JPS58136718A - Manufacture of nonoriented electrical band steel with superior magnetic characteristic - Google Patents

Abstract

PURPOSE:To manufacture the titled band steel with high magnetic flux density and superior iron loss by finishing the hot rolling of a low carbon steel slab contg. specified chemical components at a gamma-phase temp. and coiling the resulting band steel at a specified temp. to make the ferrite grains coarse. CONSTITUTION:A low carbon steel slab contg. <=0.02% C, <=1.5% Si or Si+ Al and <=1.0% Mn or further contg. <=0.20% P is heated and hot rolled. The hot rolling is finished at a gamma-phase temp. in the range of the Ar3 point - 500 deg.C defined by the components in the steel. The resulting hot rolled band steel is coiled at 700 deg.C - the A3 point to make the ferrite grains of the strip coarse and to adjust the grain size No. to <=4. This hot rolled band steel is pickled and cold rolled once or subjected to cold rolling, process annealing and cold rolling in order, and it is annealed.

Description

【発明の詳細な説明】[Detailed description of the invention]

この発明は磁気特性の優れた無方向性電磁銅帯の製造方
法に関し、とくに磁束密度が極めて高く、鉄損の低い、
フルプロセス、またはセミプロセス用無方向性電磁鋼帝
の製造を有利に成就することを可能ならしめようとする
本のである。 無方向性電磁銅帯は、各種のモーターなどの回転機や、
変圧器、安定器などの静止機器の鉄心材料として用いら
れ、これらの電気機器の効率向上、あるいは小型化のた
め、使用される電磁銅帯の磁束密度の向上および鉄損の
低減が益々必要とされる。 ところで、無方向性電磁鋼板の磁性を向上させるために
は、冷間圧延前の素材の結晶粒径をできるだけ大きく１
〜ておくことが有利であることはすでに知られていると
おりである。 発明者らは先に特願昭５５−１１０８１４号にて、所定
範囲内の化学成分を有する電磁鋼素材を熱延鋼帯に熱間
圧延する際、熱間圧延全了温Ｉ＃をその鋼の化学成分に
応じて次の（１）式にて表わされる温度すなわちＡｒ８
変態点温度、 Ａｒ８＝（ｓ９ｔ−９０ｏ（０％）＋５０（Ｓｉ％）−
８８（Ｍｎ％）＋１１（Ｐ％）＋８８０　（Ａｔ％））
”０　　　　　　・・・・・・・・・・・・・・・・・
（１）以上とな１〜、ついでこの熱延鋼帯をＡ８変変態
度以下の温度で８０秒以上１５分以下の時間、焼鈍して
磁気特性の優れた無方向性電磁鋼帯を得る方法を提案し
た。この方法はＡｒ８変態点温変以上の温度で、すなわ
ち、鋼組織がγ相の状態で熱間圧延全終了し、次いでＡ
８変態点温度以下の温度で焼鈍すると、その焼鈍が箱焼
鈍のような長時間焼鈍でなく、１５分以下という短時間
で、しかも脱炭を必要とせずに比較的安価に熱延鋼帯の
結晶組織を粗大化できることの知見に由来している。 （７かるにこの場合には一般に、熱間圧延後、熱処理を
施すことなく直ちに酸洗、冷間圧延を行う通常の方法に
比１〜、短時間とは云え一工程が増加するため、若干コ
スト高となるのはやむを得ない。 そこでこの°発明は、冷間圧延前の熱延鋼帯の結晶粒径
を粗大化させることに関する限りは上掲の先行発明にお
ける研究成果を踏襲して磁気特性が優れた無方向性電磁
鋼帯の製造過程につき、該発明では不可欠とThe present invention relates to a method for manufacturing a non-oriented electromagnetic copper strip with excellent magnetic properties, and in particular, a method for producing a non-oriented electromagnetic copper strip with extremely high magnetic flux density and low core loss.
This book attempts to make it possible to advantageously achieve the production of non-oriented electrical steel for full process or semi-process use. Non-directional electromagnetic copper strips are used in rotating machines such as various motors,
It is used as core material for stationary equipment such as transformers and ballasts, and in order to improve the efficiency or downsize these electrical equipment, it is increasingly necessary to improve the magnetic flux density and reduce iron loss of the electromagnetic copper strips used. be done. By the way, in order to improve the magnetism of non-oriented electrical steel sheets, it is necessary to increase the grain size of the material before cold rolling by 1
It is already known that it is advantageous to keep The inventors previously disclosed in Japanese Patent Application No. 110814/1983 that when hot-rolling an electrical steel material having a chemical composition within a predetermined range into a hot-rolled steel strip, the final hot rolling temperature I# of the steel is The temperature expressed by the following formula (1) according to the chemical composition of Ar8
Transformation point temperature, Ar8=(s9t-90o(0%)+50(Si%)-
88 (Mn%) + 11 (P%) + 880 (At%))
”0 ・・・・・・・・・・・・・・・・・・
(1) A method for obtaining a non-oriented electrical steel strip with excellent magnetic properties by annealing the hot rolled steel strip at a temperature below A8 transformation state for a period of 80 seconds or more and 15 minutes or less. proposed. In this method, hot rolling is completed at a temperature higher than the Ar8 transformation point, that is, the steel structure is in the γ phase, and then A
When annealing is performed at a temperature below 8 transformation point temperature, the annealing process is not a long annealing like box annealing, but a short time of 15 minutes or less, and it is possible to produce hot rolled steel strips at a relatively low cost without the need for decarburization. This comes from the knowledge that it is possible to coarsen the crystal structure. (7) In this case, there is a slight increase in the number of steps compared to the usual method of pickling and cold rolling immediately after hot rolling without heat treatment, although it is a short time. It is unavoidable that the cost will be high.Therefore, this invention follows the research results of the above-mentioned prior invention and improves the magnetic properties as far as coarsening the grain size of the hot rolled steel strip before cold rolling is concerned. Regarding the manufacturing process of non-oriented electromagnetic steel strip with excellent

【−ていた
熱延鋼帯の焼鈍を省略Ｌ、より有利に、しかし磁気特性
においては何ら遜色のない無方向性電磁鋼板の製造方法
を確立したものである。 ちなみに無方向性電磁鋼板の製造法に関し特開昭５４−
７６４２２号公報によると熱間圧延後その熱廷板を７５
０“０〜１０００℃の温度でコイルに巻き取り、熱処コ
イル自身の保有熱で焼鈍することにより結晶粒度ＡＳＴ
Ｍ　Ｎｏ、５〜６に再結晶でき、かくして従来の熱延後
別途行なう焼鈍を省略し、これと同等の効果を与えるこ
とはすでに提案されているが、これはｓｉ　２．５〜４
．０％、Ａ１１．０％以下の材料に適用することを１指
して自己焼鈍をできるだけ筒い温度で行なうためにより
昼い温度で熱間圧延を終了しようという考えに基づいて
いる。 しかし、Ｓｉ含有駿が２．５％以上ともなると商温でも
完全なγ相領域を有しない点で、この発明におけるよう
な完全にγ相を生じる素材について、そのＡｒ８変態点
温度直上のγ相状態で熱延を終了することによって微細
結晶となし、ついでＡ８変態点温度以下７００°Ｃ以上
の温度で巻取ることにより２次再結晶的に結晶粒’ｋ　
Ｎｏ、４以下の大粒に成長させる発想とは自然法則の利
用のしかた技術的思想の本質を全く異にしている。 上記のように熱間圧延終了温度を、その鋼の化学成分に
応じ、（１）式にて算出されるＡｒ８変態点温度と、そ
の温度より５０”０商い温度との範囲内のγ相温度領域
に定めると、熱延鋼帯に加えた焼鈍過程での結晶粒の二
次杏結晶粒成長速度が、核温度領域より高い温度で熱間
圧延を終了した場合に比し、より早く、筐た低温で粒成
長することを、その後に知見した。 この特徴を有利に活用すべくさらに研究を進めて、熱間
圧延終了温度を上記の温度領域（Ａｒ８〜Ａｒａ　＋　
５０°０）内にシフ、シかもその後の巻取り温度をＡ８
変態点温度以下、７００℃以上とすることにより、熱延
鋼帯の結晶粒を、フェライト粒度Ｎ０．４以下に、容易
に粗大化できることが見出され、ここに、熱延鋼帯の焼
鈍工程をとくに加えることなく安価に、そしてとくに成
品状態においてはもちろん、歪取り焼鈍が加えられた後
でも、磁束密度；鉄損に関１〜て磁気特性の優れた無方
向性電磁鋼帯の製造方法を完成させることができた。 この発明は、低次＊鋼スラブを加熱し引続き熱間圧延を
加えて熱延鋼帯とし、この熱延鋼帯を通常の方法による
酸洗、１回の冷間圧延またけ中間焼鈍ヲ挾む２回の冷間
圧延およびその後の焼鈍各工程に供する無方向性電磁鋼
帯の製造方法において、 −に６己スラフ゛が、００．０２％以下、Ｓｌもしくは
ＳｌとＡＡの金剛の何れか１．５％以下、Ｍｌ　１．０
％以下、そしてＰｉ含むとき０．２０％以下を含有する
組成になるものとし、そのスラブ加熱に引続く熱間圧延
を、該スラブの鋼中成分に応じて定まるＡｒ８変態点温
度より５０℃を越えて高くはない範囲内のγ相温度領域
で終了（−１ついでこの熱延鋼帯をＡ８實態点温変以下
、７１１　（１℃以、ヒの潟ｉ域で巻取ることにより、
熱延鋼帯のフェライト結晶粒を粒度Ｎ００４以下の粗大
粒とする過程を経ること 全特徴とする磁気特性の優れた無方向性電磁鋼帯の製造
方法である。 さて、無方向性電磁鋼帯には、規定の磁気特性を付与し
て製鉄所から出荷されるいわゆるフルプロセス成品のほ
か、銅帯の打抜き、せん断などの加工後に、いわゆる歪
取り焼鈍を施すことにより所定の磁気％性が得られるよ
うにしたセミプロセス成品とがある。これらのフルプロ
セスあるいはセミプロセス用各電磁銅帯は倒れも製造工
程から１回の冷間圧延による場合と、中間焼鈍を挾む２
回の冷間圧延を行なう場合とに′□分けられ、１回の冷
間圧延による方法は磁束密度が高い特徴があゆ、２回の
冷間圧延による方法は、主として２回目の冷間圧下率が
２０％以下の軽圧下とするもので、若干の磁束密度の低
下があるが、鉄損値が低い特徴がある。 この発明は熱延鋼帯のフェライト結晶粒径を粗大化させ
ることにより、上記冷延１回法および２回法の、フルプ
ロセスまたはセミプロセス成品の何れに適用しても、優
れた磁気特性を得ることができる。 この発明はγ相組織の温度領域で熱間圧延を終了し、熱
焼後の巻取り温度をＡ８変態点温変以下、７００°０以
上とするが、この際０が０．０２％より多いと、巻取り
後の結晶粒の粒成長を阻害する。 加えて無方向性電磁鋼帯では成品の磁気特性および磁気
時効による劣化の面から成品のＣ量を０．００４％以下
とする必要があり、こ＼に素材のＯｉｌが多すぎると焼
鈍時に脱炭させるに際（７て鋼帯表向に磁気的に有害な
酸化増を生成する。これらの理由からこの発明では素材
のＧ量ｆ：０．０２％以下とする。 この発明は、熱間圧延終了温度をその鋼のγ相領域とす
ることを基本とＩ２、こ＼にＳｉまたは（Ｓｉ　＋　Ａ
ｔ）が１．５％をこえて多葉になるとγ相が存在する温
度が尚くなって、熱延終了温度を筒くする必要から事実
上熱間圧延が困難になる。したがってｓｉ、または（ｓ
：ｉ＋Ａｚ）ｉｔを１．５％以下とする。 Ｍｎは脱酸剤としてまたＳによる熱間脆性を抑制するた
めに添加されるが、１．０％より多いと磁気的に有害と
なるので１．０％以下とする。 Ｐは電磁鋼帯の硬度を高め、打抜性を向上させるために
添加されることがあるが、０．２０％より多いと板が脆
くなるので、ｏ、２ｏ％以下とする必要がある。 この発明では熱間圧延終了温度を、その鋼素材の化学成
分に応じて、 （８９１−９００（０％）＋５０（Ｓｉ％）−８８（Ｍ
ｎ％）＋１９０（Ｐ％）＋８８０（１１％）１℃ に従って算出されるムｒ８変態点温度より５０℃を越え
て高くはない範囲内のγ相領域とする。熱間圧延終了温
度をその鋼のγ相領域のできるだけ低温域とすることで
熱間加工を容易にし、Ｌ７かも巻保りによる自己焼鈍作
用にてフェライト結晶粒を粒度Ｎ００４以下に容易に粗
大化できる。この理由は上述のγ相領域の低温域で熱間
加工することにより、熱延後の結晶粒径がいちじるしく
微細となり、熱延鋼帯巻取り後の焼鈍作用で二次再結晶
的に粒成長が起るためである。 熱間圧延終了温度がＡｒ８変態点温度より低いα＋γ相
域、またはα相領域となると、それがたとえ８５０　”
０以上の高温であったとしても熱間圧延後のフェライト
結晶粒が若干粗大化するが、この発明で所期したような
二次再結晶的粒成長は起らず、粒度Ｎ０．４以下の和大
粒を得ることはできない。 またＡｒ８変態点温度より５０′０を超える高い温度で
熱間圧延を終了させても萱だ二次再結晶的粒成長が起り
難くなり、高温巻取りを行なったと１７でもこの発明に
よるような、粗大結晶の熱延鋼帯を得ることができない
。したがってこの発明では熱間圧延終了温度をその鋼素
材の化学成分より定壕るＡｒ８変態点温度と、この温度
より５０“０高い温度との範囲内のγ相領域とする。 この発明は上述のように熱間圧延終了温度′ｆ特色のあ
る領域とすることによって、次の焼鈍過程での結晶粒の
成長性を容易に１７たことが特徴であり、この特徴の故
に熱延鋼帯の巻取り温度を通常の場仕と比べてより筒め
ることて一層焼鈍効果を有利にかつ容易に発揮させるこ
とができる。巻取り温度がＡ８変態点温度より商いとき
は結晶粒の二次書結晶的粗大化が起らず、また７００”
Ｏ，ｊ、り低い場合も粒成長しにくい。したがって熱延
後の巻取り温度をＡ８変態点温度以下、７（］（１’０
以上とする。 無方向性電磁銅帯の製造において、冷間圧延前の熱延鋼
帯の結晶粒径が大きいほど、磁束密度が高く鉄損（ｔｉ
が低い優れた成品が得られることは知られているとおり
であるが、とくに磁束密度Ｂ５゜値の極めて優れた成品
を得るためには冷延前のフェライト結晶粒の大きさが粒
度Ｎ０．４．５以下の大粒であることが必☆であるとこ
ろ、この発明により粒度Ｎ０．４以下の粗大粒を廟する
熱延鋼帯が確実に得られるのである。 つぎに本発明を実施例について説明する。。 実施例１ 転炉で溶製Ｌ、ＲＨ式真空処理１７た俗調を連紗１＠造
にて、２２（Ｊｌｎｍ厚みのスラブＡ　、　Ｂ　、　０
およびＤを作った。それらの化学成分は（ｌ’ｌ　ｉｌ
も雨量％で、００．０１８％、ｓｉ、ｏ、２７％、Ｍｎ
　（１，８５％、Ｐ　Ｏ，０１５％、８０．００４％、
ＡｔＯ，（１（１（１４％であった。 この素材の化学成分に従い計算式（１）にて求めたＡｒ
８変態点温度は８６５℃である。 上記各スラブｆ１２８０°０に加熱し７、熱間圧延終了
温ｉを、’Ａ　、　Ｂ　、材につきとくにそれぞれ８９
０°０，９１５°０とし、２．８朋厚に熱延１−７、ま
たこの熱延後の巻取り温度をいずれも７　ｆ３　（１’
Ｏとして巻取り、放冷した。比較のためにＯ材を巻取り
温度、仕上り厚みはＡ、Ｂ材と同様と【７たが熱間圧延
終了温度をＡｒ８変態点泥匿よりも低い８８５℃とした
。萱だ最後にＤ材は全く通常の方法に従（ｌｌ　　ｌ い熱間圧延終了温度は８００”０、巻取り温度を５６０
°０とした。 第１図にこれらのＡ、Ｂ、Ｏ，Ｄ材による各熱延＆鋼帯
の結晶組織を示す顕微鋭写スを、フェライト結晶粒＃Ｎ
Ｏ，ＶＣあわせ示した。 ついで、これらの熱延鋼帯を通常の１同冷処法により成
品とした。すなわち、酸洗後（１，５（ｌ　ｍｌＡ厚さ
に冷間圧延し、８００°ＯＳ２分間の光輝焼鈍を行なっ
た。これらの成品および、需要家で打抜き等の力ｌ１後
さらＶＣ歪取り焼鈍を行なう場合を想定（−た７５０”
０２時間の歪取焼鈍後の磁性を第１表に示す。 ＋　　１２　１ 第１図の熱延鋼帯の結晶粒度は、この発明に従う人材が
Ｎｏ、　０．５で最も粒径が大きく、ついでＢ材はＮｏ
、　８．５で次に大きいのに対し、比較品の０１では比
較的大きい粒径であるがＮ００５でありＤ材はＮｏ、　
７．５でより小さい。この発明によるＡ、　Ｂ材は計算
式（１）に従うＡｒ８変態点温度よりそれぞれ２５℃、
５０°Ｃ高い温度で熱間圧延ｆ終了したものである。こ
れらを比較するとＢ材は人材より結晶粒径かや＼小さく
なっていて、熱間圧延終了温度がＡｒ８変態点よりも５
０℃を超えて高いとき結晶粒径が小さくなることの臨界
的々傾向が認められる。 第１衣の磁性をみると、この発明のＡ、Ｂ材によるもの
は比較材０．Ｄに比し、成品の磁中密度Ｂ、。値が極め
て高く、鉄損Ｗ　１５１５０値も低い。又歪取焼鈍後で
は磁束密度とともに鉄損も極めて優れていることが明ら
かである。 実施例２ 実施例１と同様な方法で、ＯＯ，（＋　＋１　（１％、
８１０．０９％、Ｍｎ　１１．２２％、ＰＯ，（１３８
％、Ｓ　Ｔ１　、００４％、ＡｔＯ，０００７％を含む
２５０趨厚みのスラブＥ、Ｆ、Ｇを作った。これらの化
学成分により計算式（１）にて求めたＡｒ８変態点温度
は８７７°Ｃである。 各スラブは１８００“Ｃに加熱Ｌ、熱間圧延終了温度を
Ｈ材は８９５℃とし、これに対する比較のためにＨ材は
Ａｒ８変態点温度よりも低い８６５℃で、しかし巻取源
Ｖはいずれも７５０〜７６０℃と同じにし、またＧ材に
ついては従来どおり熱焼終了温度を８２０℃、巻取温度
を５６０℃として（いずれもすべて２．３ｉｍ厚みの熱
延鋼帯とした。 熱延鋼帯の結晶粒度は、フェライト粒１ｉ　ＮＯ，でＥ
は０．Ｆは５．Ｇは７であった。 これらの熱延コイルは放冷後、通常の冷延１同法工程に
より成品とした。すなわち酸洗後冷延にて０．５０１１
１１１厚さとし、連続焼鈍炉にて７５０°０．２分間の
光輝焼鈍を會なった。これらの成品および７５０℃、２
時間歪取焼鈍後の磁性を第２表に示す。 【　１５　゛ １１６　　′ これらの結果から、この発明のＨ材では、熱延鋼帯の結
晶粒度がＮＯ，（ｌで大きく、これに対１〜Ａｒ８変態
点温度より低い８６５℃で熱延を終了した比較例のＨ材
によるものは粒度Ｎ０１５で粒径が小さく、また従来法
のＧ材によるものはさらに小粒であり、その結果発明品
は成品の磁束密度が高く鉄損が低い、歪取焼鈍後は磁束
密度とともに鉄損が極めて優れていることが明らかであ
る。 実施例３ 実施例１と同様な方法で、ＯＯ，０１２％、８１０．８
４％、Ｍｎ　０．５０％、ｐｏ、ｏｏ７％、ＡｔＯ，０
００７％を含む２２０關厚みのスラブＨ，ＩおよびＪを
製作した。これらの化学成分につき計算式（１）にて求
めたＡｒ８変態点温度は８８０”０である。 各スラブを１２８０°Ｃに加熱し、Ｈ材は熱間圧延終了
温度をこの発明に従い９００℃、巻取温度を７７０℃と
シフ、比較のため工材は熱間圧延終了温度をＡｒ８変態
点温度より低い８７０℃と１７、巻取温度は７６０°０
とし、Ｊ材については熱間圧延終了温度を従来どおり８
３０°０と１７、巻取温度も６５０℃とした。これらの
熱延鋼帯は伺れも２，８１綿厚みに揃えである。 各熱延鋼帯の結晶粒度は、フェライト粒子ｍ）　Ｎｏ。 で、Ｈは２、工は５、Ｊは６であった。 次に各熱延鋼帯を通常の方法により、酸洗後０．５０朋
に冷延し、８５０℃、２分間の連続焼鈍を行なって、フ
ルプロセス成品とした。成品の磁性を第８表に示す。 Ａｒ８変態点温度より２０°Ｃ高い温度で熱間圧延を終
了し、７７０°０で巻取った発明品は熱延鋼帯のフェラ
イト結晶粒度がＮＯ，２で粒径が比較品より大きいため
、磁性が優れていることが明らかである。 ・　１９　′ 実施例４ 実施例】と同様な方法により、化学成分がＣＯ，００７
％、Ｓｉ　０．３２％、Ｍｎ　ｏ、ａ　５％、Ｐｏ、０
２１％、ＳＱ、（１０５％、Ａ／！、０．００　（１５
％の２２ｏｍｍＪ厚みのスラフに、Ｌを製作（〜だ。こ
の素材の化学成分より計算式（１）にて求めたＡｒ８変
態温度は８７４℃である。 Ｋ、Ｌ両スラブｆ１２８０″Ｏに加熱し、Ｋ材はこの発
明に従って熱間圧延終了温匿全８９５°Ｃ１巻取温度を
７６０℃とした。１だ比較のためにＬ材は、従来どおり
熱間圧延終了温度を８（）０℃、巻取温度を６６０°０
と（７、いずれも２．３編厚みの熱延鋼帯を作った。 熱延鋼帯の結晶粒紅は、Ｋ材がＮＯ，１であったのに対
しＬ材はＮＯ，８であった。 これらの熱延鋼帯を通常のいわゆる中間焼鈍を挾む２回
冷延法によりセミプロセス成品とした。 すなわち熱延鋼帯を酸洗後掲１回の冷間圧延後中間焼鈍
として７５０　”Ｏ％２分間の連続焼鈍を行ない、第２
回の冷間圧下率を８％としてＱ、５ＱＩＩＩＩ１１厚さ
に１２０　） 仕上げた。 両成品につき７５０”０．２時間の虫取り焼鈍を行なっ
た後の磁性を第４表に示Ｅ−た。 第４表 この結果から発明品は２回冷ｉＡ法セミプロセス用にお
いても磁束密興が高く、鉄損が極めて優れていることが
明らかである。 以上各実施例は、倒れも連続鋳造スラブを素材とする場
合について示したが、鋼塊の分塊圧延による素材を用い
ても、この発明の条件を満たすことにより、はソ同等の
効果が得られるのはいうまでもない。 かくしてこの発明によれば、化学成分を特定した熱延鋼
帯の熱間圧延終了温度を、該化学成分に応じて重重るＡ
ｒ８変態点温度より５０°０をこえて高くはない範囲内
のｒ相温度領域と１７、この熱延後の巻取り温＠、をＡ
８′＆態点温度以下、７００°Ｃ以−ヒの温度範囲と］
−で、熱延鋼帯を、別途焼鈍過程に付する安なく熱１ｇ
銅帯のフェライト結晶粒を粒度Ｎ０．４以下の粗大粒と
することができ、これによって、フルプロセス、セミプ
ロセス用ヲ問わず、無方向性電磁鋼帯成品の磁気特性の
著しい改善に役立つ。This method omitted the annealing of the hot-rolled steel strip, which had previously been used, and established a method for producing non-oriented electrical steel sheets that is more advantageous but comparable in magnetic properties. By the way, regarding the manufacturing method of non-oriented electrical steel sheets,
According to Publication No. 76422, after hot rolling, the hot rolled plate is
The crystal grain size of
It has already been proposed that it can be recrystallized to M No. 5 to 6, thereby omitting the conventional annealing that is performed separately after hot rolling, and giving the same effect.
．． 0%, A11.0% or less, and is based on the idea that hot rolling should be completed at a more moderate temperature in order to perform self-annealing at as low a temperature as possible. However, if the Si content is 2.5% or more, it does not have a complete γ phase region even at commercial temperature, so for materials that completely produce a γ phase as in the present invention, the γ phase region just above the Ar8 transformation point temperature does not exist. By finishing hot rolling in this state, fine crystals are formed, and then by winding at a temperature of 700°C or lower below the A8 transformation point temperature, crystal grains are formed by secondary recrystallization.
The essence of the technical idea of how to utilize natural laws is completely different from the idea of growing large grains of No. 4 or less. As mentioned above, the hot rolling end temperature is determined according to the chemical composition of the steel, and the γ phase temperature is within the range of the Ar8 transformation point temperature calculated by equation (1) and a temperature 50"0 quotient from that temperature. If the area is determined, the secondary apricot grain growth rate of the crystal grains during the annealing process applied to the hot rolled steel strip will be faster than when hot rolling is finished at a temperature higher than the core temperature area. It was subsequently discovered that grains grow at low temperatures.In order to take advantage of this feature, further research was carried out, and the end temperature of hot rolling was set in the above temperature range (Ar8~Ara +
The subsequent winding temperature may be within 50°0).
It has been found that the crystal grains of a hot rolled steel strip can be easily coarsened to a ferrite grain size of N0.4 or less by controlling the temperature to be below the transformation point temperature and above 700°C. A method for producing a non-oriented electrical steel strip that is inexpensive and has excellent magnetic properties in terms of magnetic flux density and iron loss, especially in the finished product state, and even after strain relief annealing, without adding any was able to complete it. This invention involves heating a low-order* steel slab and subsequently hot rolling it into a hot-rolled steel strip, pickling the hot-rolled steel strip by a conventional method, and subjecting it to one cold rolling step and intermediate annealing. In the method for producing a non-oriented electrical steel strip, which is subjected to two cold rolling steps and subsequent annealing steps, - 6 self-slough is 00.02% or less, and either one of Sl or a diamond of Sl and AA is used. .5% or less, Ml 1.0
% or less, and 0.20% or less when containing Pi, and the hot rolling following heating of the slab is performed at a temperature of 50°C below the Ar8 transformation point temperature determined according to the steel components of the slab. Finished in the γ-phase temperature range within a range not exceeding -1. Then, this hot rolled steel strip is wound in the A8 real state temperature range of 711 (1°C or higher),
This is a method for producing a non-oriented electrical steel strip with excellent magnetic properties, which is characterized by going through a process of making the ferrite crystal grains of the hot rolled steel strip into coarse grains with a grain size of N004 or less. Now, non-oriented electromagnetic steel strips include so-called full-process products that are shipped from steel mills with prescribed magnetic properties, as well as products that undergo so-called strain relief annealing after punching, shearing, etc. of copper strips. There are semi-processed products in which a predetermined magnetic percentage can be obtained. Each of these electromagnetic copper strips for full process or semi-process can be produced by one cold rolling process or two intermediate annealing processes.
There are two types of cold rolling: the one-time cold rolling method is characterized by high magnetic flux density, and the two-time cold rolling method mainly involves the second cold rolling reduction. Although the magnetic flux density is slightly reduced due to the light reduction of 20% or less, it is characterized by a low iron loss value. By coarsening the ferrite grain size of the hot-rolled steel strip, this invention provides excellent magnetic properties when applied to either full-process or semi-processed products of the one-step or two-step cold rolling method. Obtainable. In this invention, hot rolling is completed in the temperature range of the γ phase structure, and the coiling temperature after hot sintering is set to be below the A8 transformation point temperature change and above 700°0, but in this case, 0 is more than 0.02%. This inhibits grain growth of crystal grains after winding. In addition, for non-oriented electrical steel strips, it is necessary to keep the C content in the product to 0.004% or less in view of the product's magnetic properties and deterioration due to magnetic aging. When carbonizing (7), magnetically harmful oxidation is generated on the surface of the steel strip. For these reasons, in this invention, the G content f of the material is set to 0.02% or less. The basic idea is to set the rolling end temperature to the γ phase region of the steel, I2, where Si or (Si + A
When t) exceeds 1.5% and becomes multi-lobed, the temperature at which the γ phase exists becomes too low, making hot rolling practically difficult because the hot rolling end temperature needs to be controlled. Therefore si or (s
:i+Az)it is 1.5% or less. Mn is added as a deoxidizing agent and to suppress hot embrittlement caused by S, but if it exceeds 1.0%, it becomes magnetically harmful, so it is limited to 1.0% or less. P is sometimes added to increase the hardness of the electromagnetic steel strip and improve its punchability, but if it is more than 0.20%, the plate becomes brittle, so it must be kept at 20% or less. In this invention, the hot rolling end temperature is set according to the chemical composition of the steel material (891-900 (0%) + 50 (Si%) - 88 (M
n%) + 190 (P%) + 880 (11%) 1°C The γ phase region is within a range not higher than 50°C than the mr8 transformation point temperature calculated according to the following formula. By setting the hot rolling end temperature to the lowest possible range of the γ phase region of the steel, hot working is facilitated, and the ferrite crystal grains are easily coarsened to a grain size of N004 or less by the self-annealing effect of L7 winding and retaining. can. The reason for this is that hot working in the low temperature range of the γ phase region mentioned above makes the grain size after hot rolling extremely fine, and the annealing action after winding the hot rolled steel strip causes grain growth through secondary recrystallization. This is because If the hot rolling end temperature is in the α+γ phase region or α phase region lower than the Ar8 transformation point temperature, even if it is 850 ”
Even if the temperature is higher than 0.0, the ferrite crystal grains after hot rolling will become slightly coarser, but the secondary recrystallization grain growth as expected in this invention will not occur, and the grain size will be lower than 0.4. It is not possible to obtain large grains. Furthermore, even if the hot rolling is finished at a temperature higher than 50'0 above the Ar8 transformation temperature, it becomes difficult for secondary recrystallization grain growth to occur, and when high temperature winding is performed, the method according to the present invention It is not possible to obtain a hot-rolled steel strip with coarse crystals. Therefore, in this invention, the hot rolling end temperature is set in the γ phase region within the range of the Ar8 transformation point temperature determined by the chemical composition of the steel material and a temperature 50"0 higher than this temperature. By setting the hot rolling end temperature 'f in a characteristic range as shown in FIG. The annealing effect can be exerted even more advantageously and easily by setting the winding temperature to a higher temperature than in normal field processing.When the winding temperature is lower than the A8 transformation point temperature, the secondary crystal of the crystal grains 700" without target coarsening occurring.
Grain growth is also difficult when O,j, is low. Therefore, the coiling temperature after hot rolling should be below the A8 transformation point temperature, 7(](1'0
The above shall apply. In the production of non-oriented electromagnetic copper strips, the larger the grain size of the hot-rolled steel strip before cold rolling, the higher the magnetic flux density and the higher the iron loss (ti).
It is known that an excellent product with a low magnetic flux density B5° value can be obtained, but in particular, in order to obtain an extremely excellent product with a low magnetic flux density B5° value, the size of the ferrite crystal grains before cold rolling must be adjusted to a grain size of N0.4. Although large grains with a grain size of N0.5 or less are essential, the present invention reliably provides a hot rolled steel strip having coarse grains with a grain size of N0.4 or less. Next, the present invention will be explained with reference to examples. . Example 1 Slabs A, B, 0 with a thickness of 22 (Jlnm) were made by melting L and RH type vacuum processing in a converter at 17
and D. Their chemical composition is (l'l il
Also the rainfall percentage is 00.018%, si, o, 27%, Mn
(1,85%, P O,015%, 80.004%,
AtO, (1 (1 (14%). Ar calculated using formula (1) according to the chemical composition of this material
8 The transformation point temperature is 865°C. Each of the above slabs was heated to f1280°07, and the hot rolling end temperature i was set to 89 for each of 'A, B and material.
0°0,915°0, hot rolled 1-7 to a thickness of 2.8 mm, and the coiling temperature after this hot rolling was 7 f3 (1'
It was wound up as O and allowed to cool. For comparison, material O was rolled at the same temperature and finished thickness as materials A and B, but the hot rolling end temperature was 885° C., which is lower than the Ar8 transformation point. Finally, material D was rolled according to the usual method (the hot rolling end temperature was 800"0 and the coiling temperature was 560").
It was set to 0. Figure 1 shows microscopic photographs showing the crystal structures of each hot rolled and steel strip made of these A, B, O, and D materials.
O and VC are also shown. Then, these hot-rolled steel strips were made into finished products by a conventional cooling process. That is, after pickling, the products were cold rolled to a thickness of 1.5 (l mlA) and bright annealed at 800°OS for 2 minutes. (-750")
Table 1 shows the magnetism after strain relief annealing for 02 hours. + 12 1 The grain size of the hot-rolled steel strip in Fig. 1 is No. 0.5, which is the largest grain size for the personnel according to this invention, followed by No. 0.5 for material B.
, 8.5, which is the next largest, while the comparison product 01 has a relatively large particle size, but it is N005, and the D material is No.
It is smaller at 7.5. Materials A and B according to the present invention have temperatures of 25°C and 25°C, respectively, from the Ar8 transformation temperature according to formula (1).
Hot rolling f was completed at a temperature 50°C higher. Comparing these, material B has a slightly smaller grain size than human material, and the hot rolling end temperature is 55% lower than the Ar8 transformation point.
There is a critical tendency for the grain size to become smaller when the temperature exceeds 0°C. Looking at the magnetism of the first coating, those made of materials A and B of this invention are 0.0% of the comparison material. Compared to D, the magnetic density of the finished product is B. The value is extremely high, and the iron loss W 15150 value is also low. It is also clear that after strain relief annealing, both magnetic flux density and iron loss are extremely excellent. Example 2 In the same manner as in Example 1, OO, (+ +1 (1%,
810.09%, Mn 11.22%, PO, (138
%, S T1 , 004%, AtO, 0007%, and 250 mm thick slabs E, F, and G were made. The Ar8 transformation point temperature determined by formula (1) from these chemical components is 877°C. Each slab was heated to 1800"C, and the hot rolling end temperature for H material was 895°C. For comparison, the H material was 865°C, which is lower than the Ar8 transformation point temperature. However, the winding source V was Also, for material G, the heat-sintering finish temperature was 820°C and the coiling temperature was 560°C (both were hot-rolled steel strips with a thickness of 2.3 mm). The crystal grain size of the band is ferrite grain 1i NO, and E
is 0. F is 5. G was 7. These hot-rolled coils were left to cool and then subjected to the usual cold-rolling step 1 to form finished products. That is, 0.5011 after pickling and cold rolling.
111, and bright annealing was performed at 750° for 0.2 minutes in a continuous annealing furnace. These products and 750℃, 2
The magnetism after time strain relief annealing is shown in Table 2. [15゛116' From these results, it can be seen that in material H of this invention, the grain size of the hot-rolled steel strip is large at NO, (l, and hot rolling is completed at 865°C, which is lower than the transformation point temperature of 1 to Ar8. The comparative example made of H material has a grain size of N015 and is small, and the conventional method made of G material has even smaller grains.As a result, the invented product has a high magnetic flux density and low iron loss, and is stress relief annealed. It is clear that the iron loss as well as the magnetic flux density are extremely excellent.Example 3 Using the same method as Example 1, OO, 012%, 810.8
4%, Mn 0.50%, po, oo7%, AtO, 0
Slabs H, I and J having a thickness of 220 mm and containing 0.007% were manufactured. The Ar8 transformation point temperature determined using formula (1) for these chemical components is 880"0. Each slab was heated to 1280°C, and the H material was heated to a hot rolling end temperature of 900°C according to the present invention. The coiling temperature is 770°C, and for comparison, the hot rolling end temperature of the work material is 870°C, which is lower than the Ar8 transformation point temperature.The coiling temperature is 760°C.
As for J material, the hot rolling end temperature is kept at 8.
30° 0 and 17, and the winding temperature was also 650°C. These hot-rolled steel strips have a uniform thickness of 2.81 mm. The grain size of each hot rolled steel strip is ferrite grain m) No. So, H was 2, Engineering was 5, and J was 6. Next, each hot-rolled steel strip was pickled and cold-rolled to a thickness of 0.50 mm by a conventional method, and then continuously annealed at 850° C. for 2 minutes to obtain a full-processed product. The magnetic properties of the products are shown in Table 8. In the invented product, which finished hot rolling at a temperature 20°C higher than the Ar8 transformation point temperature and was wound at 770°0, the ferrite crystal grain size of the hot rolled steel strip was NO.2, and the grain size was larger than that of the comparative product. It is clear that the magnetism is excellent.・19' Example 4 By the same method as in Example], the chemical component was CO,007.
%, Si 0.32%, Mno, a 5%, Po, 0
21%, SQ, (105%, A/!, 0.00 (15
% of the slough with a thickness of 22 omJ (~). The Ar8 transformation temperature determined from the chemical composition of this material using formula (1) is 874°C. Both the K and L slabs were heated to f1280″O. According to the present invention, the temperature at the end of hot rolling for material K was 895°C, and the winding temperature was 760°C. Winding temperature 660°0
and (7), hot-rolled steel strips with a thickness of 2.3 knits were made in both cases. These hot-rolled steel strips were made into semi-processed products by the usual two-time cold rolling method with so-called intermediate annealing in between. That is, the hot-rolled steel strips were pickled, then cold rolled once, and then intermediate annealed to produce a semi-processed product. "O%Continuous annealing for 2 minutes,
The cold rolling rate was set to 8% and the thickness was 120mm. Table 4 shows the magnetism of both products after 750" 0.2 hour annealing. Table 4 From the results, the invented product has a high magnetic flux density even in the double cooling iA method semi-process. It is clear that the iron loss is high and the iron loss is extremely excellent.Although each of the above examples shows the case where the material is made of a continuously cast slab with no collapse, it is also possible to use a material made by blooming a steel ingot. It goes without saying that by satisfying the conditions of this invention, an effect equivalent to that of SO can be obtained.Thus, according to this invention, the hot rolling end temperature of a hot rolled steel strip whose chemical composition has been specified can be determined by A weighs heavily depending on chemical composition
The r-phase temperature region is within a range not exceeding 50°0 higher than the r8 transformation point temperature, and the winding temperature after hot rolling is A.
Temperature range below 8'& freezing point temperature and above 700°C]
-, the hot-rolled steel strip is subjected to a separate annealing process at a low cost of 1 g.
The ferrite crystal grains of the copper strip can be made into coarse grains with a grain size of N0.4 or less, which helps to significantly improve the magnetic properties of non-oriented electrical steel strip products, regardless of whether they are used for full process or semi-process.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は熱延鋼帯のフェライト結晶粒度を、この発明の
方法と比較法および従来法とについて対比ｔ−だ金属顕
微暁写真である。 Ａ　　オ立度Ｎ００５（Ｘ３０）　　　　Ｂ　＃Ｌ度ぬ
３．５　（３０うＣＭ度Ｎｏ、　ｓ、ｏ　（ｘ３ｏ＞　
　　　Ｄ　ｍｔｘＮｏ、７５　ｔｘ３ｏｒ１、明細書第
４頁第１８行の「Ｓｉ　２．５〜４．０％」手続補正書 １、事件の表示 昭和５７年　特　許　願第１８９（ＨＪ　号・の製造方
法 ３、補正をする者 事件との関係　特許出願人 （１２５）川崎製鉄株式会社 ２、同第５頁第１０〜１１行の「自然法則の利用のしか
た技術思想」を「自然法則の利用のしかた、つまり技術
的思想」に訂正する。 ８、同第６頁第９行の「磁束密度；鉄損に関して」を「
磁束密度、鉄損に関して」に訂正する。 ４、第１図を別紙訂正図のとおりに訂正する。FIG. 1 is a metal microscopic photograph comparing the ferrite grain size of a hot-rolled steel strip using the method of the present invention, a comparative method, and a conventional method. A Standing degree No. 005 (X30) B #L degree No. 3.5 (30 degrees CM No., s, o (x3o>
D mtx No., 75 tx3or1, “Si 2.5-4.0%” on page 4, line 18 of the specification, procedural amendment 1, case description 1982 Patent Application No. 189 (HJ No. 3) , Relationship with the person making the amendment Patent applicant (125) Kawasaki Steel Co., Ltd. 2, page 5, lines 10-11 of ``technical thought on how to use the laws of nature'' was changed to ``how to use the laws of nature''. In other words, it is corrected to ``technical thought.''
Regarding magnetic flux density and iron loss.'' 4. Correct Figure 1 as shown in the attached correction diagram.

Claims (1)

【特許請求の範囲】 Ｌ　低炭素鋼スラブを加熱し引続き熱間圧延を加えて熱
延鋼帯とし、この熱延鋼帯を通常の方法による酸洗、１
回の冷間圧延または中間焼鈍を挾む２回の冷間圧延およ
びその後の焼鈍各工程に供する無方向性電磁銅帯の製造
方法において、 上記スラブが、（３０，０２％以下、ＳｉもしくはＳｉ
とＡｔの合計の何れか１．５％以下、Ｍｎ１．０％以下
、そしてＰを含むとき０．２０％以下をそれぞれ含有す
る組成になるものとし、そのスラブ加熱に引続く熱間圧
延を、該スラブの鋼中成分に応じて定まるＡｒ８変態点
温度より５０℃を越えて高くはない範囲内のγ相温度領
域で終了し、ついでこの熱延鋼帯をＡ８変態点温度以下
、７００℃以上の温度域で巻取ることにより、熱延鋼帯
の７工クイト結晶粒を粒度ＮＯ，，４以下の粗大粒とす
る過程を経ること を特徴とする特許 銅帯の製造方法。[Claims] L A low carbon steel slab is heated and subsequently hot rolled to form a hot rolled steel strip, and this hot rolled steel strip is pickled by a normal method.
In the method for manufacturing a non-oriented electromagnetic copper strip, which is subjected to two cold rolling steps or intermediate annealing steps, and the subsequent annealing steps, the slab contains (30.02% or less, Si or Si
The composition shall contain 1.5% or less of any of the sums of and At, 1.0% or less of Mn, and 0.20% or less when P is included, and the hot rolling subsequent to slab heating shall be performed. The hot-rolled steel strip is heated to a temperature range of γ phase within a range not more than 50°C higher than the Ar8 transformation point temperature, which is determined depending on the steel components of the slab, and then the hot-rolled steel strip is heated to a temperature below the A8 transformation point temperature and above 700°C. A method for producing a patented copper strip, which comprises a process of converting the 7-kuite crystal grains of the hot-rolled steel strip into coarse grains with a grain size of NO. 4 or less by winding the strip at a temperature of