电磁搅拌对GCr15轴承钢凝固组织的影响  

Effects of Electromagnetic Stirring on Solidification Microstructure of GCr15 Bearing Steels

作　　者：徐宇[1] 李壮[1] 王恩刚[1] 张兴武[1] 

机构地区：[1]东北大学材料电磁过程教育部重点实验室

出　　处：《特种铸造及有色合金》2015年第11期1143-1146,共4页Special Casting & Nonferrous Alloys

基　　金：国家自然科学基金资助项目(50834009);教育部科学技术研究重大项目(311014);高等学校学科创新引智计划资助项目(B07015)

摘　　要：采用电磁搅拌法在自制连铸机上制备了GCr15轴承钢钢坯,研究了电磁搅拌与二冷水强度对GCr15轴承钢凝固组织的影响。结果表明,当电流强度为250A,频率为12Hz时,钢水凝固前沿的枝晶被折断和熔断。由于液相温度梯度减小,成分过冷度增大,使凝固时的柱状晶转变为等轴晶;当二冷水流量由2.0m3/h提升至3.5m3/h时,铸坯中心组织出现了更加细小的等轴晶;同时电磁搅拌会使连铸坯中的二次枝晶间距变小,C和Cr分布更均匀。Effects of electromagnetic stirring（EMS）parameters,such as electromagnetic stirring intensity and secondary cooling water volume,on the GCr15 bearing steels prepared in self-developed continuous casting machine were investigated to improve the solidification structure.The results indicate that with electric current of 250 Aand frequency of 12 Hz,the dendrite in solidification front of the liquid steel can be broken and melt.Due to the decrease of liquid temperature gradient to increase the composition super cooled degree,the columnar grain is transformed into equiaxed grain.With the secondary cooling intensity increased from 2.0m3/h to 3.5m3/h,finer dispersed and compact equiaxed grain structure in the centre of billet can be observed.Furthermore,the secondary dendrite arm spacing is decreased,and the carbon and chromium in the billet are more uniformly distributed with EMS.

关 键 词：GCR15轴承钢 电磁搅拌 二次枝晶间距 温度梯度 

分 类 号：TG260[金属学及工艺—铸造]