JP2003049219A - Method for producing high clean thin steel sheet and steel sheet - Google Patents
Method for producing high clean thin steel sheet and steel sheetInfo
- Publication number
- JP2003049219A JP2003049219A JP2001239555A JP2001239555A JP2003049219A JP 2003049219 A JP2003049219 A JP 2003049219A JP 2001239555 A JP2001239555 A JP 2001239555A JP 2001239555 A JP2001239555 A JP 2001239555A JP 2003049219 A JP2003049219 A JP 2003049219A
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- Japan
- Prior art keywords
- steel sheet
- mass
- thin steel
- concentration
- low carbon
- 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.)
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Links
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- Treatment Of Steel In Its Molten State (AREA)
- Heat Treatment Of Sheet Steel (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、清浄性に優れた低
炭素薄鋼板の製造方法およびこの製造方法により得られ
る薄鋼板に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a low carbon steel sheet having excellent cleanliness and a steel sheet obtained by this production method.
【０００２】[0002]
【従来の技術】転炉や真空処理容器で精錬された溶鋼中
には、多量の溶存酸素が含まれており、この過剰酸素は
酸素との親和力が強い強脱酸元素であるＡｌにより脱酸
されるのが一般的である。このため、溶存酸素は全てア
ルミナ系介在物となり、これが凝集合体して粗大なアル
ミナクラスターとなる。このアルミナクラスターは、例
えばＤＩ缶に用いる薄鋼板で製缶時にワレ発生の原因と
なり、薄鋼板の品質を大きく低下させるため、アルミナ
系介在物の低減対策は重要な課題となっている。2. Description of the Related Art A large amount of dissolved oxygen is contained in molten steel refined in a converter or a vacuum processing vessel, and this excess oxygen is deoxidized by Al, which is a strong deoxidizing element having a strong affinity with oxygen. It is generally done. Therefore, all of the dissolved oxygen becomes alumina-based inclusions, which aggregate and coalesce into coarse alumina clusters. This alumina cluster causes, for example, a crack in a thin steel plate used for DI cans during can manufacturing, and greatly deteriorates the quality of the thin steel plate. Therefore, a countermeasure for reducing alumina-based inclusions is an important issue.
【０００３】これに対して、従来は特開平５−１０４２
１９号公報の介在物吸着用フラックスを溶鋼表面に添加
してアルミナ系介在物を除去する方法、或いは特開昭６
３−１４９０５７号公報の注入流を利用してＣａＯフラ
ックスを溶鋼中に添加し、これによりアルミナ系介在物
を吸着除去する方法が提案、実施されてきた。一方、ア
ルミナ系介在物を除去するのではなく、生成させない方
法として、特開平５−３０２１１２号公報にあるように
溶鋼をＭｇで脱酸し、Ａｌでは殆ど脱酸しない薄鋼板用
溶鋼の溶製方法も開示されている。On the other hand, in the past, the conventional technique is Japanese Patent Laid-Open No. 5-1042.
The method of removing the alumina-based inclusions by adding the flux for adsorbing the inclusions of JP-A No. 19 to the surface of the molten steel, or JP-A-Sho 6
A method has been proposed and implemented in which a CaO flux is added to molten steel by utilizing the injection flow of Japanese Patent No. 3-149057, and thereby alumina inclusions are adsorbed and removed. On the other hand, as a method in which alumina inclusions are not removed, but not generated, as described in JP-A-5-302112, molten steel is deoxidized with Mg and Al is hardly deoxidized. Methods are also disclosed.
【０００４】[0004]
【発明が解決しようとする課題】しかしながら、上述し
たアルミナ系介在物を除去する方法では、低炭素溶鋼中
に多量に生成したアルミナ系介在物を内部欠陥が発生し
ない程度まで低減することは非常に難しい。また、アル
ミナ系介在物を全く生成しないＭｇ脱酸では、Ｍｇの蒸
気圧が高く、溶鋼への歩留まりが非常に低いため、低炭
素鋼のように溶存酸素濃度が高い溶鋼をＭｇだけで脱酸
するには多量のＭｇを必要とし、製造コストを考えると
実用的なプロセスとは言えない。However, in the method for removing the alumina-based inclusions described above, it is extremely difficult to reduce the alumina-based inclusions that are produced in a large amount in the low carbon molten steel to the extent that internal defects do not occur. difficult. In addition, in Mg deoxidation that does not generate alumina inclusions at all, since the vapor pressure of Mg is high and the yield to molten steel is very low, molten steel with a high dissolved oxygen concentration such as low carbon steel is deoxidized with Mg alone. In order to do so, a large amount of Mg is required, which is not a practical process considering the manufacturing cost.
【０００５】これらの問題を鑑み、本発明は低炭素薄鋼
板で介在物生成量を極限まで低下させることにより、確
実に内部欠陥を防止できる低炭素薄鋼板の製造方法を提
示することを課題とする。In view of these problems, it is an object of the present invention to provide a method for producing a low carbon thin steel sheet which can reliably prevent internal defects by reducing the amount of inclusions produced in the low carbon thin steel sheet to the utmost. To do.
【０００６】[0006]
【課題を解決するための手段】上記課題を解決するため
に、本発明は以下の構成を要旨とする。
（１）低炭素薄鋼板の製造方法において、溶鋼中のＣ濃
度を０．１質量％から２．０質量％に脱炭素処理した後
Ａｌで脱酸し、該溶鋼を連続鋳造して得られた鋳片を熱
間圧延、更には冷間圧延した後に、薄鋼板の状態で水素
雰囲気下で加熱してＣ濃度を０．０８質量％以下まで脱
炭することを特徴とする低炭素薄鋼板の製造方法。
（２）低炭素薄鋼板の製造方法において、溶鋼中のＣ濃
度を０．１質量％から２．０質量％に脱炭素処理した後
Ｔｉで脱酸し、該溶鋼を連続鋳造して得られた鋳片を熱
間圧延、更には冷間圧延した後に、薄鋼板の状態で水素
雰囲気下で加熱してＣ濃度を０．０８質量％以下まで脱
炭することを特徴とする低炭素薄鋼板の製造方法。
（３）低炭素薄鋼板の製造方法において、溶鋼中のＣ濃
度を０．１質量％から２．０質量％に脱炭素処理した後
Ａｌで脱酸し、該溶鋼を連続鋳造して得られた鋳片を熱
間圧延、更には冷間圧延した後に、薄鋼板の状態で水素
濃度５％以上の雰囲気下で加熱してＣ濃度を０．０８質
量％以下まで脱炭することを特徴とする低炭素薄鋼板の
製造方法。
（４）低炭素薄鋼板の製造方法において、溶鋼中のＣ濃
度を０．１質量％から２．０質量％に脱炭素処理した後
Ａｌで脱酸し、該溶鋼を連続鋳造して得られた鋳片を熱
間圧延、更には冷間圧延した後に、薄鋼板の状態で水素
濃度５％以上で、且つ温度８００℃以上の雰囲気で加熱
してＣ濃度を０．０８質量％以下まで脱炭することを特
徴とする低炭素薄鋼板の製造方法。
（５）低炭素薄鋼板の製造方法において、溶鋼中のＣ濃
度を０．１質量％から２．０質量％に脱炭素処理した後
Ｔｉで脱酸し、該溶鋼を連続鋳造して得られた鋳片を熱
間圧延、更には冷間圧延した後に、薄鋼板の状態で水素
濃度５％以上の雰囲気下で加熱してＣ濃度を０．０８質
量％以下まで脱炭することを特徴とする低炭素薄鋼板の
製造方法。
（６）低炭素薄鋼板の製造方法において、溶鋼中のＣ濃
度を０．１質量％から２．０質量％に脱炭素処理した後
Ｔｉで脱酸し、該溶鋼を連続鋳造して得られた鋳片を熱
間圧延、更には冷間圧延した後に、薄鋼板の状態で水素
濃度５％以上で、且つ温度８００℃以上の雰囲気で加熱
してＣ濃度を０．０８質量％以下まで脱炭することを特
徴とする低炭素薄鋼板の製造方法。
（７）前記（１）から（６）に記載のいずれかの方法で
製造して得られた薄鋼板において、直径０．５μｍから
２０μｍの微細酸化物が鋳片内に１個／mm3 以上、１０
０個／mm3 未満分散していることを特徴とする低炭素薄
鋼板。In order to solve the above problems, the present invention has the following structures. (1) In the method for producing a low carbon thin steel sheet, the carbon concentration in molten steel is decarbonized from 0.1% by mass to 2.0% by mass, deoxidized with Al, and the molten steel is continuously cast. A low carbon thin steel sheet, characterized in that, after hot rolling and further cold rolling of the cast slab, the thin steel sheet is heated in a hydrogen atmosphere to decarburize to a C concentration of 0.08 mass% or less. Manufacturing method. (2) In the method for producing a low carbon thin steel sheet, the carbon concentration in molten steel is decarbonized from 0.1% by mass to 2.0% by mass, deoxidized with Ti, and the molten steel is continuously cast. A low carbon thin steel sheet, characterized in that, after hot rolling and further cold rolling of the cast slab, the thin steel sheet is heated in a hydrogen atmosphere to decarburize to a C concentration of 0.08 mass% or less. Manufacturing method. (3) In the method for producing a low carbon thin steel sheet, the carbon concentration in molten steel is decarbonized from 0.1% by mass to 2.0% by mass, deoxidized with Al, and the molten steel is continuously cast. After hot-rolling and further cold-rolling the slab, the thin steel sheet is heated in an atmosphere having a hydrogen concentration of 5% or more to decarburize the C concentration to 0.08 mass% or less. A method for producing a low carbon thin steel sheet. (4) In the method for producing a low carbon thin steel sheet, the carbon concentration in molten steel is decarbonized from 0.1% by mass to 2.0% by mass, deoxidized with Al, and the molten steel is continuously cast. After hot rolling and further cold rolling of the slab, the thin steel sheet is heated in an atmosphere of hydrogen concentration of 5% or more and at a temperature of 800 ° C. or more to remove the C concentration to 0.08 mass% or less. A method for producing a low carbon thin steel sheet, which comprises charcoal-making. (5) In the method for producing a low carbon thin steel sheet, the carbon concentration in molten steel is decarbonized from 0.1% by mass to 2.0% by mass, deoxidized with Ti, and the molten steel is continuously cast. After hot-rolling and further cold-rolling the slab, the thin steel sheet is heated in an atmosphere having a hydrogen concentration of 5% or more to decarburize the C concentration to 0.08 mass% or less. A method for producing a low carbon thin steel sheet. (6) In the method for producing a low carbon thin steel sheet, the carbon concentration in molten steel is decarbonized from 0.1% by mass to 2.0% by mass, deoxidized with Ti, and the molten steel is continuously cast. After hot rolling and further cold rolling of the slab, the thin steel sheet is heated in an atmosphere of hydrogen concentration of 5% or more and at a temperature of 800 ° C. or more to remove the C concentration to 0.08 mass% or less. A method for producing a low carbon thin steel sheet, which comprises charcoal-making. (7) In the thin steel sheet obtained by the method according to any one of (1) to (6), one fine oxide having a diameter of 0.5 μm to 20 μm is contained in the cast piece at a rate of 1 / mm 3 or more. 10,
A low carbon thin steel sheet characterized in that less than 0 pieces / mm 3 are dispersed.
【０００７】[0007]
【発明の実施の形態】以下に本発明を詳細に説明する。
本発明の低炭素鋼板の製造法は、転炉や電気炉等の製鋼
炉で精錬して、Ｃ濃度を０．１質量％〜２．０質量％に
調整した溶鋼を鋳造し、得られた鋳片を熱間圧延、冷間
圧延した後、水素雰囲気炉で脱炭処理し、低炭素薄鋼板
を得るものである。この低炭素薄鋼板製造の基本思想
は、転炉や電気炉等の製鋼炉で溶鋼中の溶存酸素濃度が
最も低下するＣ濃度範囲で脱炭処理を終了し、その後の
Ａｌ脱酸等で生じる介在物量を極限まで低下させた薄鋼
板を製造した上で、薄鋼板の状態で脱炭させ低炭素鋼と
して材質を確保することにある。BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below.
The method for producing a low carbon steel sheet of the present invention was obtained by refining in a steelmaking furnace such as a converter or an electric furnace and casting molten steel with a C concentration adjusted to 0.1% by mass to 2.0% by mass. The slab is hot-rolled and cold-rolled, and then decarburized in a hydrogen atmosphere furnace to obtain a low carbon thin steel sheet. The basic idea of the production of this low carbon thin steel sheet is that the decarburization treatment is completed within a C concentration range where the dissolved oxygen concentration in the molten steel is the lowest in a steelmaking furnace such as a converter or an electric furnace, and is generated by subsequent Al deoxidation or the like The purpose is to manufacture a thin steel sheet with the amount of inclusions reduced to the limit, and then decarburize the thin steel sheet to secure the material as a low carbon steel.
【０００８】転炉や真空処理容器で脱炭処理された溶鋼
中には、Ｃ濃度に応じた溶存酸素が含まれており、この
溶存酸素は通常Ａｌの添加により殆ど脱酸される（下記
（１）式の反応）ため、溶鋼中にアルミナ系介在物を生
成する。
２Ａｌ＋３Ｏ＝Ａｌ2 Ｏ3 （１）Molten steel decarburized in a converter or a vacuum treatment vessel contains dissolved oxygen depending on the C concentration, and this dissolved oxygen is usually almost deoxidized by the addition of Al (see the following ( Therefore, alumina-based inclusions are generated in the molten steel because of the reaction of the formula (1)). 2Al + 3O = Al 2 O 3 (1)
【０００９】特に、低炭素薄鋼板のようにＣ濃度を０．
０４質量％以下まで大きく低下させると、溶鋼中の溶存
酸素濃度は０．０５質量％程度まで増大するため、脱酸
後の溶鋼清浄性は大きく低下する。また、溶鋼中の溶存
酸素濃度が高くなると、同時に取鍋スラグの酸素濃度も
上昇するため、脱酸後にスラグによる溶鋼再酸化が生
じ、アルミナ系介在物量が更に増大する。このため、低
炭素鋼では鋳片段階において全酸素濃度で３０〜４０pp
m 程度の介在物を含んでいる。これに対して、本発明で
は、溶存酸素が比較的低下するＣ濃度、即ち０．１質量
％から２．０質量％の範囲で脱炭処理を終了し、溶存酸
素濃度を０．０２質量％以下とする。その後、Ａｌで脱
酸しても、生成する介在物量は従来の低炭素鋼に比べて
非常に少なくなり、さらに取鍋スラグの酸素濃度も低下
しているため、脱酸後のスラグによる溶鋼汚染は急激に
減少する。現状、Ｃ濃度が１．０質量％程度の軸受鋼で
は、鋳片段階の全酸素濃度で５ppm 程度の超清浄鋼が製
造されており、Ｃ濃度を上げて溶存酸素濃度を低減する
ことは溶鋼清浄性の向上に大きく寄与すると考えられ
る。なお、本発明は、その原理から考えて、Ａｌ脱酸だ
けに適用されるものではなく、Ｔｉ脱酸の場合でも十分
な介在物低減効果が得られる。Particularly, as in the case of a low carbon thin steel sheet, the C concentration is set to 0.
When the content is greatly reduced to 04 mass% or less, the dissolved oxygen concentration in the molten steel increases to about 0.05 mass%, so that the cleanliness of the molten steel after deoxidation is significantly reduced. Further, when the dissolved oxygen concentration in the molten steel becomes high, the oxygen concentration in the ladle slag also increases at the same time, so that the molten steel is reoxidized by the slag after deoxidation, and the amount of alumina-based inclusions further increases. For this reason, in low carbon steel, the total oxygen concentration is 30 to 40 pp at the casting stage.
It contains about m inclusions. On the other hand, in the present invention, the decarburization treatment is terminated at a C concentration in which dissolved oxygen is relatively lowered, that is, in the range of 0.1% by mass to 2.0% by mass, and the dissolved oxygen concentration is 0.02% by mass. Below. After that, even if deoxidized with Al, the amount of inclusions produced is much smaller than that of conventional low carbon steel, and the oxygen concentration in the ladle slag is also reduced, so the molten steel is contaminated by the slag after deoxidation. Decreases sharply. At present, ultra-clean steel with a total oxygen concentration of about 5 ppm in the cast slab is produced for bearing steel with a C concentration of about 1.0% by mass, and it is necessary to increase the C concentration to reduce the dissolved oxygen concentration. It is considered that it contributes greatly to the improvement of cleanliness. In consideration of the principle, the present invention is not applied only to Al deoxidation, and a sufficient inclusion reduction effect can be obtained even in the case of Ti deoxidation.
【００１０】しかし、本方法により溶鋼の清浄性を向上
させても、Ｃ濃度が高いと加工性が要求される薄鋼板の
用途、例えば缶用素材として使用できない。本発明で
は、高Ｃ濃度で鋳造した鋳片を熱間圧延し、更には冷間
圧延まで実施した後に、薄板の状態で水素雰囲気下で脱
炭することを考案した。高Ｃ濃度の薄板を水素雰囲気中
で加熱すると、（２）式の反応により鋼板中のＣはＣＨ
4 ガスとして低下していく。
Ｃ＋２Ｈ2 ＝ＣＨ4 （２）However, even if the cleanliness of molten steel is improved by this method, if the C concentration is high, it cannot be used as a thin steel sheet application requiring workability, for example, as a material for cans. In the present invention, it was devised to hot-roll a slab cast with a high C concentration, and further to perform cold rolling, and then decarburize the thin plate in a hydrogen atmosphere. When a thin plate with a high C concentration is heated in a hydrogen atmosphere, C in the steel plate becomes CH due to the reaction of equation (2).
4 As gas decreases. C + 2H 2 = CH 4 (2)
【００１１】雰囲気中の水素濃度は５％以上であれば良
く、５％未満になると（２）式の反応速度が急激に低下
する。薄鋼板の板厚が厚くなると脱炭時間が非常に長く
なるため、板厚は３mm以下であることが好ましい。ま
た、脱炭時の雰囲気温度は８００℃以上にすることが望
ましく、８００℃未満では脱炭時間が長くなりすぎる。
（２）式の反応速度は、鋼板中におけるＣの拡散に律速
されているため、（２）式の脱炭反応を短時間で行わせ
るためには、雰囲気中の水素濃度を高めるよりは、むし
ろ板厚を薄くし、加熱温度を上げることが効果的であ
る。また、薄鋼板は、缶用素材等の加工が厳しい用途に
用いられるため、鋼板中のＣ濃度は０．０８％以下にす
ることが好ましい。It suffices that the hydrogen concentration in the atmosphere is 5% or more, and if it is less than 5%, the reaction rate of the formula (2) is drastically reduced. Since the decarburization time becomes very long when the plate thickness of the thin steel plate becomes thick, the plate thickness is preferably 3 mm or less. Further, it is desirable that the atmosphere temperature during decarburization is 800 ° C. or higher, and if the temperature is lower than 800 ° C., the decarburization time becomes too long.
Since the reaction rate of equation (2) is controlled by the diffusion of C in the steel sheet, in order to carry out the decarburization reaction of equation (2) in a short time, rather than increasing the hydrogen concentration in the atmosphere, Rather, it is effective to reduce the plate thickness and raise the heating temperature. Further, since the thin steel sheet is used for applications where processing of materials for cans is difficult, it is preferable that the C concentration in the steel sheet be 0.08% or less.
【００１２】本発明により製造された低炭素薄鋼板中の
介在物を顕微鏡観察したところ、直径０．５μｍから２
０μｍの微細酸化物が鋳片内に１個／mm3 以上、１００
個／mm3 未満分散しており、このような酸化物分散状態
を有する薄鋼板では、ＤＩ缶の製缶試験を実施してもワ
レ発生率は１ppm 以下であった。Microscopic observation of inclusions in the low carbon thin steel sheet produced according to the present invention revealed that the diameter of the inclusions was 0.5 μm to 2 μm.
0 μm fine oxide is 1 piece / mm 3 or more in the slab, 100
Dispersion of less than 1 piece / mm 3 was observed, and in the case of a thin steel sheet having such an oxide dispersion state, the crack occurrence rate was 1 ppm or less even when a DI can manufacturing test was carried out.
【００１３】以上の結果から、本発明により溶鋼中の溶
存酸素濃度を低下させると共に、スラグからの溶鋼再酸
化を抑制できるため、内部欠陥の発生を防止でき、薄鋼
板の品質は大きく向上する。From the above results, according to the present invention, the dissolved oxygen concentration in the molten steel can be lowered and the molten steel reoxidation from the slag can be suppressed, so that the occurrence of internal defects can be prevented and the quality of the thin steel sheet is greatly improved.
【００１４】[0014]
【実施例】以下に、実施例及び比較例を挙げて、本発明
について説明する。
実施例１：転炉での脱炭処理により、Ｃ濃度を１．０質
量％まで低下させ、その後Ａｌを添加して脱酸し、Ｃ濃
度１．０質量％、Ａｌ濃度０．０４質量％の溶鋼を３０
０ｔ溶製した。この溶鋼を連続鋳造法で厚み２５０mm、
幅１０００mmのスラブに鋳造した。鋳造した鋳片は８５
００mm長さに切断し、１コイル単位とした。このように
して得られたスラブは、常法により熱間圧延、冷間圧延
し、最終的には０．１８mm厚みで幅１０００mmコイルの
冷延鋼板とした。この冷延鋼板を温度１１００℃の３０
％水素雰囲気下で加熱処理し、Ｃ濃度０．０４質量％の
低炭素薄鋼板とした。この鋼板を用いて製缶試験を実施
した結果、ワレの発生率は１ppm 以下であった。EXAMPLES The present invention will be described below with reference to Examples and Comparative Examples. Example 1: C concentration was reduced to 1.0% by mass by decarburization treatment in a converter, and thereafter Al was added to deoxidize C to 1.0% by mass and Al concentration was 0.04% by mass. 30 molten steel
It was melted for 0t. This molten steel is 250mm thick by continuous casting method,
Cast into a slab with a width of 1000 mm. The cast slab is 85
It was cut to a length of 00 mm to make one coil unit. The slab thus obtained was hot-rolled and cold-rolled by a conventional method to finally obtain a cold-rolled steel sheet having a coil thickness of 0.18 mm and a width of 1000 mm. This cold-rolled steel sheet was heated at a temperature of 1100 ° C for 30
% Hydrogen atmosphere to obtain a low carbon thin steel sheet having a C concentration of 0.04 mass%. As a result of carrying out a can manufacturing test using this steel sheet, the occurrence rate of cracks was 1 ppm or less.
【００１５】実施例２：転炉での脱炭処理により、Ｃ濃
度を１．０質量％まで低下させ、その後Ｔｉを添加して
脱酸し、Ｃ濃度１．０質量％、Ａｌ濃度０．０２質量％
の溶鋼を３００ｔ溶製した。この溶鋼を連続鋳造法で厚
み２５０mm、幅１０００mmのスラブに鋳造した。鋳造し
た鋳片は８５００mm長さに切断し、１コイル単位とし
た。このようにして得られたスラブは、常法により熱間
圧延、冷間圧延し、最終的には０．１８mm厚みで幅１０
００mmコイルの冷延鋼板とした。この冷延鋼板を温度１
１００℃の３０％水素雰囲気下で加熱処理し、Ｃ濃度
０．０４質量％の低炭素薄鋼板とした。この鋼板を用い
て製缶試験を実施した結果、ワレの発生率は１ppm 以下
であった。Example 2: The decarburization treatment in the converter lowers the C concentration to 1.0% by mass, and then Ti is added to deoxidize the C concentration to 1.0% by mass and the Al concentration to 0.1% by mass. 02 mass%
The molten steel of No. 3 was melted for 300 tons. This molten steel was cast by a continuous casting method into a slab having a thickness of 250 mm and a width of 1000 mm. The cast slab was cut to a length of 8500 mm to make one coil unit. The slab thus obtained is hot-rolled and cold-rolled by a conventional method, and finally has a thickness of 0.18 mm and a width of 10 mm.
It was a cold rolled steel plate with a 00 mm coil. This cold rolled steel sheet has a temperature of 1
Heat treatment was performed in a 30% hydrogen atmosphere at 100 ° C. to obtain a low carbon thin steel sheet having a C concentration of 0.04 mass%. As a result of carrying out a can manufacturing test using this steel sheet, the occurrence rate of cracks was 1 ppm or less.
【００１６】比較例１：転炉でのＣ濃度を０．０４質量
％まで低下させ、その後Ａｌを添加して脱酸し、Ｃ濃度
０．０４質量％、Ａｌ濃度０．０４質量％の溶鋼を３０
０ｔ溶製した。この溶鋼を連続鋳造法で厚み２５０mm、
幅１０００mmのスラブに鋳造した。鋳造した鋳片は８５
００mm長さに切断し、１コイル単位とした。このように
して得られたスラブは、常法により熱間圧延、冷間圧延
し、最終的には０．１８mm厚みで幅１０００mmコイルの
冷延鋼板とした。この鋼板を用いて製缶試験を実施した
結果、ワレの発生率は５０ppm であた。Comparative Example 1: C concentration in a converter is reduced to 0.04% by mass, Al is then added to deoxidize, and molten steel having a C concentration of 0.04% by mass and an Al concentration of 0.04% by mass. 30
It was melted for 0t. This molten steel is 250mm thick by continuous casting method,
Cast into a slab with a width of 1000 mm. The cast slab is 85
It was cut to a length of 00 mm to make one coil unit. The slab thus obtained was hot-rolled and cold-rolled by a conventional method to finally obtain a cold-rolled steel sheet having a coil thickness of 0.18 mm and a width of 1000 mm. As a result of carrying out a can manufacturing test using this steel sheet, the occurrence rate of cracks was 50 ppm.
【００１７】[0017]
【発明の効果】以上に説明したように、本発明による
と、低炭素薄鋼板で介在物生成量を極限まで低下させる
ことができるため、確実に内部欠陥を低減でき、且つ加
工性、成形性に優れた薄鋼板を製造することが可能とな
る。As described above, according to the present invention, since the amount of inclusions formed can be reduced to a minimum with a low carbon thin steel sheet, internal defects can be reliably reduced, and the workability and formability can be surely reduced. It is possible to manufacture a thin steel sheet excellent in heat resistance.
───────────────────────────────────────────────────── フロントページの続き Ｆターム(参考） 4K013 AA07 BA02 BA08 BA14 EA18 EA19 4K037 EA04 EA05 EC01 FH00 ─────────────────────────────────────────────────── ─── Continued front page F-term (reference) 4K013 AA07 BA02 BA08 BA14 EA18 EA19 4K037 EA04 EA05 EC01 FH00
Claims (7)
中のＣ濃度を０．１質量％から２．０質量％に脱炭素処
理した後Ａｌで脱酸し、該溶鋼を連続鋳造して得られた
鋳片を熱間圧延、更には冷間圧延した後に、薄鋼板の状
態で水素雰囲気下で加熱してＣ濃度を０．０８質量％以
下まで脱炭することを特徴とする低炭素薄鋼板の製造方
法。1. A method for producing a low carbon thin steel sheet, which comprises decarbonizing a carbon concentration in molten steel from 0.1% by mass to 2.0% by mass, deoxidizing with Al, and continuously casting the molten steel. The obtained slab is hot-rolled, further cold-rolled, and then heated in a thin steel sheet in a hydrogen atmosphere to decarburize the carbon concentration to 0.08 mass% or less. Manufacturing method of thin steel sheet.
中のＣ濃度を０．１質量％から２．０質量％に脱炭素処
理した後Ｔｉで脱酸し、該溶鋼を連続鋳造して得られた
鋳片を熱間圧延、更には冷間圧延した後に、薄鋼板の状
態で水素雰囲気下で加熱してＣ濃度を０．０８質量％以
下まで脱炭することを特徴とする低炭素薄鋼板の製造方
法。2. A method for producing a low carbon thin steel sheet, wherein the carbon concentration in molten steel is decarbonized from 0.1% by mass to 2.0% by mass, deoxidized with Ti, and the molten steel is continuously cast. The obtained slab is hot-rolled, further cold-rolled, and then heated in a thin steel sheet in a hydrogen atmosphere to decarburize the carbon concentration to 0.08 mass% or less. Manufacturing method of thin steel sheet.
中のＣ濃度を０．１質量％から２．０質量％に脱炭素処
理した後Ａｌで脱酸し、該溶鋼を連続鋳造して得られた
鋳片を熱間圧延、更には冷間圧延した後に、薄鋼板の状
態で水素濃度５％以上の雰囲気下で加熱してＣ濃度を
０．０８質量％以下まで脱炭することを特徴とする低炭
素薄鋼板の製造方法。3. A method for producing a low carbon thin steel sheet, wherein the carbon concentration in molten steel is decarbonized from 0.1% by mass to 2.0% by mass, deoxidized with Al, and the molten steel is continuously cast. The obtained slab is hot-rolled, further cold-rolled, and then heated in a thin steel sheet state under an atmosphere of hydrogen concentration of 5% or more to decarburize to a C concentration of 0.08 mass% or less. A method for producing a low carbon thin steel sheet characterized.
中のＣ濃度を０．１質量％から２．０質量％に脱炭素処
理した後Ａｌで脱酸し、該溶鋼を連続鋳造して得られた
鋳片を熱間圧延、更には冷間圧延した後に、薄鋼板の状
態で水素濃度５％以上で、且つ温度８００℃以上の雰囲
気で加熱してＣ濃度を０．０８質量％以下まで脱炭する
ことを特徴とする低炭素薄鋼板の製造方法。4. A method for producing a low carbon thin steel sheet, wherein the carbon concentration in molten steel is decarbonized from 0.1% by mass to 2.0% by mass, deoxidized with Al, and the molten steel is continuously cast. The obtained slab is hot-rolled, further cold-rolled, and then heated in an atmosphere of a thin steel sheet with a hydrogen concentration of 5% or more and a temperature of 800 ° C. or more to have a C concentration of 0.08 mass% or less. A method for manufacturing a low carbon thin steel sheet, which comprises decarburizing up to.
中のＣ濃度を０．１質量％から２．０質量％に脱炭素処
理した後Ｔｉで脱酸し、該溶鋼を連続鋳造して得られた
鋳片を熱間圧延、更には冷間圧延した後に、薄鋼板の状
態で水素濃度５％以上の雰囲気下で加熱してＣ濃度を
０．０８質量％以下まで脱炭することを特徴とする低炭
素薄鋼板の製造方法。5. A method for producing a low carbon thin steel sheet, wherein a carbon concentration in molten steel is decarbonized from 0.1% by mass to 2.0% by mass, deoxidized with Ti, and the molten steel is continuously cast. The obtained slab is hot-rolled, further cold-rolled, and then heated in a thin steel sheet state under an atmosphere of hydrogen concentration of 5% or more to decarburize to a C concentration of 0.08 mass% or less. A method for producing a low carbon thin steel sheet characterized.
中のＣ濃度を０．１質量％から２．０質量％に脱炭素処
理した後Ｔｉで脱酸し、該溶鋼を連続鋳造して得られた
鋳片を熱間圧延、更には冷間圧延した後に、薄鋼板の状
態で水素濃度５％以上で、且つ温度８００℃以上の雰囲
気で加熱してＣ濃度を０．０８質量％以下まで脱炭する
ことを特徴とする低炭素薄鋼板の製造方法。6. A method for manufacturing a low carbon thin steel sheet, wherein the carbon concentration in molten steel is decarbonized from 0.1% by mass to 2.0% by mass, deoxidized with Ti, and the molten steel is continuously cast. The obtained slab is hot-rolled, further cold-rolled, and then heated in an atmosphere of a thin steel sheet with a hydrogen concentration of 5% or more and a temperature of 800 ° C. or more to have a C concentration of 0.08 mass% or less. A method for manufacturing a low carbon thin steel sheet, which comprises decarburizing up to.
で製造して得られた薄鋼板において、直径０．５μｍか
ら２０μｍの微細酸化物が鋳片内に１個／mm 3 以上、１
００個／mm3 未満分散していることを特徴とする低炭素
薄鋼板。7. The method according to any one of claims 1 to 6.
In the thin steel sheet produced by
1 μm / mm of fine oxide of 20 μm 3Above 1
00 / mm3Low carbon characterized by less than dispersed
Thin steel plate.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010196114A (en) * | 2009-02-25 | 2010-09-09 | Jfe Steel Corp | Method for producing bearing steel |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS53120624A (en) * | 1977-03-31 | 1978-10-21 | Sumitomo Metal Ind Ltd | Manufacture of cold rolled damping steel sheet |
| JPS56139623A (en) * | 1980-03-31 | 1981-10-31 | Sumitomo Metal Ind Ltd | Production of vibration control steel plate for working |
| JPS56139624A (en) * | 1980-03-31 | 1981-10-31 | Toyo Kohan Co Ltd | Production of shadow mask |
-
2001
- 2001-08-07 JP JP2001239555A patent/JP4608148B2/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS53120624A (en) * | 1977-03-31 | 1978-10-21 | Sumitomo Metal Ind Ltd | Manufacture of cold rolled damping steel sheet |
| JPS56139623A (en) * | 1980-03-31 | 1981-10-31 | Sumitomo Metal Ind Ltd | Production of vibration control steel plate for working |
| JPS56139624A (en) * | 1980-03-31 | 1981-10-31 | Toyo Kohan Co Ltd | Production of shadow mask |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010196114A (en) * | 2009-02-25 | 2010-09-09 | Jfe Steel Corp | Method for producing bearing steel |
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