BOF-RH-CC与BOF-LF-CC流程对冷镦钢ML08Al洁净度的影响

分析了“BOF-RH-CC”和“BOF-LF-CC”两种工艺流程生产的ML08Al钢中非金属夹杂物类型、数量密度及总氧变化。结果表明,两种流程转炉脱氧合金化后钢中非金属夹杂物主要为Al₂O₃;采用“BOF-LF-CC”流程,LF精炼结束钢中部分非金属夹杂物由Al₂O₃转变为Al₂O₃·CaO和Al₂O₃·MgO;而采用“BOF-RH-CC”流程,RH真空后钢中非金属夹杂物仍然以Al₂O₃为主。转炉出钢脱氧合金化后,钢水中总氧含量27.8×10^-6～31.5×10^-6,经过LF精炼后,总氧含量为20.2×10^-6～22.5×10^-6,而经过RH处理后,总氧含量为14.7×10^-6～15.3×10^-6。LF精炼和RH真空处理对夹杂物数量的去除率分别为49.6%和80.9%。因此,“BOF-RH-CC”工艺流程生产的ML08Al钢水洁净度优于“BOF-LF-CC”工艺流程生产的钢水。

Effect of BOF-RH-CC and BOF-LF-CC Process on Cleanness of Cold Heading Steel ML08Al

The types and quantity density of non-metallic inclusions, and the change of total oxygen in steel ML08Al produced by the two processes BOF-RH-CC and BOF-LF-CC are analyzed. The results show that the main non-metallic inclusions in steel after BOF deoxidizing alloying of two process are Al₂O₃, in the process of "BOF-LF-CC" , the partial non- metallic inclusions in steel at the end of LF refining are changed from Al₂O₃ to Al₂O₃ ? CaO and Al₂O₃ ? MgO, but in the process of "BOF-RH-CC" , after RH vacuum the non-metallic inclusions Al₂O₃ are still dominated. After deoxidizing alloying, the total oxygen content in BOF molten steel is 27. 8 x 10^-6 ~31. 5 x 10^-6 , the total oxygen content in steel at LF end is 20. 2 x 10^-6 ~22. 5 x 10^-6 , but the total oxygen content in steel at RH end is 14. 7 X 10^-6~ 15. 3 x 10 ^-6. The removal rates of inclusions by LF refining and RH vacuum treatment are 49. 6% and 80. 9% respectively. Therefore, the cleanness of the cold heading steel ML08Al produced by the process of "BOF-RH-CC" is better than that produced by the process of “BOF-LF-CC”.