JPH0819467B2 - Non-oriented electrical steel sheet manufacturing method - Google Patents
Non-oriented electrical steel sheet manufacturing methodInfo
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- JPH0819467B2 JPH0819467B2 JP2048357A JP4835790A JPH0819467B2 JP H0819467 B2 JPH0819467 B2 JP H0819467B2 JP 2048357 A JP2048357 A JP 2048357A JP 4835790 A JP4835790 A JP 4835790A JP H0819467 B2 JPH0819467 B2 JP H0819467B2
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Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、無方向性電磁鋼板の製造方法に関するもの
である。The present invention relates to a method for manufacturing a non-oriented electrical steel sheet.
近年、小型モーター等の高効率化を中心に、コア材と
して用いられる電磁鋼板についても高磁束密度化の要求
が強い。In recent years, there has been a strong demand for high magnetic flux density in electromagnetic steel sheets used as core materials, centering on high efficiency of small motors and the like.
このような背景のもとで、Si≦1.0%のいわゆる低級
電磁鋼板は、鉄損は比較的高いものの磁束密度が高いと
いう特徴を有し、このためにその需要が増大しつつあ
る。そしてこれと呼応して、低級電磁鋼板の特性改善お
よび製造コスト低減に対する努力も数多くなされてお
り、なかでも製造コスト低減に関し、従来の「連続鋳造
→常温まで冷却→スラブ再加熱→熱間圧延」といういわ
ゆる再加熱法に代え、連続鋳造後、スラブの顕熱を利用
して再加熱なしに或いは軽加熱した後に熱間圧延を行
う、いわゆる直送圧延法が、加熱原単位を低減できる圧
延方法として注目を集めている。Against this background, the so-called low grade electrical steel sheet with Si ≦ 1.0% has a feature that the magnetic flux density is high although the iron loss is relatively high, and therefore the demand thereof is increasing. In response to this, many efforts have been made to improve the properties of low-grade electrical steel sheets and reduce manufacturing costs. Among them, regarding the reduction of manufacturing costs, conventional "continuous casting → cooling to room temperature → slab reheating → hot rolling" Instead of the so-called reheating method, after continuous casting, hot rolling is performed without reheating using sensible heat of the slab or after light heating, the so-called direct-feed rolling method is a rolling method that can reduce the heating unit consumption. It is getting attention.
一般に知られるように、電磁鋼板の製造において磁気
特性、特に粒径に強く依存する鉄損を低下させるために
は、粒成長性を阻害するMnSおよびAlNの析出・粗大化が
要件となるが、上記した直送圧延を行う場合にはこれが
極めて困難になる。これは、再加熱法では連続鋳造後常
温までスラブが徐冷される間および再加熱時のスラブ昇
温中に、MnSおよびAlNの析出・粗大化が自然に達成され
るのに対し、直送圧延法では、スラブの降温(軽加熱を
行う場合にはその際の昇温も含む)に費やされる時間が
再加熱法に比べて極端に短く、そのままではこの期間中
でのMnS、AlNの析出・粗大化があまり期待できないから
である。そこでこのような問題を解決するために、従
来、以下に示すような技術が開示されている。As is generally known, in the production of magnetic steel sheets, in order to reduce iron loss, which strongly depends on grain size, in particular, precipitation and coarsening of MnS and AlN that inhibit grain growth are required, This becomes extremely difficult when the above-mentioned direct feed rolling is performed. This is because in the reheating method, precipitation and coarsening of MnS and AlN are naturally achieved while the slab is gradually cooled to room temperature after continuous casting and during slab temperature increase during reheating. In the method, the time spent for lowering the temperature of the slab (including the temperature increase at the time of light heating) is extremely shorter than that in the reheating method, and as it is, precipitation of MnS, AlN during this period This is because coarsening cannot be expected so much. Therefore, in order to solve such a problem, the following techniques have been conventionally disclosed.
特開昭52−108318号、 特開昭54−41219号 スラブを900℃前後で40min超保持し、MnSおよびAlNを
析出・粗大化させた後、1100℃前後に再加熱し熱間圧延
を行う。JP-A-52-108318 and JP-A-54-41219 Hold the slab for more than 40 minutes at around 900 ° C to precipitate and coarsen MnS and AlN, then reheat to around 1100 ° C and perform hot rolling. .
特開昭58−123825号 S≦0.003%と極低S化し、事実上MnSフリーにする
か、或いはCa、REM添加によりMnSの析出・粗大化を容易
にさせた上で、スラブを900〜1150℃で30min超保持し、
その後熱間圧延を行う。JP-A-58-123825 S has an extremely low S of 0.003% and is virtually free of MnS, or Ca and REM are added to facilitate precipitation and coarsening of MnS, and then the slab is 900-1150. Hold for more than 30 min at ℃,
After that, hot rolling is performed.
特開昭60−190521号 スラブを900℃以下まで徐冷し、MnS、AlNの析出・粗
大化を図った上で熱間圧延に供する。JP, 60-190521, A Slab is gradually cooled to 900 ° C or less, and is subjected to hot rolling after precipitation and coarsening of MnS and AlN.
このように従来MnS、AlNの析出・粗大化のための技術
が種々開示されているが、これらはそれぞれ次のような
問題を抱えており、十分なものとは言い難い。As described above, various techniques for precipitation / coarsening of MnS and AlN have conventionally been disclosed, but each of them has the following problems, and it cannot be said to be sufficient.
特開昭52−108318号、 特開昭54−41219号 高温、長時間の保持を必要とし、その間のスケール増
加により表面性状が劣化する。またスケール増加を防止
するために保熱カバーを用いる場合には、保持そのもの
に長時間を要することに加えて、保熱カバーの装脱着に
も時間を要し、生産性の低下をきたす。さらに再加熱を
必須とするため、加熱原単位の低減を目的とする直送圧
延の意義そのものが薄れる。JP-A-52-108318, JP-A-54-41219 It is necessary to maintain at a high temperature for a long time, and the surface property is deteriorated due to an increase in scale during that time. Further, when the heat retaining cover is used to prevent the scale from increasing, it takes a long time to hold the heat retaining cover itself, and it also takes time to attach and detach the heat retaining cover, resulting in a decrease in productivity. Further, since reheating is indispensable, the significance itself of direct feed rolling for the purpose of reducing the heating unit is diminished.
特開昭58−123825号 極低S化やCa、REM添加のために製鋼コストが高い。
加えた上述した特開昭52−108318号や特開昭54−41219
号と同様に、高温、長時間の保持が必要であるため、そ
れらと同様の問題を生じる。JP, 58-123825, A The steelmaking cost is high because of extremely low S and addition of Ca and REM.
In addition, the above-mentioned JP-A-52-108318 and JP-A-54-41219
Similar to No. 6, it requires high temperature and long-term holding, and therefore causes the same problems as those.
特開昭60−190521号 スラブの徐冷のみではMnS、AlNの析出・粗大化は不十
分であり、鉄損の上昇を招く。また、熱間圧延の開始が
900℃以下となるため、ミル負荷が著しく増大するとと
もに、巻取温度の確保が困難となり、熱延板の再結晶・
流成長不足に起因した磁気特性の劣化を生じる。JP, 60-190521, A The slow cooling of the slab is insufficient for the precipitation and coarsening of MnS and AlN, which causes an increase in iron loss. Also, the start of hot rolling
Since the temperature is 900 ° C or less, the load on the mill increases significantly and it becomes difficult to secure the coiling temperature, resulting in recrystallization of the hot rolled sheet.
The magnetic properties are deteriorated due to insufficient flow growth.
このように従来技術は特性、生産性、コストのいずれ
かに課題を残している。As described above, the conventional techniques have problems in any of the characteristics, productivity, and cost.
本発明はこのような実情に鑑み、磁気特性および生産
性を低下させることなく、しかも低コストという直送圧
延の意義を十分に発揮し得る無方向性電磁鋼板の製造方
法を提供しようとするものである。In view of such circumstances, the present invention intends to provide a method for producing a non-oriented electrical steel sheet that can fully demonstrate the significance of direct rolling, which is low cost, without lowering magnetic properties and productivity. is there.
本発明者らは、Si≦1.0%の低級無方向性電磁鋼板の
製造に直送圧延を適用する場合の条件について鋭意研究
を重ねた結果、Mn、S、Al量およびMn/S比の適正化を行
った特定成分の鋼スラブを連続鋳造後、成分に応じて決
まる特定の冷却速度以下で特定の温度域に冷却したとき
に、MnSおよびAlNの析出・粗大化が加速されること、し
たがって、その後はスラブの高温保持や再加熱を行うこ
となく、直ちに熱間圧延を行うだけで、再加熱法と同等
ないしはそれ以上の磁気特性を具備した無方向性電磁鋼
板が得られることを新たに知見し、本発明法を完成させ
たものである。The inventors of the present invention have conducted earnest researches on the conditions when applying direct rolling to the production of low-oriented non-oriented electrical steel sheets with Si ≦ 1.0%, and as a result, optimized the Mn, S, Al amounts and Mn / S ratio. After continuous casting of the steel slab of the specified component that was performed, when it is cooled to a specific temperature range below a specific cooling rate determined according to the component, the precipitation and coarsening of MnS and AlN are accelerated, therefore, After that, it is newly found that a non-oriented electrical steel sheet having magnetic properties equivalent to or better than that of the reheating method can be obtained simply by hot rolling immediately without holding the slab at a high temperature or reheating. Then, the method of the present invention has been completed.
本発明は、以下に述べるように技術的認識ないし要素
に基づき構成されたものである。The present invention is constructed based on technical recognition or elements as described below.
(1)Si≦1.0%の低級材は、低Si鋼であることに起因
して元来粒成長性に優れ、しかも要求される鉄損値がそ
れ程厳しくないため、粒成長性不足による鉄損劣化が懸
念される直送圧延法に適した材料といえる(Si>1.0%
の高級材はこの対極にある)。(1) Low grade steel with Si ≦ 1.0% is originally excellent in grain growth due to being a low Si steel, and the iron loss value required is not so severe. It can be said that it is a material suitable for the direct-rolling method in which deterioration is a concern (Si> 1.0%
High-quality materials are at the opposite end of this).
(2)MnSの析出・粗大化は主としてMnの拡散律速と考
えられ、Mn量を高め、MnSの析出・粗大化を促進せしめ
る。(2) Precipitation and coarsening of MnS are considered to be mainly diffusion-controlling Mn, and increase the amount of Mn to promote precipitation and coarsening of MnS.
(3)さらに、Mn/S比を高めることでMnSの析出・粗大
化を一層促進し、粒成長性を損なうことのないようにす
る。(3) Further, by increasing the Mn / S ratio, precipitation and coarsening of MnS are further promoted, and the grain growth property is not impaired.
(4)Sについては、従来技術は極低S化によるMnSフ
リーを指向しているが、本発明法では全く逆の思想とす
る。すなわち、本発明法ではMnSをAlNの析出・粗大化に
際しての核として活用するため、Sを所要量添加しMnS
数を必要量確保する。但し、言うまでもなく過度のS添
加は、たとえMn/S比を高めMnSを粗大化したとしても、M
nSの絶対量そのものが徒らに増加し粒成長性を劣化させ
る。したがって、この点からSの上限が決まる。(4) Regarding S, the prior art is directed to MnS-free by making the S extremely low, but in the method of the present invention, the idea is completely opposite. That is, in the method of the present invention, since MnS is utilized as a nucleus for precipitation / coarsening of AlN, Sn is added in a required amount.
Secure the required number. However, needless to say, excessive S addition causes Mn / S ratio to increase, even if MnS is coarsened.
The absolute amount of nS itself increases unnecessarily and deteriorates the grain growth. Therefore, the upper limit of S is determined from this point.
(5)上記のように、粗大且つ十分な量析出したMnSがA
lN析出核として働くため、AlN析出・粗大化が促進され
る。その場合MnSと同様、AlNの析出・粗大化も主として
Alの拡散律速であるため、Al量は所要量以上添加する。(5) As described above, the coarse and sufficient amount of MnS deposited is A
Since it acts as lN precipitation nuclei, AlN precipitation and coarsening are promoted. In that case, as with MnS, the precipitation and coarsening of AlN are mainly
Since the diffusion rate of Al is limited, the required amount of Al is more than the required amount.
(6)上記(2)で述べたように、Mn/S比はMnS粗大化
のためにある値以上を必要とするが、同時にその上限も
存在する。これは、Mn/S比が過度に高いとAlNの析出・
粗大化の核となるべきMnSが粗大化し過ぎ、この結果MnS
の数が減り、AlNの析出・粗大化が遅滞するからであ
る。さらに、このMn/S比の上限はAl量に応じて決められ
るべきものである。すなわち、Al量が多い程AlNの析出
・粗大化は加速するため、AlNの析出・粗大化を助ける
核となるべきMnSの必要最低量が引き下げられるためで
ある。(6) As described in (2) above, the Mn / S ratio requires a certain value or more for MnS coarsening, but at the same time, there is an upper limit. This is because if the Mn / S ratio is excessively high, precipitation of AlN
MnS, which should be the core of coarsening, becomes too coarse. As a result, MnS
This is because the number of AlN decreases and the precipitation and coarsening of AlN is delayed. Furthermore, the upper limit of this Mn / S ratio should be determined according to the amount of Al. That is, as the amount of Al increases, the precipitation / coarsening of AlN accelerates, and the minimum required amount of MnS that serves as a nucleus that assists the precipitation / coarsening of AlN is reduced.
(7)このようにしてMnS、AlNの析出・粗大化が促進さ
せるように成分を調整したスラブを、連続鋳造後、特定
の冷却速度以下で冷却し、この間に主としてMnSの析出
・粗大化をなさしめる。ここで、特定の冷却速度以下と
したのは、上述のように成分を調整した鋼であっても、
冷却速度が早過ぎると、MnSの析出・粗大化のための時
間が十分確保されないからである。なお、この冷却速度
の上限がMnSの析出・粗大化を左右するMn量、Mn/S比に
応じて決まること、さらに、Al量によって、AlNの析出
・粗大化に必要なMnS核の最低量が変化することから、A
l量にも依存することは言うまでもない。また、冷却速
度の下限も考慮の必要がある。もちろんMnSの析出・粗
大化に対しては徐冷である程望ましいが、極端な徐冷は
実質上、従来技術が行っている保熱に等しく、表面製状
の劣化や生産性の低下を招くからである。(7) After continuous casting, the slab whose composition has been adjusted to promote the precipitation and coarsening of MnS and AlN in this way is cooled at a specific cooling rate or lower, and during this time the precipitation and coarsening of MnS is mainly detected. Give it. Here, the specific cooling rate or less, even if the steel adjusted the composition as described above,
This is because if the cooling rate is too fast, sufficient time for precipitation and coarsening of MnS cannot be secured. The upper limit of this cooling rate is determined according to the Mn amount and the Mn / S ratio that influence the precipitation and coarsening of MnS, and the minimum amount of MnS nuclei necessary for precipitation and coarsening of AlN depends on the Al amount. Changes, so A
Needless to say, it depends on the quantity. In addition, it is necessary to consider the lower limit of the cooling rate. Of course, slower cooling is more preferable for precipitation and coarsening of MnS, but extreme slow cooling is practically equivalent to the heat retention performed by the conventional technology, resulting in deterioration of surface shape and productivity. Because.
(8)スラブが冷却されるべき温度範囲もまた重要であ
る。すなわち、この温度が低過ぎると、続く熱間圧延で
スラブの変形能不足に起因した割れが発生したり、ミル
負荷が過大となりスラブの再加熱が必要となる。一方、
温度が高過ぎると、過飽和度との関係でMnSの析出・粗
大化の駆動力小さくなり、(7)で述べた適正冷却を行
ったとしても、MnSの析出・粗大化が十分達成されず、
このためスラブの高温保持が必須となってしまう。(8) The temperature range in which the slab should be cooled is also important. That is, if this temperature is too low, cracks due to insufficient deformability of the slab will occur in the subsequent hot rolling, or the mill load will become excessive and it will be necessary to reheat the slab. on the other hand,
If the temperature is too high, the driving force for MnS precipitation / coarsening becomes small in relation to the degree of supersaturation, and even if the proper cooling described in (7) is performed, MnS precipitation / coarsening is not sufficiently achieved.
Therefore, it is essential to keep the slab at a high temperature.
(9)このように上記Mn、S、Al量およびMn/S比の適正
化を行い、当該スラブを特定温度域に特定の冷却速度以
下で冷却した場合には、MnSの析出・粗大化が促進さ
れ、これを核としてスラブ冷却、熱間圧延および冷延板
の焼鈍という各段階でのAlNの析出・粗大化も促進さ
れ、これより再加熱法と比べて遜色のない磁気特性が得
られる。(9) When the above Mn, S, Al amount and Mn / S ratio are optimized in this way and the slab is cooled in a specific temperature range at a specific cooling rate or lower, MnS precipitation / coarsening occurs. It is accelerated, and the precipitation and coarsening of AlN at each stage of slab cooling, hot rolling, and annealing of cold-rolled sheet are promoted by using this as a nucleus, and magnetic properties comparable to those of the reheating method are obtained. .
本発明はこのような事項に基づきなされたもので、そ
の特徴とする構成は以下の通りである。The present invention has been made on the basis of such matters, and its characteristic configuration is as follows.
(1)重量%にて、C≦0.0050%、0.1%≦Si≦1.0%、
0.5%≦Mn≦1.5%、P≦0.15%、0.003%≦S≦0.015
%、0.01%≦Al≦0.40%、N≦0.0050%、残部Feおよび
不可避的不純物からなり、且つ、 60≦(〔Mn〕/〔S〕)≦580〔Al〕1/2+17 但し、〔Mn〕:Mn含有量(重量%) 〔S〕:S含有量(重量%) 〔Al〕:Al含有量(重量%) を満足する成分の鋼を連続鋳造でスラブとなし、該スラ
ブを、 但し、〔Mn〕:Mn含有量(重量%) 〔S〕:S含有量(重量%) 〔Al〕:Al含有量(重量%) を満足する冷却速度CR(℃/min)で1000〜1100℃の温度
域に冷却し、次いで保熱または再加熱することなく直ち
に、巻取温度650℃以上の熱間圧延を行い、酸洗および
冷間圧延後、700℃以上900℃以下の温度にて焼鈍するこ
とを特徴とする無方向性電磁鋼板の製造方法。(1) In weight%, C ≦ 0.0050%, 0.1% ≦ Si ≦ 1.0%,
0.5% ≦ Mn ≦ 1.5%, P ≦ 0.15%, 0.003% ≦ S ≦ 0.015
%, 0.01% ≤ Al ≤ 0.40%, N ≤ 0.0050%, balance Fe and unavoidable impurities, and 60 ≤ ([Mn] / [S]) ≤ 580 [Al] 1/2 +17 where [Mn ]: Mn content (% by weight) [S]: S content (% by weight) [Al]: Steel having a composition satisfying the Al content (% by weight) is formed into a slab by continuous casting, and the slab is However, [Mn]: Mn content (wt%) [S]: S content (wt%) [Al]: Al content (wt%) Cooling rate CR (℃ / min) 1000 ~ 1100 Cool to a temperature range of ℃, then immediately hot-roll at a coiling temperature of 650 ℃ or higher without heat retention or reheating, and after pickling and cold rolling, at a temperature of 700 ℃ to 900 ℃. A method for manufacturing a non-oriented electrical steel sheet, which comprises annealing.
(2)重量%にて、C≦0.0050%、0.1%≦Si≦1.0%、
0.5%≦Mn≦1.5%、P≦0.15%、0.003%≦S≦0.015
%、0.01%≦Al≦0.40%、N≦0.0050、残部Feおよび不
可避的不純物からなり、且つ、 60≦(〔Mn〕/〔S〕)≦580〔Al〕1/2+17 但し、〔Mn〕:Mn含有量(重量%) 〔S〕:S含有量(重量%) 〔Al〕:Al含有量(重量%) を満足する成分の鋼を連続鋳造でスラブとなし、該スラ
ブを、 但し、〔Mn〕:Mn含有量(重量%) 〔S〕:S含有量(重量%) 〔Al〕:Al含有量(重量%) を満足する冷却速度CR(℃/min)で1000〜1100℃の温度
域に冷却し、次いで保熱または再加熱することなく直ち
に、巻取温度650℃以上の熱間圧延を行い、酸洗および
冷間圧延後、700℃以上900℃以下の温度にて焼鈍し、次
いで絶縁被膜等の塗布・焼付けを行うことを特徴とする
無方向性電磁鋼板の製造方法。(2) In% by weight, C ≦ 0.0050%, 0.1% ≦ Si ≦ 1.0%,
0.5% ≦ Mn ≦ 1.5%, P ≦ 0.15%, 0.003% ≦ S ≦ 0.015
%, 0.01% ≤ Al ≤ 0.40%, N ≤ 0.0050, balance Fe and inevitable impurities, and 60 ≤ ([Mn] / [S]) ≤ 580 [Al] 1/2 +17 where [Mn] : Mn content (% by weight) [S]: S content (% by weight) [Al]: Al steel (Al% (% by weight)) However, [Mn]: Mn content (wt%) [S]: S content (wt%) [Al]: Al content (wt%) Cooling rate CR (° C / min) 1000 ~ 1100 Cool to a temperature range of ℃, then immediately hot-roll at a coiling temperature of 650 ℃ or more without heat retention or reheating, after pickling and cold rolling, at a temperature of 700 ℃ to 900 ℃ A method for manufacturing a non-oriented electrical steel sheet, which comprises annealing, then applying and baking an insulating coating and the like.
以下、試験例に基づき本発明の詳細およびその限定理
由につき説明する。Hereinafter, the details of the present invention and the reasons for limitation thereof will be described based on test examples.
(1)Mn量、S量、Al量およびMn/S比 C:0.0027%、Si:0.31%、P:0.085%、Al:0.08%、N:
0.0029%が一定でMn量およびS量を種々変えた鋼(鋼a
群)について、そのスラブを連続鋳造後、20℃/minの冷
却速度で1070℃まで冷却し、直ちに仕上温度850℃、巻
取温度670℃の条件で熱間圧延して得られた熱延板(直
送圧延材)と、上記スラブを常法にしたがい一旦室温ま
で冷却し、その後1220℃に再加熱し、上記直送圧延材と
同一条件で熱間圧延した熱延板(再加熱材)とを、それ
ぞれ酸洗後、仕上厚0.5mmに冷間圧延し、次いで750℃で
焼鈍し、これら焼鈍板の磁気特性をJISエプスタイン法
で測定(以下の各試験例でも同一の測定法を用いた)し
た。第1図はこれら直送圧延材と再加熱材の鉄損(W
15/50)と磁束密度(B50)の下、すなわち、 ΔW15/50=〔W15/50(直送圧延材)〕− 〔W15/50(再加熱材)〕 ΔB50=〔B50(直送圧延材)〕−〔B50(再加熱材)〕 をMn量とS量との関係で示している。(1) Mn amount, S amount, Al amount and Mn / S ratio C: 0.0027%, Si: 0.31%, P: 0.085%, Al: 0.08%, N:
Steel with a constant 0.0029% and various Mn and S contents (steel a
Group), the slab was continuously cast, then cooled to 1070 ° C at a cooling rate of 20 ° C / min, and immediately hot-rolled under the conditions of finishing temperature 850 ° C and coiling temperature 670 ° C. (Direct-rolled material) and a hot-rolled sheet (reheated material) hot-rolled under the same conditions as the direct-rolled material after cooling the slab once to room temperature according to the ordinary method, then reheating to 1220 ° C. , After pickling, cold-rolled to a finished thickness of 0.5 mm, then annealed at 750 ° C, and measured the magnetic properties of these annealed plates by JIS Epstein method (the same measurement method was used in the following test examples). did. Fig. 1 shows the iron loss (W
15/50 ) and the magnetic flux density (B 50 ), that is, ΔW 15/50 = [W 15/50 (direct rolled material)]-[W 15/50 (reheated material)] ΔB 50 = [B 50 (Direct rolled material)-[B 50 (reheated material)] is shown by the relationship between the amount of Mn and the amount of S.
また、C:0.0034%、Si:0.80%、P:0.051%、Al:0.27
%、N:0.0033%が一定でMn量およびS量を種々変えた鋼
(鋼b群)について、そのスラブを連属鋳造後、30℃/m
inの冷却速度で1020℃まで冷却し、直ちに仕上温度820
℃、巻取温度700℃の条件で熱間圧延して得られた熱延
板(直送圧延材)と、上記スラブを常法にしたがい一旦
室温まで冷却し、その後1250℃に再加熱し、上記直送圧
延材と同一条件で熱間圧延して得られた熱延板(再加熱
材)とを、それぞれ酸洗後、仕上厚0.5mmに冷間圧延
し、次いで850℃で焼純し、これら焼純板の磁気特性を
測定した。第2図はこれら直送圧延材と再加熱材との上
記ΔW15/50およびΔB50をMn量とS量との関係で示して
いる。Also, C: 0.0034%, Si: 0.80%, P: 0.051%, Al: 0.27
%, N: 0.0033% is constant, and Mn content and S content are variously changed (steel b group).
Cool to 1020 ℃ at a cooling rate of in, and immediately finish at 820
℃, the hot rolled plate obtained by hot rolling under the conditions of the coiling temperature 700 ℃ (directly rolled material), the slab is cooled to room temperature according to a conventional method, then reheated to 1250 ℃, The hot-rolled sheet (reheated sheet) obtained by hot rolling under the same conditions as the direct-rolled sheet was pickled, cold-rolled to a finished thickness of 0.5 mm, and then purified at 850 ° C. The magnetic properties of the pure plate were measured. FIG. 2 shows the above ΔW 15/50 and ΔB 50 of the direct-rolled material and the reheated material in the relationship between the amount of Mn and the amount of S.
以上の第1図および第2図に示す結果から、直送圧延
材が再加熱材と比べて遜色ない鉄損値(ΔW15/50<0.3
W/kg)と再加熱材よりも高位の磁束密度(ΔB50>0.01
T)を持つのは、鋼a群、鋼b群という鋼種にかかわり
なく、Mn≧0.5%、0.003%≦S≦0.015%、〔Mn/S〕≧6
0の領域であることが判る。なお、Mn/Sの上限について
は、鋼a群で181、鋼b群で318と、上記(6)で述べた
ように、Al量に依存して変化している。これについては
後述する。From the results shown in FIGS. 1 and 2 above, the iron loss value (ΔW 15/50 <0.3
W / kg) and higher magnetic flux density than reheated material (ΔB 50 > 0.01
T) has Mn ≥ 0.5%, 0.003% ≤ S ≤ 0.015%, [Mn / S] ≥ 6 regardless of the steel types of steel group a and steel group b.
It can be seen that the area is 0. The upper limit of Mn / S is 181 in the steel group a and 318 in the steel group b, which varies depending on the Al amount as described in (6) above. This will be described later.
また、本発明に関する上記(1)〜(9)の説明で
は、MnSおよびAlNの析出・粗大化の促進と、これによる
粒成長性および鉄損改善という側面からだけ述べたが、
磁束密度についても上限限定された成分範囲において
は、直送圧延材のほうが再加熱材より高くなっており、
本発明では磁束密度の向上をも図ることができる。この
理由の詳細は必ずしも明確ではないが、次のような理由
が考えられる。すなわち、粒成長性の観点からは、直送
圧延材と再加熱材とではMnS、AlNの析出状況に差はない
ものの、プロセスの違いに起因して、再加熱材よりも直
送圧延材のほうが、析出物が微細で数が多く、さらに直
送圧延材ではAlNの大半はMnSを核として析出する等、両
者には細かい面での析出物の分布状態、性状に差があ
る。そして、このような違いに基づき、直送圧延材では
冷間圧延時の歪の入り方、分布が再加熱材とは異なり、
これが続く焼鈍後の集合組織形成に影響を及ぼし、上述
したような磁速密度の向上をもたらすものと考えられ
る。Further, in the above description of (1) to (9) regarding the present invention, the description has been made only from the viewpoint of promoting precipitation / coarsening of MnS and AlN, and improving grain growth and iron loss by this.
As for the magnetic flux density, in the component range where the upper limit is limited, the directly rolled material is higher than the reheated material,
The present invention can also improve the magnetic flux density. Although the details of this reason are not always clear, the following reasons can be considered. That is, from the viewpoint of grain growth property, although there is no difference in the precipitation state of MnS, AlN between the direct-feed rolled material and the reheated material, due to the difference in the process, the direct-feed rolled material is more preferable than the reheated material. The precipitates are fine and large in number, and most of the AlN in the directly rolled material precipitates with MnS as the nuclei, etc. There is a difference in the distribution state and properties of the precipitates on the fine side. And, based on such a difference, in the direct-rolled material, the way of entering strain during cold rolling, the distribution is different from the reheated material,
It is considered that this affects the texture formation after the subsequent annealing and brings about the improvement of the magnetic velocity density as described above.
なお、この磁束密度はMnSの析出量を通じ、0.003%≦
S<0.005%ではΔB50=0.01〜0.02T、0.005%≦S≦0.
015%ではΔB50>0.02Tと、S量によって異なってい
る。したがって、鉄損値だけの観点からは0.003%≦S
≦0.015%で十分であるが、磁束密度を加味した観点か
らは、0.005%≦S≦0.015%とすることが好ましい。It should be noted that this magnetic flux density is 0.003% ≤ through the precipitation amount of MnS.
When S <0.005%, ΔB 50 = 0.01 to 0.02T, 0.005% ≦ S ≦ 0.
At 015%, ΔB 50 > 0.02T, which differs depending on the amount of S. Therefore, 0.003% ≦ S from the viewpoint of iron loss value only
≦ 0.015% is sufficient, but from the viewpoint of considering the magnetic flux density, 0.005% ≦ S ≦ 0.015% is preferable.
C:0.0027%、Si:0.31%、P:0.085%、N:0.0029%が一
定(鋼a群と同一)で、Mn量、S量およびMn/S比をMn≧
0.5%、0.003%≦S≦0.015%、Mn/S≧60の範囲(本発
明範囲)で変え、さらにAl量を種々変えた鋼(鋼c群)
と、C:0.0034%、Si:0.80%、P:0.051%、N:0.0033%が
一定(鋼b群と同一)で、Mn量、S量およびMn/S比を上
記鋼c群と同様の範囲で変え、さらにAl量を種々変えた
鋼(鋼d群)について、鋼c群については上述した鋼a
群(第1図)と同一製造プロセスで、また鋼d群につい
ては上述した鋼b群(第2図)と同一製造プロセスで、
それぞれ直送圧延材と再加熱材の焼鈍板を製造し、その
磁気特性を測定した。第3図はこれら直送圧延材と再加
熱材とのΔW15/50およびΔB50をMn/S比とAl量との関係
で示している。これによれば、上記(6)で述べたよう
に、直送圧延材のMn/S比の上限はAl量の関数として与え
られ、(Mn/S)≦(580〔Al〕1/2+17)の場合にのみ、
ΔW15/50<0.3W/kg、ΔB50>0.01Tという、再加熱材と
同程度の鉄損と再加熱材よりも高位の磁束密度を持つこ
とが判る。C: 0.0027%, Si: 0.31%, P: 0.085%, N: 0.0029% are constant (same as steel a group), Mn amount, S amount and Mn / S ratio are Mn ≧
Steels with different amounts of Al (0.5%, 0.003% ≤ S ≤ 0.015%, Mn / S ≥ 60)
And C: 0.0034%, Si: 0.80%, P: 0.051%, N: 0.0033% are constant (same as steel b group), and Mn amount, S amount and Mn / S ratio are the same as those of the steel c group. For steels (steel d group) in which the Al content was changed variously in the range, and for steel c group, steel a described above was used.
In the same manufacturing process as the group (Fig. 1) and for the steel d group, the same manufacturing process as the above-mentioned steel group b (Fig. 2),
The annealed plates of the direct rolled material and the reheated material were manufactured, and their magnetic properties were measured. FIG. 3 shows the ΔW 15/50 and ΔB 50 of these direct-rolled material and reheated material by the relationship between the Mn / S ratio and the Al content. According to this, as described in (6) above, the upper limit of the Mn / S ratio of the straight rolled material is given as a function of the amount of Al, and (Mn / S) ≤ (580 [Al] 1/2 +17) Only if
It can be seen that ΔW 15/50 <0.3 W / kg and ΔB 50 > 0.01 T have the same iron loss as the reheated material and a higher magnetic flux density than the reheated material.
また、同図によれば、上記(5)で述べたAl量の下限
が0.01%であることも判る。Also, according to the figure, it is understood that the lower limit of the Al amount described in (5) above is 0.01%.
以上の結果から、本発明では第4図に示すようにMn
量、S量、Al量およびMn/S比を以下のように規定した。From the above results, in the present invention, as shown in FIG.
The amount, the amount of S, the amount of Al, and the Mn / S ratio were defined as follows.
0.5%≦Mn≦1.5% 0.003%≦S≦0.015% (好ましくは0.005%≦S≦0.015%) 0.01%≦Al≦0.40% 60≦(〔Mn〕/〔S〕)≦580〔Al〕1/2+17 ここで、Mn量の上限を、1.5%としたのは、Mnを1.5%
を超えて添加しても磁気特性の改善はみられず、却って
コスト上昇を招くためである。同様に0.40%を超えるAl
の添加も徒らなコスト上昇を招き、加えて磁束密度の急
激な劣化も招くため、Al量の上限は0.40%とした。0.5% ≦ Mn ≦ 1.5% 0.003% ≦ S ≦ 0.015% (preferably 0.005% ≦ S ≦ 0.015%) 0.01% ≦ Al ≦ 0.40% 60 ≦ ([Mn] / [S]) ≦ 580 [Al] 1 / 2 +17 Here, the upper limit of the amount of Mn is set to 1.5% because Mn is 1.5%.
This is because the magnetic characteristics are not improved even if added in excess of the above, and rather the cost is increased. Similarly, Al exceeding 0.40%
The addition of Al causes an unnecessary increase in cost, and also causes a drastic deterioration of the magnetic flux density. Therefore, the upper limit of the Al content is set to 0.40%.
(2)その他の成分 C:0.0050%を超えて含有させると、磁気特性の劣化およ
び磁気時効の増大を招くため、本発明ではC≦0.0050%
の極低炭素鋼をその対象とする。(2) Other components C: If contained in excess of 0.0050%, deterioration of magnetic properties and increase in magnetic aging are caused. Therefore, in the present invention, C ≦ 0.0050%.
The target is ultra low carbon steel.
Si:固有抵抗の増加を通じて鉄損の低下をもたらす元素
であるが、この効果が十分に発揮されるには0.1%以上
の添加が必要である。但し、1.0%を超えるSiの添加は
磁束密度の急激な低下を招くため、上限は1.0%とす
る。Si: An element that causes a decrease in iron loss through an increase in specific resistance, but it is necessary to add 0.1% or more to fully exhibit this effect. However, addition of Si in excess of 1.0% causes a rapid decrease in magnetic flux density, so the upper limit is made 1.0%.
P:磁気特性をあまり損なうことなく、硬度上昇および打
ち抜き性の向上をもたらす元素である。但し、0.15%超
の添加はこれらの効果が飽和するのみならず、磁気特性
の急激な劣化につながるため、その上限は0.15%とす
る。P: An element that increases hardness and improves punchability without significantly impairing magnetic properties. However, addition of more than 0.15% not only saturates these effects but also leads to rapid deterioration of magnetic properties, so the upper limit is made 0.15%.
N:上記(5)で述べたように、AlNの析出・粗大化はMnS
核の数とAl量に強く依存するため、この意味からはN量
は特に規定する必要はない。但し、Nが0.0050%を超え
ると、固溶N自体の増加を通じて磁気特性が劣化するた
め、上限は0.0050%とする。N: As described in (5) above, precipitation and coarsening of AlN is caused by MnS
Since it strongly depends on the number of nuclei and the amount of Al, it is not necessary to specify the amount of N in this sense. However, if N exceeds 0.0050%, the magnetic properties deteriorate due to an increase in solid solution N itself, so the upper limit is made 0.0050%.
(3)連続鋳造後のスラブ冷却条件 C:0.0027%、Si:0.31%、P:0.085%、N:0.0029%が一
定(鋼a群と同一)で、Mn量、S量、Al量およびMn/S比
を本発明範囲で種々変えた鋼(鋼a群)と、C:0.0034
%、Si:0.80%、P:0.051%、N:0.0033%が一定(鋼b群
と同一)で、Mn量、S量、Al量およびMn/S比を本発明範
囲で種々変えた鋼(鋼f群)について、直送圧延材につ
いては連続鋳造後のスラブ冷却速度CRを種々変えた製造
プロセスを採用しつつ、直送圧延材および再加熱材の焼
純板を製造し、それらの磁気特性を測定した。その製造
プロセスは、直送圧延材について上記スラブ冷却速度を
変えた以外は、鋼e群について上述した鋼a群(第1
図)と、また鋼f群については上述した鋼b群(第2
図)とそれぞれ同一とした。なお、上記スラブ冷却速度
CRは、スラブの1/4幅、板厚1/4位置での1400℃からの平
均冷却速度(℃/min)で規定した。(3) Slab cooling conditions after continuous casting C: 0.0027%, Si: 0.31%, P: 0.085%, N: 0.0029% are constant (same as steel a group), Mn content, S content, Al content and Mn Steel with various A / S ratios within the range of the present invention (Steel a group) and C: 0.0034
%, Si: 0.80%, P: 0.051%, N: 0.0033% are constant (same as steel b group), and steels having various Mn content, S content, Al content and Mn / S ratio within the scope of the present invention ( For steel group f), for the straight rolled material, the manufacturing process with various slab cooling rate CR after continuous casting was adopted, and the straightened rolled material and the reheated material were manufactured and their magnetic properties were evaluated. It was measured. The manufacturing process is the same as the above-described steel group a (steel group a (first group) except that the slab cooling rate is changed for the straight rolled material).
Fig.), And the steel f group, the steel b group described above (second
(Fig.). The above slab cooling rate
CR was defined as the average cooling rate (℃ / min) from 1400 ℃ at 1/4 width of slab and 1/4 thickness.
第5図はこれら直送圧延材と再加熱材とのΔW15/50
およびΔB50をMn量、Al量およびMn/S比の関係とスラブ
冷却速度CRとの関係で示している。これによれば、上記
(7)で述べたようにスラブ冷却速度CRの上限は、Mn
量、Al量、Mn/S比の関数である として各鋼種毎に異なり、スラブを連続鋳造後、上記冷
却速度以下で冷却された場合にのみ、ΔW15/50<0.3W/
kg、ΔB50>0.01Tと良好な磁気特性が得られている。ま
た、上記(7)で述べたように、極端な徐冷は実質上ス
ラブの高温保持と等しく、表面性状の劣化や生産性の低
下を招くため、これを防ぐ意味から冷却速度CRの下限は
5℃/minとする必要がある。Fig. 5 shows the ΔW 15/50 between these directly rolled materials and reheated materials.
And ΔB 50 are shown by the relationship between the Mn amount, the Al amount and the Mn / S ratio and the slab cooling rate CR. According to this, as described in (7) above, the upper limit of the slab cooling rate CR is
Amount, Al amount, Mn / S ratio As is different for each steel type, ΔW 15/50 <0.3W / only when the slab is continuously cast and then cooled at the above cooling rate or less.
Good magnetic properties such as kg and ΔB 50 > 0.01T are obtained. Further, as described in (7) above, extreme slow cooling is substantially equivalent to keeping the slab at a high temperature, which leads to deterioration of surface quality and productivity, and in order to prevent this, the lower limit of the cooling rate CR is It should be 5 ° C / min.
次に、C:0.0041%、Si:0.12%、Mn:0.52%、P:0.111
%、S:0.008%、Al:0.03%、N:0.0033%、Mn/S=65の組
成を有する鋼、すなわち、本発明鋼にあってはMn、Al、
Mn/S比がいずれも低めであり、MnSおよびAlNの析出・粗
大化に対して成分的にかなり不利な鋼(鋼g:この鋼のス
ラブ冷却速度の上限は、上記の計算により52℃/minであ
る)と、C:0.0023%、Si:0.85%、Mn:1.47%、P:0.051
%、S:0.006%、Al:0.37%、N:0.0017%、Mn/S=245の
組成を有する鋼、すなわち、本発明鋼にあってはMn、A
l、Mn/S比がいずれも高めであり、MnSおよびAlNの析出
・粗大化に対して成分的にかなり有利な鋼(鋼h:この鋼
のスラブ冷却速度の上限は、上限の計算により138℃/mi
nである)について、下記条件の製造プロセスにより直
送圧延材および再加熱材の焼鈍板を製造し、それらの磁
気特性を測定した。製造プロセス中、直送圧延材につい
ては、その連続鋳造後のスラブ冷却速度CRを、鋼gでは
7℃/min(本発明の上限値以下)、45℃/min(同上限値
以下)および55℃/min(同上限値超)の3水準、鋼hで
は20℃/min(同上限値以下)、130℃/min(同上限値以
下)および145℃/min(同上限値超)の3水準とし、こ
れらの冷却速度でスラブを種々の温度まで冷却後、直ち
に熱間圧延を開始した。一方、比較材としての再加熱材
については、その再加熱温度を鋼gでは1220℃、鋼hで
は1250℃として熱間圧延を行った。なお、熱間圧延以降
のプロセスは、鋼gについては上述した鋼a群(第1
図)と、また鋼hについては上述した鋼b群(第2図)
と同一である。Next, C: 0.0041%, Si: 0.12%, Mn: 0.52%, P: 0.111
%, S: 0.008%, Al: 0.03%, N: 0.0033%, steel having a composition of Mn / S = 65, that is, Mn, Al in the steel of the present invention,
A steel with a relatively low Mn / S ratio and a compositionally disadvantageous to the precipitation and coarsening of MnS and AlN (steel g: The upper limit of the slab cooling rate of this steel is 52 ° C / min), C: 0.0023%, Si: 0.85%, Mn: 1.47%, P: 0.051
%, S: 0.006%, Al: 0.37%, N: 0.0017%, steel having a composition of Mn / S = 245, that is, Mn, A in the steel of the present invention.
l, Mn / S ratio are both high, and the composition is considerably advantageous for precipitation and coarsening of MnS and AlN (Steel h: The upper limit of the slab cooling rate of this steel is 138 ℃ / mi
(for n), annealed sheets of the straight rolled material and the reheated material were manufactured by the manufacturing process under the following conditions, and their magnetic properties were measured. During the manufacturing process, the slab cooling rate CR after continuous casting is 7 ° C./min (less than or equal to the upper limit of the present invention), 45 ° C./min (less than or equal to the upper limit of the present invention), and 55 ° C. / min (exceeding the same upper limit), steel h has 3 levels of 20 ° C / min (below the same upper limit), 130 ° C / min (below the same upper limit) and 145 ° C / min (over the same upper limit) After the slab was cooled to various temperatures at these cooling rates, hot rolling was immediately started. On the other hand, with respect to the reheated material as a comparative material, the reheating temperature was 1220 ° C. for steel g and 1250 ° C. for steel h, and hot rolling was performed. In addition, in the process after the hot rolling, for the steel g, the above-described steel a group (first
Fig.), And also for steel h, the steel b group described above (Fig. 2)
Is the same as
第6図は、鋼g、鋼hそれぞれについて、直送圧延材
と再加熱材とのΔW15/50をスラブ冷却温度との関係で
示している。これによれば、鋼g、鋼hとも、すなわち
MnS、AlNの析出・粗大化に有利な成分であると否とにか
かわらず、スラブの冷却速度が本発明範囲にある場合
(鋼gでは、7℃/min、45℃/min、鋼hでは20℃/min、
130℃/min)には、スラブ冷却温度が1000〜1100℃の範
囲において、直送圧延材はΔW15/50<0.3W/kgと、再加
熱材に比べて遜色のない鉄損を示す。これに対し、スラ
ブ冷却温度が1100℃超では、例え本発明鋼を本発明が規
定するスラブ冷却速度で冷却したとしても、ΔW15/50
>0.7W/kgとなり、優れた鉄損は得られない。FIG. 6 shows the ΔW 15/50 of the direct rolled material and the reheated material in relation to the slab cooling temperature for each of steel g and steel h. According to this, both steel g and steel h, that is,
If the cooling rate of the slab is within the range of the present invention regardless of whether or not it is an advantageous component for precipitation and coarsening of MnS and AlN (for steel g, 7 ° C / min, 45 ° C / min, for steel h, 20 ℃ / min,
At 130 ° C / min), in the slab cooling temperature range of 1000 to 1100 ° C, the directly rolled material exhibits ΔW 15/50 <0.3W / kg, which is comparable to the reheated material in iron loss. On the other hand, if the slab cooling temperature exceeds 1100 ° C, even if the present invention steel is cooled at the slab cooling rate specified by the present invention, ΔW 15/50
> 0.7 W / kg, so excellent iron loss cannot be obtained.
このような臨界温度の存在は上記(8)で述べたよう
に、MnSの析出・粗大化の駆動力の点から説明できる。
すなわぢ、連続鋳造後、所定の冷却速度でスラブが冷却
される際、温度が低下すればする程、MnSの過飽和度、
析出・粗大化の駆動力が増加する結果、MnSの析出・粗
大化は指数関数的変化をたどる。つまり、スラブ温度が
ある温度以下ではじめてMnSの析出・粗大化が急激に進
展することになる。したがって、MnSの析出・粗大化を
十分達成し、ひいてはこのMnSを核としてAlNの析出・粗
大化を促進するためには、スラブ冷却温度をある温度以
下とすることが必要となる。本発明法においては、この
温度が1100℃に該当する。The existence of such a critical temperature can be explained in terms of the driving force for precipitation and coarsening of MnS, as described in (8) above.
That is, when the slab is cooled at a predetermined cooling rate after continuous casting, the lower the temperature, the higher the degree of supersaturation of MnS,
As the driving force for precipitation / coarsening increases, the precipitation / coarsening of MnS follows an exponential change. In other words, the precipitation and coarsening of MnS rapidly progresses only when the slab temperature is below a certain temperature. Therefore, in order to achieve sufficient precipitation / coarsening of MnS and further promote precipitation / coarsening of AlN using MnS as a nucleus, it is necessary to set the slab cooling temperature to a certain temperature or lower. In the method of the present invention, this temperature corresponds to 1100 ° C.
一方、スラブの冷却温度が1000℃を下回ると、上記
(8)で述べたように、スラブの変形能不足のため熱延
板でエッジ割れが発生したり、あるいは950℃未満では
ミル負荷増大のために熱間圧延自体が不可能となってし
まう。On the other hand, when the cooling temperature of the slab is lower than 1000 ° C, as described in (8) above, edge cracking occurs in the hot rolled sheet due to insufficient deformability of the slab, or when the temperature is lower than 950 ° C, the mill load increases. Therefore, hot rolling itself becomes impossible.
なお、スラブの冷却速度が本発明の規定する範囲を超
える場合(鋼gで55℃/min、鋼hで145℃/min)には、
本発明鋼であっても、スラブの冷却温度にかかわりな
く、ΔW15/50>0.7W/kgであり、優れた鉄損が得られな
いことも確認できる。When the cooling rate of the slab exceeds the range specified by the present invention (55 g / min for steel g and 145 ° C./min for steel h),
Even with the steel of the present invention, ΔW 15/50 > 0.7 W / kg, regardless of the cooling temperature of the slab, and it can be confirmed that excellent iron loss cannot be obtained.
また、ΔB50については、スラブ冷却速度を本発明範
囲内とし、スラブ冷却温度を1100℃以下とした場合に
は、いずれも0.02Tを超えたが、スラブ冷却温度が1100
℃超であったり、スラブ冷却速度が本発明範囲外の場合
には、いずれも0.02Tを下回る結果となった。Regarding ΔB 50 , when the slab cooling rate was within the range of the present invention and the slab cooling temperature was 1100 ° C. or less, both exceeded 0.02T, but the slab cooling temperature was 1100.
When the temperature was higher than 0 ° C or the slab cooling rate was out of the range of the present invention, the result was less than 0.02T.
以上の結果から、本発明においては連続鋳造後、スラ
ブを鋼成分に応じて定まる所定の冷却速度以下で冷却す
ることに加え、その際のスラブの冷却温度域を1000℃以
上1100℃以下と規定する必要がある。From the above results, in the present invention, after continuous casting, in addition to cooling the slab at a predetermined cooling rate or less determined depending on the steel composition, the cooling temperature range of the slab at that time is specified to be 1000 ° C or more and 1100 ° C or less. There is a need to.
但し、上記冷却温度域の規定は、コストミニマム、生
産性マキシマムを前提としたものであり、コスト上ある
いは生産性上多少の余裕があり、スラブの再加熱が許容
される場合には、再加熱はMnSの析出・粗大化にはむし
ろ有利に働くため、スラブ冷却温度は1000℃を下回って
もよい。しかしながら、本発明者らの試算では、この温
度が600℃未満となると、再加熱に要するコスト、時間
が指数関数的に増加するため、600℃未満へのスラブの
降温は避けるべきである。また再加熱温度については、
熱間圧延性確保のため1000℃以上とすべきであることは
言うまでもないが、1150℃を超えると、一旦析出・粗大
化したMnSが再溶解するため、再加熱温度の上限は1150
℃とすることが望ましい。再加熱時間については、スラ
ブの均熱性確保、スケール増加防止の意味から10min以
上30min以下が適当と考えられる。However, the above cooling temperature range specifications are based on the assumption of minimum cost and maximum productivity, and there is some margin in terms of cost or productivity, and if reheating of the slab is allowed, reheating is recommended. Slab cooling temperature may be lower than 1000 ° C., since it acts rather favorably for precipitation and coarsening of MnS. However, according to the calculation by the present inventors, when the temperature is lower than 600 ° C., the cost and time required for reheating exponentially increase, and therefore the temperature decrease of the slab below 600 ° C. should be avoided. Regarding the reheating temperature,
Needless to say, the temperature should be 1000 ° C or higher to secure hot rolling property, but if it exceeds 1150 ° C, MnS once precipitated / coarsed is redissolved, so the upper limit of reheating temperature is 1150 ° C.
It is desirable to set the temperature to ° C. The reheating time is considered to be 10 minutes or more and 30 minutes or less in order to ensure the uniform heating of the slab and prevent scale increase.
(4)その他の製造条件 熱延条件: 巻取温度が650℃未満では、MnS、AlNの析出・粗大化
が不十分となることに加えて、熱延板の再結晶・粗粒化
の進展も遅滞し、その結果、直送圧延材、再加熱材とも
磁気特性の絶対値そのものが劣化する。このため巻取温
度は650℃以上とする必要がある。(4) Other manufacturing conditions Hot rolling conditions: When the coiling temperature is lower than 650 ° C, precipitation and coarsening of MnS and AlN are insufficient, and progress of recrystallization and coarsening of the hot rolled sheet Is also delayed, and as a result, the absolute values of the magnetic properties themselves of both the straight-rolled material and the reheated material deteriorate. Therefore, the winding temperature must be 650 ° C or higher.
仕上温度については、MnS、AlNの析出・粗大化の進展
に対いては影響が小さいため特に規定する必要はない
が、巻取温度を確保する点から750℃以上とすることが
望ましい。The finishing temperature does not need to be specified because it has little effect on the progress of precipitation and coarsening of MnS and AlN, but it is preferably 750 ° C or higher from the viewpoint of ensuring the winding temperature.
酸洗、冷間圧延条件: 特に規定の必要はなく、常法で行うことが可能であ
る。Pickling and cold rolling conditions: There is no particular requirement, and it can be carried out by a conventional method.
焼鈍条件: 焼鈍温度が700℃未満の場合、上記熱延巻取温度と同
様に磁気特性の絶対値そのものが劣化するため、下限は
700℃とする。一方、焼鈍温度が900℃を超えると徒らな
コスト上昇を招くばかりでなく、フェライト粒の過度の
粗大化により、磁気特性上好ましくない集合組織が発達
し、これに起因して磁束密度が低下するため、上限は90
0℃とする。Annealing conditions: If the annealing temperature is less than 700 ° C, the absolute value of the magnetic properties itself deteriorates as with the hot rolling temperature above, so the lower limit is
Set to 700 ° C. On the other hand, if the annealing temperature exceeds 900 ° C, not only will the cost be unnecessarily increased, but excessive coarsening of the ferrite grains will develop an unfavorable texture in terms of magnetic properties, which will lower the magnetic flux density. Therefore, the upper limit is 90
Set to 0 ° C.
第1表に示す鋼を用い、そのスラブを連続鋳造後、種
々の冷却速度にて種々の温度まで冷却した後、直ちに熱
間圧延して得られた熱延板(直送圧延材)と、比較材と
して上記スラブを一旦室温まで冷却した後、所定の温度
に再加熱し、次いで直送圧延材と同一条件で熱間圧延し
て得られた熱延板(再加熱材)について、これらを酸洗
後、仕上厚0.5mmに冷間圧延し、続いて3minの焼鈍を行
った。このようにして得られた鋼板のエプスタイン磁気
特性(直送圧延材および再加熱材の磁気特性と、両者の
磁気特性の差)を具体的な製造条件とともに第2−a表
〜第2−c表および第3−a表〜第3−c表に示す。Using the steels shown in Table 1, the slabs were continuously cast, cooled to various temperatures at various cooling rates, and immediately hot-rolled. For the hot rolled sheet (reheated material) obtained by cooling the slab as a material once to room temperature, then reheating it to a prescribed temperature, and then hot rolling it under the same conditions as the straight rolled material After that, it was cold-rolled to a finished thickness of 0.5 mm and subsequently annealed for 3 minutes. The Epstein magnetic properties (the magnetic properties of the straight-rolled material and the reheated material, and the difference between the magnetic characteristics of the two) obtained in this manner are shown in Tables 2-a to 2-c together with specific manufacturing conditions. And Tables 3-a to 3-c.
第2−a表〜第2−c表は鋼成分の影響を調べたもの
で、比較材については成分以外の条件はいずれも本発明
条件を満足している。同表によれば、本発明法による直
送圧延材は、ΔW15/50<0.3W/kg、ΔB50>0.01Tと、再
加熱材に較べて遜色のない鉄損値と、再加熱材よりも高
位の磁束密度を示すのに対し、比較鋼では、ΔB50につ
いては本発明鋼と同等の値を示すものはあるものの、鉄
損に関してはいずれもΔW15/50>0.7W/kgであり、直送
圧延により鉄損が大幅に劣化することが判る。Tables 2-a to 2-c show the effects of the steel components, and the comparative materials all satisfy the conditions of the present invention except for the components. According to the table, the directly rolled material according to the method of the present invention has ΔW 15/50 <0.3 W / kg, ΔB 50 > 0.01 T, which is comparable to the reheated material, and the iron loss value is higher than that of the reheated material. Also shows a high magnetic flux density, whereas some comparative steels show the same ΔB 50 as the invention steel, but the iron loss is ΔW 15/50 > 0.7 W / kg. It can be seen that the direct loss rolling significantly deteriorates the iron loss.
第3−a表〜第3−c表は、製造条件のうちスラブ冷
却速度とスラブ冷却温度の影響を調べたものである。こ
の場合もスラう冷却速度とスラブ冷却温度が本発明条件
を満足する直送圧延は、ΔW15/50<0.3W/kg、ΔB50>
0.01Tと、再加熱材と較べても遜色のない鉄損値と、再
加熱材よりも高位の磁束密度が得られている。これに対
し、スラブ冷却速度やスラブ冷却温度が本発明範囲外の
比較例では、ΔB50は本発明材と同等のものはあるもの
の、鉄損はいずれもΔW15/50>0.7W/kgであり、直送圧
延材の鉄損は再加熱材に較べて大幅に上昇してしまう。Tables 3-a to 3-c show the effects of the slab cooling rate and the slab cooling temperature in the manufacturing conditions. Also in this case, ΔW 15/50 <0.3 W / kg, ΔB 50 > for direct feed rolling in which the slab cooling rate and the slab cooling temperature satisfy the conditions of the present invention.
An iron loss value of 0.01T, which is comparable to that of the reheated material, and a magnetic flux density higher than that of the reheated material were obtained. On the other hand, in Comparative Examples in which the slab cooling rate and the slab cooling temperature are out of the range of the present invention, ΔB 50 is the same as that of the present invention material, but the iron loss is ΔW 15/50 > 0.7 W / kg. However, the core loss of the straight-rolled material is significantly higher than that of the reheated material.
〔発明の効果〕 以上述べた本発明によれば、無方向性電磁鋼板の製造
に直接圧延を適用するにあたり、従来技術では必須であ
った鋼成分の特殊な調整や、スラブの高温・長時間保
持、再加熱といったコスト上昇や生産性低下を招く工程
を必要とせず、直送圧延本来の利点であるコストミニマ
ム、生産性マキシマムを実現しつつ、再加熱材と同等な
いしはそれ以上の磁気特性を有する無方向性電磁鋼板を
製造することができる。 [Advantages of the Invention] According to the present invention described above, in applying the direct rolling to the production of the non-oriented electrical steel sheet, the special adjustment of the steel composition, which was indispensable in the prior art, and the high temperature / long time of the slab were required. It does not require steps such as holding and reheating that increase costs and decreases productivity, and realizes the minimum cost and productivity maximum that are the original advantages of direct-feed rolling, and has magnetic properties equivalent to or better than those of reheated materials. A non-oriented electrical steel sheet can be manufactured.
第1図および第2図は、直送圧延材と再加熱材の磁気特
性の差(ΔW15/50、ΔB50)に対するMn量、S量および
Mn/S比の影響とその適正範囲を示すグラフである。第3
図は、直送圧延材と再加熱材の磁気特性の差に対するAl
量、Mn/S比の影響とその適正範囲を示すグラフである。
第4図は、Mn量、S量、Al量およびMn/S比に関する本発
明範囲を示すグラフである。第5図は、直送圧延材と再
加熱材の磁気特性の差に対する直送圧延材のスラブ冷却
速度の影響とその適正範囲を示すグラフである。第6図
は、直送圧延材と再加熱材の鉄損W15/50の差に対する
直送圧延材のスラブ冷却温度の影響とその適正範囲を示
すグラフである。FIGS. 1 and 2 is, Mn ratios for differences in the magnetic characteristics of the hot direct rolling material and reheating material (ΔW 15/50, ΔB 50), S amount and
6 is a graph showing the influence of the Mn / S ratio and its appropriate range. Third
The figure shows Al against the difference in the magnetic properties of the straight rolled material and the reheated material.
6 is a graph showing the influence of the amount and Mn / S ratio and its appropriate range.
FIG. 4 is a graph showing the range of the present invention regarding the amount of Mn, the amount of S, the amount of Al, and the Mn / S ratio. FIG. 5 is a graph showing the influence of the slab cooling rate of the straight-rolled material on the difference in magnetic characteristics between the straight-rolled material and the reheated material, and its appropriate range. FIG. 6 is a graph showing the influence of the slab cooling temperature of the straight-rolled material on the difference in iron loss W 15/50 between the straight-rolled material and the reheated material and its appropriate range.
Claims (2)
1.0%、0.5%≦Mn≦1.5%、P≦0.15%、0.003%≦S≦
0.015%、0.01%≦Al≦0.40%、N≦0.0050%、残部Fe
および不可避的不純物からなり、且つ、 60≦(〔Mn〕/〔S〕)≦580〔Al〕1/2+17 但し、〔Mn〕:Mn含有量(重量%) 〔S〕:S含有量(重量%) 〔Al〕:Al含有量(重量%) を満足する成分の鋼を連続鋳造でスラブとなし、該スラ
ブを、 但し、〔Mn〕:Mn含有量(重量%) 〔S〕:S含有量(重量%) 〔Al〕:Al含有量(重量%) を満足する冷却速度CR(℃/min)で1000〜1100℃の温度
域に冷却し、次いで保熱または再加熱することなく直ち
に、巻取温度650℃以上の熱間圧延を行い、酸洗および
冷間圧延後、700℃以上900℃以下の温度にて焼鈍するこ
とを特徴とする無方向性電磁鋼板の製造方法。1. In weight%, C ≦ 0.0050%, 0.1% ≦ Si ≦
1.0%, 0.5% ≦ Mn ≦ 1.5%, P ≦ 0.15%, 0.003% ≦ S ≦
0.015%, 0.01% ≦ Al ≦ 0.40%, N ≦ 0.0050%, balance Fe
And unavoidable impurities, and 60 ≦ ([Mn] / [S]) ≦ 580 [Al] 1/2 +17 where [Mn]: Mn content (wt%) [S]: S content ( Wt%) [Al]: A steel having a composition satisfying the Al content (wt%) is formed into a slab by continuous casting, and the slab is However, [Mn]: Mn content (wt%) [S]: S content (wt%) [Al]: Al content (wt%) Cooling rate CR (℃ / min) 1000 ~ 1100 Cool to a temperature range of ℃, then immediately hot-roll at a coiling temperature of 650 ℃ or more without heat retention or reheating, after pickling and cold rolling, at a temperature of 700 ℃ to 900 ℃ A method for manufacturing a non-oriented electrical steel sheet, which comprises annealing.
1.0%、0.5%≦Mn≦1.5%、P≦0.15%、0.003%≦S≦
0.015%、0.01%≦Al≦0.40%、N≦0.0050、残部Feお
よび不可避的不純物からなり、且つ、 60≦(〔Mn〕/〔S〕)≦580〔Al〕1/2+17 但し、〔Mn〕:Mn含有量(重量%) 〔S〕:S含有量(重量%) 〔Al〕:Al含有量(重量%) を満足する成分の鋼を連続鋳造でスラブとなし、該スラ
ブを、 但し、〔Mn〕:Mn含有量(重量%) 〔S〕:S含有量(重量%) 〔Al〕:Al含有量(重量%) を満足する冷却速度CR(℃/min)で1000〜1100℃の温度
域に冷却し、次いで保熱または再加熱することなく直ち
に、巻取温度650℃以上の熱間圧延を行い、酸洗および
冷間圧延後、700℃以上900℃以下の温度にて焼鈍し、次
いで絶縁皮膜等の塗布・焼付けを行うことを特徴とする
無方向性電磁鋼板の製造方法。2. In% by weight, C ≦ 0.0050%, 0.1% ≦ Si ≦
1.0%, 0.5% ≦ Mn ≦ 1.5%, P ≦ 0.15%, 0.003% ≦ S ≦
0.015%, 0.01% ≤ Al ≤ 0.40%, N ≤ 0.0050, balance Fe and inevitable impurities, and 60 ≤ ([Mn] / [S]) ≤ 580 [Al] 1/2 +17 where [Mn ]: Mn content (% by weight) [S]: S content (% by weight) [Al]: Steel having a composition satisfying the Al content (% by weight) is formed into a slab by continuous casting, and the slab is However, [Mn]: Mn content (wt%) [S]: S content (wt%) [Al]: Al content (wt%) Cooling rate CR (℃ / min) 1000 ~ 1100 Cool to a temperature range of ℃, then immediately hot-roll at a coiling temperature of 650 ℃ or higher without heat retention or reheating, and after pickling and cold rolling, at a temperature of 700 ℃ to 900 ℃. A method for manufacturing a non-oriented electrical steel sheet, which comprises annealing, followed by application of an insulating film and baking.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2048357A JPH0819467B2 (en) | 1990-02-28 | 1990-02-28 | Non-oriented electrical steel sheet manufacturing method |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2048357A JPH0819467B2 (en) | 1990-02-28 | 1990-02-28 | Non-oriented electrical steel sheet manufacturing method |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH03249130A JPH03249130A (en) | 1991-11-07 |
JPH0819467B2 true JPH0819467B2 (en) | 1996-02-28 |
Family
ID=12801104
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JP2048357A Expired - Fee Related JPH0819467B2 (en) | 1990-02-28 | 1990-02-28 | Non-oriented electrical steel sheet manufacturing method |
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Country | Link |
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JP (1) | JPH0819467B2 (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
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FR2757541B1 (en) * | 1996-12-19 | 1999-01-22 | Lorraine Laminage | MAGNETIC STEEL SHEET WITH NON-ORIENTED GRAINS |
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1990
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