JPH0499216A - Production of al-free weakly deoxidized steel - Google Patents
Production of al-free weakly deoxidized steelInfo
- Publication number
- JPH0499216A JPH0499216A JP2212672A JP21267290A JPH0499216A JP H0499216 A JPH0499216 A JP H0499216A JP 2212672 A JP2212672 A JP 2212672A JP 21267290 A JP21267290 A JP 21267290A JP H0499216 A JPH0499216 A JP H0499216A
- Authority
- JP
- Japan
- Prior art keywords
- steel
- treatment
- free oxygen
- less
- free
- 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
- 229910000532 Deoxidized steel Inorganic materials 0.000 title claims description 5
- 238000004519 manufacturing process Methods 0.000 title claims description 5
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 26
- 239000010959 steel Substances 0.000 claims abstract description 26
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 21
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 20
- 239000001301 oxygen Substances 0.000 claims abstract description 20
- 238000007872 degassing Methods 0.000 claims abstract description 12
- ODINCKMPIJJUCX-UHFFFAOYSA-N Calcium oxide Chemical compound [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 claims abstract description 8
- 235000012255 calcium oxide Nutrition 0.000 claims abstract description 4
- 239000000292 calcium oxide Substances 0.000 claims abstract description 4
- 239000002893 slag Substances 0.000 abstract description 4
- 230000001105 regulatory effect Effects 0.000 abstract 1
- 238000007796 conventional method Methods 0.000 description 7
- 238000000034 method Methods 0.000 description 5
- 239000000203 mixture Substances 0.000 description 4
- 239000000047 product Substances 0.000 description 4
- 230000007423 decrease Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000007711 solidification Methods 0.000 description 2
- 230000008023 solidification Effects 0.000 description 2
- 230000009466 transformation Effects 0.000 description 2
- 235000019738 Limestone Nutrition 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 239000006028 limestone Substances 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
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Ａｌレス弱脱酸鋼の製造方法に関するものであ
る。DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for producing Al-free weakly deoxidized steel.
（従来の技術）
従来技術として、第１図に示す従来法で説明する。鋼の
変態核となる１０ｍ以下の微小酸化物の個数を増加させ
るため、ＲＨの脱ガス処理中に、鋼中フリー酸素が１１
００ｐｐ以上の時に、ＴｉやＺｒなどの弱脱酸元素を投
入する。鋼中フリー酸素の値を制御するために、脱ガス
処理にＯＢ処理を行い、続いてＡｌ投入を行う。(Prior Art) As a prior art, a conventional method shown in FIG. 1 will be explained. In order to increase the number of micro oxides of 10 m or less that serve as transformation nuclei in steel, during the RH degassing treatment, free oxygen in the steel was reduced to 11
When the amount is 00 pp or more, a weak deoxidizing element such as Ti or Zr is added. In order to control the value of free oxygen in the steel, OB treatment is performed for degassing treatment, followed by Al injection.
（発明が解決しようとする課Ｂ） 本発明の課題を、従来法を示す第２図により説明する。(Problem B that the invention attempts to solve) The problem of the present invention will be explained with reference to FIG. 2, which shows a conventional method.
微小酸化物の個数を増加させるために、ＲＨ脱ガス処理
中に、鋼中フリー酸素が１００ｐｐｍ以上で弱脱酸元素
を投入する従来法を実施すると、弱脱酸元素と平衡にな
るまで、鋼中フリー酸素が減少し、従来法に示すように
、Ａｌ、０３やＴｉＯ系の脱酸生成物量が増加し、これ
が鋳片上面側に集積し、ＵＳＴ不台の原因となる。In order to increase the number of micro oxides, when the conventional method of adding a weak deoxidizing element during RH degassing treatment when the free oxygen in the steel is 100 ppm or more is carried out, the steel Free oxygen in the steel decreases, and as shown in the conventional method, the amount of Al, 03, and TiO-based deoxidation products increases, which accumulates on the upper surface of the slab and causes UST failure.
（課題を解決するための手段）
本発明は前記の課題を有利に解決するものであって、そ
の要旨は溶鋼のＲＨ処理前に、取鍋内に生石灰を投入し
、スラグ中のＴ、 Ｆｅを２％以下にならしめ、へ！；
０．００１％以下で鋼中フリー酸素を１１００ｐｐ以下
にし、ＲＨ処理中には、脱ガスにより鋼中フリー酸素を
５０ｐｐｍ以下まで処理し、その後↑ｊ （Ｚｒ）を投
入し、ＲＨ処理後には、Ａｌ；１０ｐｐｏ＋以下で鋼中
フリー酸素を３０ｐｐｍ以下とすることを特徴とするＡ
ｌレス弱脱酸鋼の製造方法にある。(Means for Solving the Problems) The present invention advantageously solves the above-mentioned problems, and the gist thereof is that before the RH treatment of molten steel, quicklime is charged into a ladle, and T, Fe in the slag is Keep it below 2% and go! ;
At 0.001% or less, the free oxygen in the steel is reduced to 1100 ppm or less, and during the RH treatment, the free oxygen in the steel is reduced to 50 ppm or less by degassing, and then ↑j (Zr) is introduced, and after the RH treatment, A characterized in that Al: 10 pp+ or less and free oxygen in the steel is 30 ppm or less
A method for manufacturing l-less weakly deoxidized steel.
以下図面に基づいて本発明を説明する。The present invention will be explained below based on the drawings.
本発明で用いる鋼種の成分系を表１（最終製品の成分系
）で示す。特にＡＩに間しては、ＡＩ末脱酸状態であり
、ＴｉはＯとＮにバランスするように微量添加する。Table 1 (composition system of final product) shows the composition of the steel used in the present invention. In particular, the AI is in a deoxidized state, and a small amount of Ti is added to balance O and N.
本発明の方法を第１図で説明する。ＲＨ脱ガス処理中に
、ＯＢ処理を行なわず、またＡ！投入を行わず、またＡ
Ｉの混入の原因となる組成中にＡｌを含む合金元素の添
加は、ＲＨ肌脱ガス処理前行う。The method of the invention will be explained with reference to FIG. During RH degassing treatment, OB treatment was not performed and A! No input, and A
Addition of an alloying element containing Al in the composition, which causes I contamination, is performed before the RH skin degassing treatment.
また、ＲＨ処理前に、住石灰を投入し、取鍋スラグの改
質を行う。ＲＨ脱ガス処理中に、数分毎に鋼中フリー酸
素を測定し、鋼中フリー酸素の降下がなくなり始めた時
点で弱脱酸元素を投入する。Furthermore, before the RH treatment, limestone is added to reform the ladle slag. During the RH degassing treatment, the free oxygen in the steel is measured every few minutes, and a weak deoxidizing element is added when the free oxygen in the steel starts to stop dropping.
本発明の方法の効果を本発明を示す第２図で説明する。The effect of the method of the invention will be explained with reference to FIG. 2, which shows the invention.
弱脱酸元素の投入時の酸素値が低いため、ＴｉＯ系の脱
酸生成物量が減少し、ｔＪｓＴ不合となる鋳片上面側に
集積する介在物が減少する。Since the oxygen value at the time of introducing the weak deoxidizing element is low, the amount of TiO-based deoxidizing products decreases, and the number of inclusions that accumulate on the upper surface side of the slab, which causes tJsT failure, decreases.
本発明の方法を可能とさせた考え方を以下に示す。The idea that made the method of the present invention possible is shown below.
鋼の変態核となる微小酸化物の生成理論より、鋼中ｓｏ
１．ＡＩが１０ｐｐｍ以下の状態では、凝固温度で弱脱
酸元素と平衡する酸素値が１０μ以下の酸化物個数を決
めるため、ＲＨ脱ガス処理での弱脱酸元素投入から鋳片
凝固までの脱酸生成物量には微小酸化物個数は影響しな
いことが判明した。また、ＵＳＴ不台の発生原因が脱酸
材投入時点から凝固時点までに成長した脱酸生成物が介
在物となっていることであることが介在物組成分析結果
より判明した。そこで、Ａｌレス弱脱酸鋼の製造におい
ては、鋼中ｓｏ１．ＡＩをＩ Ｏｐｐｍ以下および鋼中
フリー酸素をｌ ＯＯｐｐｒａ以下を目標さした。Based on the theory of the formation of micro oxides that serve as transformation nuclei in steel, the so
1. When AI is 10 ppm or less, in order to determine the number of oxides with an oxygen value of 10μ or less that is in equilibrium with the weak deoxidizing element at the solidification temperature, deoxidation is necessary from the addition of the weak deoxidizing element in the RH degassing treatment to the solidification of the slab. It was found that the number of micro oxides did not affect the amount of products. In addition, the inclusion composition analysis results revealed that the cause of UST failure was inclusions formed by deoxidation products that grew from the time when the deoxidizer was added to the time when it solidified. Therefore, in the production of Al-free weakly deoxidized steel, so1. The aim was to keep the AI below IOppm and the free oxygen in the steel below 1OOppra.
（発明の効果）
第３図は、従来法と本発明法のＵＳＴ不合発生率を示し
たものであるが、本発明により、ＵＳＴ不合発生率はほ
とんど皆無となった。(Effects of the Invention) FIG. 3 shows the incidence of UST failure in the conventional method and the method of the present invention, and according to the present invention, the incidence of UST failure was almost completely eliminated.
第１図は、本発明によるＲＨ脱ガス時間と鋼中フリー〔
０〕との関係を従来法と比較して示す図、第２図は、本
発明による脱酸生成物に消費されるFigure 1 shows the RH degassing time and the free temperature in steel according to the present invention.
0] compared with the conventional method, Figure 2 shows the relationship between
〔０〕の内訳を従来
法と比較して示す図、第３図はＵＳＴ不合発生率を示す
図である。
第
２図
ｑ線球〉
く４４し明ち配）FIG. 3 is a diagram showing the breakdown of [0] in comparison with the conventional method, and FIG. 3 is a diagram showing the UST failure occurrence rate. Figure 2 q-ray ball>
Claims (1)
中のＴ．Ｆｅを２％以下にならしめ、Ａｌ；０．００１
％以下で鋼中フリー酸素を１００ｐｐｍ以下にし、ＲＨ
処理中には、脱ガスにより鋼中フリー酸素を５０ｐｐｍ
以下まで処理し、その後Ｔｉ（Ｚｒ）を投入し、ＲＨ処
理後には、Ａｌ；１０ｐｐｍ以下で鋼中フリー酸素を３
０ｐｐｍ以下とすることを特徴とするＡｌレス弱脱酸鋼
の製造方法。Before RH treatment of molten steel, quicklime is put into the ladle to remove T. Fe leveled to 2% or less, Al; 0.001
% or less, the free oxygen in the steel is 100 ppm or less, and the RH
During treatment, free oxygen in the steel is reduced to 50 ppm by degassing.
After that, Ti (Zr) is added, and after the RH treatment, the free oxygen in the steel is reduced to 3 with Al: 10 ppm or less.
A method for producing Al-less weakly deoxidized steel, characterized in that the Al content is 0 ppm or less.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2212672A JPH0733539B2 (en) | 1990-08-11 | 1990-08-11 | Method for producing Al-less weakly deoxidized steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2212672A JPH0733539B2 (en) | 1990-08-11 | 1990-08-11 | Method for producing Al-less weakly deoxidized steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0499216A true JPH0499216A (en) | 1992-03-31 |
| JPH0733539B2 JPH0733539B2 (en) | 1995-04-12 |
Family
ID=16626489
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2212672A Expired - Fee Related JPH0733539B2 (en) | 1990-08-11 | 1990-08-11 | Method for producing Al-less weakly deoxidized steel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0733539B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20040046397A (en) * | 2002-11-27 | 2004-06-05 | 주식회사 포스코 | Degassing process of molten steel by making an analysis of slag |
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 |
| JPS621811A (en) * | 1985-06-26 | 1987-01-07 | Nippon Steel Corp | Manufacture of rail having superior damage resistance |
-
1990
- 1990-08-11 JP JP2212672A patent/JPH0733539B2/en not_active Expired - Fee Related
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 |
| JPS621811A (en) * | 1985-06-26 | 1987-01-07 | Nippon Steel Corp | Manufacture of rail having superior damage resistance |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20040046397A (en) * | 2002-11-27 | 2004-06-05 | 주식회사 포스코 | Degassing process of molten steel by making an analysis of slag |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0733539B2 (en) | 1995-04-12 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |