JPH0250190B2 - - Google Patents
Info
- Publication number
- JPH0250190B2 JPH0250190B2 JP57184167A JP18416782A JPH0250190B2 JP H0250190 B2 JPH0250190 B2 JP H0250190B2 JP 57184167 A JP57184167 A JP 57184167A JP 18416782 A JP18416782 A JP 18416782A JP H0250190 B2 JPH0250190 B2 JP H0250190B2
- Authority
- JP
- Japan
- Prior art keywords
- iron loss
- grain size
- impurities
- oriented silicon
- silicon steel
- 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 - Lifetime
Links
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 97
- 229910052742 iron Inorganic materials 0.000 claims description 48
- 239000012535 impurity Substances 0.000 claims description 23
- 229910000976 Electrical steel Inorganic materials 0.000 claims description 20
- 229910052710 silicon Inorganic materials 0.000 claims description 7
- 229910000831 Steel Inorganic materials 0.000 description 21
- 239000010959 steel Substances 0.000 description 21
- 239000013078 crystal Substances 0.000 description 18
- 239000000463 material Substances 0.000 description 12
- 238000000137 annealing Methods 0.000 description 11
- 230000000694 effects Effects 0.000 description 9
- 239000000203 mixture Substances 0.000 description 9
- 238000005097 cold rolling Methods 0.000 description 5
- 239000011162 core material Substances 0.000 description 5
- 230000009467 reduction Effects 0.000 description 5
- 230000003009 desulfurizing effect Effects 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 239000000047 product Substances 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 3
- 238000007796 conventional method Methods 0.000 description 3
- 238000007664 blowing Methods 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 238000009749 continuous casting Methods 0.000 description 2
- 238000006477 desulfuration reaction Methods 0.000 description 2
- 230000023556 desulfurization Effects 0.000 description 2
- 230000004907 flux Effects 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 229910052761 rare earth metal Inorganic materials 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 229910052684 Cerium Inorganic materials 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000007872 degassing Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 238000004134 energy conservation Methods 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 230000020169 heat generation Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000005098 hot rolling Methods 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 230000005389 magnetism Effects 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000001000 micrograph Methods 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 238000005554 pickling Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
Landscapes
- Soft Magnetic Materials (AREA)
Description
この発明は、鉄損の少ない無方向性珪素鋼板に
かかり、特にＳ、Ｏ、Ｎ含有量の極低下にあわせ
平均結晶粒径を所定範囲のものにしたものよりな
る、極めて小さい鉄損値を示す無方向性珪素鋼板
に関するものである。
無方向性珪素鋼板は、回転機のローター、ステ
ーター等の鉄心に多く用いられるが、特に大型回
転機用鉄心材料については、省エネルギーや安全
操業の面から、電力損失や発熱量の軽減を目指す
傾向が強く、鉄損の少ない無方向性珪素鋼板の開
発が強く要請される現状にある。
ところで、従来無方向性珪素鋼板の鉄損値を低
くするために、SiおよびAlの添加量を増やし、
電気抵抗を高めて鉄損を低下させる方法が知られ
ている。しかし、鉄損を現在水準よりさらに向上
させる必要があるときに、今以上にSiやAlの添
加量を増すと、冷間加工性が悪くなるので、現在
の水準以上の添加量にすることは困難を伴う。そ
の他、熱間加工性を改善するために添加している
Mnについては、磁気特性に与える影響が小さ
く、また多量に添加すると逆に磁気特性を劣化さ
せるので鉄損値を低下させる元素として不適当で
ある。
そこで、本発明者らは、Ｓ、Ｏ、Ｎといつた鋼
中不純物に着目し、これら不純物と鉄損の関係、
およびこれら不純物と結晶粒径ならびに鉄損の関
係を研究することにより、従来技術では得られな
かつた極めて低い鉄損の無方向性珪素鋼板を得る
ことが可能になることを知見するに到つた。
すなわち、鋼中不純物としてのＳ、Ｏ、Ｎの含
有量がＳ15ppm、Ｏ20ppm、Ｎ25ppmであ
ると鉄損が少なく、かつこうした純度の良い材料
では最良の鉄損値をもたらすところの結晶粒径の
値が、従来最適と思われていた結晶粒径の値とは
異なることを見出し、本発明を完成させた。
要するに、本発明は、機械的諸性質を阻害する
ことなく鉄損値のみが在来水準を超えて低いもの
になる無方向性珪素鋼板を、不純物：Ｓ、Ｏ、Ｎ
を極低下すること平均結晶粒径を最適の範囲のも
のにすることにより得たのである。
このことから、本発明者らは、先ず不純物成分
（Ｓ、Ｏ、Ｎ）が鉄損に及ぼす影響を知るため、
上記各不純物の濃度を種々変化させた3.2％Si−
0.60％Al−0.20％Mnを含有する鋼を出鋼し、常
法に従う圧延、熱処理を経て厚み0.35mmの無方向
性珪素鋼板を製造した。その結果、Ｃは0.005％
以下であるならば、鉄損に及ぼす影響が小さいの
に対し、Ｓ、Ｏ、Ｎについてはその影響が大きく
鉄損と極めて強い相関が認められた。そのうち、
Ｓ、Ｏについては、含有量の低減が鉄損の改善に
直接結びつくことは既に特公昭56−22931号や特
開昭53−66816号として提案された中に開示され
ており、Ｏ含有量を25ppm以下、Ｓ含有量を
50ppm以下（望ましくは30ppm以下）に規制する
ことが提案されている。Ｎ含有量についても、
30ppm以下に規制することが望ましい実施態様で
あることが知られている。
しかしながら、これらの報告や実施例における
含有量は、例えば、Ｓを例にとると低くてもその
含有量は20〜30ppm程度のものしか報告されてい
ず、それ以上さらに低いレベルまでの不純物の影
響については不明である。
そこで、本発明者らは、そのより低いレベルで
の不純物の影響について調査した。その結果によ
ると、Ｓ：15ppm、Ｏ：20ppm、Ｎ：25ppmのレ
ベルまで下げると鉄損の低減効果は著しいものと
なり、例えばＳ＝15ppm、Ｏ＝20ppm、Ｎ＝
25ppmに下げると、鉄損値はW10/50≒0.90、
W10/50≒2.20すなわちS8級相当の鉄損のものが得
られることが判つた。ところが、その含有量をさ
らに低いレベルのものに下げても、鉄損の低減は
期待した程には大きくなく、S7級相当（W10/50
0.85、W15/502.00）の鉄損材料を得ることはで
きなかつた。
本発明者らは、この原因を把むべく種々の検討
を行つた結果、最良の鉄損値を示す鋼板の適正結
果粒径が、約130μｍと考えられていた従来の値
よりも大きい場合に低鉄損となることを見出し
た。第１図は、上述の実験において、最終仕上げ
焼鈍条件を従来から通常行つている950℃×５分
としたものと、結晶粒を粗大化させるべく、1030
℃×５分としたものについて、不純物Ｓ、Ｏ、Ｎ
各含有量と鉄損の関係を示したものである。この
図から判るように、Ｓ15ppm、Ｏ20ppm、Ｎ
25ppmの不純物を含む領域においては、従来採
用していた焼鈍条件に代え高い温度で焼鈍して結
晶粒を粗大化傾向に導いた鋼の方がより低い鉄損
値を示す。さらに、本発明者らは、Ｓ15ppm、
Ｏ20ppm、Ｎ25ppmの高純度の材料を用い
て、焼鈍時間、焼鈍温度を種々変化させたものに
ついて研究を進めた結果、焼鈍時間や焼鈍温度の
選択のみが、鉄損改善に有効に作用するのではな
く、最良の鉄損値をもたらすための最適結晶粒径
が高純度化によつて、粗粒側に移行したことが原
因であることを新規に見出した。これを第２図を
用いて詳しく説明する。
第２図は、鉄損と平均結晶粒径との関係を示し
たもので、ａは、不純物として、Ｓ＝32ppm、Ｏ
＝22ppm、Ｎ＝26ppm含有させた従来の材料、ｂ
は、不純物としてＳ＝8ppm、Ｏ＝7ppm、Ｎ＝
14ppm含有させた本発明の材料で、ともにSiは
3.2％、Alは0.60％、Mnは0.20％である。鉄損は
ヒステリシス損と渦電流損からなるが、ヒステリ
シス損は結晶粒径が大きくなると急激に低下し、
逆に渦電流損の方は結晶粒径が大きくなると増加
してくるという相反する作用のもとで、第２図に
示すように、ある適正な結晶粒径のところで、両
者が均衡された状態となり、その位置で鉄損値が
極小値をとる。この最も低鉄損値を示す平均結晶
粒径を最適平均結晶粒径と呼称している。
一般に、かかる最適平均結晶粒径は、Si＋Al
の含有量によつて異なり、SiやAlの含有量が増
加する程大きくなることが知られている。ところ
がこの第２図に示されるように、材料のＳ、Ｏ、
Ｎの含有量によつて最適とする平均結晶粒径が変
化することは、これまで知られていなかつたこと
である。
そこで、本発明の組成範囲内であるＳ
15ppm、Ｏ20ppm、Ｎ25ppmである材料の最
適平均結晶粒径と従来より用いられている材料の
最適平均結晶粒径について、（Si＋Al）％との関
係を求めた。その結果、第３図に示すが、S7級
の低鉄損値を示す本発明材料の最適平均結晶粒径
は、従来用いられている材料の最適平均結晶粒径
よりは粗粒側に移行していて明確な区別があり、
図中判断されるその粒径の値は100＋3.5×〔Si＋
Al％〕2と170＋50×〔Si＋Al％〕2で狭まれる範囲で
ある。従来材よりも範囲が広い理由は、第２図に
示されるように極小値付近での特性の変化が小さ
いためである。第３図において特に、最適平均結
晶粒径の頻度の高い範囲は120＋3.5×〔Si＋Al％〕
2と160＋50×〔Si＋Al％〕2で狭まれる範囲である
ことより、統計的処理を行えば、この範囲に最も
特性のよくなる領域があると推定できる。
要するに本発明で目指す低鉄損値の材料を得る
には、Ｓ、Ｎ、Ｏの含有量を極低下することにあ
わせ、その特性をさらに生かすには平均結晶粒径
が粗粒側に移行したある限られた範囲内のものに
調整することが必要である。
なお、Ｓ、Ｏ、Ｎ含有量の極めて低くした材料
で、最適平均結晶粒径が粗粒側に移行したときに
低鉄損値を示す理由は次のように推定される。す
なわち、鉄損はヒステリシス損と渦電流損とから
なつていることは前述したが、このうち、渦電流
損は、Ｓ、Ｏ、Ｎといつた不純物には関与しな
い。一方、ヒステリシス損は、材料の不純物や、
粒界密度が増加すると増加する。しかるに、粒界
密度の高い細粒側では、粒界密度がヒステリシス
損劣化の主要因となるため、不純物低減の効果が
現われにくく、逆に、粒界密度の低い粗粒側で
は、不純物が劣化の主要因となるため、不純物低
減の効果が大きく現われる。要するに、不純物減
少によるヒステリシス損の減少は細粒側で小さく
粗粒側で大きいことになるのである。しかも、渦
電流損は変らず、ヒステリシス損のみこのように
変化するのであるから、総和としての鉄損が極小
を示す最適平均結晶粒径は、当然粗粒側に移行し
本発明のような現象をもたらしたものと推定され
るのである。
以上説明したように、本発明者らは、Ｓ
15ppm、Ｏ20ppm、Ｎ25ppmの極低下した不
純物領域にある鋼では、平均結晶粒径（μｍ）
が、
100＋3.5×〔Si％＋Al％〕2170＋5.0×〔Si
％＋Al％〕2
の範囲に含まれるようなものをつくると極めて低
い鉄損の無方向性珪素鋼板が得られることを新規
に見出した。
なお、このような性質をもつ無方向性珪素鋼板
は、上記成分組成に限定される限り従来の一般的
な製造方法の採用でよい。例えば、吹練を行つた
溶鋼を脱ガス処理し、所定の成分組成のものに調
整後、鋳型に注入して造塊後分塊圧延を行いスラ
ブ（鋼片）とするか、連続鋳造法によりスラブに
した後、常法に従つて熱間圧延、冷間圧延工程を
経て製品とするものである。
以下に本発明の成分組成の範囲について述べ
る。
Ｃは、0.005重量％を超えると時効を起こし、
特性を劣化させるので、0.005重量％以下とする。
Siは、4.0重量％を超えると冷延性が悪くなる
ので、4.0重量％までとする。また2.5重量％未満
では、電気抵抗が低く、鉄損が増加して、本発明
の所期した効果である低鉄損の無方向性珪素鋼板
が得られなくなるので、2.5重量％を下限とする。
Alは、Siと同様電気抵抗を高めて、低鉄損化
に効果があるが、1.0重量％を超えるとSi同様冷
間加工性が悪くなり、0.25重量％未満では鉄損が
大幅に劣化するので、0.25重量％から1.0重量％
までとする。
Mnは、熱間加工性の面から0.1重量％以上必要
であるが、1.0重量％を超えると磁性が劣化する
ので、0.1重量％から1.0重量％までとする。
さらに、本発明鋼は、とくに不純物として含む
もののうち、Ｓ15ppm、Ｏ20ppm、Ｎ
25ppmをいずれも満足することが、低鉄損の実現
には必要であり、かつ、最終製品板が有するその
平均結晶粒径（μｍ）が（Si＋Al）％との関
係で、
100＋3.5×〔Si％＋Al％〕2170＋5.0×〔Si
％＋Al％〕2
なる大きさに調整されていることが要求され、こ
うした成分組成および結晶粒径を有するものにす
ることによつて極めて低い鉄損値を示す無方向性
珪素鋼板とすることができるのである。このよう
な平均結晶粒径のものにすることが、上記の極低
Ｓ、Ｏ、Ｎ成分組成と相乗的に作用することと相
俟つて、所期した効果が得られる。第４図は、正
に従来の無方向性珪素鋼板ｂの平均結晶粒径
（124μｍ）と本発明鋼ａ平均結晶粒径（208μｍ）
との比較を示す。
次に、本発明鋼の特性についての試験結果を、
第１表にもとづいて説明する。
This invention relates to a non-oriented silicon steel sheet with low core loss, and in particular, a non-oriented silicon steel sheet with an extremely low core loss value, which is made of a non-oriented silicon steel sheet with an extremely low S, O, and N content and an average crystal grain size within a predetermined range. The present invention relates to a non-oriented silicon steel plate. Non-oriented silicon steel sheets are often used for cores of rotors, stators, etc. of rotating machines.In particular, core materials for large rotating machines tend to aim to reduce power loss and heat generation from the standpoint of energy conservation and safe operation. Currently, there is a strong demand for the development of non-oriented silicon steel sheets with strong iron loss and low iron loss. By the way, in order to lower the iron loss value of conventional non-oriented silicon steel sheets, the amount of Si and Al added was increased.
A method of increasing electrical resistance and lowering iron loss is known. However, when it is necessary to further improve iron loss from the current level, increasing the amount of Si or Al added will worsen cold workability, so increasing the amount beyond the current level is not recommended. accompanied by difficulties. Others are added to improve hot workability.
Mn has a small effect on the magnetic properties, and when added in large amounts, the magnetic properties deteriorate, so it is not suitable as an element for reducing the iron loss value. Therefore, the present inventors focused on impurities in steel such as S, O, and N, and determined the relationship between these impurities and iron loss.
By studying the relationship between these impurities, grain size, and iron loss, we have found that it is possible to obtain a non-oriented silicon steel sheet with extremely low iron loss, which has not been possible with conventional techniques. In other words, when the content of S, O, and N as impurities in the steel is S15ppm, O20ppm, and N25ppm, the iron loss is small, and the value of the crystal grain size that brings about the best iron loss value for such high-purity materials. However, the present invention was completed based on the discovery that the value of the crystal grain size is different from the value conventionally considered to be optimal. In short, the present invention provides a non-oriented silicon steel sheet with impurities: S, O, N, which has only an iron loss value that is lower than the conventional level without impeding mechanical properties.
This was achieved by minimizing the average crystal grain size and bringing it within the optimum range. Based on this, the inventors first determined that in order to understand the influence of impurity components (S, O, N) on iron loss,
3.2%Si− with various concentrations of each of the above impurities
A steel containing 0.60% Al-0.20% Mn was tapped, and a non-oriented silicon steel plate with a thickness of 0.35 mm was manufactured through rolling and heat treatment according to conventional methods. As a result, C is 0.005%
If it is below, the effect on iron loss is small, whereas S, O, and N have a large effect and have an extremely strong correlation with iron loss. One of these days,
Regarding S and O, it has already been disclosed in Japanese Patent Publication No. 56-22931 and Japanese Patent Application Laid-Open No. 53-66816 that reducing the content directly leads to improvement of iron loss, and 25ppm or less, S content
It is proposed to regulate it to 50ppm or less (preferably 30ppm or less). Regarding the N content,
It is known that a desirable embodiment is to limit the amount to 30 ppm or less. However, in these reports and examples, for example, taking S as an example, even if the content is low, it is reported that the content is only about 20 to 30 ppm, and the influence of impurities even lower than that is reported. It is unknown about Therefore, the present inventors investigated the influence of impurities at lower levels. According to the results, the effect of reducing iron loss is significant when lowering it to the levels of S: 15ppm, O: 20ppm, and N: 25ppm. For example, S = 15ppm, O = 20ppm, N =
When lowered to 25ppm, the iron loss value is W 10/50 ≒ 0.90,
It was found that W 10/50 ≒ 2.20, that is, an iron loss equivalent to class S8 could be obtained. However, even if the content was lowered to a lower level, the reduction in iron loss was not as great as expected, and the iron loss was reduced to a level equivalent to S7 class (W 10/50
0.85, W 15/50 2.00) could not be obtained. The present inventors conducted various studies to understand the cause of this, and found that the appropriate grain size of the steel plate that exhibits the best iron loss value is larger than the conventional value of approximately 130 μm. It was discovered that the iron loss was low. Figure 1 shows that in the above experiment, the final annealing conditions were 950°C x 5 minutes, which has been conventionally used, and 1030°C to coarsen the grains.
℃ × 5 minutes, impurities S, O, N
This shows the relationship between each content and iron loss. As you can see from this figure, S15ppm, O20ppm, N
In the region containing 25 ppm of impurities, steel that is annealed at a higher temperature instead of the conventionally used annealing conditions to cause the crystal grains to tend to coarsen exhibits a lower iron loss value. Furthermore, the present inventors have determined that S15ppm,
As a result of conducting research on materials with high purity of 20ppm O and 25ppm N and varying the annealing time and temperature, we found that only the selection of the annealing time and temperature has an effective effect on iron loss improvement. We have newly discovered that this is due to the fact that the optimum crystal grain size for providing the best iron loss value has shifted to the coarse grain side due to high purification. This will be explained in detail using FIG. 2. Figure 2 shows the relationship between iron loss and average grain size, where a is impurity S=32ppm, O
= 22ppm, conventional material containing N = 26ppm, b
As impurities, S=8ppm, O=7ppm, N=
The materials of the present invention contain 14ppm, and both contain Si.
3.2%, Al 0.60%, and Mn 0.20%. Iron loss consists of hysteresis loss and eddy current loss, and hysteresis loss decreases rapidly as the grain size increases.
On the other hand, eddy current loss increases as the crystal grain size increases, and as shown in Figure 2, the two are balanced at a certain appropriate grain size. The iron loss value takes a minimum value at that position. The average crystal grain size exhibiting the lowest iron loss value is called the optimal average crystal grain size. Generally, the optimum average grain size is Si+Al
It is known that it varies depending on the content of Si and Al, and increases as the content of Si and Al increases. However, as shown in Fig. 2, the S, O,
It has not been known until now that the optimum average crystal grain size changes depending on the N content. Therefore, S which is within the composition range of the present invention
The relationship between (Si+Al)% and the optimal average crystal grain size of the material, which is 15 ppm, 20 ppm of O, and 25 ppm of N, and the optimal average crystal grain size of the conventionally used material were determined. As a result, as shown in Figure 3, the optimum average grain size of the present invention material, which exhibits a low iron loss value of class S7, shifts to the coarser grain side than the optimum average crystal grain size of conventionally used materials. There is a clear distinction between
The value of the particle size determined in the figure is 100 + 3.5 × [Si +
The range is narrowed by Al%] 2 and 170 + 50 × [Si + Al%] 2 . The reason why the range is wider than that of conventional materials is that, as shown in FIG. 2, the change in characteristics near the minimum value is small. In Figure 3, the most frequent range of optimal average grain size is 120+3.5×[Si+Al%]
Since the range is narrowed by 2 and 160 + 50 x [Si + Al%] 2 , it can be estimated that there is a region with the best characteristics in this range if statistical processing is performed. In short, in order to obtain a material with a low iron loss value, which is the goal of the present invention, the contents of S, N, and O must be extremely reduced, and in order to make the most of its properties, the average grain size must be shifted to the coarse grain side. It is necessary to adjust within a certain limited range. The reason why a material with extremely low S, O, and N contents exhibits a low iron loss value when the optimum average crystal grain size shifts to the coarse grain side is presumed as follows. That is, although it was mentioned above that iron loss consists of hysteresis loss and eddy current loss, eddy current loss does not involve impurities such as S, O, and N. On the other hand, hysteresis loss is caused by material impurities,
It increases as the grain boundary density increases. However, on the fine grain side where the grain boundary density is high, the grain boundary density is the main cause of hysteresis loss deterioration, so the effect of impurity reduction is difficult to appear.On the other hand, on the coarse grain side where the grain boundary density is low, impurities deteriorate. The effect of impurity reduction is significant. In short, the reduction in hysteresis loss due to the reduction of impurities is smaller on the fine grain side and larger on the coarse grain side. Moreover, since the eddy current loss does not change and only the hysteresis loss changes in this way, the optimum average grain size at which the total iron loss is minimal will naturally shift to the coarse grain side, resulting in the phenomenon of the present invention. It is assumed that this caused the As explained above, the present inventors have discovered that S
For steels in the extremely reduced impurity range of 15ppm, O20ppm, and N25ppm, the average grain size (μm)
However, 100 + 3.5 × [Si% + Al%] 2 170 + 5.0 × [Si
%+Al%] It was newly discovered that non-oriented silicon steel sheets with extremely low iron loss can be obtained by manufacturing a steel sheet that falls within the range of 2 . Incidentally, a non-oriented silicon steel sheet having such properties may be produced by conventional general manufacturing methods as long as the composition is limited to the above-mentioned composition. For example, after blowing molten steel, it is degassed and adjusted to a predetermined composition, then poured into a mold, ingot-formed, and then bloomed to form a slab (steel billet), or by continuous casting. After being made into a slab, it is made into a product through hot rolling and cold rolling processes according to conventional methods. The range of the component composition of the present invention will be described below. C causes aging when it exceeds 0.005% by weight,
Since it deteriorates the properties, the content should be 0.005% by weight or less. If Si exceeds 4.0% by weight, cold rollability deteriorates, so it is limited to 4.0% by weight or less. Furthermore, if it is less than 2.5% by weight, the electrical resistance will be low and the iron loss will increase, making it impossible to obtain a non-oriented silicon steel sheet with low iron loss, which is the desired effect of the present invention, so 2.5% by weight is the lower limit. . Like Si, Al increases electrical resistance and is effective in reducing iron loss, but if it exceeds 1.0% by weight, cold workability deteriorates like Si, and if it is less than 0.25% by weight, iron loss deteriorates significantly. So 0.25wt% to 1.0wt%
up to. Mn is required to be 0.1% by weight or more from the viewpoint of hot workability, but if it exceeds 1.0% by weight, the magnetism deteriorates, so the content is set from 0.1% by weight to 1.0% by weight. Furthermore, the steel of the present invention contains 15 ppm of S, 20 ppm of O, and 20 ppm of N as impurities.
It is necessary to satisfy both 25ppm to achieve low iron loss, and the average crystal grain size (μm) of the final product sheet is 100 + 3.5 × [in relation to (Si + Al)%]. Si% + Al%] 2 170 + 5.0× [Si
%+Al%] 2 , and by having such a composition and grain size, it is possible to produce a non-oriented silicon steel sheet that exhibits an extremely low iron loss value. It can be done. The use of such an average crystal grain size works synergistically with the extremely low S, O, and N component compositions described above, and the desired effect can be obtained. Figure 4 shows the average grain size (124 μm) of the conventional non-oriented silicon steel sheet b and the average grain size (208 μm) of the invention steel a.
A comparison is shown below. Next, the test results regarding the characteristics of the steel of the present invention are as follows.
This will be explained based on Table 1.
【表】
転炉で吹練した後、脱ガス処理を施し、次いで
Si：3.2％、Al：0.60％、Mn：0.20％を目標にし
て、合金成分を添加し調整した溶鋼を、連続鋳造
によりスラブとした。この際、脱酸処理、脱硫処
理を、Ca等を用いる脱硫フラツクス、または
REM（希土類元素：Ceが約50％）を上記脱硫フ
ラツクスと併用する脱硫剤で脱硫を行い、しかも
その脱酸・脱硫の条件を変えることにより、Ｓや
Ｏの量を制御し、また鋳込み時の大気による酸化
や窒化の程度をArシールの程度を変えることに
より、ＯやＮの量を制御した。この結果第１表に
示される成分を有するスラブを得た。これらのス
ラブは1200℃で加熱した後熱間圧延で2.0mmの板
厚のコイルとし、酸洗後に２分割し、一方は950
℃×３分の連続焼鈍後、0.50mmの板厚に冷間圧延
し、連続仕上げ焼鈍を施す１回冷延法で製品板を
得て磁気測定を行つた。他の一方は、冷間圧延に
より0.70mmの板厚とし、950℃×３分の中間連続
焼鈍後、さらに冷間圧延により0.35mmの板厚にし
て、連続仕上げ焼鈍を施す２回冷延法によつて製
品板としこれを磁気測定を行つた。なお、上記の
製造工程においては、連続仕上げ焼鈍を施す前の
段階で平均結晶粒径（）が本発明鋼で目指す所
定の範囲内に収まるような焼鈍条件の管理すなわ
ち温度や時間を調整することが重要である。以上
の製造工程を経て得られた各試験板の磁気特性測
定結果を第１表に示した。また、この第１表に
は、板厚断面において測定した平均結晶粒径を併
記する。同時に第４図にこれらの仕上げ焼鈍後の
鋼板の板厚断面ミクロ写真の例を示した。
第１表において、符号，は成分組成を本発
明の特許請求範囲内にしたものについて、平均結
晶粒径を本発明範囲内の150〜250μｍとしたもの
とその範囲を外れる比較例とを対比したが、本発
明鋼の場合0.35mmの鋼板でW10/500.85、W15/50
2.00と極めて良好な鉄損を示した。また、符号
，，については、それぞれＳ、Ｏ、Ｎが本
発明で規定する範囲を外して高くする一方、適正
な平均結晶粒径にした例の従来範囲内比較鋼の例
であるが、鉄損も、0.35mmの鋼板でW10/50≒0.95、
W15/50≒2.25と、従来の値にとどまるものであつ
た。
以上説明したように本発明によれば、Ｓ、Ｏ、
Ｎを極低下した組成鋼について併せて最適平均結
晶粒径を粗粒側の所定の大きさに規制したことに
より、従来程度を著しく飛躍する低鉄損の無方向
性珪素鋼板を得ることができる。[Table] After blowing in a converter, degassing treatment is performed, and then
The molten steel was prepared by adding alloying ingredients to achieve a target of Si: 3.2%, Al: 0.60%, and Mn: 0.20%, and was made into a slab by continuous casting. At this time, deoxidation treatment and desulfurization treatment are performed using desulfurization flux using Ca etc.
By desulfurizing REM (rare earth element: approximately 50% Ce) with a desulfurizing agent used in combination with the above desulfurizing flux, and by changing the deoxidizing and desulfurizing conditions, the amount of S and O can be controlled, and during casting. The amount of O and N was controlled by changing the degree of oxidation and nitridation caused by the atmosphere and the degree of Ar sealing. As a result, a slab having the components shown in Table 1 was obtained. These slabs were heated to 1200℃, then hot rolled into coils with a thickness of 2.0mm, and after pickling, they were divided into two parts, one of which was made into a 950mm thick coil.
After continuous annealing for 3 minutes at ℃, cold rolling was performed to a thickness of 0.50 mm, and continuous finish annealing was performed to obtain a product sheet using a single cold rolling method, and magnetic measurements were performed on the product sheet. The other method involves cold rolling to a thickness of 0.70 mm, intermediate continuous annealing at 950°C for 3 minutes, and then cold rolling to a thickness of 0.35 mm, followed by continuous finish annealing. This was used as a product plate and magnetic measurements were performed on it. In addition, in the above manufacturing process, the annealing conditions should be managed, that is, the temperature and time should be adjusted so that the average grain size () falls within the predetermined range aimed at by the steel of the present invention at the stage before continuous finish annealing. is important. Table 1 shows the results of measuring the magnetic properties of each test plate obtained through the above manufacturing process. Table 1 also lists the average crystal grain size measured in the cross section of the plate. At the same time, FIG. 4 shows examples of microphotographs of plate thickness cross sections of these steel plates after final annealing. In Table 1, the symbol indicates a comparison between those whose component compositions were within the claimed range of the present invention, and whose average crystal grain size was 150 to 250 μm, which was within the range of the present invention, and a comparative example outside that range. However, in the case of the invention steel, W 10/50 0.85, W 15/50 with 0.35 mm steel plate
It showed an extremely good iron loss of 2.00. In addition, the symbols , , and , are examples of comparative steels within the conventional range in which S, O, and N were increased outside the range specified by the present invention, but the average grain size was set to an appropriate average grain size. The loss is also W 10/50 ≒ 0.95 with a 0.35mm steel plate,
W 15/50 ≒ 2.25, which remains at the conventional value. As explained above, according to the present invention, S, O,
By regulating the optimum average grain size to a predetermined size on the coarse grain side for composition steel with extremely low N content, it is possible to obtain a non-oriented silicon steel sheet with significantly lower core loss than conventional ones. .
第１図は、板厚0.35mmのSi：3.2％、Mn：0.2
％、Al：0.6％含有する無方向性珪素鋼板につい
て、Ｓ、Ｏ、Ｎ含有量と鉄損の関係を示したグラ
フである。第２図は板厚0.35mmのSi：3.2％、
Mn：0.2％、Al：0.6％含有する無方向性珪素鋼
板について、平均結晶粒径と鉄損の関係を示した
グラフである。第３図は、最良の鉄損値を得るた
めの最適平均結晶粒径と（Si＋Al）％との関係
を示すグラフである。第４図は、本発明無方向性
珪素鋼板ａと比較鋼ｂとについての結晶粒の大き
さを比較して示す金属組織の顕微鏡写真である。
Figure 1 shows a plate thickness of 0.35mm with Si: 3.2% and Mn: 0.2.
%, Al: 0.6% is a graph showing the relationship between S, O, and N contents and iron loss for a non-oriented silicon steel plate containing 0.6%. Figure 2 shows Si: 3.2% with a plate thickness of 0.35 mm.
It is a graph showing the relationship between average grain size and iron loss for a non-oriented silicon steel sheet containing Mn: 0.2% and Al: 0.6%. FIG. 3 is a graph showing the relationship between the optimum average grain size and (Si+Al)% for obtaining the best iron loss value. FIG. 4 is a microscopic photograph of the metal structure showing a comparison of the grain sizes of the non-oriented silicon steel sheet a of the present invention and the comparative steel b.
Claims (1)
％、Al：0.25〜1.0％、Mn：0.1〜1.0％を含み、
残部が不可避不純物とFeよりなるものにおいて、
不純物としてのＯ、ＮおよびＳの含有量を、Ｓ
15ppm、Ｏ20ppm、Ｎ25ppmに抑えることに
あわせ、上記SiおよびAl含有量との関連で示さ
れる平均結晶粒径が、 100＋3.5×〔Si％＋Al％〕2Ｄ170＋5.0×〔Si
％＋Al％〕2 の範囲内の値を示すものよりなる鉄損の少ない無
方向性珪素鋼板。[Claims] 1% by weight, C: 0.005% or less, Si: 2.5 to 4.0
%, Al: 0.25~1.0%, Mn: 0.1~1.0%,
In the case where the remainder consists of unavoidable impurities and Fe,
The content of O, N and S as impurities is determined by S
In line with suppressing to 15ppm, O20ppm, and N25ppm, the average grain size shown in relation to the above Si and Al contents is 100 + 3.5 × [Si% + Al%] 2 D170 + 5.0 × [Si
%+Al%] A non-oriented silicon steel plate with low iron loss, which exhibits a value within the range of 2 .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57184167A JPS5974258A (en) | 1982-10-20 | 1982-10-20 | Nondirectional silicon steel plate with small iron loss |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57184167A JPS5974258A (en) | 1982-10-20 | 1982-10-20 | Nondirectional silicon steel plate with small iron loss |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5974258A JPS5974258A (en) | 1984-04-26 |
| JPH0250190B2 true JPH0250190B2 (en) | 1990-11-01 |
Family
ID=16148532
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP57184167A Granted JPS5974258A (en) | 1982-10-20 | 1982-10-20 | Nondirectional silicon steel plate with small iron loss |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5974258A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2014129106A1 (en) | 2013-02-22 | 2014-08-28 | Ｊｆｅスチール株式会社 | Hot-rolled steel sheet for manufacturing non-oriented electromagnetic steel sheet and method for manufacturing same |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62287043A (en) * | 1986-06-04 | 1987-12-12 | Nippon Kokan Kk <Nkk> | High-silicon steel sheet having excellent magnetic characteristic |
| JPH0617548B2 (en) * | 1987-06-25 | 1994-03-09 | 住友金属工業株式会社 | Non-oriented electrical steel sheet with excellent rust resistance |
| KR100316896B1 (en) * | 1993-09-29 | 2002-02-19 | 에모또 간지 | Non-oriented silicon steel sheet having low iron loss and method for manufacturing the same |
| US6139650A (en) * | 1997-03-18 | 2000-10-31 | Nkk Corporation | Non-oriented electromagnetic steel sheet and method for manufacturing the same |
| JP2021123764A (en) * | 2020-02-06 | 2021-08-30 | 日本製鉄株式会社 | Non-oriented electromagnetic steel sheet and method for manufacturing the same |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS563625A (en) * | 1979-06-23 | 1981-01-14 | Noboru Tsuya | Thin sheet of high silicon steel nondirectional in (100) plane and very low in coercive force and its manufacture |
| JPS56130424A (en) * | 1980-03-18 | 1981-10-13 | Kawasaki Steel Corp | Production of nondirectional silicon steel sheet |
-
1982
- 1982-10-20 JP JP57184167A patent/JPS5974258A/en active Granted
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS563625A (en) * | 1979-06-23 | 1981-01-14 | Noboru Tsuya | Thin sheet of high silicon steel nondirectional in (100) plane and very low in coercive force and its manufacture |
| JPS56130424A (en) * | 1980-03-18 | 1981-10-13 | Kawasaki Steel Corp | Production of nondirectional silicon steel sheet |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2014129106A1 (en) | 2013-02-22 | 2014-08-28 | Ｊｆｅスチール株式会社 | Hot-rolled steel sheet for manufacturing non-oriented electromagnetic steel sheet and method for manufacturing same |
| US10026534B2 (en) | 2013-02-22 | 2018-07-17 | Jfe Steel Corporation | Hot-rolled steel sheet for producing non-oriented electrical steel sheet and method of producing same |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5974258A (en) | 1984-04-26 |
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