slabs containing no inhibitor-forming components, each controlled to less than lO massppm (less than the analysis limit value), were manufactured by continuous mirror manufacturing. The balance was iron and inevitable impurities. After the steel slab was heated to 1200 ° C, it was hot-rolled to finish a hot-rolled sheet having a thickness of 2.0, and annealed at 1050 ° C for 60 seconds.

 Then, it was finished into a cold-rolled sheet with a thickness of 0.30 by cold rolling, and recrystallized and annealed at 900 ° C for 10 seconds in a dry atmosphere with a dew point of -45 ° C.

After recrystallization annealing, the first patch annealing was performed. Table 8 shows the annealing separators. Accordingly, it was applied before or after recrystallization annealing. Application of annealing separator was performed using a roll coater primary, then baked at the ultimate temperature ² 50 ° C, and allowed to cool. Baking was carried out by baking with propane. The first patch annealing was performed in a nitrogen atmosphere at 865 ° C. for 50 hours to complete the secondary recrystallization.

After that, the applicability of the annealing separator, the adhesion of the annealing separator after drying, and the annealing separation effect after the first patch annealing were investigated, and for samples with good results, the subsequent steps were further performed. , And product plate. 'In a subsequent step, first, they performed continuously annealed to form a good subscale, then coated with an annealing separator composed mainly of M _g 0. Since the first batch annealing was performed with 100 to 150 mass ppm of C remaining, decarburization was performed simultaneously in the continuous annealing performed to form this subscale. The continuous annealing was performed at 850 ° C for 80 seconds in an oxidizing atmosphere with a dew point of 60 ° C. Further, annealing separator Mg0 as solid content: 92. 5 mas s%, Ti0 2: 7. 5 mas s. /. Used was used. Next, a second batch annealing was performed. In the steel composition of this embodiment, it is not necessary to perform high-temperature annealing at around 1200 ° C., which is necessary for purifying the inhibitor component, as long as the conditions permit formation of a forsterite coating. Therefore, in the second batch annealing, the temperature was kept at 1100 ° C, which is lower than before, for 5 hours, and the atmosphere was changed to hydrogen.

Finally, a tension coating was applied and baked and a strain relief annealing was performed. Tensile coatings containing phosphoric acid and oxalic acid were used and baked at 800 ° C. The strain relief annealing was performed in a nitrogen atmosphere at 800 for 3 hours. The components of the annealing separator and the application conditions were the same as in Example 1 under the conditions corresponding to each No. shown in Table 5. Table 8 shows the order of the separating agent application process (before or after recrystallization annealing), the applicability of the annealing separating agent, the adhesion of the annealing separating agent after drying, and the annealing separation effect after the first patch annealing. As in Example 1, for the steel produced by the method of the present invention, regardless of the sequence of the step of applying the annealing separator, good coatability of the annealing separator, adhesion of the annealing separator after drying, Separation effect after first and first patch annealing Is obtained. This shows that the annealing separator of the present invention is effective even when applied to a component system containing no inhibitor.

 Table 9 shows the magnetic properties, forsterite coating properties, and the Al, C, N, and B values after the second batch annealing when the sample to which the annealing separator of the present invention was applied was subjected to subsequent steps to obtain a product plate. Shows the S and Se contents. The method of investigating each characteristic was the same as in Example 1.

When the annealing separator within the scope of the present invention was applied, both the magnetic properties and the forsterite coating properties were achieved, and the impurity concentration was at a level without any problem.

Table 8

Annealing separation agent application

 Annealing Annealing

 Process sequence Peeling amount

 Coating properties Separation agent Separation Remarks (g / m2 of recrystallization annealing)

 Adhesion effect

 Before / after)

Before o X 1.15 Δ 45 comparative example after 〇 X 1.00 O 0 comparative example before 〇 X 1.00 △ 35 comparative example after o X 1.00 o 0 comparative example after o X 1.05 o 0 comparative example after o X 1.15 〇 0 comparative example after o O 0 X 60 Comparative example after o O 0 O 3 Invention example after o 〇 0 〇 3 Invention example rule 〇 〇 0 o 3 Invention example after o 〇 0 〇 2 Invention example 刖 o 〇 0 o 0 Invention example after 〇 0 o 0 invention example after o 〇 0 o 0 invention example after o O 0 o 0 invention example after 0.8 o 0 invention example after 〇 o 0 〇 0 invention example 刖 X o 0 Δ40 comparative example after X o 0 A 25 Comparative Example After 0 〇 0 Comparative Example After oo 0.2 O 0 Invention Example After Om 2 O 0 Comparative Example After o 〇 0 O 0 Invention Example After X 〇 0 Δ35 Comparative Example After oo 0 O 0 Invention Example After oo 0 O 0 Invention example after o o 0 O 0 Invention example after o 〇 0 O 0 Invention example after oo 0 O 0 Invention example after oo 0 o 0 Invention example Table 9

(Example 3)

 A grain-oriented electrical steel sheet having no forsterite coating and excellent magnetic properties and workability was prepared by the following method.

C: 0. 020mas s%, Si : 3. 31mass ° / o Mn: 0. 060nmss% Oyopi Sb: comprises 450 mas SPPM, as a further inhibitor-forming component A1: ³ 00 massppm and N: 70 massppm Steel slabs containing iron and unavoidable impurities were manufactured by the continuous production method. After heating the steel slab to 1200 ° C., it was hot-rolled into a hot-rolled sheet having a thickness of 1.8 mm, and annealed at 950 for 60 seconds. Then, cold rolling was performed to form a cold rolled sheet with a thickness of 0.27 mm, recrystallization annealing was performed at 880 ° C for 10 s in a dry atmosphere with a dew point of -45 ° C, and then finish annealing was performed. .

The annealing separator was applied before or after recrystallization annealing according to Table 10. Coating was carried out using a roll coater, and was baked at an ultimate plate temperature of 250 ° C and then allowed to cool. The baking was done by baking bread over open fire. 45 at 860 ° C for finish annealing After secondary recrystallization by holding in an N ₂ atmosphere for a period of time, purification was performed by holding in an H ₂ atmosphere at 1200 ° C. for 5 hours. As in Example 1, the components of the annealing separator and the application conditions were set under the conditions corresponding to each No. shown in Table 5.

 After that, the applicability of the annealing separator, the adhesion of the annealing separator after drying, and the annealing separation effect after finish annealing were investigated, and for samples with good results, the subsequent process was further performed. And

 In the subsequent steps, application and baking of the insulating film and annealing for strain relief were performed. The insulating coating used was a cuprate-based one containing a commonly used organic resin, and was baked at a temperature of 300 ° C. The strain relief annealing was performed in a nitrogen atmosphere at 750 ° C for 2 hours. Table 10 shows the applicability of the annealing separator, the adhesion of the annealing separator after drying, the annealing separation effect after finish annealing, the magnetic properties, the properties of the insulating coating, and the 1,2,3,36 content after finish annealing. Is shown. In Nos. 14 and 19, since the viscosity of the annealing separator was out of the range of the present invention, the applicability was extremely poor, and adhesion of the steel sheet occurred in portions where the application was not possible. In Nos. 12 and 15, the ratio of the Al compound to the Si compound was out of the preferred range of the present invention, and in No. 12, the adhesion of the annealing separator to the steel sheet was poor because the amount of the A1 compound, which is a film-forming component, was small. On the other hand, in No. 15, since the amount of the reactive 髙 ぃ A1 compound was large, the coating liquid was not stable and a uniform film could not be formed. As a result, the appearance was poor.

 No .:! To 4 had insufficient adhesion to the steel sheet because the main component of the annealing separator was outside the present invention. In No. 5, the adhesion of the steel sheet occurred at the time of finish annealing because the amount of the applied annealing separator was insufficient. At N 0.17, the applied amount of the annealing separating agent was too large, so that the adhesion to the steel sheet was insufficient and peeling occurred. Nos. 1-1, 4-1, 5, 6-1, 14 and 19 were not able to evaluate the magnetic properties and flexural peel resistance due to the adhesion of the steel sheets.

In Nos. 1, 4, 6, 11, and 16, the order of applying the annealing separator was two before and after recrystallization annealing. The annealing separator of the present invention has good coating properties of the separating agent, adhesion of the separating agent after drying, and finish annealing regardless of the sequence of the annealing separating agent application step. An annealing separation effect at the time is obtained. In Comparative Examples Nos. 1 and 4, there was a difference in the annealing separation effect depending on the application sequence of the annealing separating agent. This is considered to be due to the difference in the amount of the annealing separator attached during the final annealing for the same reason as in Example 1.

The one to which the annealing separator according to the present invention is applied has good applicability of the annealing separator, adhesion of the annealing separator after drying, annealing separation effect after finish annealing, magnetic properties, insulation coating properties, and impurities in the base iron. It can be seen that this indicates the purification of In particular, the film properties were better than those of the forsterite films shown in Examples 1 and 2. This shows that the annealing separator of the present invention can be advantageously applied to a grain-oriented electrical steel sheet that uses an inhibitor and requires purification by high-temperature annealing.

Table 10

(Example 4)

 A grain-oriented electrical steel sheet having no forsterite coating and excellent in magnetic properties and workability was prepared by the following method.

C: 0. 018mas s%, Si : 3. 32mass 0 / o, Mn: 0. 070mass% Oyopi Sb: include 300Massppm, further Al: 40mas sppm, N: 25massppm , S: 15 massppm Oyopi Se : A steel slab containing no inhibitor-forming component, each of which was suppressed to less than 10 massppm, was produced by a continuous casting method. The balance was iron and inevitable impurities. After the steel slab was heated to 1200, it was hot-rolled into a hot-rolled sheet having a thickness of 1.8 mm, and annealed at 950 ° C for 6.0 seconds. Then, it was finished into a cold-rolled sheet having a thickness of 0.35 mm by cold rolling, and was subjected to recrystallization annealing under the conditions of 880 ° C for 10 s in a dry atmosphere with a dew point of -45 ° C, followed by finish annealing.

The annealing separator was applied before or after recrystallization annealing according to Table 11. The coating was performed using a mouth coater, and was baked at an ultimate plate temperature of 250 ° C and then allowed to cool. The baking was performed by baking bread directly on the fire. In the finish annealing is secondary recrystallization by holding at ⁸⁷ 5 ° C with 45 hours between the N ₂ atmosphere and maintained at subsequent 1000 ° C in a 5:00 between Ar atmosphere. After finish annealing, decarburization annealing was performed in an oxidizing atmosphere to reduce the amount of C in the base steel. After that, as in Example 1, the components of the annealing separator and the application conditions were set under the conditions corresponding to each No. shown in Table 5. After that, the applicability of the annealing separator, the adhesion of the annealing separator after drying, and the annealing separation effect after finish annealing were examined, and for samples with good results, the subsequent steps were further performed. Board.

In the subsequent steps, application and baking of the insulating coating and annealing for strain relief were performed. The insulating film used was a chromate-based material containing a commonly used organic resin, and was baked at a temperature of 300 ° C. The strain relief annealing was performed in a nitrogen atmosphere at 750 ° C for 2 hours. Table 11 shows the applicability of the annealing separator, the adhesion of the annealing separator after drying, the annealing separation effect after finish annealing, the magnetic properties, the insulating coating properties, and the Al, C, N, S, and Se after finish annealing. Shows the content. As in Example 3, good results were obtained with steel to which the annealing separator according to the present invention was applied irrespective of the sequence of the annealing separator applying step.

Table 11 1 Content in base steel

 Burning

 Annealing (after finish annealing)

 s S blunt g g slow burning (mass ppm)

 Separation

 Blunt

¹ J release \

Release M Minute B ₈

o.Strong cloth o Bright light Peeling agent m release (T)

 Si density \ 例 Example Dense 3 Effective ratio ^ about (N)? Resulting after Al N C S Se 3

 Sex

 Foreword

1 after OX 1.10 0 0 1.85 1.34 50 40 26 15 15 ku 10 comparison-1 before o X 1.00 mm 15 ― ― 1 38 28 10 11 ku 10 comparison-2 after o X 1.05 0 0 1.84 1.36 55 38 22 14 11 ku 10 Compare

 one

-1 刖 o X 1.05 △ 20 ― ― ― 38 28 10 11 10 10 Compare -2 After 〇 X 1.15 〇 0 1.88 1.29 45 41 24 18 15 く 10 Compare

After 4 o X 1.00 〇 0 1.83 1.38 50 38 26 12 14 ku 10 Compare

5 After 〇 〇 0 X 80 ― ― 1 40 30 16 13 ku 10 Compare

6 After 〇 0 0 0 2 1.83 1.40 15 40 24 20 13 ku 10 Invention

7 After o 〇 0 O 4 1.82 1.34 20 41 22 17 10 ku 10 Invention-1 Before o 〇 0 〇 3 1.88 1.29 20 38 28 10 11 ku 10 Invention-2 After o 〇 0 0 3 1.88 1.28 20 35 19 15 16 K 10 Invention

9 After o O 0 0 3 1.84 1.25 20 39 28 19 20 ku 10 Invention-1 Before o 〇 0 0 0 1.88 1.30 15 38 28 10 11 ku 10 Invention-2 After o 〇 0 〇 0 1.88 1.24 15 36 18 15 15 1010 after invention 1 o 〇 0 〇 0 1.88 1.25 20 36 18 15 16 1010 invention-1 before room 0.7 0 0 1.84 1.28 55 38 28 10 11 1010 invention -2 after 〇0.5 0 0 1.87 1.26 45 40 26 21 15 ku 10 Invention 3 after o O 0 0 0 1.85 1.39 15 41 19 26 11 ku 10 Invention 4 after X 〇 0 um 29 ― ― ― 40 24 16 13 ku 10 Comparison 5 after 〇 0 0 0 1.84 1.37 15 40 25 18 16 ku 10 Compare 6 after o 〇 0 0 0 1.83 1.38 15 40 21 14 17 ku 10 Invention 7 〇 Δ 0.80 0 0 1.83 1.41 50 41 22 19 18 ku 10 Compare 8 after 〇 〇 0 〇 0 1.88 1.25 20 37 27 21 11 ku 10 Invention 9 after X 〇 0 Δ 19 ― ― ― 40 23 16 16 ku 10 Comparison 0 after 〇 〇 0 0 0 1.84 1.35 20 37 20 11 12 ku 10 Invention 1 after 〇 〇 0 〇 0 1.85 1.45 15 39 24 9 18 ku 10 Invention 2 after 〇 0 〇 0 1.88 1.37 15 40 21 18 11 ku 10 Invention 3 after 〇 〇 0 〇 0 1.86 1.36 20 40 23 15 13 ku 10 4 after O O 0 〇 0 1.85 1.35 20 39 25 14 14 ° 10 Hatsurei 5 after X X 0 〇 0 1.88 1.32 20 40 21 19 14 ° 10 invention (Example 5)

 A grain-oriented electrical steel sheet was prepared by applying the annealing separator shown in Table 12. The manufacturing process is as shown in Table 13. Steps A and B (the method using the final annealing) were performed in Example 3, and Steps C and D (the method using the two patch annealings) were performed according to Example 1. Slab and manufacturing conditions were applied. As for the annealing separator, the components other than the main components and the application conditions were the same as in Example 1. No. 6 was substantially recognized as a solution because no light scattering was recognized by the light scattering method.

 The results are shown in Table 13, and all the annealing separators of the present invention show excellent results. Above all, as a compound that is stable at high temperatures, the effect of annealing separation is high when a Si compound is contained, and it is particularly preferable to use the Si compound alone as a compound that is stable at high temperatures. That is, the coating amount and the viscosity were the same as those of Nos. 1 to 5 and 7 shown in Table 13, and Example 1 (colloidal silica) alone using the colloid solution Si compound (colloidal silica) was used. 13) and Example 3 (No. 13 in Table 10) showed the best characteristics, and were better than the results of this example shown in Table 13. Table 1 2

 AI compound separation agent

.

Viscosity Solid content ratio (mass <½)

| ¾Temp C Naha (g / m ² ) (mPa-s)

 AI compounds and others

 Compound

 Colloidal silica,

 Basic acetic acid AI

110 ₂ powder _{- 1.2 1.8 AI 2 0 3 /} (Al90 3 + Si02 + Ti0 2): 50 Koroita 'Rushirika,

Basic acetate AI sulfate _{Sr 1.2 1 .8 AI 2 0 3} / (AI 2 03 + Si02 + Ti02): 50

0 ₂ Fine powder

 Colloidal

 Basic acetic acid AI: 60

Ti02 ― 1.2 1.8 ΑΙ ₂ Ο ₃ / (ΑΙ ₂ θ3 + Τίθ9)

 Basic acetic acid AI

_{SrO, BaO - 1.2 1.8 AI 2} 0 3 / (Al20 3 + SrO + BaO): 70 basic acetate AI CaO powder sulfate _{Mg 1.2 1.8 AI 2 O 3 /} (AI 2 O 3 + CaO): 80 basic acetate AI colloidal resilica ― 0.1 1.8 AI ₂ O ₃ / (AI ₂ O ₃ + SiO ₂ ): 90 Basic acetic acid AI Zr0 ₂ fine powder ― 1.2 1.8 Αΐ2〇3 / (ΑΙ ₂ Ο ₃ + Ζ (2): 70 Table 13

 B: Annealing separation agent application → Recrystallization annealing → Finish annealing

 C: Recrystallization annealing → Application of annealing separator → First batch annealing → Continuous annealing ~ Second batch annealing

 D: Application of annealing separator → Recrystallization annealing → First batch annealing → Continuous annealing ~ Second patch annealing

(Example 6)

 Each steel slab having the components described in Table 14 was manufactured from molten steel by a continuous casting method, and a grain-oriented electrical steel sheet was prepared in the same manner as in Example 5 according to the classification in Table 15. However, for No. 2, the C content before secondary recrystallization was not particularly adjusted, and therefore the decarburization treatment was omitted. For No. 1 and No. 7, recrystallization annealing was performed in an oxidizing atmosphere with a dew point of 30 ° C, and the C content before secondary recrystallization annealing was adjusted to 100 to 150 mass ppm.

 The conditions for applying the annealing separator were in accordance with No. 13 in Table 5.

Table 15 shows the results. The magnetic properties also depend on the composition of the steel sheet, but all achieve the expected magnetic properties for each component. Table 14

 * A: Recrystallization 燁 Annealing → Annealing separation agent applied-'' Finish annealing

 B: Application of annealing separator → Recrystallization annealing-'Finish annealing

 C: Recrystallization annealing → application of annealing separator-1st patch annealing-►Continuous annealing ~ 2nd patch annealing

D: Application of annealing separator → Recrystallization annealing-First patch annealing-Continuous annealing ~ Second patch annealing Industrial potential

 INDUSTRIAL APPLICABILITY The annealing separator for grain-oriented electrical steel sheets according to the present invention has good coatability and adhesion to a steel sheet, and can secure a stable operation in the step of applying the annealing separator and the subsequent steps. It also has excellent operability, such as achieving adhesion, without impeding purification and decarburization, and eliminating the need for coating removal work.

 By applying this annealing separator to the manufacturing process of grain-oriented electrical steel sheet, it is possible to obtain a grain-oriented electrical steel sheet with excellent magnetic properties and forsterite coating properties and magnetic properties without a forsterite coating.方向 It becomes easy to manufacture directional electromagnetic steel sheets with excellent workability.

Claims

The scope of the claims

1. A method of annealing a grain-oriented electrical steel sheet, comprising applying an annealing separator to the steel sheet and annealing the coated steel sheet.

 The annealing separator,

 A1 compound in the form of a solution or colloid solution,

 A method for annealing a grain-oriented electrical steel sheet, further comprising a compound stable at high temperatures and having a viscosity of 25 (mPa-s) or less.

2. The method for annealing a grain-oriented electrical steel sheet according to claim 1, wherein the annealing separating agent contains the compound stable at a high temperature in the form of a solution or a colloid solution.

3. The content of the A1 compound is 40 to 95 mass in terms of a solid content ratio represented by the following formula (1). /. The method for annealing a grain-oriented electrical steel sheet according to claim 1, wherein:

 A1 compound solid content ratio = (solid content of the A1 compound) / {(solid content of the A1 compound) + (solid content (sum) of the high temperature stable compound)} Formula (1)

However, the solid content of the A1 compound is converted to A1 ₂ 0 _3, a stable compound wherein the elevated temperature is assumed to be converted into the primary compounds produced when baked after applying the annealing separator .

4. The compound that is stable at high temperature is at least one compound selected from the group consisting of Si compound, Sr compound, Ca compound, Zr compound, Ti compound and Ba compound.

The method for annealing a grain-oriented electrical steel sheet according to claim 1, wherein the content of the A1 compound is 40 to 95 ma _SS ° / ₀ at a solid content ratio represented by the following formula (2):

 Solid content ratio of A1 compound = (solid content of A1 compound) / {(solid content of A1 compound) + (previously described solid content of at least one compound (sum))} Formula (2)

 Here, the solid content of each compound is a value converted into the weight of each of the following compounds:

A1 compounds _{'· · Α1 2 0 3,} Si compounds' · · 3ί0 _2,

Sr compound '''SrC ^ Ca compound ·' ·. 3θ, Zr compound · · 'Zr0 _2, Ti compound · ·' Ti0 _2,

Ba compound · '· Β ₃₀ .

5. The annealing method for a grain-oriented electrical steel sheet according to claim 4, wherein the annealing separating agent contains the at least one compound in the form of a solution or a roll solution.

6. A method for annealing a directional electromagnetic steel sheet, comprising applying an annealing separator to the steel sheet and annealing the applied steel sheet,

 The annealing separator,

A main component A1 compound Contact Yopi Si compound, 40 ~ 95 mass ° with the value ratio in terms of _{Al 2 0 3 / (A1 2} 0 3 + Si0 2) of the A1 compound and Si compound /. The method for annealing grain-oriented electrical steel sheets that has a viscosity of 25 mPa's or less and is in a solution or colloid solution state

7. The A1 compound, wherein the A1 compound is one or both of an A1 compound having a hydroxyl group and an organic acid group, and a dehydration product of the A1 compound having a hydroxyl group and an organic acid group. 7. The method for annealing a grain-oriented electrical steel sheet according to any one of 6.

8. The A1 compound is basic acetic acid Al, basic formic acid Al, basic hydrochloric acid Al, basic nitric acid Al, basic oxalic acid Al, basic sulfamic acid Al, basic lactic acid A1 and basic citrate 8. The method for annealing a grain-oriented electrical steel sheet according to claim 7, wherein the method is one or a mixture of two or more kinds selected from A1.

9. The annealing separator further S or a compound containing S, 25Mas _S y in solid content obtained for the case where baking after applying the annealing separator. The method for annealing a grain-oriented electrical steel sheet according to any one of claims 1 to 6, comprising:

10. The method for annealing a grain-oriented electrical steel sheet according to claim 9, wherein the S or the compound containing S is at least one selected from Sr sulfate, Mg sulfate and Mg sulfide.

11. Contains Al compound in the form of solution or colloid solution, and

 A liquid further containing at least one compound selected from the group consisting of Si compounds, Sr compounds, Ca compounds, Zr compounds, Ti compounds and Ba compounds, wherein the content of the A1 compound is represented by the following formula (2 ) In the solid content ratio of 40 to

95mass ^_0/0,

 Use of a liquid having a viscosity of 25 mPa's or less as an annealing separator: solid content ratio of A1 compound = (solid content of A1 compound) / {(solid content of A1 compound) + (at least one of Compound solids (sum)) Formula (2)

 Here, the solid content of each compound is a value converted into the weight of each of the following compounds:

A1 compound ··· Α1 ₂ 0 ₃ , Si compound ··· Ξί0 ₂ ,

Sr compound5 ': τ0, Ca compound' '' CaCK

Zr compound _{· · 'Ζι · 0 2,} Ti compound · ·' Ti0 _2,

Ba compound ··· Β3θ.

12. The use of a liquid according to claim 11, wherein the liquid contains the at least one compound in the form of a solution or a colloid solution.

13. a main component A1 compound Contact Yopi Si compound, 40～95Mass a value ratio in terms of _{Al 2 0 3 / (A1 2} 0 3 + Si0 2) of the A1 compound and Si compound. /. Use of a liquid having a viscosity of 25 mPa's or less and being in the form of a solution or a colloid solution as an annealing separator.

14. C: 0.08mass _^0/0 less, Si: 2.0 ~ 8.0mass% Mn : 0.005~: L.0mass 0/0 The process of the rolled to steel slabs created from including the molten steel to a final thickness and Subjecting the steel sheet to recrystallization annealing;

 Applying batch annealing to the steel sheet by the method according to any one of claims 1 to 10, a first batch annealing step,

 Has,

Here, the above-mentioned annealing separating agent applied before annealing in the first batch annealing step is referred to as a first annealing separating agent, and Here, the recrystallization annealing is performed either before the application of the first annealing separating agent or after the application of the first annealing separating agent and before the patch annealing. And, and

The coating amount per one surface of the first annealing separator and 0. 005~5g / ni ^2,

 Thereafter, a step of performing continuous annealing on the steel sheet;

 A second patch annealing step of applying a second annealing separator containing MgO to the steel sheet, and thereafter performing patch annealing.

 Manufacturing method of grain-oriented electrical steel sheet.

15. The slab, 150 ppm of A1 below, N, S, the production method of the grain-oriented electrical steel sheet according to claim 14 is a slab made from molten steel having a composition having reduced respectively below 50p _P m or Se.

16. Rolling the slab to the final thickness to form a steel plate,

 Hot rolling the A1 slab into a hot rolled steel sheet,

 Performing a hot rolled sheet annealing to anneal the hot rolled steel sheet as necessary,

 A process of performing cold rolling once or cold rolling two or more times with intermediate annealing to obtain a final thickness,

 The method for producing a grain-oriented electrical steel sheet according to claim 14, comprising:

17. C: 0. 08mass _^0/0 less, Si: 2. 0 ~ 8. 0mass %, Mn: 0. 005 ~ 1. by rolling the 0Mass% slab made from including the molten steel to a final thickness steel And a step of performing recrystallization annealing on the steel sheet,

 A finish annealing step in which the steel sheet is subjected to patch annealing by the method according to any one of claims 1 to 10,

 Has,

 Here, the recrystallization annealing is performed either before the application of the annealing separating agent in the finish annealing step or after the application of the annealing separating agent and before the patch annealing. And, and

The coating amount per one side of the annealing separator and 0. 005~5g / m ^2,

Manufacturing method of grain-oriented electrical steel sheet.

18. The slab, 150 ppm of A1 below, N, S, the production method of the grain-oriented electrical steel sheet according to claim 17 is a slab made from molten steel having a composition having reduced respectively below 50p _P m or Se.

19. The process of rolling a slab to a final thickness to form a steel plate,

 Hot rolling the A1 slab into a hot rolled steel sheet,

 Performing a hot rolled sheet annealing to anneal the hot rolled steel sheet as necessary,

A process of performing cold rolling once or cold rolling two or more times with intermediate annealing to obtain a final thickness,

 The method for producing a grain-oriented electrical steel sheet according to claim 17, comprising:

20. A step of hot rolling a slap made from molten steel containing C: 0.08 mass% or less, Si: 2.0 to 8.0 mass%, Mn: 0.005 to: L. 0 mass%,

 Next, a step of performing a single cold rolling or two or more cold rollings sandwiching intermediate annealing to obtain a final thickness,

 Next, a step of performing recrystallization annealing,

Then it has a step of applying finish annealing by the method according to claim 6, and the coating amount of the annealing separator to be applied to one surface per 0. 005~5g / m ² before annealing in the final annealing, direction Manufacturing method of conductive electrical steel sheet.

21. C: 0.08 mass% or less, Si: 2.0 to 8.0 mass%, Mn: 0.005 to 1.0 mass%, and A1 is 150 ppm or less. N, S, Se Hot rolling a slab made from molten steel having a component composition reduced to 50 ppm or less,

 Next, a step of performing a single cold rolling or two or more cold rollings sandwiching intermediate annealing to obtain a final thickness,

 Next, a step of performing recrystallization annealing,

Then it has a step of applying finish annealing by the method according to claim 6, and the coating amount of the annealing separator to be applied to one surface per 0. 005~5g / m ² before annealing in the final annealing, direction Manufacturing method of conductive electrical steel sheet.