JPS643564B2 - - Google Patents
Info
- Publication number
- JPS643564B2 JPS643564B2 JP25116683A JP25116683A JPS643564B2 JP S643564 B2 JPS643564 B2 JP S643564B2 JP 25116683 A JP25116683 A JP 25116683A JP 25116683 A JP25116683 A JP 25116683A JP S643564 B2 JPS643564 B2 JP S643564B2
- Authority
- JP
- Japan
- Prior art keywords
- rolling
- hot
- stand
- silicon steel
- finish rolling
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000005096 rolling process Methods 0.000 claims description 32
- 238000000034 method Methods 0.000 claims description 17
- 238000005098 hot rolling Methods 0.000 claims description 12
- 229910000976 Electrical steel Inorganic materials 0.000 claims description 11
- 238000010438 heat treatment Methods 0.000 claims description 9
- 229910000831 Steel Inorganic materials 0.000 claims description 6
- 239000010959 steel Substances 0.000 claims description 6
- 229910052717 sulfur Inorganic materials 0.000 claims description 6
- 229910052748 manganese Inorganic materials 0.000 claims description 4
- 238000000137 annealing Methods 0.000 description 10
- 238000005097 cold rolling Methods 0.000 description 7
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 6
- 239000000463 material Substances 0.000 description 5
- 210000005069 ears Anatomy 0.000 description 4
- 239000003112 inhibitor Substances 0.000 description 4
- 238000001953 recrystallisation Methods 0.000 description 4
- 239000013078 crystal Substances 0.000 description 3
- 238000005261 decarburization Methods 0.000 description 3
- 229910052742 iron Inorganic materials 0.000 description 3
- 239000006104 solid solution Substances 0.000 description 3
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 2
- 238000005336 cracking Methods 0.000 description 2
- 238000005530 etching Methods 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 239000001257 hydrogen Substances 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 210000000988 bone and bone Anatomy 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 238000009749 continuous casting Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000011162 core material Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000010494 dissociation reaction Methods 0.000 description 1
- 230000005593 dissociations Effects 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 238000007712 rapid solidification Methods 0.000 description 1
- 229910052711 selenium Inorganic materials 0.000 description 1
- 229910052718 tin Inorganic materials 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B3/00—Rolling materials of special alloys so far as the composition of the alloy requires or permits special rolling methods or sequences ; Rolling of aluminium, copper, zinc or other non-ferrous metals
- B21B3/02—Rolling special iron alloys, e.g. stainless steel
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/12—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of articles with special electromagnetic properties
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
- B21B1/22—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length
- B21B1/24—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length in a continuous or semi-continuous process
- B21B1/26—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length in a continuous or semi-continuous process by hot-rolling, e.g. Steckel hot mill
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Crystallography & Structural Chemistry (AREA)
- Thermal Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Electromagnetism (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Metal Rolling (AREA)
- Manufacturing Of Steel Electrode Plates (AREA)
Description
(技術分野)
本発明は、一方向性けい素鋼板の製造に際して
の熱間圧延技術の分野に属し、方向性けい素鋼ス
ラブを高温加熱したときに生ずる熱間圧延時の耳
荒れ、耳割れの如き耳きずを有効に阻止して製品
歩留り向上を果すことのできる熱間圧延法につい
ての提案である。
(従来技術とその問題点)
方向性けい素鋼板は、高い磁束密度と低い鉄損
とをもつ優れた磁気特性により変圧器などの鉄心
材料として広く用いられている。近年、この種の
技術分野でも、磁気特性の優れた方向性けい素鋼
板をより安価に供給することが望まれており、製
造コストを如何に低減させるかが当該技術者にと
つて解決すべき共通の課題である。
一般に、磁気特性の優れた方向性けい素鋼板を
得るためには、最終焼鈍に際して{110}〈001〉
方位(ゴス方位)が選択成長する2次再結晶現象
を制御し、ゴス方位の高度に集積した均一な2次
再結晶組織とすることが必要である。ゴス方位の
再結晶集合組織を得るには、適切な析出分散相を
活用することが有効であり、このためにMnS、
MnSe、AlN等のインヒビターと呼ばれる不純物
を利用する。この技術は、まずスラブ加熱時に
MnS、MnSe等を十分解離固溶させてから適切な
熱間圧延を施すことにより、インヒビターとして
好ましい分散相を得ることが重要である。このイ
ンヒビターの解離固溶(溶体化処理)に要するス
ラブ加熱温度は、1300〜1420℃という高温域で長
時間行なわれるのが普通である。
しかしながら、1300℃以上の高温域での長時間
加熱は、スラブ結晶粒の異常成長を誘発し、粗大
化した結晶粒は熱間圧延においても十分再結晶せ
ず、粗い結晶粒を残したままとなりしばしばホツ
トコイルの耳部の割れに代表される耳きずの原因
となつていた。かようなホツトコイルの耳きず
は、次工程の冷間圧延で破断の原因ともなり、冷
間圧延前にその耳荒れ部を耳切り除去しなければ
ならず、歩留りを大きく低下させ、製造コストア
ツプの主因となつていた。
要するに、とりわけ連鋳スラブに顕著に見られ
る上述した現象は、連鋳スラブにあつては急速凝
固により柱状晶組織が形成されやすく、その柱状
晶組織は通常造塊材に較べ異常成長しやすいので
粗圧延後に未再結晶粒として残りやすい傾向があ
る。これらの粗大未再結晶粒は、著しく靭性に乏
しく、熱間仕上圧延後段でホツトコイルの耳きず
となつていくのである。
従来、かかる耳きず防止については、既に特公
昭57−4690号として開示された技術があり、粗圧
延時の圧下スケジユールを変更することで、粗大
粒の再結晶を促進する方法であるが、この方法は
通常の水平ロールだけの圧延機では被圧延材の側
面には十分応力が加わらず、大きな効果は期待で
きない。その他、特開昭55−62124号として開示
された仕上圧延時の開始と終了の温度差を制限す
る方法、特開昭57−165102号として開示された仕
上圧延時の被圧延材の長手方向、幅方向の温度差
を制限する方法など温度制御による方法が提案さ
れている。これらは、いずれも温度的不均一を排
除することで耳きず防止を図るものだが、ストリ
ツプ両側縁部(耳部)の現象に対しては、むしろ
消極的方法があり、根本的な解決手段を与えるま
でには至つていない。
(発明への端緒)
本発明者らは、耳割れ等がどの時点で起き、ど
の様に発展するか等圧延途中の現象を追跡調査し
た結果、以下に述べるような知見を得た。すなわ
ち、粗圧延を終了したシートバー段階での幅方向
の両側縁部(耳部)は、粗大結晶粒が十分再結晶
せず粗大延伸粒と細かな再結晶粒の混ざり合つた
状態にある。これは、加熱後の粗大粒が粗圧延の
段階ではエツチングを加えても厚みが大きいため
効果が薄く、板の両端面からの抗力が小さいため
粒界ですべりが生じて十分な応力が伝達されず、
未再結晶粒として残るからと考えられる。この場
合のシートバー両側縁部の形状は、粗大粒が不連
続に飛び出して複雑なうねりを生じたものとなつ
ている。
通常、被圧延板は圧延に際してその両側縁部に
は、3軸応力が作用し、ストリツプは幅拡がりと
なる。このとき、ストリツプの両側縁部、即ち耳
部の形状が不規則にうねつている場合、局部的な
応力集中が起こり、内部にクラツクが生じやがて
耳割れの原因となる。事実、シートバー段階での
幅方向両側縁部の平坦度が高いほど耳きずの程度
は緩和され、仕上げ圧延前の被圧延材の両側縁部
の形状が耳きず(特に耳割れ)に大きく影響する
ということが判つた。
(発明の目的と要旨構成)
本発明は、仕上圧延の初期段階における被圧延
材の両側縁部の形状によりホツトコイルの耳きず
状況が左右されるという上述の知見により、磁気
特性の劣化を伴なうことなく上記耳きずを効果的
に防止することを目的とし、仕上圧延の初期にシ
ートバー、ストリツプの両側端面をエツジヤーロ
ールにて機械的に矯正することを主たる特徴とす
る特許請求の範囲に掲記したとおりの方法を採用
することで、前述の従来技術の限界を超えたので
ある。
(発明の構成)
本発明が適用される方向性けい素鋼板の主要製
造工程は、Si:2.5〜4.1%を含有する鋼を造塊法
あるいは連続鋳造法によりスラブとし、これに熱
間圧延を施しホツトコイルと成すこと。次に1
回、あるいは中間焼鈍を挾む2回以上の冷間圧延
により最終板厚とした後、脱炭焼鈍及び仕上焼鈍
を施すことから成り、前記工程における本発明の
特徴とするところは、スラブの再加熱、粗圧延後
の仕上圧延工程にある。すなわち、仕上圧延後、
第1スタンドの入側及び出側のいずれか一方また
は両方の位置でエツジヤロール(竪ロール)によ
るエツジングを加えて、シートバー、ストリツプ
の両側端面に幅圧下を加え両側縁部の形状を平坦
に矯正する点にある。以下に、上記製造工程にお
ける各条件限定の理由を述べる。
本発明で用いる鋼の成分組成は、重量%で、
Si:2.5〜4.1%を必須成分とし、その他C:0.01
〜0.08%、Mn:0.03〜0.1%、S及び/又はSe:
0.005〜0.1%を含有させ、残り鉄および若干の不
可避成分である。
Si量は、2.5%より少ないと磁気特性が十分得
られず、4.1%より多いと冷間圧延が困難となる
ため、Si:2.5〜4.1%に限定した。C量は、0.01
%より少ないと熱延時に十分な量のγ相が生成せ
ず、0.08%より多いと後工程の脱炭に長時間を要
するのでC0.01〜0.08%に限定した。MnとSおよ
びSeとは析出分散相として使用するインヒビタ
ーを形成するので、それぞれの含有量がMn:
0.03%、S及び/又はSe:0.005%より少ないと
析出分散相の量的不足を生じ、一方それぞれ0.1
%を超えるとスラブ加熱時の溶体化不足が生じ適
切な分散相が得られないので、Mn:0.03〜0.1
%、S及び/又はSe:0.005〜0.1%に限定する。
その他Cr、Ni、Cu、Mo、Sb、P、Snなどの溶
質原子を意識的に添加する場合があるが、この場
合も本発明の効果は失なわれない。
上記成分を含有するスラブは、プツシヤーある
いはウオーキングビームタイプスラブ加熱炉にて
1300〜1420℃の温度に加熱されるが、それはスラ
ブの加熱温度が1300℃より低いと析出分散相とし
て使用する不純物の固溶が不十分となり、高すぎ
ると膨大なスケールの発生による歩留り、炉寿命
の低下を招くため、1300〜1420℃の範囲が好まし
い。その後、粗圧延機にて複数パス圧延され20〜
60mm程度の板厚のシートバーとされる。
本発明の特徴の1つである仕上圧延機第1スタ
ンド入側、出側におけるいずれか少なくとも一
方、または両方の位置で行うエツジングは、5〜
40mmの矯正圧下とする。この幅圧下の範囲は、第
1図に示すように、5mmより少ないと形状矯正の
効果が少なく、一方40mmを超えるとドツクボーン
の形成により形状不良が生じるため、その範囲を
5〜40mmに限定した。この矯正圧下は側縁部の応
力集中を防止し、内部クラツクの発生を抑える目
的のもので、スラブ幅に関係なく5〜40mmの範囲
で側縁部の形状を平坦に矯正すれば良い。
なおこの圧下は本質的には第1スタンドに限定
されるものではないが、第2スタンド以降ではス
トリツプの板厚が薄くなり幅圧下による形状不良
が起りやすくなるので、第1スタンドの前後で行
うこととした。
次に、仕上圧延開始前温度を1100℃以上とした
のは、この温度以下になるとしばしば析出分散相
のサイズが不均一となり磁気特性が劣化するため
である。
次いで1回あるいは中間焼鈍を含む2回以上の
冷間圧延を行い成品厚とした後、780〜850℃の湿
水素雰囲気中で1次再結晶を兼ねる脱炭焼鈍を3
〜15分程度行い1200℃以上の最終仕上焼鈍を行
う。
なお、第2図に本発明の好適実施態様を示す
が、図示の1は粗エツジヤー、2は粗圧延機、3
はクロツプシヤー、4は入側エツジヤー、5は仕
上圧延機の第1スタンドで6はその第2スタンド
でそれらの間には出側エツジヤー7が配置されて
おり、8がその最終スタンドである。
(実施例)
C:0.04%、Si:2.95%、Mn:0.07%、S:
0.02%残部が主としてFeよりなる溶鋼を連続鋳造
し、230mm厚のスラブを得た。これを1350℃に加
熱し、下記の(a)〜(c)の3条件で熱間圧延し、厚み
2.4mmのホツトコイルを製造した。
製造工程の条件として仕上第1スタンド入・出
側両エツジヤーでの幅殺しを全く行なわれない条
件(a)とし、第1スタンド入側エツジヤーで10mmの
幅圧下を施したものを条件(b)とし、入・出側両エ
ツジヤーでそれぞれ10mm(合計20mm)の幅圧下を
したものを条件(c)とする。
得られたホツトコイルは、900℃で3分間の均
一化焼鈍を行つた後、約70%の1次冷延を行い、
950℃で3分間の中間焼鈍後約60%の2次冷延を
施して0.3mmの成品厚とした。その後、820℃の湿
水素中にて4分間脱炭焼鈍を施した。次いで、
MgOを主成分とする焼鈍分離剤を塗布し、1200
℃で最終仕上焼鈍を行つた。
その結果を次表に示す。
(Technical field) The present invention belongs to the field of hot rolling technology for producing unidirectional silicon steel sheets, and relates to the field of hot rolling technology for manufacturing unidirectional silicon steel sheets, and the present invention relates to the field of hot rolling technology for producing unidirectional silicon steel plates, and is concerned with the rough edges and cracks that occur during hot rolling when oriented silicon steel slabs are heated to high temperatures. This is a proposal for a hot rolling method that can effectively prevent ear flaws such as the above and improve product yield. (Prior art and its problems) Grain-oriented silicon steel sheets are widely used as iron core materials for transformers and the like due to their excellent magnetic properties, including high magnetic flux density and low iron loss. In recent years, even in this type of technical field, it has been desired to supply grain-oriented silicon steel sheets with excellent magnetic properties at a lower cost, and the question for engineers concerned is how to reduce manufacturing costs. This is a common issue. Generally, in order to obtain grain-oriented silicon steel sheets with excellent magnetic properties, {110}<001>
It is necessary to control the secondary recrystallization phenomenon in which the orientation (Goss orientation) selectively grows, and to obtain a uniform secondary recrystallization structure in which the Goss orientation is highly concentrated. In order to obtain a recrystallized texture with Goss orientation, it is effective to utilize an appropriate precipitated dispersed phase, and for this purpose, MnS,
Impurities called inhibitors such as MnSe and AlN are used. This technology first begins when heating the slab.
It is important to obtain a dispersed phase preferable as an inhibitor by sufficiently dissociating MnS, MnSe, etc. into a solid solution and then performing appropriate hot rolling. The slab heating temperature required for this dissociation and solid solution (solution treatment) of the inhibitor is usually in the high temperature range of 1300 to 1420°C for a long period of time. However, long-term heating in a high temperature range of 1300℃ or higher induces abnormal growth of slab grains, and the coarse grains do not recrystallize sufficiently even during hot rolling, leaving coarse grains. This is often the cause of ear scratches, such as cracks in the ears of hot coils. Such edge flaws in hot coils can cause breakage in the next process of cold rolling, and the rough edges must be removed before cold rolling, which greatly reduces yield and increases manufacturing costs. It was the main cause. In short, the above-mentioned phenomenon that is especially noticeable in continuously cast slabs is because columnar crystal structures are easily formed in continuous cast slabs due to rapid solidification, and these columnar crystal structures are more likely to grow abnormally than normal agglomerated materials. They tend to remain as unrecrystallized grains after rough rolling. These coarse unrecrystallized grains have extremely poor toughness and turn into ear flaws in the hot coil in the later stages of hot finish rolling. Conventionally, there is a technique already disclosed in Japanese Patent Publication No. 57-4690 to prevent such ear scratches, which is a method of promoting recrystallization of coarse grains by changing the rolling schedule during rough rolling. With a conventional rolling mill that uses only horizontal rolls, sufficient stress is not applied to the side surfaces of the rolled material, and great effects cannot be expected. In addition, a method for limiting the temperature difference between the start and end of finish rolling disclosed in JP-A No. 55-62124, a longitudinal direction of a material to be rolled during finish rolling disclosed as JP-A-57-165102; Methods based on temperature control, such as a method of limiting the temperature difference in the width direction, have been proposed. All of these methods aim to prevent ear scratches by eliminating temperature unevenness, but when it comes to the phenomenon of the edges (ears) on both sides of the strip, there are rather passive methods that do not require a fundamental solution. I haven't gotten to the point where I can give it. (Introduction to the Invention) The present inventors conducted a follow-up investigation of phenomena during rolling, such as when edge cracking occurs and how it develops, and as a result, the following findings were obtained. That is, in the widthwise side edges (edges) at the stage of the sheet bar after rough rolling, the coarse crystal grains are not sufficiently recrystallized and the coarse drawn grains and fine recrystallized grains are mixed together. This is because the thickness of the coarse grains after heating is large during rough rolling, so the effect is small, and the resistance from both end faces of the plate is small, so slippage occurs at the grain boundaries and sufficient stress is not transmitted. figure,
This is thought to be because they remain as unrecrystallized grains. In this case, the shape of both side edges of the sheet bar is such that coarse grains jump out discontinuously and create complex undulations. Normally, when a plate to be rolled is rolled, triaxial stress is applied to both side edges thereof, and the strip becomes wider. At this time, if the shape of both side edges of the strip, that is, the ears, is irregularly undulating, local stress concentration occurs, causing internal cracks and eventually causing ear cracks. In fact, the higher the flatness of both edges in the width direction at the sheet bar stage, the less severe the edge scratches will be, and the shape of the edges of the rolled material before finish rolling has a large effect on edge scratches (particularly edge cracks). It turned out that it does. (Objective and Summary of the Invention) The present invention is based on the above-mentioned knowledge that the shape of the edges of the rolled material at the initial stage of finish rolling affects the condition of the edges of the hot coil. The main feature of the claim is to mechanically correct both side end surfaces of the sheet bar and strip using an edger roll at the beginning of finish rolling, with the aim of effectively preventing the above-mentioned ear scratches without causing any scratches. By adopting the method described in , the limitations of the prior art described above were exceeded. (Structure of the Invention) The main manufacturing process of grain-oriented silicon steel sheets to which the present invention is applied is to form steel containing 2.5 to 4.1% Si into a slab using an ingot method or continuous casting method, and then hot rolling the steel into a slab. What to do with hot coils. Next 1
After obtaining the final thickness by cold rolling twice or more times with intermediate annealing in between, decarburization annealing and final annealing are performed. It is in the finish rolling process after heating and rough rolling. That is, after finish rolling,
Etching is applied using an edger roll (vertical roll) at either or both of the entrance and exit sides of the first stand, and width reduction is applied to both end surfaces of the seat bar and strip to flatten the shape of both side edges. It is in the point of doing. The reasons for limiting each condition in the above manufacturing process will be described below. The composition of the steel used in the present invention is, in weight%,
Si: 2.5-4.1% as essential component, other C: 0.01
~0.08%, Mn: 0.03~0.1%, S and/or Se:
It contains 0.005 to 0.1%, with the remainder being iron and some unavoidable components. The amount of Si was limited to 2.5 to 4.1% because if it was less than 2.5%, sufficient magnetic properties could not be obtained, and if it was more than 4.1%, cold rolling would be difficult. The amount of C is 0.01
If it is less than 0.08%, a sufficient amount of γ phase will not be generated during hot rolling, and if it is more than 0.08%, it will take a long time to decarburize in the subsequent process, so it was limited to 0.01 to 0.08%. Mn, S and Se form an inhibitor used as a precipitated dispersed phase, so the content of each Mn:
0.03%, S and/or Se: less than 0.005% will cause a quantitative shortage of the precipitated dispersed phase, while each 0.1
If it exceeds Mn: 0.03 to 0.1, insufficient solutionization occurs during slab heating and an appropriate dispersed phase cannot be obtained.
%, S and/or Se: limited to 0.005 to 0.1%.
Other solute atoms such as Cr, Ni, Cu, Mo, Sb, P, and Sn may be intentionally added, but the effects of the present invention are not lost in this case as well. Slabs containing the above components are heated in a pusher or walking beam type slab heating furnace.
The slab is heated to a temperature of 1,300 to 1,420℃, but if the heating temperature of the slab is lower than 1,300℃, solid solution of impurities used as the precipitated dispersed phase will be insufficient, and if it is too high, the yield will be reduced due to the generation of huge scale, and the furnace A temperature range of 1300 to 1420°C is preferable since this results in a decrease in service life. After that, it is rolled in multiple passes in a rough rolling mill for 20~
It is said to be a sheet bar with a thickness of about 60mm. One of the features of the present invention is the etching performed at least one or both of the entry side and exit side of the first stand of the finishing mill.
A correction reduction of 40 mm is applied. As shown in Figure 1, if the width reduction is less than 5 mm, the effect of shape correction will be small, while if it exceeds 40 mm, defective shape will occur due to the formation of dot bones, so the range was limited to 5 to 40 mm. . This straightening reduction is for the purpose of preventing stress concentration on the side edges and suppressing the occurrence of internal cracks, and it is sufficient to flatten the shape of the side edges within a range of 5 to 40 mm regardless of the slab width. Note that this reduction is not essentially limited to the first stand, but from the second stand onward the thickness of the strip becomes thinner and defects in shape due to width reduction are more likely to occur, so it is carried out before and after the first stand. I decided to do so. Next, the reason why the temperature before starting finish rolling is set to 1100° C. or higher is that when the temperature is lower than this temperature, the size of the precipitated dispersed phase often becomes non-uniform and the magnetic properties deteriorate. After that, cold rolling is performed once or twice or more including intermediate annealing to obtain a finished product thickness, and then decarburization annealing, which also serves as primary recrystallization, is performed for 3 times in a wet hydrogen atmosphere at 780 to 850°C.
Perform final annealing at 1200℃ or higher for about 15 minutes. In addition, FIG. 2 shows a preferred embodiment of the present invention, in which 1 is a rough edger, 2 is a rough rolling mill, and 3
is a crop shear, 4 is an inlet edger, 5 is the first stand of the finishing mill, 6 is the second stand, an outlet edger 7 is disposed between them, and 8 is the final stand. (Example) C: 0.04%, Si: 2.95%, Mn: 0.07%, S:
Molten steel with the balance of 0.02% mainly consisting of Fe was continuously cast to obtain a slab with a thickness of 230 mm. This was heated to 1350℃ and hot-rolled under the following three conditions (a) to (c).
A 2.4mm hot coil was manufactured. Condition (a) in the manufacturing process is that no width reduction is performed on both the inlet and outlet edgers of the first stand, and condition (b) is that a width reduction of 10 mm is applied with the edger on the inlet side of the first stand. Condition (c) is that the width reduction is 10 mm each (total 20 mm) on both the input and output edgers. The obtained hot coil was uniformly annealed at 900°C for 3 minutes, then subjected to primary cold rolling of approximately 70%.
After intermediate annealing at 950°C for 3 minutes, secondary cold rolling of approximately 60% was performed to give a finished product thickness of 0.3 mm. Thereafter, decarburization annealing was performed for 4 minutes in wet hydrogen at 820°C. Then,
Apply an annealing separator mainly composed of MgO, and
Final annealing was performed at ℃. The results are shown in the table below.
【表】
(発明の効果)
以上説明したように、方向性けい素鋼板につい
て、仕上圧延機の初期段階でエツジヤーにより適
正な幅圧下を行うという本発明熱間圧延法によれ
ば、ホツトコイルの幅方向両側縁部(耳部)の耳
きずをなくすことができる。[Table] (Effects of the Invention) As explained above, according to the hot rolling method of the present invention, in which a grain-oriented silicon steel sheet is subjected to appropriate width reduction by an edger in the early stage of the finish rolling mill, the width of the hot coil can be reduced. Ear scratches on both side edges (ears) can be eliminated.
第1図は、エツジヤー幅圧下量と耳割れ程度と
の関係を示すグラフ、第2図は、本発明法の実施
に供される熱間圧延設備の略線図である。
1……粗エツジヤー、2……粗圧延機、3……
クロツプシヤー、4……仕上圧延機の第1スタン
ド入側エツジヤー、5……仕上圧延機の第1スタ
ンド、6……仕上圧延機の第2スタンド、7……
仕上圧延機の第1スタンド出側エツジヤー、8…
…仕上圧延機の最終スタンド。
FIG. 1 is a graph showing the relationship between edger width reduction and degree of edge cracking, and FIG. 2 is a schematic diagram of hot rolling equipment used to implement the method of the present invention. 1... Rough edger, 2... Rough rolling mill, 3...
Crop shear, 4... First stand entrance edger of finishing rolling mill, 5... First stand of finishing rolling mill, 6... Second stand of finishing rolling mill, 7...
Finishing mill's first stand exit edger, 8...
...The final stand of the finishing rolling mill.
Claims (1)
%、Mn:0.03〜0.1%、S及び/又はSe:0.005〜
0.1%、残部Feおよび不可避成分からなるけい素
鋼スラブを、1300〜1420゜の温度に加熱して粗圧
延、仕上圧延と経る熱間圧延を施して熱間圧延鋼
帯を得る方法において、 上記熱間仕上げ圧延に当り、 (イ) 仕上圧延開始温度を1100℃以上とすること、 (ロ) 仕上圧延機の第1スタンドの入側、出側のい
ずれか一方または両方の位置で、エツジヤロー
ルによる5〜40mmの幅圧下を加えること、 なる条件を満足するように圧延することを特徴と
する方向性けい素鋼板の熱間圧延方法。[Claims] 1% by weight, Si: 2.5-4.1%, C: 0.01-0.08
%, Mn: 0.03~0.1%, S and/or Se: 0.005~
In the method of obtaining a hot rolled steel strip by heating a silicon steel slab consisting of 0.1%, the balance being Fe and unavoidable components to a temperature of 1300 to 1420° and subjecting it to rough rolling and finish rolling, a hot rolled steel strip is obtained. For hot finish rolling, (a) The start temperature of finish rolling shall be 1100℃ or higher; (b) Rolling by an edger roll at either or both of the entry side and exit side of the first stand of the finishing rolling mill. A method for hot rolling a grain-oriented silicon steel sheet, characterized by applying a width reduction of 5 to 40 mm, and rolling to satisfy the following conditions.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP25116683A JPS60145204A (en) | 1983-12-29 | 1983-12-29 | Hot rolling method of anisotropic silicon steel plate |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP25116683A JPS60145204A (en) | 1983-12-29 | 1983-12-29 | Hot rolling method of anisotropic silicon steel plate |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS60145204A JPS60145204A (en) | 1985-07-31 |
JPS643564B2 true JPS643564B2 (en) | 1989-01-23 |
Family
ID=17218655
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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JP25116683A Granted JPS60145204A (en) | 1983-12-29 | 1983-12-29 | Hot rolling method of anisotropic silicon steel plate |
Country Status (1)
Country | Link |
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JP (1) | JPS60145204A (en) |
Families Citing this family (2)
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JP3345540B2 (en) * | 1995-06-30 | 2002-11-18 | 川崎製鉄株式会社 | Manufacturing method of grain-oriented electrical steel sheet |
WO2022250112A1 (en) | 2021-05-28 | 2022-12-01 | Jfeスチール株式会社 | Method for manufacturing grain-oriented electromagnetic steel sheet |
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1983
- 1983-12-29 JP JP25116683A patent/JPS60145204A/en active Granted
Also Published As
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JPS60145204A (en) | 1985-07-31 |
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