JPH0499811A - Refining method for making inclusion in steel fine - Google Patents
Refining method for making inclusion in steel fineInfo
- Publication number
- JPH0499811A JPH0499811A JP21753990A JP21753990A JPH0499811A JP H0499811 A JPH0499811 A JP H0499811A JP 21753990 A JP21753990 A JP 21753990A JP 21753990 A JP21753990 A JP 21753990A JP H0499811 A JPH0499811 A JP H0499811A
- Authority
- JP
- Japan
- Prior art keywords
- cao
- steel
- alloy
- molten steel
- slag
- 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.)
- Pending
Links
Landscapes
- Treatment Of Steel In Its Molten State (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は取鍋精錬等による鋼中介在物を微細化する精錬
方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a refining method for refining inclusions in steel by ladle refining or the like.
（従来の技術）
従来技術としては特公昭５９−２２７６５号公報で示す
ように、取鍋内の予め脱酸処理した溶鋼にＣａＯ含有フ
ラックスをキャリアーガスにより吹込み、脱酸、脱硫し
た後、引きつづいて該溶鋼にＣａ合金を吹込み、溶鋼中
の硫化物形態を制御することが公知である。その実施例
をみると、ＣａＯ含有フラックス、Ｃａ合金をそれぞれ
、４．５ ｋｇ／ＴＳ、１．８ｋｇ／ＴＳ吹込んでいる
。(Prior art) As shown in Japanese Patent Publication No. 59-22765, the prior art is that CaO-containing flux is blown into molten steel that has been previously deoxidized in a ladle using a carrier gas, deoxidized and desulfurized, and then pulled. It is known to subsequently inject a Ca alloy into the molten steel to control the sulfide morphology in the molten steel. In the example, 4.5 kg/TS and 1.8 kg/TS of CaO-containing flux and Ca alloy were injected, respectively.
（発明が解決しようとする課題）
従来技術の課題としては、ＣａＯ含有フラックス、Ｃａ
合金を多量に吹込むためＣａＯ−Ａｌ２Ｏ３の球状介在
物が多量に生成する。ＣａＯ−Ａｔ ２０３の球状介在
物は軟質のため、鋼中に含まれる場合、鋼材を圧延する
際はよく伸び、鋼と介在物との間にキ裂は生ぜず品質上
の問題はない反面、綱の表面に介在する場合、鋼材を圧
延する際は鋼と介在物との軟らかさの違いによってロー
ル圧延中に表面に疵が発生し、品質上の問題となってい
る。(Problems to be solved by the invention) Problems with the prior art include CaO-containing flux, Ca
Since a large amount of alloy is injected, a large amount of spherical inclusions of CaO-Al2O3 are generated. The spherical inclusions of CaO-At 203 are soft, so when they are included in steel, they elongate well when rolling the steel material, and no cracks occur between the steel and the inclusions, causing no quality problems. When the inclusions are present on the surface of the steel, defects occur on the surface during rolling due to the difference in softness between the steel and the inclusions, which poses a quality problem.
（課題を解決するための手段）
本発明は前記従来技術の課題を有利に解決するものであ
って、その要旨とするところは、取鍋内の予め脱酸した
溶鋼に、ＣａＯ（３，８〜４．２ ｋｇ／ＴＳ）を吹込
み、その後Ｃａ合金を０．１〜０．７ ｋｇ／Ｔｓ吹込
む処理をし、鋼中にＣａを１〜４ｐｐｍｉ融させること
を特徴とする鋼中介在物を微細化する精錬方法にある。(Means for Solving the Problems) The present invention advantageously solves the problems of the prior art, and its gist is that CaO (3,8 - 4.2 kg/TS), and then a Ca alloy is injected at 0.1 to 0.7 kg/TS to melt 1 to 4 ppmi of Ca into the steel. It lies in the refining method of making things finer.
以下本発明を図面に基づいて説明する。The present invention will be explained below based on the drawings.
本発明が適用される鋼種は、第１表で示す低臭Ａｔキル
ド鋼である。The steel type to which the present invention is applied is the low-odor At-killed steel shown in Table 1.
二の鋼種は一般に薄鋼板となり、表面性状の優れている
ことが品質特性として要求される。The second type of steel is generally a thin steel plate, and is required to have excellent surface properties as a quality characteristic.
本発明では、取鍋内にて溶鋼を予めＡＩ脱酸して、第１
表に示す成分系のように溶製する。最初に、スラグ中の
Ｔ、Ｆ ｅを下げるためにＣａＯを吹込み、スラグ中Ｆ
ｅＯの活量を下げる。これにより、（Ｆｅｄ） ＋ Ｃ
ａ （Ｆｅ） ＋ （Ｃａｂ）で示されるＣａ
の酸化反応を抑制することができる。In the present invention, the molten steel is deoxidized by AI in advance in the ladle, and the first
Melt according to the component system shown in the table. First, CaO is blown into the slag to lower T and Fe in the slag.
Decrease the activity of eO. This gives (Fed) + C
Ca denoted by a (Fe) + (Cab)
can suppress the oxidation reaction of
吹込むＣａＯ量は３．８〜４．２ ｋｇ／ＴＳが最適で
あり、これ未満ではスラグ中ＦｅＯの活量を十分に下げ
ることができず、これを超えると、ＣａＯ原単位が増加
するのみで過剰供給となる。The optimal amount of CaO to be injected is 3.8 to 4.2 kg/TS; if it is less than this, the activity of FeO in the slag cannot be sufficiently lowered, and if it exceeds this, the CaO basic unit will only increase. There will be an oversupply.
この処理を行った後に溶鋼中にＣａを添加する目的で、
Ｃａ合金を吹込む。鋼中Ｃａ、ＡＮ酸化反応のΔＧは、
−３２６ｋＪ （ａｔ １６００’Ｃ）１６２ｋＪ
（ａｔ １６００°Ｃ）であり、１６００″Ｃの温度域
ではＣａＯ方が優先的に酸化される。このためＣａ合金
吹きした溶鋼では、溶鋼中で多量の微細なＣａＯが生成
し、後に生成するＡｌ２Ｏ２の核となり、多量の微細な
八１．０３− ＣａＯ系介在物を生成する。これにより
、ＡｌｚＯｚ系の巨大なりラスターの生成を防ぐことが
でき、圧延時に生成する表面疵を低減することができる
。In order to add Ca to the molten steel after this treatment,
Inject Ca alloy. ΔG of Ca and AN oxidation reaction in steel is -326kJ (at 1600'C) 162kJ
(at 1600°C), and in the temperature range of 1600"C, CaO is preferentially oxidized. Therefore, in molten steel blown with Ca alloy, a large amount of fine CaO is generated in the molten steel, and later formed. It becomes a nucleus of Al2O2 and generates a large amount of fine 81.03- CaO-based inclusions.This can prevent the formation of giant AlzOz-based rasters and reduce surface flaws generated during rolling. can.
鋼中に溶融させるＣａ量は１〜４ ｐｐｍの範囲内であ
り、このためにＣａ合金粉体を０．１〜０．７ ｋｇ／
ＴＳ添加する。溶融Ｃａ量がこの範囲未満では、Ｃａ添
加による十分な介在物分散効果は望めない。又、この範
囲を超えると、Ｃａ −ＡＩ原単位が増加し、コスト面
で利点はない。The amount of Ca to be melted into steel is within the range of 1 to 4 ppm, and for this purpose Ca alloy powder is added at a rate of 0.1 to 0.7 kg/
Add TS. If the amount of molten Ca is less than this range, a sufficient effect of dispersing inclusions by adding Ca cannot be expected. Moreover, if it exceeds this range, the Ca-AI basic unit will increase and there will be no advantage in terms of cost.
Ｃａ合金吹込み前には、ＣａＯを３．８〜４．２ ｋｇ
／ＴＳ吹込み、スラグを希釈してＦｅＯの活量を下げＣ
ａの歩留を上げる。ＣａＯ吹込量がこの量未満では、ス
ラグ改質が十分にできず、Ｃａ合金添加時のＣａ歩留が
悪くなる。又、ＣａＯ吹込量がこの量を超えると、Ｃａ
Ｏ原単位が増大し、コスト面で不利となる。Before injecting Ca alloy, add 3.8 to 4.2 kg of CaO.
/TS injection, dilutes slag and lowers FeO activity C
Increase the yield of a. If the amount of CaO injected is less than this amount, slag modification cannot be performed sufficiently, and the Ca yield when adding Ca alloy becomes poor. Also, if the amount of CaO injected exceeds this amount, Ca
The O consumption rate increases, which is disadvantageous in terms of cost.
（実施例）
第１図は本発明による鋳片介在物の組成を表す図である
。図は、介在物組成をＡ１２０３ＣａＯ〜ＦｅＯ系の二
元図で表したものであり、左下の頂点は＾１２０３、右
下の頂点は６０％Ａｆ２０３ 、’ｔｏ％Ｆｅ０１上
の頂点は６０％Ａｌ２０３４０％ＣａＯである。図中本
発明の介在物は黒丸で示している。(Example) FIG. 1 is a diagram showing the composition of slab inclusions according to the present invention. The figure shows the inclusion composition in a binary diagram of the A1203CaO~FeO system, where the lower left vertex is ^1203, the lower right vertex is 60%Af203, and the vertex on 'to%Fe01 is 60%Al20340%. It is CaO. In the figure, the inclusions of the present invention are indicated by black circles.
従来の処理法による表面疵厳格材の鋳片介在物の組成は
白丸で示している。The composition of slab inclusions in materials with severe surface defects produced by conventional treatment methods is shown by white circles.
（発明の効果）
第２図は、鋳片介在物の平均粒径について、本発明と従
来法とで比較した図である。(Effects of the Invention) FIG. 2 is a diagram comparing the average grain size of slab inclusions between the present invention and the conventional method.
本発明によれば、鋼中に溶融したＣａが、微細な多量の
ＣａＯとなり、Ａｌ２Ｏ３生成の核となるため、生成す
るＡ１ｚＯ＋−ＣａＯ系の介在物径を小さくすることが
できる。According to the present invention, Ca molten in steel turns into a large amount of fine CaO, which becomes the nucleus for Al2O3 production, so that the diameter of the generated A1zO+-CaO inclusions can be reduced.
第１図は本発明による鋳片介在物の組成を表す図、第２
図は鋳片介在物の平均粒径について、本発明と従来法と
で比較した図である。FIG. 1 is a diagram showing the composition of slab inclusions according to the present invention, and FIG.
The figure is a diagram comparing the average grain size of slab inclusions between the present invention and the conventional method.
Claims (1)
ｋｇ／ＴＳ）を吹込み、その後Ｃａ合金を０．１〜０．
７ｋｇ／ＴＳ吹込む処理をし、鋼中にＣａを１〜４ｐｐ
ｍ溶融させることを特徴とする鋼中介在物を微細化する
精錬方法。CaO (3.8 to 4.2
kg/TS), and then Ca alloy was injected at 0.1 to 0.
7kg/TS injection treatment to add 1 to 4pp of Ca into the steel.
A refining method for refining inclusions in steel, characterized by melting them.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21753990A JPH0499811A (en) | 1990-08-17 | 1990-08-17 | Refining method for making inclusion in steel fine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21753990A JPH0499811A (en) | 1990-08-17 | 1990-08-17 | Refining method for making inclusion in steel fine |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0499811A true JPH0499811A (en) | 1992-03-31 |
Family
ID=16705842
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP21753990A Pending JPH0499811A (en) | 1990-08-17 | 1990-08-17 | Refining method for making inclusion in steel fine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0499811A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8289120B2 (en) | 2010-02-17 | 2012-10-16 | Kabushiki Kaisha Toshiba | Electronic component, vehicle and electronic apparatus |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5735243A (en) * | 1980-08-11 | 1982-02-25 | Kyokuto Denki Kk | Hot air flow type heating apparatus |
| JPS5922765A (en) * | 1982-07-30 | 1984-02-06 | Fujitsu Ltd | Space control system of line dot printer |
-
1990
- 1990-08-17 JP JP21753990A patent/JPH0499811A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5735243A (en) * | 1980-08-11 | 1982-02-25 | Kyokuto Denki Kk | Hot air flow type heating apparatus |
| JPS5922765A (en) * | 1982-07-30 | 1984-02-06 | Fujitsu Ltd | Space control system of line dot printer |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8289120B2 (en) | 2010-02-17 | 2012-10-16 | Kabushiki Kaisha Toshiba | Electronic component, vehicle and electronic apparatus |
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