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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。
The GCr15 bearing steel billet was prepared by self-made continuous casting machine by electromagnetic stirring method. The effect of electromagnetic stirring and secondary cooling water on the solidification structure of GCr15 bearing steel was studied. The results show that when the current density is 250A and the frequency is 12Hz, the dendrite in the front of molten steel is broken and blown. As the temperature gradient of the liquid phase decreases, the undercooling increases and the columnar crystals during solidification transform into equiaxed grains. When the secondary cooling water flow rate increases from 2.0m3 / h to 3.5m3 / h, the center of the slab appears More fine equiaxed grains; at the same time, the secondary dendritic spacing in the slab will be smaller and the distribution of C and Cr will be more uniform.