JPH09287015A - Method for refining harmful inclution in steel - Google Patents
Method for refining harmful inclution in steelInfo
- Publication number
- JPH09287015A JPH09287015A JP9986296A JP9986296A JPH09287015A JP H09287015 A JPH09287015 A JP H09287015A JP 9986296 A JP9986296 A JP 9986296A JP 9986296 A JP9986296 A JP 9986296A JP H09287015 A JPH09287015 A JP H09287015A
- Authority
- JP
- Japan
- Prior art keywords
- molten steel
- deoxidizing
- steel
- inclusions
- ppm
- 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.)
- Granted
Links
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は鋼の製造に関するも
のであり、有害な粗大介在物を減少させる技術に関する
ものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to steel production, and more particularly to a technique for reducing harmful coarse inclusions.
【０００２】[0002]
【従来の技術】鋼の製造において、脱酸処理や溶鋼の二
次酸化によって発生した非金属介在物は品質に著しい悪
影響を与えることが知られている。そこで、従来より鋼
中に存在する介在物を減少させる方法が数多く提案され
ており、これらは「高清浄鋼」（第１２６・１２７回西
山記念技術講座、日本鉄鋼協会編、昭和６３年１１月）
に記載されている。これらの方法は、介在物個数を極力
少なくする方法と介在物を無害化する方法に大別され
る。2. Description of the Related Art In the production of steel, it is known that non-metallic inclusions generated by deoxidation treatment or secondary oxidation of molten steel have a significant adverse effect on quality. Therefore, many methods of reducing inclusions existing in steel have been proposed, and these are “highly clean steel” (126th 127th Nishiyama Memorial Technical Lecture, Iron and Steel Institute of Japan, November 1988). )
It is described in. These methods are roughly classified into a method of minimizing the number of inclusions and a method of rendering the inclusions harmless.
【０００３】前者の例は二次精錬での撹拌や連鋳での再
酸化防止技術であり、同書１１頁には撹拌により脱酸生
成物の浮上・分離が促進されると記載されており、又同
書１３頁には再酸化防止技術としてタンディシュ内の不
活性ガスシールが記載されている。また、後者の例とし
ては介在物の組成制御があげられ、同書１５頁には目標
とする介在物組成の例があげられている。The former example is a technique for preventing reoxidation in agitation in secondary refining and continuous casting, and it is described on page 11 of the same document that agitation promotes floating and separation of deoxidized products. On page 13 of the same document, an inert gas seal in the tundish is described as a technology for preventing reoxidation. An example of the latter is control of the composition of inclusions, and page 15 of the same book gives an example of a target inclusion composition.
【０００４】しかしながら、近年需要家の品質要求は厳
格となっており、それに合わせて介在物の総量を極限ま
で低減させるためには、介在物除去コストが著しく増大
してしまう。また、介在物の組成を制御して、高い変形
能をもたせて無害化する方法は有効であるが、介在物組
成のばらつきや分布のばらつきを考慮すると、有害な介
在物が残留する可能性がある。However, in recent years, the quality requirements of customers have become strict, and in order to reduce the total amount of inclusions to the utmost limit, the cost for removing inclusions increases remarkably. Further, it is effective to control the composition of inclusions so as to have high deformability and render them harmless.However, in consideration of variations in the composition of inclusions and variations in distribution, harmful inclusions may remain. is there.
【０００５】一方で、例えばＡｌキルド鋼、特にＴｉ含
有極低炭素鋼（Ｔｉ含有量０．０１〜０．１％前後）の
表面欠陥として知られているスリバー疵は鋳片の表層近
傍に捕捉された５００μm以上の粗大なアルミナクラス
ターが主原因であることが知られている。従って、これ
ら５００μm以上の粗大なアルミナクラスターを低減す
る必要がある。On the other hand, for example, sliver flaws known as surface defects of Al-killed steel, especially Ti-containing ultra-low carbon steel (Ti content of about 0.01 to 0.1%) are trapped near the surface layer of the slab. It is known that the above-mentioned coarse alumina clusters of 500 μm or more are the main cause. Therefore, it is necessary to reduce these coarse alumina clusters of 500 μm or more.
【０００６】[0006]
【発明が解決しようとする課題】前述したように、鋳片
に捕捉される粗大なアルミナクラスターの個数を低減で
きれば、製品の品質、特に表面欠陥を向上することがで
きる。本発明は介在物の無害化法として、粗大なサイズ
の介在物、特にアルミナクラスターを凝固直前に微細化
する方法を提供することを目的とする。As described above, if the number of coarse alumina clusters trapped in the slab can be reduced, the product quality, especially surface defects, can be improved. An object of the present invention is to provide a method of detoxifying inclusions having a coarse size, particularly alumina clusters, immediately before solidification, as a method of detoxifying inclusions.
【０００７】[0007]
【課題を解決するための手段】本発明は前述の課題を解
決したものであり、その要旨は、重量％でＡｌ：０．０
１〜０．１％の組成を有する炭素鋼を製造するに際し、
溶鋼の脱酸処理工程において、Ａｌを添加した後にＺ
ｒ，Ｃａ，Ｍｇのうちいずれか一種を以下の式で表され
る濃度となるように溶鋼中に添加することを特徴とする
溶鋼中介在物の微細化方法である。SUMMARY OF THE INVENTION The present invention has solved the above-mentioned problems, and its gist is that Al: 0.0% by weight.
In producing carbon steel having a composition of 1-0.1%,
In the deoxidizing process of molten steel, after adding Al, Z
In the method of refining inclusions in molten steel, one of r, Ca, and Mg is added to the molten steel so as to have a concentration represented by the following formula.
【０００８】0.05×[(a・MX)／(b・M0)]×[(C1(O)−C
2(O)]≦C(X)≦1.0×[(a・MX)／(b・M0)]×[C1(O)−C2(O)] ここで、ＭX：脱酸元素(Ｚr,Ｃa,Ｍg)の原子量、
Ｍ0：Ｏの原子量、ａ,ｂ：脱酸元素Ｘの酸化物(Ｘ
aＯb）の化学量論的係数（Ｚrの場合 ａ＝1,ｂ＝2、Ｃ
a、Ｍgの場合ａ＝1,ｂ＝1) Ｃ(Ｘ):溶鋼中のトータル脱酸元素(Ｘ:Zr,Ca,Mgのうち
の1種)濃度(ppm) Ｃ1(Ｏ)：Ａlを添加する前の溶鋼中フリー酸素濃度(pp
m) Ｃ2(Ｏ)：Ａlを添加した後の溶鋼中フリー酸素濃度(pp
m)。0.05 × [(a · M X ) / (b · M 0 )] × [(C 1 (O) −C
2 (O)] ≦ C (X) ≦ 1.0 × [(a · M X ) / (b · M 0 )] × [C 1 (O) −C 2 (O)] where M X : deoxidation Atomic weight of elements (Zr, Ca, Mg),
M 0 : atomic weight of O, a, b: oxide of deoxidizing element X (X
a O b ) stoichiometric coefficient (for Zr a = 1, b = 2, C
In the case of a and Mg, a = 1, b = 1) C (X): Total deoxidizing element (X: one of Zr, Ca, Mg) concentration in molten steel (ppm) C 1 (O): Al Free oxygen concentration in molten steel (pp)
m) C 2 (O): Free oxygen concentration in molten steel after adding Al (pp
m).
【０００９】以下、本発明の具体的構成を示す。本発明
者らは鋼中の介在物を微細化する手段として、酸素との
親和力が強く、かつ酸素と化合し、溶鋼中でクラスタリ
ングをしにくく、微細に分散する傾向のある酸化物を形
成する元素を添加する方法を開示した（特開平３−４７
６６４）。これは、Ａｌを０．０１％以下含有する炭素
鋼において、ＭｎＳの析出核として有効なＭｎＯ・Ｓｉ
Ｏ2を微細化するために、ＭｎとＳｉで脱酸した後に、
より脱酸力の強いＺｒを添加するものである。一方、本
発明においては、Ａｌを０．０１％〜０．１０％含有す
る炭素鋼において、生成したＡｌ2Ｏ3を微細化するため
にＡｌ添加後にＡｌよりも強い脱酸力を持つ元素を添加
するものである。The specific constitution of the present invention will be described below. As a means for refining inclusions in steel, the present inventors form an oxide that has a strong affinity with oxygen and combines with oxygen to make it difficult to cluster in molten steel and tend to be finely dispersed. A method for adding an element has been disclosed (JP-A-3-47).
664). This is MnO.Si which is effective as a precipitation nucleus of MnS in carbon steel containing 0.01% or less of Al.
In order to make O 2 finer, after deoxidizing with Mn and Si,
Zr having stronger deoxidizing power is added. On the other hand, in the present invention, in the carbon steel containing 0.01% to 0.10% of Al, in order to refine the generated Al 2 O 3 , an element having a stronger deoxidizing power than Al after addition of Al is added. It is to be added.
【００１０】[0010]
【発明の実施の形態】次ぎに本発明について詳しく述べ
る。まず、本発明者らは鋼中のＡｌ2Ｏ3系介在物を微細
化するために種々の脱酸元素を用いて、種々の添加量に
よる脱酸実験を行った。その結果、Ａｌで脱酸した後に
Ａｌよりも脱酸力の強いＺｒ、Ｍｇ、Ｃａを次の式で表
される量を添加することでＡｌ2Ｏ3系介在物が最も微細
に分散することを見いだした。BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described in detail. First, the present inventors conducted deoxidation experiments with various addition amounts using various deoxidizing elements in order to refine Al 2 O 3 -based inclusions in steel. As a result, Al 2 O 3 -based inclusions are dispersed in the finest by adding Zr, Mg, and Ca, which have a stronger deoxidizing power than Al, after deoxidizing with Al. I found it.
【００１１】0.05×[(a・MX)／(b・M0)]×[(C1(O)−C
2(O)]≦C(X)≦1.0×[(a・MX)／(b・M0)]×[C1(O)−C2(O)] ここで、ＭX：脱酸元素(Ｚr,Ｃa,Ｍg)の原子量、
Ｍ0：Ｏの原子量、ａ,ｂ：脱酸元素Ｘの酸化物(Ｘ
aＯb）の化学量論的係数（Ｚrの場合 ａ＝1，ｂ＝2、
Ｃa、Ｍgの場合ａ＝1,ｂ＝1) Ｃ(Ｘ):溶鋼中のトータル脱酸元素(Ｘ:Zr,Ca,Mgのうち
の1種)濃度(ppm) Ｃ1(Ｏ)：Ａlを添加する前の溶鋼中フリー酸素濃度(pp
m) Ｃ2(Ｏ)：Ａlを添加した後の溶鋼中フリー酸素濃度(pp
m)。0.05 × [(a · M X ) / (b · M 0 )] × [(C 1 (O) −C
2 (O)] ≦ C (X) ≦ 1.0 × [(a · M X ) / (b · M 0 )] × [C 1 (O) −C 2 (O)] where M X : deoxidation Atomic weight of elements (Zr, Ca, Mg),
M 0 : atomic weight of O, a, b: oxide of deoxidizing element X (X
a O b ) stoichiometric coefficient (for Zr, a = 1, b = 2,
In the case of Ca and Mg, a = 1, b = 1) C (X): Total deoxidizing element (X: one of Zr, Ca, Mg) concentration in molten steel (ppm) C 1 (O): Al Free oxygen concentration in molten steel (pp)
m) C 2 (O): Free oxygen concentration in molten steel after adding Al (pp
m).
【００１２】この原理は次のように考えられる。初めに
Ａｌで脱酸すると、溶鋼中には Ａｌ2Ｏ3系酸化物が生
成する。また、これによって鋼中溶存酸素濃度が低下す
る。ここで、Ａｌよりも脱酸力の強いＺｒ、Ｃａ、Ｍｇ
を添加すると、溶存酸素とこれらの強脱酸元素が結合
し、ＺｒＯ2、ＣａＯ、ＭｇＯといった酸化物を形成す
る。This principle is considered as follows. When Al is first deoxidized, Al 2 O 3 -based oxide is formed in the molten steel. This also reduces the dissolved oxygen concentration in the steel. Here, Zr, Ca, and Mg, which have stronger deoxidizing power than Al
Is added, dissolved oxygen and these strong deoxidizing elements are bonded to form oxides such as ZrO 2 , CaO and MgO.
【００１３】しかしながら、その過程において添加量に
よっては、溶存酸素が低いために先に生成していたＡｌ
2Ｏ3系酸化物の一部を還元し、Ａｌ2Ｏ3との複合酸化物
を形成するか、あるいは溶鋼中に酸化物単体として存在
する。いずれの場合でも、Ａｌ2Ｏ3は量が減少し、粒径
も微細化する。However, in the process, depending on the amount added, the amount of dissolved oxygen is low, so that the Al generated previously
Part of the 2 O 3 -based oxide is reduced to form a composite oxide with Al 2 O 3 , or it exists as a simple oxide in molten steel. In any case, the amount of Al 2 O 3 is reduced and the grain size is also made finer.
【００１４】次に本発明の式中に示した数式の決定理由
について述べる。本発明に示した添加量算出式は、上述
の原理に基づきＡｌ2Ｏ3として存在する酸素を後から添
加した強脱酸元素と結合させうる量を提示している。Ａ
ｌ2Ｏ3として存在する酸素はＣ1(Ｏ)−Ｃ2(Ｏ)で示さ
れ、この全ての酸素と結合する脱酸元素の量は、Ｃ
1(Ｏ)−Ｃ2(Ｏ)に[(ａ・ＭX)／(ｂ・Ｍ0)]を乗じること
で得られる。さらに得られた脱酸元素の量に係数を乗じ
ることで、本発明の課題に対して十分な効果が得られる
脱酸元素の添加量範囲を提示できる。本発明ではこの係
数が０．０５から１．０である。Next, the reasons for determining the mathematical formulas shown in the formulas of the present invention will be described. The addition amount calculation formula shown in the present invention presents the amount by which oxygen existing as Al 2 O 3 can be bonded to the strong deoxidizing element added later based on the above-mentioned principle. A
Oxygen existing as l 2 O 3 is represented by C 1 (O) -C 2 (O), and the amount of deoxidizing element bonded to all oxygen is C
It is obtained by multiplying 1 (O) -C 2 (O) by [(a · M X ) / (b · M 0 )]. Further, by multiplying the obtained amount of the deoxidizing element by a coefficient, the addition amount range of the deoxidizing element with which a sufficient effect can be obtained with respect to the problem of the present invention can be presented. In the present invention, this coefficient is 0.05 to 1.0.
【００１５】係数が０．０５以下では脱酸元素添加によ
るＡｌ2Ｏ3の還元が不十分であり、微細化効果は期待で
きない。また、係数が１を越える場合は過剰の脱酸元素
が溶鋼中に存在することになり、これらは溶存酸素と結
合し酸化物を形成する。また、酸素と結合できなかった
量は鋼中に残存する。これが大気からの汚染あるいはス
ラグ中の酸素と結合して酸化物を後に形成し、クラスタ
ーとなりうる。従って、脱酸元素の添加量は、Ａｌ2Ｏ3
を完全に還元してしまう量を上限とすることが必要であ
る。When the coefficient is less than 0.05, the reduction of Al 2 O 3 by the addition of the deoxidizing element is insufficient, and the miniaturization effect cannot be expected. On the other hand, when the coefficient exceeds 1, excessive deoxidizing elements are present in the molten steel and these combine with dissolved oxygen to form oxides. Further, the amount that could not be combined with oxygen remains in the steel. This can become a cluster by forming an oxide later by combining with pollution from the atmosphere or oxygen in the slag. Therefore, the addition amount of the deoxidizing element is Al 2 O 3
It is necessary to set the upper limit to the amount that completely reduces.
【００１６】また、本発明の脱酸元素の添加方法である
が、合金の形態でＲＨ等の二次精錬工程で添加する方法
が最も一般的であるが、最も効果的な方法は、鋳造直前
にタンディッシュあるいは鋳型内に添加する方法であ
り、これらの場合は合金を充填したワイヤーの形態で連
続的に添加する方法が考えられる。また、溶鋼中フリー
酸素濃度の測定であるが、汎用的に使用されている酸素
センサー等で測定可能である。Regarding the method of adding the deoxidizing element of the present invention, the method of adding it in the form of an alloy in the secondary refining process such as RH is the most general, but the most effective method is immediately before casting. In this case, a method of continuously adding in the form of a wire filled with an alloy can be considered. Further, although it is a measurement of the free oxygen concentration in the molten steel, it can be measured by a commonly used oxygen sensor or the like.
【００１７】[0017]
【実施例】高周波誘導溶解実験において、Ａｒ雰囲気、
ＭｇＯ坩堝中で溶鋼を１kg溶解し、１５７０℃に保持し
た後Ａｌ，Ｔｉを添加し、約３０秒後に脱酸元素を添加
し、約３０秒間保定した後電源を切り、坩堝中で空冷凝
固させた。Ａｌ添加前後の溶鋼中フリー酸素は酸素セン
サーで測定した。得られたインゴットを切断加工し、光
学顕微鏡で１０μm以上の介在物分布を調査し、最大介
在物粒径を求めた。EXAMPLE In a high-frequency induction melting experiment, an Ar atmosphere,
Melt 1 kg of molten steel in a MgO crucible, hold at 1570 ° C, add Al and Ti, add deoxidizing element after about 30 seconds, hold for about 30 seconds, turn off the power, and air-cool and solidify in the crucible. It was Free oxygen in the molten steel before and after the addition of Al was measured with an oxygen sensor. The obtained ingot was cut and processed, and the distribution of inclusions of 10 μm or more was examined with an optical microscope to determine the maximum inclusion particle size.
【００１８】表１に各試料の成分と脱酸元素添加量およ
び得られた最大介在物粒径を示す。この結果からＺｒ、
Ｃａ、Ｍｇ等を添加しない従来法あるいは本発明の条件
範囲を外れた場合では粗大な５００μm以上のアルミナ
クラスターが存在するのに対し、本発明条件では最大粒
径で５００μm以下の介在物となっている。Table 1 shows the components of each sample, the amount of deoxidizing element added, and the maximum particle size of the obtained inclusions. From this result, Zr,
Coarse alumina clusters of 500 μm or more are present when the conventional method in which Ca, Mg, etc. are not added or when the condition is out of the condition range of the present invention. There is.
【００１９】[0019]
【表１】 [Table 1]
【００２０】[0020]
【発明の効果】以上説明したように、本発明の方法を用
いれば、従来の方法では低減できなかった粗大なアルミ
ナクラスターを微細化する事ができ、製品欠陥を減少さ
せることが可能となる。従って、製品における表面欠陥
の発生が低減することが期待できる。As described above, by using the method of the present invention, coarse alumina clusters, which cannot be reduced by the conventional method, can be made finer, and product defects can be reduced. Therefore, it can be expected that the occurrence of surface defects in the product is reduced.
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 庁内整理番号 ＦＩ 技術表示箇所 Ｃ２１Ｃ 7/06 Ｃ２１Ｃ 7/06 ─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 6 Identification code Internal reference number FI Technical indication C21C 7/06 C21C 7/06
Claims (1)
を有する炭素鋼を製造するに際し、溶鋼の脱酸処理工程
において、Ａｌを添加した後にＺｒ，Ｃａ，Ｍｇのうち
いずれか一種を以下の式で表される濃度となるように溶
鋼中に添加することを特徴とする鋼中有害介在物の微細
化方法。 0.05×[(a・MX)／(b・M0)]×[(C1(O)−C2(O)]≦C(X)≦1.0
×[(a・MX)／(b・M0)]×[C1(O)−C2(O)] ここで、ＭX：脱酸元素(Ｚr,Ｃa,Ｍg)の原子量、
Ｍ0：Ｏの原子量、 ａ,ｂ：脱酸元素Ｘの酸化物(ＸaＯb）の化学量論的係数
（Ｚrの場合 ａ＝1，ｂ＝2、Ｃa、Ｍgの場合ａ＝1,ｂ
＝1) Ｃ(Ｘ):溶鋼中のトータル脱酸元素(Ｘ:Zr,Ca,Mgのうち
の1種)濃度(ppm) Ｃ1(Ｏ)：Ａlを添加する前の溶鋼中フリー酸素濃度(pp
m) Ｃ2(Ｏ)：Ａlを添加した後の溶鋼中フリー酸素濃度(pp
m)1. When manufacturing a carbon steel having a composition of Al: 0.01 to 0.1% in weight%, one of Zr, Ca and Mg is added after Al is added in a deoxidation treatment step of molten steel. A method of refining harmful inclusions in steel, characterized in that one of the above is added to the molten steel so as to have a concentration represented by the following formula. 0.05 × [(a ・ M X ) / (b ・ M 0 )] × [(C 1 (O) −C 2 (O)] ≦ C (X) ≦ 1.0
× [(a ・ M X ) / (b ・ M 0 )] × [C 1 (O) −C 2 (O)] where M X : atomic weight of deoxidizing element (Zr, Ca, Mg),
M 0 : atomic weight of O, a, b: stoichiometric coefficient of oxide (X a O b ) of deoxidizing element X (in the case of Zr, a = 1, b = 2, in the case of Ca, Mg a = 1) , b
= 1) C (X): Total deoxidizing element (X: one of Zr, Ca, Mg) concentration in molten steel (ppm) C 1 (O): Free oxygen concentration in molten steel before adding Al (pp
m) C 2 (O): Free oxygen concentration in molten steel after adding Al (pp
m)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP09986296A JP3647969B2 (en) | 1996-04-22 | 1996-04-22 | Method for refinement of harmful inclusions in steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP09986296A JP3647969B2 (en) | 1996-04-22 | 1996-04-22 | Method for refinement of harmful inclusions in steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH09287015A true JPH09287015A (en) | 1997-11-04 |
| JP3647969B2 JP3647969B2 (en) | 2005-05-18 |
Family
ID=14258622
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
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| JP09986296A Expired - Fee Related JP3647969B2 (en) | 1996-04-22 | 1996-04-22 | Method for refinement of harmful inclusions in steel |
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| JP (1) | JP3647969B2 (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000061322A1 (en) * | 1999-04-08 | 2000-10-19 | Nippon Steel Corporation | Cast steel piece and steel product excellent in forming characteristics and method for treatment of molted steel therefor and method for production thereof |
| FR2792234A1 (en) * | 1999-04-15 | 2000-10-20 | Lorraine Laminage | Low or ultra-low carbon steel ladle treatment,, after or during aluminum killing and prior to continuous casting, comprises calcium addition in the presence of a small quantity of magnesium |
| EP1589124A1 (en) * | 2003-01-27 | 2005-10-26 | Nippon Steel Corporation | High strength high toughness high carbon steel wire rod and process for producing the same |
| EP2690182A1 (en) * | 2012-07-25 | 2014-01-29 | Tata Steel IJmuiden BV | Process for producing an extra-low-carbon or ultra-low-carbon steel slab, strip or sheet, and a slab, strip or sheet produced thereby |
| WO2015113937A1 (en) * | 2014-01-28 | 2015-08-06 | Tata Steel Ijmuiden B.V. | Process for producing an elc or ulc steel slab, strip or sheet, and to a slab, strip or sheet produced thereby |
| JP2015232162A (en) * | 2014-06-10 | 2015-12-24 | 新日鐵住金株式会社 | Carbon steel cast slab, manufacturing method of carbon steel cast slab and steel material |
| JP2016176110A (en) * | 2015-03-20 | 2016-10-06 | 新日鐵住金株式会社 | Carbon steel slab and method for producing the carbon steel slab |
-
1996
- 1996-04-22 JP JP09986296A patent/JP3647969B2/en not_active Expired - Fee Related
Cited By (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100706973B1 (en) * | 1999-04-08 | 2007-04-13 | 신닛뽄세이테쯔 카부시키카이샤 | Cast steel piece with fine solidification sturcture and excellent forming characteristics and steel product and seamless steel pipe produced by using the same |
| US6585799B1 (en) | 1999-04-08 | 2003-07-01 | Nippon Steel Corporation | Cast steel piece and steel product excellent in forming characteristics and method for treatment of molted steel therefor and method for production thereof |
| US6918969B2 (en) | 1999-04-08 | 2005-07-19 | Nippon Steel Corporation | Cast steel and steel material with excellent workability, method for processing molten steel therefor and method for manufacturing the cast steel and steel material |
| WO2000061322A1 (en) * | 1999-04-08 | 2000-10-19 | Nippon Steel Corporation | Cast steel piece and steel product excellent in forming characteristics and method for treatment of molted steel therefor and method for production thereof |
| KR100550678B1 (en) * | 1999-04-08 | 2006-02-09 | 신닛뽄세이테쯔 카부시키카이샤 | Method for treatment of molten steel for making solidification structure of cast steel piece fine |
| FR2792234A1 (en) * | 1999-04-15 | 2000-10-20 | Lorraine Laminage | Low or ultra-low carbon steel ladle treatment,, after or during aluminum killing and prior to continuous casting, comprises calcium addition in the presence of a small quantity of magnesium |
| WO2000062957A1 (en) * | 1999-04-15 | 2000-10-26 | Usinor | Treatment for improving the castability of aluminium killed continuously cast steel |
| JP2002542034A (en) * | 1999-04-15 | 2002-12-10 | ユジノール | Treatment to improve castability of aluminum killed continuous cast steel |
| EP1589124A1 (en) * | 2003-01-27 | 2005-10-26 | Nippon Steel Corporation | High strength high toughness high carbon steel wire rod and process for producing the same |
| EP1589124A4 (en) * | 2003-01-27 | 2007-10-17 | Nippon Steel Corp | High strength high toughness high carbon steel wire rod and process for producing the same |
| EP2690182A1 (en) * | 2012-07-25 | 2014-01-29 | Tata Steel IJmuiden BV | Process for producing an extra-low-carbon or ultra-low-carbon steel slab, strip or sheet, and a slab, strip or sheet produced thereby |
| WO2014016387A1 (en) * | 2012-07-25 | 2014-01-30 | Tata Steel Ijmuiden Bv | Process for producing an extra-low-carbon or ultra-low-carbon steel slab, strip or sheet, and to a slab, strip or sheet produced thereby |
| WO2015113937A1 (en) * | 2014-01-28 | 2015-08-06 | Tata Steel Ijmuiden B.V. | Process for producing an elc or ulc steel slab, strip or sheet, and to a slab, strip or sheet produced thereby |
| JP2015232162A (en) * | 2014-06-10 | 2015-12-24 | 新日鐵住金株式会社 | Carbon steel cast slab, manufacturing method of carbon steel cast slab and steel material |
| JP2016176110A (en) * | 2015-03-20 | 2016-10-06 | 新日鐵住金株式会社 | Carbon steel slab and method for producing the carbon steel slab |
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