JPS613839A - Manufacture of cold rolled nonoriented electromagnetic steel sheet - Google Patents

Abstract

PURPOSE:To manufacture a cold rolled nonoriented electromagnetic steel sheet by hot rolling a steel slab contg. specified amounts of C, Mn, Si and Al under specified conditions and by subjecting the hot rolled steel sheet to coiling, self- annealing, pickling, cold rolling and finich annealing. CONSTITUTION:The silicon steel slab contg., by weight, <0.04% C, 0.1-1% Mn, <4% Si and <1% Al is hot rolled, and the hot rolled steel sheet is coiled at >=700 deg.C, self-annealed, pickled, cold rolled, and subjected to finish annealing to manufacture a cold rolled nonoriented electromagnetic steel sheet. At this time, after the hot rolled steel sheet is coiled, self-annealed and said sheet is held for 8min-1hr, and water-cooled.

Description

【発明の詳細な説明】 【技術分野） 冷延無方向性けい素鋼板の製造に関して、この明細書で
述べる技術的内容は、熱延板を自己焼鈍させて讃窒化層
を薄くし歩留を良くすることにつ、いての開発成果を提
案するところにある。[Detailed Description of the Invention] [Technical Field] Regarding the production of cold-rolled non-oriented silicon steel sheets, the technical content described in this specification is to self-anneal the hot-rolled sheets to thin the nitrided layer and improve the yield. It is about proposing the results of development that can be improved.

（背景技術） 従来より・Ｓｉ含有量が１．８％以上のけい素鋼板を製
造するに際しては、最終製品での筋状の凹凸、いわゆる
リジングの発生を防止したり、電磁・特性を改良したり
するために、熱延板を冷延前に、焼鈍するのが一般的で
ある。(Background technology) Conventionally, when manufacturing silicon steel sheets with a Si content of 1.8% or more, it has been necessary to prevent the occurrence of streak-like unevenness, so-called ridging, in the final product, and to improve the electromagnetic properties. In order to achieve this, hot rolled sheets are generally annealed before cold rolling.

この母板焼鈍は、電磁特性の改良を目的として、Ｓｉ　
１．８％未満の電磁鋼板製造においてもしはしは行なわ
れている。This mother plate annealing is performed to improve the electromagnetic properties of Si.
In the production of electrical steel sheets with a ratio of less than 1.8%, this is done.

この母板焼鈍は、連続焼鈍でも箱焼鈍でも良いが、連続
焼鈍の場合はｓ　ｏ　ｏ　”ｃがら１０００　”Ｃの間
・箱焼鈍の場合は７００　’Ｃから９００　’Ｃの間で
行うのが普通で”ある。This mother plate annealing may be continuous annealing or box annealing, but in the case of continuous annealing, it is recommended to perform it between 1000'C and 700'C to 900'C in the case of box annealing. It's normal.

近年省エネルギーや工程合理化の立場がら、こ゛の連続
焼鈍や箱焼鈍にかわって熱延後高温で巻取り、それ自体
の保有熱で自己焼鈍させる方法が行なわれるようにな・
った。In recent years, from the perspective of energy saving and process rationalization, continuous annealing and box annealing have been replaced by a method in which the material is coiled at a high temperature after hot rolling and self-annealed using its own heat.
It was.

（従来技術と問題点） この点例えば、特公昭５７−４８１８２号公報１゛・に
は、熱延後７５０℃〜１０００℃で巻取り、自己焼鈍さ
せることが述べられている。また発明者らも特開ｗ３Ｂ
？−１８８４６８号公報において熱延時の仕上最終スタ
ンドの圧下率を２０％以上とすることにより、７００℃
以上の巻取りで容易に・自己焼鈍が起ることを示した。(Prior Art and Problems) Regarding this point, for example, Japanese Patent Publication No. 57-48182 No. 1 describes that after hot rolling, winding is performed at 750° C. to 1000° C. and self-annealing is performed. In addition, the inventors also
? - In Publication No. 188468, by setting the rolling reduction ratio of the finishing stand during hot rolling to 20% or more, 700℃
It was shown that self-annealing easily occurs with the above winding.

第１図に巻取温度を７８０℃としたものと、通常の５６
０℃にしたものの写真を示す。通常の巻取温度を６００
℃以下とした場合、熱延板の表面に生成する酸窒化層の
厚さは一般に、５〜６μｍ厚くても１０μｍ以下である
のに対し７００℃以上の高温で巻取りそのまま放置した
熱延板では、２０μｍから厚いものでは８０μｍにも達
する酸窒化層が生成する。Figure 1 shows one with a winding temperature of 780°C and one with a winding temperature of 56°C.
A photograph of the product at 0°C is shown. The normal winding temperature is 600.
℃ or less, the thickness of the oxynitride layer formed on the surface of the hot-rolled sheet is generally 5 to 6 μm, at most 10 μm or less. In this case, an oxynitride layer with a thickness ranging from 20 μm to 80 μm is formed.

熱延板の酸窒化層が厚くなると、冷延前の酸洗の能率が
悪くなるばかりでなく、酸洗後の歩出りも悪くなる。When the oxynitrided layer of the hot rolled sheet becomes thick, not only the efficiency of pickling before cold rolling becomes poor, but also the yield after pickling becomes poor.

通常熱延板は、２．０〜２．６−の厚さに仕上げられる
が、巻取温度が低く酸窒化層が１０μｍ以下の場合、酸
洗による歩留低下は、おおむね１％以”、下多くても１
％程度なのに対し、７００℃以上で１巻取り酸゛窒化層
が２０〜８０μｍ生成した場合は、酸洗による歩留低下
は、２〜８％にも及ぶ。Hot-rolled sheets are usually finished to a thickness of 2.0 to 2.6 mm, but if the coiling temperature is low and the oxynitride layer is 10 μm or less, the yield decrease due to pickling is approximately 1% or less. At most 1
%, whereas if the oxidized nitrided layer of 20 to 80 .mu.m thick is formed in one winding at 700.degree. C. or higher, the yield decrease due to pickling reaches as much as 2 to 8%.

（発明の端緒） 発明者らは、７００℃以上の高温で巻取りをし一□て熱
延板の自己焼鈍を起させ、しかも熱延板表面の酸窒化層
の厚さが、平均鵞片側１０μｍ以下にとどめる技術手段
について数多実験を積重ねた結果、高温巻取径８分以上
１時間以内の保持を行ってから水冷するこ七により、上
記両要禎を満足さｉパせ得ることを見いだし、この発明
を完成させるに至った。(Start of the Invention) The inventors have discovered that self-annealing of a hot-rolled sheet occurs by winding it at a high temperature of 700°C or higher, and that the thickness of the oxynitrided layer on the surface of the hot-rolled sheet is on the average As a result of numerous experiments on technical means to keep the diameter at 10 μm or less, we have found that both of the above requirements can be met by holding the coiled diameter at a high temperature for at least 8 minutes and at most 1 hour, and then cooling it with water. This discovery led to the completion of this invention.

Ｃ発明の目的） 無方向性電磁鋼板の熱延過程を経たのちの自己焼鈍を、
熱延板表面における酸窒化層の著大な抑（−′制の下に
成就させることがこの発明の目的である。C) Purpose of the invention) Self-annealing of non-oriented electrical steel sheet after hot rolling process,
It is an object of the present invention to achieve this with significant suppression of the oxynitrided layer on the surface of the hot rolled sheet.

（発明の１１１成） この発明は１ ．０　：　０．０４重量％以下 Ｉｎ　：　０．１〜１．０重量％ Ｓｉ　：　４．０　！ｊｉ％以下　、 ムｌ　：　１．０重１％以下 を含有する組成の含Ｓｉ鋼スラブを熱延し、ついで７０
０℃以上で巻取って自己焼鈍させ、しかる後酸洗、冷延
、仕上焼鈍を行ない冷延無方向性電磁−鋼板を製造する
に際し、熱延板を巻取り後８分以上１時間以内保持する
自己焼鈍会、水冷することを特徴とする冷延無方向性電
磁鋼板の製造方法である。(111 compositions of the invention) This invention consists of 1. 0: 0.04% by weight or less In: 0.1 to 1.0% by weight Si: 4.0! A Si-containing steel slab having a composition containing 1% or less, mul: 1.0 wt.
When producing a cold rolled non-oriented electrical steel sheet by winding and self-annealing at 0°C or higher, then pickling, cold rolling, and final annealing, the hot rolled sheet must be held for at least 8 minutes and at most 1 hour after winding. This is a method for producing a cold-rolled non-oriented electrical steel sheet, which is characterized by self-annealing and water cooling.

この発明において鋼成分を限定する理由についてまず述
べる。First, the reason for limiting the steel components in this invention will be described.

Ｃは磁性を劣化させるので０．０４％以下とした。Since C deteriorates magnetism, it was set to 0.04% or less.

Ｋｎは熱延脆性を改善するので０．１％以上としたが、
１．０％を超えると磁性を劣化さ′せるので１．０％以
下とした。Since Kn improves hot rolling brittleness, it was set at 0.1% or more, but
If it exceeds 1.0%, the magnetism deteriorates, so it is set to 1.0% or less.

Ｓｌは電気抵抗を増加させて鉄損を滅らす有用１な元素
であるが、４．０％をこえると脆くなり、冷延が困難と
なるので４．０１以下とした。Sl is a useful element that increases electrical resistance and eliminates iron loss, but if it exceeds 4.0%, it becomes brittle and cold rolling becomes difficult, so it was set to 4.01 or less.

ムｌは磁性を向上させるのに有効な元素であるが１．０
％をこえるとやはり脆くなるので１．０％以下゛、とじ
た。Mulch is an effective element for improving magnetism, but 1.0
If it exceeds 1.0%, it becomes brittle, so it was kept at 1.0% or less.

次に熱延仕上完了のあと、７００℃以上の高温で巻取っ
ても８分未満にて水冷した場合には、自己焼鈍効果が不
完全なので８分以上を必要とし〜また１時間以上放置す
ると、酸窒化層の厚さか　。Next, after completion of hot rolling, if you wind it at a high temperature of 700°C or higher but water cool it for less than 8 minutes, the self-annealing effect will be incomplete, so you will need more than 8 minutes.Also, if you leave it for more than 1 hour, , the thickness of the oxynitride layer.

１０８ｍをこえるものがあり、また自己焼鈍効果も、１
時間をこえた保持でもそれ以上の改善がみられないので
１時間以内とした。There are some that exceed 108m, and the self-annealing effect is 1.
Since no further improvement was observed even after holding the test for more than 1 hour, the test was held for no more than 1 hour.

次に製造方法について更に詳細に説明する。製鋼は、平
炉、転炉、電気炉など公知のいずれの方□“法でも良い
。また製鋼での溶ａｌｌ後、もちろん真空処理を施して
も良い。要は前記成分範囲内に成分を調整することであ
る。Next, the manufacturing method will be explained in more detail. Steel production may be done by any known method such as open hearth, converter furnace, or electric furnace.Also, after melting in steelmaking, vacuum treatment may of course be performed.The key is to adjust the ingredients within the above-mentioned range. That's true.

前記成分の溶鋼は、鋳型に鋳込んだ後分塊圧延によりス
ラブとしても良いし、連続鋳造により直。The molten steel having the above components may be cast into a mold and then made into a slab by blooming rolling, or directly by continuous casting.

接スラブにしてもよい。It may be made into a contact slab.

得られたスラブは、公知の方法に従い通常の均熱炉で加
熱し次いで熱延を行うが、この熱延自体は公知の方法で
よいが、仕上ｍ終スタンドの圧下率を２０％以上とする
ことが好ましい。The obtained slab is heated in a normal soaking furnace according to a known method and then hot rolled.This hot rolling itself may be done by a known method, but the rolling reduction of the finishing stand is 20% or more. It is preferable.

・　熱延された鋼板は、ダウンコイラーに巻取るがこの
巻取温度は７００℃以上とする必要があり、７００℃以
上とすることにより再結晶に十分な熱エネルギーが確保
できるからである。- The hot-rolled steel plate is wound up on a down coiler, and the winding temperature must be 700°C or higher, because sufficient thermal energy for recrystallization can be secured by setting the temperature to 700°C or higher.

７００℃以上で巻取られた熱延板をコイル状絆で８分〜
１時間保持し自己焼鈍させた後水冷する。A hot-rolled sheet rolled at 700°C or higher is wrapped in a coiled bond for 8 minutes.
After being held for 1 hour and self-annealed, it is cooled with water.

この水冷は、貯水により冷却してもよい。This water cooling may be performed by storing water.

このようにして得られた熱延板は、酸窒化層が１０μｍ
以下であって通常の熱延板のようにあらためて母板焼鈍
をすることなく、通常の酸洗処理“°゛に付し冷延後最
終焼鈍し製品にすることができる。The hot rolled sheet thus obtained had an oxynitride layer of 10 μm thick.
It is possible to make a final annealed product after cold rolling by subjecting it to a normal pickling treatment without having to perform another mother plate annealing like a normal hot rolled sheet.

もちろんその製品は、母板焼鈍処理を省略したにも拘ら
ず母板焼鈍した製品と同等の優れた電磁特性を持ち、か
つ酸洗歩留か母板で水冷しない高温巻取材に比べてはる
かに優れている。以下実施例で示す。Of course, despite omitting the base plate annealing treatment, the product has excellent electromagnetic properties equivalent to products that are annealed to the base plate, and has a much higher pickling yield than high-temperature rolled material that is not water-cooled on the base plate. Are better. Examples will be shown below.

実施例１ Ｓｉ　１．８６％、ムｌ　Ｇ、２８　％、Ｉｎ　０．１
６％、ＣＯ，００４％の組成よりなる厚さ２８０ｍの鋼
スラブを１８２０℃にて均熱炉で加熱後２．０ｍ厚みに
″・熱延した。熱延後７８０℃で巻取り種々の時間で１
保持砕貯水槽去水冷した。また比較材として、水冷しな
い熱延コイルを作った。Example 1 Si 1.86%, Muller G, 28%, In 0.1
A 280 m thick steel slab with a composition of 6% CO, 004% was heated in a soaking furnace at 1820°C and then hot rolled to a thickness of 2.0m. After hot rolling, it was rolled up at 780°C for various times. de1
The holding crushed water tank was drained and cooled. In addition, as a comparison material, we made a hot-rolled coil that was not water-cooled.

次いで酸洗し０．５ｍに冷延した後８８０℃で１．５分
仕上焼鈍した。比較として、５６０℃で巻取り、熱延板
とし８５０℃で８分、母板焼鈍処理洗し以下同様の処理
をした。Next, it was pickled, cold rolled to a length of 0.5 m, and then finish annealed at 880° C. for 1.5 minutes. For comparison, a hot-rolled sheet was wound up at 560°C, and the mother plate was annealed and washed at 850°C for 8 minutes, followed by the same treatment.

結果を表−１にまとめて示す。The results are summarized in Table-1.

なお表−１の供試Ａｌ．７および８の熱延板に１つき、
断面顕微鏡写真を第１図（ａｌ（ｂ）および（Ｃ）にて
比較した。In addition, the sample Al. One for each hot-rolled plate of 7 and 8,
The cross-sectional micrographs were compared in FIG. 1 (al(b) and (C)).

表−１において供試Ａ１は保持時間が短く、特性が悪い
比較例の成績であり、同Ａ２〜５はこの発。In Table 1, sample A1 had a short retention time and had poor characteristics as a comparative example, and samples A2 to A5 had this problem.

明の条件に適合し合１目的的な実施例の結果を示し、同
Ａ６は水冷までの時間が長すぎて、酸窒化層が厚くなり
酸洗歩留が低下した比較例、また同Ａ７は水冷せず酸窒
化層が非常に厚く歩留が悪い比較例、モして同８は通常
の巻取温度５６０　”Ｃで母板”゛焼鈍した比較例の成
績である。The results of A6 are comparative examples in which the time until water cooling was too long, resulting in a thick oxynitride layer and a decrease in pickling yield. Comparative Example 8 has a very thick oxynitrided layer and poor yield without water cooling, and Comparative Example 8 has the mother plate annealed at a normal winding temperature of 560"C.

表−１より、この発明により母板焼鈍しなくても母板焼
鈍した工程で製造した製品と同等以上の電磁特性が得ら
れ、かつ酸洗歩留が水冷しない７８０℃巻取材より優れ
ていることが判る。　　　−（発明の効果］ この発明によれば、冷延無方向性電磁鋼板の熱延板にお
ける自己焼鈍の利益を、歩留、磁性特性の改善にあわせ
有利に実現できる。　　　　゛Table 1 shows that even without mother plate annealing, the present invention provides electromagnetic properties equivalent to or better than products manufactured using the mother plate annealing process, and the pickling yield is superior to that of 780°C rolled material that is not water-cooled. I understand that. - (Effects of the Invention) According to the present invention, the benefits of self-annealing in hot-rolled cold-rolled non-oriented electrical steel sheets can be advantageously realized along with improvements in yield and magnetic properties.

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

第１図（ａｌ（ｂｌ（Ｃ１は、表−１に掲げた供ＥＡｌ
．７および８の熱延板の断面における金ｍ顕微鏡Ｔ真Ｃ
倍率Ｘ’１Ｏ００１である。Figure 1 (al(bl) (C1 is the supply EAL listed in Table-1)
．． Gold m microscope T true C on the cross section of the hot rolled sheets of Nos. 7 and 8
The magnification is X'10001.

Claims (1)

【特許請求の範囲】 １、Ｃ：０．０４重量％以下 Ｍｎ：０．１〜１．０重量％ Ｓｉ：４．０重量％以下 Ａｌ：１．０重量％以下 を含有する組成の含Ｓｉ鋼スラブを熱延し、ついで７０
０℃以上で巻取つて自己焼鈍させ、しかる後酸洗、冷延
、仕上焼鈍を行ない冷延無方向性電磁鋼板を製造するに
際し、 熱延板を巻取り後８分以上１時間以内保持する自己焼鈍
をした後、水冷することを特徴とする冷延無方向性電磁
鋼板の製造方法。[Claims] 1. Si-containing composition containing C: 0.04% by weight or less Mn: 0.1 to 1.0% by weight Si: 4.0% by weight or less Al: 1.0% by weight or less The steel slab is hot rolled and then 70
When manufacturing a cold rolled non-oriented electrical steel sheet by coiling and self-annealing at 0°C or higher, then pickling, cold rolling, and final annealing, the hot rolled sheet is held for at least 8 minutes and at most 1 hour after being coiled. A method for producing a cold-rolled non-oriented electrical steel sheet, which comprises self-annealing and then water cooling.