改善55SiCrA弹簧钢小方坯内部质量的试验研究  

Experimental research on improving internal quality of 55CrSiA spring steel billet

作　　者：李朋欢[1] 包燕平[2] 安航航[2] 王林静[2] 彭尊[2] 

机构地区：[1]杭州钢铁集团公司技术中心,浙江杭州310022 [2]北京科技大学钢铁冶金新技术国家重点实验室,北京100083

出　　处：《炼钢》2016年第3期41-45,共5页Steelmaking

摘　　要：针对某厂55SiCrA弹簧钢小方坯连铸坯存在的中心等轴晶率低、比较严重的中心碳偏析、中心疏松和缩孔等内部质量问题,系统研究了不同电磁搅拌工艺参数对断面150mm×150mm结晶器内磁场特性的影响,并通过工业试验研究了结晶器电磁搅拌(M-MES)电流和频率对宏观凝固组织和铸坯碳偏析的影响。研究结果表明:结晶器电磁搅拌(M-MES)电流增大,中心等轴晶率提高,铸坯中心碳偏析减小;搅拌频率对等轴晶率和铸坯中心碳偏析的影响呈非线性;优化最佳匹配的电磁搅拌电流和频率分别为320A和3.5Hz时,中心等轴晶率从18.5%增加到32.5%,中心碳偏析指数从1.23降低到1.04,消除了中心缩孔和角部裂纹,铸坯内部质量有明显的改善。In view of the lower center equiaxed crystal ratio, more serious central carbon segregation,central porosity and shrinkage defected that affected internal quality of 55 SiCrA spring steel billet,influence of M-EMS process parameters on magnetic field distribution characteristics was systematically studied in 150mm×150mm billet mould.Moreover,research of the effect of stirring electric current and frequency of mould electromagnetic stirrer（M-MES）on macro solidified structure and central carbon segregation was also carried out by industrial experiments.The experimental results proved that with stirring electric current of M-EMS increasing,central carbon segregation index decreased and center equiaxed crystal ratio rised.There was a non-linear relationship between stirring frequency of mould electromagnetic stirrer（M-MES）and center equiaxed crystal ratio besides central carbon segregation.Center equiaxed crystal ratio increased from 18.5 % to 32.5 %,central carbon segregation index decreased from 1.23 to 1.04 and the central porosity and corner cracks were eliminated when stirring electric current was 320 Aand frequency was 3.5Hz.Finally billet internal quality was evidently improved.

关 键 词：结晶器电磁搅拌 55SiCrA弹簧钢 磁场特性 内部质量 

分 类 号：TF777.3[冶金工程—钢铁冶金]