改善60 t EAF-LF-VD-CC流程冶炼齿轮钢FAS3420H洁净度的研究

以抚顺特钢一炼钢厂的生产数据为实践依据,以改善汽车齿轮钢FAS3420H的洁净度为目的。使用扫描电镜分析水口结瘤物和棒材中氧化物夹杂的化学成分,确定了通过减少钢中的B类夹杂物来解决水口结瘤问题的方向。通过优化电弧炉供氧曲线降低钢水氧化性、优化精炼炉渣流动性和碱度提高夹杂物吸附能力等措施,解决了连铸过程水口结瘤问题,同时达到棒材的氧含量平均值为9.2×10^-6,B类夹杂物B细不高于1.0级、B粗不高于0.5级的控制水平。

Study on Improving Cleanliness of Gear Steel FAS3420H Steelmaking by 60 t EAF-LF-VD-CC Flow Sheet

On the basis of actual production data in the first steelmaking plant of FuSteel,the objective is to improve cleanliness of automobile gear steel FAS3420H. The nozzle clogging and oxide inclusion are analysized by using SEM and the aim of solving nozzle clogging is definited, that is decreasing B inclusion in steel. Several measures were implemented, such as optimizing oxygen supply curve of EAF to reduce liquid steel oxidation, optimizing fluidity and basicity of LF slag to increase adsorption capacity of inclusion. The problem of nozzle clogging is solved during production process of continuous casting. The average oxygen mass fraction in production can reach to 9. 2 x 10~6, B thin series rating of inclusions is no more than 1. 0 and B coarse series rating of inclusions is less than or equal to 0. 5 in bar.