西宁特钢的GCr15轴承钢连铸坯由90 t UHP Consteel EAF-LF(VD)-CC流程生产。通过全程保护浇铸
钢中平均氧含量减少3.15×10
-6
控制钢水过热度≤20℃
拉速0.7~0.8 m/min
二次冷却比水量0.40 L/kg
铸坯平均等轴晶率≥60%
且铸坯质量明显提高;在上述优化工艺参数下
采用3.25 Hz/250 A结晶器电磁搅拌和20 Hz/300 A凝固末端电磁搅拌
铸坯中心碳偏析指数为0.99~1.20。
Abstract
Cast bloom of GCrl5 bearing steel is produced by 90 t UHP Consteel EAF-LF(VD)-CC flow sheet at Xining Special Steel.With shielded casting practice in whole casting process
the average oxygen content in steel decreased by 3.15×10-6;by controlling the degree of superheat of molten steel ≤ 20 ℃
the casting speed 0.7~0.8 m/min and the secondary cooling water rate 0.40 L/kg
the average equiaxial crystal zone ratio of bloom was ≥ 60% and the quality of bloom obviously increased; and with above optimized process parameters and using 3.25 Hz/250 A EMS for mold and 20 Hz/300 A EMS for solidified front
the carbon segregation index in center of bloom was 0.99~1.20.