JP3338238B2 - Manufacturing method of low iron loss unidirectional electrical steel sheet - Google Patents

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【産業上の利用分野】本発明は変圧器等の鉄心に使用さ
れる低鉄損一方向性電磁鋼板の製造方法に関するもので
ある。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a low iron loss unidirectional magnetic steel sheet used for an iron core of a transformer or the like.

【０００２】[0002]

【従来の技術】一方向性電磁鋼板は主に変圧器や発電機
の鉄心材料に使用されるが、省エネルギー化が要求され
ている昨今、更に磁束密度が高く、鉄損の少ない鋼板が
市場から要求されている。一般的に、低鉄損を達成する
ためには、鋼板のＳｉ含有量を極力高め素材の固有抵抗
を上げて渦電流損を下げる方法と、製品板厚を極力薄く
し渦電流損を下げる方法が知られている。更に、低鉄損
を図るにはインヒビター、鋼板の組織、集合組織を高度
に制御する必要がある。2. Description of the Related Art Unidirectional electrical steel sheets are mainly used for core materials of transformers and generators. Recently, steel sheets with higher magnetic flux density and less iron loss have been required from the market for energy saving. Has been requested. In general, in order to achieve low iron loss, there are two ways to reduce the eddy current loss by increasing the Si content of the steel sheet as much as possible and increasing the specific resistance of the material, and to reduce the eddy current loss by reducing the product thickness as much as possible. It has been known. Further, in order to achieve low iron loss, it is necessary to control the structure and texture of the inhibitor and the steel sheet to a high degree.

【０００３】この中の一つであるインヒビター分散形態
のコントロールは、熱間圧延に先立つスラブ高温加熱中
にインヒビターを一旦溶体化させ、その後適当な冷却パ
ターンの熱間圧延を施すことが必要である。インヒビタ
ー溶体化のためのスラブ高温加熱をガス燃焼型加熱炉で
行うと、スラブ表面から熱せられるのでスラブ表層で温
度が高く、スラブ中心部で温度が低い状態になる。よっ
て、スラブ中心部まで目的の温度に達するためには、ス
ラブ表層温度は、スラブ中心部よりもかなり高い温度と
なり、またガス燃焼型加熱炉では昇温速度も１２００℃
以上で約１℃／分と遅いために１２００℃以上の高温域
に滞留する時間がかなり長くなる。従って、スラブ高温
加熱後の結晶粒径は粗大化してしまい、線状細粒と呼ば
れる二次再結晶不良を製品にもたらす原因となってい
た。この対策として、特公昭５６−１８６５４号公報に
提案されているようなスラブ急速加熱方式を用いると、
スラブ加熱の短時間化が可能となった。[0003] One of the control methods of the inhibitor dispersion form is that it is necessary to first form a solution during the high-temperature heating of the slab prior to hot rolling, and then to perform hot rolling with an appropriate cooling pattern. . When slab high-temperature heating for inhibitor solution is performed in a gas-fired heating furnace, the slab surface is heated, so that the temperature is high at the slab surface layer and low at the center of the slab. Therefore, in order to reach the target temperature up to the center of the slab, the surface temperature of the slab is considerably higher than that of the center of the slab, and the heating rate of the gas-fired heating furnace is 1200 ° C.
As described above, since the temperature is as low as about 1 ° C./minute, the time of staying in a high temperature region of 1200 ° C. or more becomes considerably long. Therefore, the crystal grain size after heating the slab at a high temperature becomes coarse, which has caused secondary recrystallization defects called linear fine grains in the product. As a countermeasure, when a slab rapid heating method as proposed in Japanese Patent Publication No. 56-18654 is used,
Shortening of slab heating is now possible.

【０００４】一方、圧下率４０〜８０％の最終冷間圧延
を行う２回冷延法で一方向性電磁鋼板を製造する方法に
おいて、１回目の冷間圧延時、２回目の冷間圧延時に時
効処理を施すことにより磁気特性が向上する方法が開示
されている（特開昭５８−２５４２５号公報参照）。ま
た、圧下率８０超〜９５％の強圧下最終冷間圧延を含む
２回以上の冷間圧延を行い一方向性電磁鋼板を製造する
方法において、熱延板焼鈍の冷却過程で６００℃〜２０
０℃の間を５℃／秒以上で冷却し、１回目の冷間圧延に
おける複数パスのパス間の少なくとも１回に鋼板を５０
〜５００℃の温度範囲で１分以上の時間保持することに
より磁気特性が向上する方法が開示されている（特開昭
６２−２０２０２４号公報参照）。On the other hand, in a method for producing a grain-oriented electrical steel sheet by a two-time cold rolling method in which a final cold rolling at a reduction ratio of 40 to 80% is carried out, the first cold rolling is performed at the time of the second cold rolling. A method of improving magnetic properties by performing aging treatment is disclosed (see Japanese Patent Application Laid-Open No. 58-25425). Further, in a method of producing a grain-oriented electrical steel sheet by performing two or more cold rolling operations including a final cold rolling operation under a high rolling reduction of more than 80 to 95%, a temperature of 600 ° C. to 20 ° C.
The steel sheet is cooled at a rate of 5 ° C./sec or more between 0 ° C. and the steel sheet is cooled at least once between a plurality of passes in the first cold rolling.
A method has been disclosed in which the magnetic properties are improved by maintaining the temperature in a temperature range of up to 500 ° C. for 1 minute or more (see Japanese Patent Application Laid-Open No. 62-202024).

【０００５】[0005]

【発明が解決しようとする課題】しかしながら、前記従
来技術の方法で得られる製品は、低鉄損という点で満足
できるものではなかった。本発明は、スラブ加熱時の高
温域におけるスラブ加熱の昇温速度を規制することによ
りスラブ加熱時の結晶粒の成長を抑制し、熱延板焼鈍で
の冷却速度を規制し、冷間圧延時のパス間時効温度およ
びパス間時効時間をある範囲に制御することにより、低
鉄損な製品を得る方法を提供するものである。However, the products obtained by the above-mentioned prior art methods have not been satisfactory in terms of low iron loss. The present invention suppresses the growth of crystal grains during slab heating by regulating the temperature rise rate of slab heating in a high temperature region during slab heating, regulates the cooling rate in hot-rolled sheet annealing, By controlling the aging temperature between passes and the aging time between passes within a certain range.

【０００６】[0006]

【課題を解決するための手段】すなわち本発明は、
（１）重量％で、Ｃ：０．０１５〜０．１００％、Ｓ
ｉ：２．０〜４．０％、Ｍｎ：０．０３〜０．１２％、
Ｓol．Ａｌ：０．０１０〜０．０６５％、Ｎ：０．００
４０〜０．０１００％、ＳおよびＳｅのうちから選んだ
１種または２種合計：０．００５〜０．０５０％、更に
Ｓｂ，Ｓｎ，Ｃｕ，Ｍｏ，Ｇｅ，Ｂ，Ｔｅ，Ａｓおよび
Ｂｉから選ばれる１種または２種以上を０．００３〜
０．３％を含有し、残部は実質的にＦｅの組成になる連
続鋳造スラブを、１３２０℃〜１４５０℃に加熱均熱し
たのち熱延し、熱延板焼鈍を施し、予備冷間圧延、中間
焼鈍、最終冷間圧延、脱炭・１次再結晶焼鈍、最終仕上
げ焼鈍によって一方向性電磁鋼板を製造する方法におい
て、上記スラブの１２００℃以上の高温域の加熱を５℃
／分以上の昇温速度で行うと共に、熱延板焼鈍の冷却過
程において７００℃〜１５０℃の間を８℃／秒以上で冷
却し、予備冷間圧延における複数パスのパス間の少なく
とも１回に鋼板を１００℃〜４００℃の温度範囲で１分
以上の時間保持することを特徴とする低鉄損一方向性電
磁鋼板の製造方法であり、（２）前記最終冷間圧延工程
における途中板厚段階の少なくとも１回のパス間で鋼板
を１５０℃〜３５０℃の温度範囲で１分以上の時間保持
することを特徴とする前項（１）記載の低鉄損一方向性
電磁鋼板の製造方法であり、また（３）前記スラブを１
２００℃以上の高温域に加熱する前に、５０％以下の圧
下率で熱間変形を加えることを特徴とする前記（１），
（２）項記載の低鉄損一方向性電磁鋼板の製造方法であ
る。That is, the present invention provides:
(1) By weight%, C: 0.015 to 0.100%, S
i: 2.0 to 4.0%, Mn: 0.03 to 0.12%,
Sol. Al: 0.010-0.065%, N: 0.00
40 to 0.0100%, one or two selected from S and Se: 0.005 to 0.050%, and further from Sb, Sn, Cu, Mo, Ge, B, Te, As and Bi One or two or more selected from 0.003 to
A continuous cast slab containing 0.3%, with the balance being substantially the composition of Fe, is heated and soaked at 1320 ° C. to 1450 ° C., hot rolled, subjected to hot rolled sheet annealing, and subjected to preliminary cold rolling. In a method for producing a grain-oriented electrical steel sheet by intermediate annealing, final cold rolling, decarburization / primary recrystallization annealing, and final finish annealing, the slab is heated at a temperature of 1200 ° C. or higher at 5 ° C.
/ Min or more, and at a rate of at least 8 ° C./sec between 700 ° C. and 150 ° C. in the cooling process of hot-rolled sheet annealing, and at least once between a plurality of passes in preliminary cold rolling. And (2) an intermediate sheet in the final cold rolling step, wherein the steel sheet is held in a temperature range of 100 ° C. to 400 ° C. for 1 minute or more. The method for producing a low iron loss unidirectional magnetic steel sheet according to the above item (1), wherein the steel sheet is held in a temperature range of 150 ° C. to 350 ° C. for at least one minute during at least one pass of the thickness step. And (3) the slab is 1
The above (1), wherein, before heating to a high temperature region of 200 ° C. or more, hot deformation is applied at a rolling reduction of 50% or less.
(2) A method for producing a low iron loss unidirectional electrical steel sheet according to the item (2).

【０００７】本発明者は、鉄損の低い一方向性電磁鋼板
を製造する方法を検討したところ、スラブ加熱時の高温
域におけるスラブ加熱を５℃／分以上の昇温速度で行
い、スラブ加熱時の結晶粒の成長を抑制し、かつ、熱延
板焼鈍の冷却過程において７００℃〜１５０℃の間を８
℃／秒以上で冷却することにより、固溶Ｃ，Ｎ，微細炭
化物，微細窒化物を富化し、冷間圧延時のパス間時効温
度およびパス間時効時間をある範囲に制御することが非
常に有効であることを見出した。The present inventor studied a method of manufacturing a grain-oriented electrical steel sheet having a low iron loss. As a result, the slab was heated in a high temperature range at the time of slab heating at a rate of 5 ° C./min or more. At the time of 700 ° C. to 150 ° C. in the cooling process of hot-rolled sheet annealing.
By cooling at a rate of at least ° C./sec, solid solution C, N, fine carbides and fine nitrides are enriched, and it is very possible to control the aging temperature between passes and the aging time between passes during cold rolling within a certain range. Found to be effective.

【０００８】図１は、本発明者が行った実験結果の一例
である。すなわち、本発明に従った成分範囲にあるＣ：
０．０７５％、Ｓｉ：３．２３％、Ｍｎ：０．０７１
％、Ｓ：０．０２５％、Ｓol．Ａｌ：０．０３０％、
Ｎ：０．００８０％、Ｓｎ：０．１１％を含有する鋳片
を、短時間加熱が可能な電気式雰囲気制御型誘導加熱炉
により到達温度１３５０℃とし、１２００℃から１３５
０℃までを種々の昇温速度で加熱した鋳片を用いて板厚
２．３０mmの熱延板を作製した。そして、これに１００
０℃×２分均熱後１５℃／秒で冷却する熱延板焼鈍を施
し、酸洗後、予備冷延を行って１．４５mmの板厚とし
た。かかる予備冷間圧延の途中板厚２．００mmと１．７
０mmの段階で種々の温度で１０分間のパス間時効を施し
た。しかる後、１０００℃×２分均熱後急冷する中間焼
鈍後、最終冷間圧延０．１７mmの最終仕上げ厚とした。
得られた冷延板を公知の方法で脱炭焼鈍し、焼付分離材
を塗布した後、最終仕上げ焼鈍を行い、コーティング液
を塗布し製品とした。かくして得られた製品板の鉄損と
スラブ昇温速度、パス間時効温度との関係について調べ
た結果を図１に示す。同図より明らかなように、スラブ
昇温速度を５℃／分以上とし、かつ、予備冷延工程で１
００〜４００℃の温度でパス間時効を施すことにより良
好な磁気特性が得られることが分かる。FIG. 1 shows an example of the results of an experiment conducted by the present inventor. That is, C in the component range according to the present invention:
0.075%, Si: 3.23%, Mn: 0.071
%, S: 0.025%, Sol. Al: 0.030%,
A slab containing 0.0080% of N and 0.11% of Sn was brought to a temperature of 1350 ° C. by an electric atmosphere control type induction heating furnace capable of heating for a short time, from 1200 ° C. to 135 ° C.
Hot rolled sheets having a thickness of 2.30 mm were produced using cast pieces heated to 0 ° C. at various heating rates. And this is 100
After hot-rolling at 0 ° C. for 2 minutes, the hot-rolled sheet was cooled at 15 ° C./sec, pickled, and pre-cold rolled to a sheet thickness of 1.45 mm. During the preliminary cold rolling, the sheet thickness was 2.00 mm and 1.7.
At the 0 mm stage, aging between passes was performed at various temperatures for 10 minutes. Then, after intermediate annealing, which was followed by rapid cooling after soaking at 1000 ° C. for 2 minutes, a final finished thickness of final cold rolling of 0.17 mm was obtained.
The obtained cold rolled sheet was decarburized and annealed by a known method, and after applying a baking separating material, final finishing annealing was performed and a coating liquid was applied to obtain a product. FIG. 1 shows the results obtained by examining the relationships among the iron loss of the product sheet thus obtained, the slab heating rate, and the inter-pass aging temperature. As is clear from the figure, the slab heating rate was set to 5 ° C./min or more, and 1
It can be seen that good magnetic properties can be obtained by aging between passes at a temperature of 00 to 400 ° C.

【０００９】図２も実験結果の一例を示す。すなわち本
発明に従った成分範囲にあるＣ：０．０７０％、Ｓｉ：
３．２０％、Ｍｎ：０．０７０％、Ｓ：０．０２２％、
Ｓol．Ａｌ：０．０３１％、Ｎ：０．００７５％、Ｓ
ｎ：０．１０％を含有する鋳片を、短時間加熱が可能な
通電加熱により到達温度１３９０℃とし、１２００℃か
ら１３９０℃までを１０℃／分の昇温速度で加熱したス
ラブを用いて板厚２．３０mmの熱延板を作製した。そし
て、これに１０００℃×２分均熱後１５℃／秒で冷却す
る熱延板焼鈍を施し、酸洗後、予備冷延をして１．３５
mmの板厚とした。かかる予備冷間圧延の途中板厚２．０
０mmと１．７０mmの段階で鋼板を２５０℃に種々の時間
保持した。しかる後、１０００℃×２分均熱後急冷する
中間焼鈍後、最終冷間圧延０．１７mmの最終仕上げ厚と
した。得られた冷延板を公知の方法で脱炭焼鈍し、焼付
分離材を塗布した後、最終仕上げ焼鈍を行い、コーティ
ング液を塗布し製品とした。かくして得られた製品板の
磁束密度、鉄損とパス間時効温度との関係について調べ
た結果を図２に示す。同図より明らかなようにパス間時
効時間を１分以上とすると良好な磁気特性が得られるこ
とが分かる。FIG. 2 also shows an example of the experimental results. That is, C: 0.070%, Si: in the component range according to the present invention.
3.20%, Mn: 0.070%, S: 0.022%,
Sol. Al: 0.031%, N: 0.0075%, S
n: A slab containing 0.10% was heated to a final temperature of 1390 ° C. by current heating capable of heating for a short time, and a slab heated from 1200 ° C. to 1390 ° C. at a rate of 10 ° C./min was used. A hot-rolled sheet having a thickness of 2.30 mm was produced. Then, this was subjected to hot rolled sheet annealing in which the temperature was soaked at 1000 ° C. for 2 minutes and then cooled at 15 ° C./sec.
mm. During the preliminary cold rolling, a sheet thickness of 2.0
The steel sheets were held at 250 ° C. for various times at the 0 mm and 1.70 mm stages. Then, after intermediate annealing, which was followed by rapid cooling after soaking at 1000 ° C. for 2 minutes, a final finished thickness of final cold rolling of 0.17 mm was obtained. The obtained cold rolled sheet was decarburized and annealed by a known method, and after applying a baking separating material, final finishing annealing was performed and a coating liquid was applied to obtain a product. FIG. 2 shows the results obtained by examining the relationship between the magnetic flux density and iron loss of the product sheet thus obtained and the inter-pass aging temperature. As is clear from the figure, when the aging time between passes is set to 1 minute or more, good magnetic characteristics can be obtained.

【００１０】図３は、冷却速度と磁性の関係を調べた実
験結果の一例を示す。すなわち本発明に従った成分範囲
にあるＣ：０．０６９％、Ｓｉ：３．２３％、Ｍｎ：
０．０７０％、Ｓ：０．０２８％、Ｓol．Ａｌ：０．０
３０％、Ｎ：０．００７４％、Ｓｎ：０．１０％を含有
する鋳片を、短時間加熱が可能な通電加熱により到達温
度１４００℃とし、１２００℃から１４００℃までを１
０℃／分の昇温速度で加熱したスラブを用いて板厚２．
３０mmの熱延板を作製した。１０００℃×２分均熱後、
Ｃの析出温度域と考えられる７００℃〜１５０℃を種々
の冷却速度で冷却する熱延板焼鈍を行い、酸洗後、板厚
１．２５mmまで予備冷間圧延を施した。かかる予備冷間
圧延の途中板厚２．００mmと１．６０mmの段階で鋼板を
２５０℃に５分保持した。しかる後、１０００℃×２分
均熱後急冷する中間焼鈍後、最終冷間圧延して０．１７
mmの最終仕上げ厚とした。得られた冷延板を公知の方法
で脱炭焼鈍し、焼付分離材を塗布した後、最終仕上げ焼
鈍を行い、コーティング液を塗布し製品とした。かくし
て得られた製品板の鉄損と熱延板焼鈍での７００℃〜１
５０℃の冷却速度との関係について調べた結果を図３に
示す。同図より明らかなように熱延板焼鈍での７００℃
〜１５０℃の冷却速度を８℃／秒以上とすることにより
良好な磁気特性が得られることが分かる。FIG. 3 shows an example of an experimental result of examining the relationship between the cooling rate and the magnetism. That is, in the component range according to the present invention, C: 0.069%, Si: 3.23%, Mn:
0.070%, S: 0.028%, Sol. Al: 0.0
A slab containing 30%, N: 0.0074%, and Sn: 0.10% is heated to a maximum temperature of 1400 ° C. by current heating capable of heating for a short time, and the temperature from 1200 ° C. to 1400 ° C.
1. Plate thickness using a slab heated at a heating rate of 0 ° C./min.
A 30 mm hot rolled sheet was produced. After soaking at 1000 ° C for 2 minutes,
The hot rolled sheet was cooled at various cooling rates from 700 ° C. to 150 ° C., which is considered to be the precipitation temperature range of C, and pickled, and then pre-cold rolled to a sheet thickness of 1.25 mm. During the preliminary cold rolling, the steel sheet was held at 250 ° C. for 5 minutes at the stage of the sheet thickness of 2.00 mm and 1.60 mm. Then, after intermediate annealing at 1000 ° C. for 2 minutes and rapid cooling, final cold rolling is performed to obtain 0.17
mm. The obtained cold rolled sheet was decarburized and annealed by a known method, and after applying a baking separating material, final finishing annealing was performed and a coating liquid was applied to obtain a product. Iron loss of the product sheet thus obtained and 700 ° C-1 in hot-rolled sheet annealing
FIG. 3 shows the results of an investigation on the relationship with the cooling rate of 50 ° C. As is clear from FIG.
It can be seen that good magnetic properties can be obtained by setting the cooling rate at -150 ° C to 8 ° C / sec or more.

【００１１】このようにこの発明は、高温スラブ加熱を
スラブの昇温速度を５℃／分以上とし、かつ、熱延板焼
鈍の冷却過程において７００℃〜１５０℃の間を８℃／
秒以上で冷却し、かつ、予備冷延工程で１００℃〜４０
０℃の温度で１分以上のパス間時効を施すことにより磁
気特性が向上するという全く新しい知見に基づいて完成
されたものである。As described above, according to the present invention, high-temperature slab heating is performed at a slab heating rate of 5 ° C./min or more, and in a cooling process of hot-rolled sheet annealing, a temperature of 8 ° C./150° C.
Cooling in seconds or more, and 100 ° C ~ 40
It has been completed based on a completely new finding that magnetic characteristics are improved by aging between passes for 1 minute or more at a temperature of 0 ° C.

【００１２】以下に本発明の諸条件を限定した理由を説
明する。Ｓｉは、下限２％未満では良好な鉄損が得られ
ず、上限４％を超えると冷延性が著しく劣化する。Ｃ
は、下限０．０１５％未満であれば２次再結晶が不安定
となり、上限の０．１００％はこれよりＣが多くなると
脱炭所要時間が長くなり経済的に不利となるために限定
した。The reasons for limiting the conditions of the present invention will be described below. If the lower limit of Si is less than 2%, good iron loss cannot be obtained, and if the upper limit of 4% is exceeded, the cold rolling property is significantly deteriorated. C
If the lower limit is less than 0.015%, the secondary recrystallization is unstable, and the upper limit is 0.100%. .

【００１３】Ｍｎは、下限０．０３％未満であれば熱間
脆化を起こし、上限０．１２％を超えるとかえって磁気
特性を劣化させる。Ｓ，Ｓｅは、ＭｎＳ，ＭｎＳｅを形
成するために必要な元素で、これらの１種または２種の
合計が下限０．００５％未満ではＭｎＳ，ＭｎＳｅの絶
対量が不足し、上限０．０５０％を超えると熱間割れを
生じ、また、最終仕上げ焼鈍での純化が困難となる。Mn causes hot embrittlement if the lower limit is less than 0.03%, and degrades magnetic properties if it exceeds the upper limit of 0.12%. S and Se are elements necessary for forming MnS and MnSe. If the total of one or two of them is less than the lower limit of 0.005%, the absolute amounts of MnS and MnSe are insufficient, and the upper limit is 0.050%. If it exceeds 300, hot cracking will occur, and it will be difficult to purify by final finish annealing.

【００１４】Ｓol．Ａｌは、ＡｌＮを形成するために必
要な元素で、下限０．０１０％未満ではＡｌＮの絶対量
が不足し、上限０．０６５％を超えるとＡｌＮの適当な
分散状態が得られない。Ｎは、ＡｌＮを形成するために
必要な元素で、下限０．００４０％未満ではＡｌＮの絶
対量が不足し、上限０．０１００％を超えるとＡｌＮの
適当な分散状態が得られない。Sol. Al is an element necessary for forming AlN. If the lower limit is less than 0.010%, the absolute amount of AlN is insufficient, and if the upper limit is more than 0.065%, an appropriate dispersion state of AlN cannot be obtained. N is an element necessary for forming AlN. If the lower limit is less than 0.0040%, the absolute amount of AlN is insufficient, and if the upper limit is more than 0.0100%, an appropriate dispersion state of AlN cannot be obtained.

【００１５】Ｓｂ，Ｓｎ，Ｃｕ，Ｍｏ，Ｇｅ，Ｂ，Ｔ
ｅ，Ａｓ，およびＢｉは粒界に偏析させ、２次再結晶を
安定化させるが、下限０．０３％未満では偏析量が不足
し、上限０．３％は経済的理由と脱炭性の悪化によるも
のである。Sb, Sn, Cu, Mo, Ge, B, T
e, As, and Bi segregate at the grain boundaries to stabilize the secondary recrystallization, but if the lower limit is less than 0.03%, the segregation amount is insufficient. It is due to deterioration.

【００１６】スラブ加熱温度は、１３２０℃〜１４５０
℃とするが、１３２０℃未満であると製品の鉄損のばら
つきが大きい。１４５０℃を超えるとスラブが溶融す
る。高温域におけるスラブ加熱に関しては、加熱時の結
晶粒径の粗大化の抑制および組織、集合組織の改善のた
めに、１２００℃以上の昇温速度を５℃／分以上とする
が、１２００℃未満では粒成長への影響が少ないために
昇温速度を規定する必要はない。昇温速度５℃／分未満
では、磁気特性の改善効果が少ないためである。The slab heating temperature is from 1320 ° C. to 1450
° C, but if it is lower than 1320 ° C, the iron loss of the product greatly varies. If it exceeds 1450 ° C., the slab melts. Regarding slab heating in a high-temperature region, the rate of temperature increase at 1200 ° C. or higher is set to 5 ° C./min or more to suppress coarsening of the crystal grain size during heating and to improve the structure and texture, but is lower than 1200 ° C. In this case, it is not necessary to regulate the heating rate because the influence on the grain growth is small. If the rate of temperature rise is less than 5 ° C./min, the effect of improving the magnetic properties is small.

【００１７】熱延板焼鈍での７００℃〜１５０℃の冷却
速度は、図３に示すように８℃／秒未満だと磁気特性の
改善効果が少ない。７００℃〜１５０℃としたのは、そ
の温度域が、Ｃの析出温度域と考えられるためである。If the cooling rate at 700 ° C. to 150 ° C. in the hot-rolled sheet annealing is less than 8 ° C./sec as shown in FIG. 3, the effect of improving the magnetic properties is small. The reason why the temperature is set to 700 ° C. to 150 ° C. is that the temperature range is considered to be a C deposition temperature range.

【００１８】予備冷間圧延時のパス間時効温度は、図
１，２に示すように、１００℃より低温だと磁気特性の
改善効果に乏しく、また４００℃を超えても磁気特性の
改善効果が少ない。時効処理は１回でも効果があるが、
圧延と時効処理を交互に繰り返すと製品の磁気特性が一
層向上する。パス間時効時間は、１分未満だと磁気特性
の改善効果が少ない。As shown in FIGS. 1 and 2, the inter-pass aging temperature during the pre-cold rolling is poor in improving the magnetic properties when the temperature is lower than 100 ° C., and even when it exceeds 400 ° C. Less is. The aging treatment is effective even once,
When the rolling and the aging treatment are alternately repeated, the magnetic properties of the product are further improved. If the aging time between passes is less than 1 minute, the effect of improving magnetic properties is small.

【００１９】予備冷間圧延でパス間時効を施し、かつ最
終冷間圧延でパス間時効を施すことにより、更に磁気特
性が向上する。最終冷間圧延時のパス間時効温度は、１
５０℃より低温だと磁気特性の改善効果に乏しく、また
３５０℃を超えても磁気特性の改善効果が少ない。時効
処理は１回でも効果があるが圧延と時効処理を交互に繰
り返すと製品の磁気特性が一層向上する。パス間時効時
間は、１分未満だと磁気特性の改善効果が少ない。By performing inter-pass aging by preliminary cold rolling and by inter-pass aging by final cold rolling, the magnetic properties are further improved. The aging temperature between passes during final cold rolling is 1
If the temperature is lower than 50 ° C., the effect of improving the magnetic properties is poor, and if it exceeds 350 ° C., the effect of improving the magnetic properties is small. Although the aging treatment is effective even once, the magnetic properties of the product are further improved by alternately repeating the rolling and the aging treatment. If the aging time between passes is less than 1 minute, the effect of improving magnetic properties is small.

【００２０】１２００℃以上の高温域のスラブ加熱前に
５０％以下の圧下で熱間変形を加えることは、スラブの
柱状晶を破壊し、熱延板の組織の均一化に有効で製品の
磁気特性のばらつきを少なくする。圧下率の上限を５０
％としたのは、これ以上圧下率を高くしても、磁気特性
の値に変化がないからである。Applying hot deformation under a pressure of 50% or less before heating the slab in a high-temperature region of 1200 ° C. or more destroys columnar crystals of the slab and is effective in homogenizing the structure of the hot-rolled sheet. Reduce variations in characteristics. The upper limit of the draft is 50
The reason for the percentage is that even if the rolling reduction is further increased, the value of the magnetic characteristics does not change.

【００２１】[0021]

【実施例】 〔実施例１〕〔Ｃ〕０．０７５％、〔Ｓｉ〕３．２５
％、〔Ｍｎ〕０．０８８％、〔Ｓ〕０．０２５％、〔Ｓ
ol．Ａｌ〕０．０２２％、〔Ｎ〕０．００８０％、〔Ｓ
ｎ〕０．１０％、〔Ｃｕ〕０．０５％を含有する鋳片
を、予備加熱をガス燃焼型加熱炉で鋳片中心部の温度が
１２００℃の温度域に達するまで加熱し、その後、試料
番号７，８は、２５％の圧下率で熱間変形を加え、それ
以外の試料については、熱間変形を加えることなく、雰
囲気制御型誘導加熱炉に導き、その後１３８０℃まで昇
温速度１℃／分または、１２℃／分の条件で高温加熱を
行った鋳片を熱間圧延し２．２mm厚の熱延板とした。そ
の熱延板に１０００℃×２分均熱後、７００℃〜１５０
℃の温度域を平均３０℃／秒で冷却する熱延板焼鈍を施
し、酸洗後、予備冷間圧延を実施して１．５０mm厚とし
た。かかる予備冷間圧延の途中板厚１．８５mmの段階で
種々の温度で３分間のパス間時効を施した。しかる後、
１０００℃×２分均熱後急冷する中間焼鈍後、最終冷間
圧延で０．１７mmの最終仕上げ厚とした。[Example 1] [C] 0.075%, [Si] 3.25
%, [Mn] 0.088%, [S] 0.025%, [S
ol. Al] 0.022%, [N] 0.0080%, [S
n] 0.10%, the slab containing [Cu] 0.05% is preheated in a gas-fired heating furnace until the temperature at the center of the slab reaches a temperature range of 1200 ° C., Sample Nos. 7 and 8 were subjected to hot deformation at a rolling reduction of 25%, and the other samples were led to an atmosphere-controlled induction heating furnace without applying hot deformation, and then heated to 1380 ° C. A slab that had been heated at a high temperature of 1 ° C./minute or 12 ° C./minute was hot-rolled to obtain a 2.2 mm thick hot-rolled sheet. After soaking the hot rolled sheet at 1000 ° C for 2 minutes, 700 ° C to 150 ° C
The hot rolled sheet was cooled at an average temperature of 30 ° C./sec in the temperature range of ° C., pickled, and then pre-cold rolled to a thickness of 1.50 mm. During the preliminary cold rolling, aging between passes was performed for 3 minutes at various temperatures at a stage of a sheet thickness of 1.85 mm. After a while
After the intermediate annealing in which the temperature was soaked at 1000 ° C. for 2 minutes and then quenched, the final cold rolling was performed to obtain a final finished thickness of 0.17 mm.

【００２２】得られた冷延板を公知の方法で脱炭焼鈍し
焼付分離材を塗布した後最終仕上げ焼鈍を行いコーティ
ング波を塗布し製品とした。この時のスラブ昇温速度、
予備冷延でのパス間時効圧延温度、高温加熱前鋳片圧下
の有無および得られた製品ｎ＝１０の平均の磁束密度Ｂ
₈ 、鉄損Ｗ_17/50 を表１に示す。これより、本発明例は
比較例と比べて低鉄損材料が得られることが分かる。The obtained cold rolled sheet was decarburized and annealed by a known method, and a baking separating material was applied. Then, final finishing annealing was performed and a coating wave was applied to obtain a product. The slab heating rate at this time,
Aging rolling temperature between passes in pre-cold rolling, presence or absence of slab reduction before high-temperature heating, and average magnetic flux density B of obtained product n = 10
_8, shows the iron loss W _17/50 in Table 1. From this, it can be seen that the present invention example can obtain a low iron loss material as compared with the comparative example.

【００２３】[0023]

【表１】 [Table 1]

【００２４】〔実施例２〕〔Ｃ〕０．０７４％、〔Ｓ
ｉ〕３．２４％、〔Ｍｎ〕０．０８７％、〔Ｓ〕０．０
１４％、〔Ｓｅ〕０．０１４％、〔Ｓｂ〕０．０２５
％、〔Ｍｏ〕０．０３％、〔Ｓol．Ａｌ〕０．０２４
％、〔Ｎ〕０．００７７％を含有する鋳片を雰囲気制御
型誘導加熱炉で到達温度を１３７０℃とし、１２００℃
〜１３７０℃まで１５℃／秒の昇温速度にて高温加熱を
行った鋳片を熱間圧延し２．３mm厚の熱延板とした。そ
の熱延板に１０００℃×２分均熱後、７００℃〜１５０
℃を平均４０℃／秒で冷却する熱延板焼鈍を施し、１．
４５mmに予備冷却した。しかる後、１１００℃×２分の
均熱後急冷する中間焼鈍をし、最終冷間圧延工程で０．
１７mmの最終仕上げ板厚とした。かかる圧延に際して下
記の３種の処理を施した。予備冷延、最終冷延ともに
パス間時効を施さなかった。予備冷延の途中板厚２．
０mmと１．７mmの時に３００℃で１０分間のパス間時効
を施した。最終冷延でのパス間時効は施さなかった。
予備冷延の途中板厚２．０mmと１．７mmの時に３００℃
で１０分間のパス間時効を施すと共に、最終冷延の途中
板厚０．７mmの時に３００℃×１０分間のパス間時効を
施した。[Example 2] [C] 0.074%, [S]
i] 3.24%, [Mn] 0.087%, [S] 0.0
14%, [Se] 0.014%, [Sb] 0.025
%, [Mo] 0.03%, [Sol. Al] 0.024
%, [N] 0.0077% in a slab is set to 1370 ° C. in an atmosphere-controlled induction heating furnace and 1200 ° C.
A slab that had been heated at a high temperature of 15 ° C./sec to ７０1370 ° C. was hot-rolled to obtain a 2.3 mm thick hot-rolled sheet. After soaking the hot rolled sheet at 1000 ° C for 2 minutes, 700 ° C to 150 ° C
Hot-rolled sheet annealing at an average temperature of 40 ° C./sec.
Precooled to 45 mm. Thereafter, intermediate annealing was performed by quenching after soaking at 1100 ° C. for 2 minutes, and the final cold rolling step was carried out.
The final finished plate thickness was 17 mm. At the time of such rolling, the following three types of processing were performed. Pre-rolling and final cold rolling were not aged between passes. 1. Thickness during pre-cold rolling
At 0 mm and 1.7 mm, inter-pass aging was performed at 300 ° C. for 10 minutes. No inter-pass aging was applied in the final cold rolling.
300 ° C when the plate thickness is 2.0mm and 1.7mm during pre-cold rolling
In addition to aging between passes for 10 minutes, when the sheet thickness was 0.7 mm during the final cold rolling, aging between passes was performed at 300 ° C. for 10 minutes.

【００２５】かくして得られた冷延板を公知の方法で脱
炭焼鈍し焼付分離材を塗布した後、最終仕上げ焼鈍を行
いコーティング液を塗布し製品とした。得られた製品ｎ
＝１０の平均磁束密度Ｂ₈ 、鉄損Ｗ_17/50 を表２に示
す。これより、本発明例は比較例と比べ低鉄損材料が得
られることが分かる。The cold-rolled sheet thus obtained was decarburized and annealed by a known method, and a baking separator was applied. Then, final finishing annealing was performed and a coating liquid was applied to obtain a product. Product n obtained
Table 2 shows the average magnetic flux density B ₈ and the iron loss W _17/50 of = 10. This indicates that the example of the present invention can obtain a low iron loss material as compared with the comparative example.

【００２６】[0026]

【表２】 [Table 2]

【００２７】〔実施例３〕〔Ｃ〕０．０７４％、〔Ｓ
ｉ〕３．２０％、〔Ｍｎ〕０．０７５％、〔Ｓｅ〕０．
０２３％、〔Ｓol．Ａｌ〕０．０２５％、〔Ｎ〕０．０
０８０％、〔Ｓｂ〕０．０２５％を含有する鋳片を通電
加熱炉で到達温度を１３７０℃とし、１２００℃〜１３
７０℃まで２０℃／秒の昇温速度にて高温加熱を行った
鋳片を熱間圧延し２．３mm厚の熱延板とした。その熱延
板に１０００℃×２分均熱の熱延板焼鈍を施した。熱延
板焼鈍での７００℃〜１５０℃の平均冷却速度は、
０．２℃／秒、２０℃／秒の２水準とした。引き続き
酸洗後、１．８０mmに予備冷延した。かかる予備冷延の
途中板厚段階で、（ａ）２．１mm厚、１．９５mm厚の時
に２５０℃×１０分のパス間時効を施す、（ｂ）処理な
し、の２通りの処理を施した。しかる後、１１００℃×
２分の均熱後急冷する中間焼鈍をし、最終冷間圧延工程
で０．２２mmの最終仕上げ板厚とした。Example 3 [C] 0.074%, [S
i] 3.20%, [Mn] 0.075%, [Se] 0.
023%, [Sol. Al] 0.025%, [N] 0.0
The slab containing 080% and [Sb] 0.025% was heated to an ultimate temperature of 1370 ° C. in an electric heating furnace, and 1200 ° C. to 13 ° C.
A slab that had been heated to a high temperature of 70 ° C. at a rate of 20 ° C./second at a high temperature was hot-rolled to obtain a hot-rolled sheet having a thickness of 2.3 mm. The hot rolled sheet was annealed at 1000 ° C. for 2 minutes. The average cooling rate of 700 ° C to 150 ° C in hot rolled sheet annealing is
Two levels of 0.2 ° C./sec and 20 ° C./sec. Subsequently, after pickling, it was pre-cold rolled to 1.80 mm. In the thickness stage of the preliminary cold rolling, two types of treatment are performed: (a) aging between passes at 250 ° C. for 10 minutes at a thickness of 2.1 mm and 1.95 mm, and (b) no treatment. did. After that, 1100 ℃ ×
Intermediate annealing was performed by quenching after soaking for 2 minutes, and a final finished sheet thickness of 0.22 mm was obtained in the final cold rolling step.

【００２８】かくして得られた冷延板を公知の方法で脱
炭焼鈍し焼付分離材を塗布した後、最終仕上げ焼鈍を行
いコーティング液を塗布し製品とした。得られた製品ｎ
＝１０の平均磁束密度Ｂ₈ 、鉄損Ｗ_17/50 を表３に示
す。これより、本発明例は比較例と比べ低鉄損材料が得
られることが分かる。The cold-rolled sheet thus obtained was decarburized and annealed by a known method, and a baking separator was applied. Then, final finishing annealing was performed and a coating liquid was applied to obtain a product. Product n obtained
Table 3 shows the average magnetic flux density B ₈ and the iron loss W _17/50 at = 10. This indicates that the example of the present invention can obtain a low iron loss material as compared with the comparative example.

【００２９】[0029]

【表３】 [Table 3]

【００３０】[0030]

【発明の効果】以上のごとく本発明によれば、鉄損の低
い一方向性電磁鋼板を工業的に安定して製造でき、その
工業的効果は非常に大きい。As described above, according to the present invention, a grain-oriented electrical steel sheet having a low iron loss can be manufactured industrially stably, and the industrial effect is very large.

【図面の簡単な説明】[Brief description of the drawings]

【図１】連続鋳造スラブの１２００℃以上の高温域の加
熱における昇温速度と予備冷間圧延時のパス間時効温度
と製品の鉄損Ｗ_17/50 の関係を示す図である。BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a diagram showing a relationship among a temperature rise rate in heating a continuous cast slab in a high temperature region of 1200 ° C. or more, an aging temperature between passes during preliminary cold rolling, and a _core loss W _17/50 of a product.

【図２】予備冷間圧延時のパス間時効時間と製品の磁束
密度Ｂ₈ 、鉄損Ｗ_17/50 の関係を示す図である。FIG. 2 is a diagram showing the relationship between the inter-pass aging time during preliminary cold rolling, the magnetic flux density B _{8 of the} product, and the iron loss W _17/50 .

【図３】熱延板焼鈍での７００℃〜１５０℃の冷却速度
と製品の磁束密度Ｂ₈ 、鉄損Ｗ_17/50 の関係を示す図で
ある。FIG. 3 is a diagram showing a relationship between a cooling rate at 700 ° C. to 150 ° C. in hot-rolled sheet annealing, a magnetic flux density B _{8 of} a product, and an iron loss W _17/50 .

───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.⁷，ＤＢ名) C21D 8/12 C22C 38/00 303 C22C 38/60 H01F 1/16 ──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) C21D 8/12 C22C 38/00 303 C22C 38/60 H01F 1/16

Claims (3)

(57)【特許請求の範囲】(57) [Claims] 【請求項１】 重量％で、 Ｃ ：０．０１５〜０．１００％、 Ｓｉ：２．０〜４．０％、 Ｍｎ：０．０３〜０．１２％、 Ｓol．Ａｌ：０．０１０〜０．０６５％、 Ｎ ：０．００４０〜０．０１００％、 ＳおよびＳｅのうちから選んだ１種または２種合計：
０．００５〜０．０５０％、更にＳｂ，Ｓｎ，Ｃｕ，Ｍ
ｏ，Ｇｅ，Ｂ，Ｔｅ，ＡｓおよびＢｉから選ばれる１種
または２種以上を０．００３〜０．３％を含有し、残部
は実質的にＦｅの組成になる連続鋳造スラブを、１３２
０℃〜１４５０℃に加熱均熱したのち熱延し、熱延板焼
鈍を施し、予備冷間圧延、中間焼鈍、最終冷間圧延、脱
炭・１次再結晶焼鈍、最終仕上げ焼鈍によって一方向性
電磁鋼板を製造する方法において、上記スラブの１２０
０℃以上の高温域の加熱を５℃／分以上の昇温速度で行
うと共に、熱延板焼鈍の冷却過程において７００℃〜１
５０℃の間を８℃／秒以上で冷却し、予備冷間圧延にお
ける複数パスのパス間の少なくとも１回に鋼板を１００
℃〜４００℃の温度範囲で１分以上の時間保持すること
を特徴とする低鉄損一方向性電磁鋼板の製造方法。C .: 0.015 to 0.100%, Si: 2.0 to 4.0%, Mn: 0.03 to 0.12%, and Sol. Al: 0.010 to 0.065%, N: 0.0040 to 0.0100%, one or two selected from S and Se:
0.005 to 0.050%, Sb, Sn, Cu, M
A continuously cast slab containing 0.003 to 0.3% of one or more selected from o, Ge, B, Te, As and Bi, with the balance being substantially Fe, 132
After heating and soaking at 0 ° C to 1450 ° C, it is hot rolled, subjected to hot rolled sheet annealing, pre-cold rolling, intermediate annealing, final cold rolling, decarburization / primary recrystallization annealing, and final finishing annealing in one direction In the method of manufacturing a conductive electrical steel sheet, the slab
Heating in a high-temperature region of 0 ° C. or more is performed at a heating rate of 5 ° C./min or more, and 700 ° C. to 1 ° C. in a cooling process of hot-rolled sheet annealing.
The steel sheet is cooled at a rate of 8 ° C./sec or more between 50 ° C. and the steel sheet is reduced at least once between a plurality of passes in the pre-cold rolling.
A method for producing a low iron loss unidirectional magnetic steel sheet, wherein the steel sheet is maintained at a temperature in a range of 1 to 400 ° C for 1 minute or more. 【請求項２】 最終冷間圧延工程における途中板厚段階
の少なくとも１回のパス間で鋼板を１５０℃〜３５０℃
の温度範囲で１分以上の時間保持することを特徴とする
請求項１記載の低鉄損一方向性電磁鋼板の製造方法。2. The steel sheet is heated at a temperature of 150 ° C. to 350 ° C. during at least one pass of a middle thickness step in the final cold rolling step.
The method for producing a low iron loss unidirectional magnetic steel sheet according to claim 1, wherein the steel sheet is held at a temperature in the range of 1 minute or more. 【請求項３】 スラブを１２００℃以上の高温域に加熱
する前に、５０％以下の圧下率で熱間変形を加えること
を特徴とする請求項１或いは２記載の低鉄損一方向性電
磁鋼板の製造方法。3. The low-loss unidirectional electromagnetic device according to claim 1, wherein before the slab is heated to a high temperature region of 1200 ° C. or more, hot deformation is applied at a rolling reduction of 50% or less. Steel plate manufacturing method.