304奥氏体不锈钢180 t AOD-LF精炼过程夹杂物衍变行为的研究

特殊钢 ›› 2017, Vol. 38 ›› Issue (1): 9-12.

304奥氏体不锈钢180 t AOD-LF精炼过程夹杂物衍变行为的研究

翟俊^1,2, 郎炜旳², 刘浏¹

1钢铁研究总院冶金工艺研究所，北京100081 ；
2山西太钢不锈钢股份有限公司技术中心，太原030003

收稿日期:2016-08-28 出版日期:2017-02-01 发布日期:2022-07-28
作者简介:翟俊（1983-),男，博士研究生，工程师。2006年西安建筑科技大学(本科)毕业，不锈钢脱氧及夹杂物的控制与研究。

A Study on Evolution Behavior of Inclusions in Austenite Stainless Steel 304 during 180 t AOD-LF Refining Process

Zhai Jun^1,2, Lang Weiyun² , Liu Liu¹

1 Institute fbr metallurgical Technology, Center Iron and Steel Institute, Beijing 100081 ；
2 Technology Center, Shanxi Taigang Stainless Steel Co Ltd, Taiyuan 030003

Received:2016-08-28 Published:2017-02-01 Online:2022-07-28

摘要/Abstract

摘要： 采用氧氮分析仪、扫描电镜、金相显微镜研究了160 t EAF-180 t AOD-LF-CC工艺生产304不锈钢的冶炼过程中全氧含量和夹杂物数量、尺寸、成分、类型等的衍变行为。AOD初始[C]2.0%3.0%,[Si]0.2%~0.4%,终点[C]0.04%~0.06%,AOD终渣为（/%）:53.9%CaO,30.1SiO₂,1.34Al₂O₃,5.22MgO,8.74CaF₂,0.39Cr₂O₃,0.53TFe,0.62MnO,LF终渣为（/%）:57.9CaO,21.6SiO₂,1.70Al₂O₃,6.30MgO,0.03Cr₂O₃,11.9CaF₂,0.26TFe,0.31 MnO。结果表明,AOD-LF-CC过程中氧含量逐渐降低,脱氧率达到71.0%,铸坯氧含量为25×10^-6;在精炼过程中大型夹杂物数量明显降低,铸坯中没有出现≥20μm的夹杂物;在精炼过程钢中夹杂物主要以低熔点的硅酸盐为主,从LF终点至铸坯夹杂物中MgO和Al₂O₃含量分别升高了12%和17.5%,因温度降低,铸坯中残余的Mg、Al和O不断结合析出MgO-Al₂O₃尖晶石,同时残余的Mg、Al与低熔点的硅酸盐夹杂物发生反应形成高熔点的硅酸盐,所以铸坯中夹杂物主要以镁铝尖晶石和高熔点硅酸盐为主。

Abstract: The evolution behavior of total oxygen content and amount, size, ingredient and type of inclusions in steel during steelmaking process of stainless steel 304 by 160 t EAF-180 t AOD-LF-CC flowsheet has been studied by nitrogen oxygen analyzer, optical and scanning electron microscope. The AOD refining process main operation data are initial [C] 2.0% 〜3.0%, [Si] 0.2% 〜0.4%, end [C] 0.04% 〜0.06% , end AOD slag ingredient (/%)： 53.9CaO, 30. 1 SiO₂, 1. 34Al₂O₃, 5. 22MgO, 8. 74CaF₂, 0. 39Cr₂O₃, 0. 53TFe, 0. 62MnO, and end LF slag ingredient (/%)： 57.9CaO, 21.6SiO2, 1.70Al₂O₃, 6. 30MgO, 0. 03Cr₂O₃, 11.9CaF₂, 0. 26TFe, 0.31MnO. Results show that in AOD- LF-CC process the oxygen content in steel decreases gradually, the deoxidized ratio is up to 71. 0% and the oxygen content in casting slab is 25 x 10^-6 ； the amount of large inclusions decreases obviously in refining process, and there is no ≥20μm inclusion occurring in casting bloom ； during refining process the main inclusions in steel are low-melting silicate, and from end LF to cast slab the MgO and Al₂O₃ content in inclusions increase respectively by 12% and 17. 5% , due to temperature decreasing, in cast slab the residual Mg, Al continuously combined with 0 to precipitate MgO-Al₂O₃ Aspinel and residual Mg and Al reacting with low-melting siHcate to form high-melting silicate, therefore the inclusions in cast slab are mainly magnesium-aluminium spinel and high-melting silicate.

Key words: 160 t EAF- 180 t AOD- LF- CC Flowsheet, Stainless Steel 304, Inclusions, Oxygen Content, Silicate, Magnesium-Aluminium Spinel

翟俊, 郎炜旳, 刘浏I. 304奥氏体不锈钢180 t AOD-LF精炼过程夹杂物衍变行为的研究[J]. 特殊钢, 2017, 38(1): 9-12.

Zhai Jun', Lang Weiyun , Liu Liu. A Study on Evolution Behavior of Inclusions in Austenite Stainless Steel 304 during 180 t AOD-LF Refining Process[J]. Special Steel, 2017, 38(1): 9-12.