38CrMoAl钢精炼过程夹杂物生成及演变规律

国内某厂冶炼38CrMoAl高铝钢时由于钢中非金属夹杂物超标而导致的钢材质量不达标情况时有发生。该钢的工业试验采用了“转炉(LD)-LF精炼(铝脱氧及合金化、高碱度渣精炼)-RH真空精炼-软吹-连铸”工艺流程。为了更好地去除钢中非金属夹杂物,采用分级分段的取样方法对工业试验进行取样,从而对钢中非金属夹杂物生成原因以及演变规律进行研究。结果表明,采用高碱度渣精炼可以有效降低夹杂物中Al₂O₃的质量分数,使之改性为钙镁铝酸盐夹杂物;RH软吹时夹杂物平均成分落在液相线内。

Inclusion generation and evolution of 38CrMoAl steel in refining process

Due to non-metallic inclusions in steel exceeding the standard when smelting 38CrMoAl high alumina steel in a domestic plant, the problem that steel quality is not up to standard is occurred occasionally. Industrial trials for the steel were conducted using the "converter (LD)-LF refining (aluminum deoxidation and alloying, high alkalinity slag refining)-RH vacuum refining-soft blowing-continuous casting" process flow.In order to better remove the non-metallic inclusions in the steel, the industrial test was conducted using the graded segment sampling method to sample the non-metallic inclusions in the steel, so as to investigate the generation causes of non-metallic inclusions in the steel and their evolution.The results show that the high alkalinity slag refining can effectively reduce the mass fraction of Al₂O₃ in the inclusions and modify them to calcium-magnesium-aluminate inclusions. The average composition of inclusions falls within the liquid phase line during RH soft blowing.