GCr15轴承钢冶炼过程钢液洁净度变化

Cleanliness of GCr15 Bearing Steel During Steelmaking Process

研究了EAF→LF→VD→软搅→CC工艺生产GCr15轴承钢冶炼过程钢中T[O]及非金属夹杂物的变化情况。通过将电炉出钢碳质量分数控制为0.2%～0.4%、出钢加铝强脱氧及造预精炼渣、LF精炼过程造高碱度强还原性炉渣、VD真空强搅拌及防止中间包二次氧化，可以生产w（T[O]）等于8×10－6的轴承钢。在炉外精炼过程中夹杂物经历了Al2O3→MgO·Al2O3→CaO-MgO-Al2O3演变。LF精炼过程夹杂物平均尺寸减小，经过VD真空处理后尺寸增加，接着在软搅和中间包过程继续减小。利用VD真空处理可以去除高达74%的夹杂物。

T[O] and inclusions during EAF→LF→VD→Purging→CC process were investigated on GCr15 bearing steel. Through controlling carbon content at EAF tapping from 0.2%to 0.4%, adding aluminum and flux during tapping for de-oxidation and pre-refining, making high basicity slag with little （TFe＋MnO） content during LF refing, stirring the steel in VD and preventing steel reoxidation in tundish, bearing steel with w（T[O]）=8 × 10-6 can be produced. Inclusions changed in order of Al2O3→MgO·Al2O3→CaO-MgO-Al2O3 during the secondary refining process. The average size of in-clusions decreased after ladle refining, while picked up after vacuum treatment, and continously decreased during purging and in tundish. Inclusion number can be reduced by 74%through VD process.