连铸工艺对M2高速钢碳化物析出的影响

EFFECT OF CONTINUOUS CASTING PROCESS ON CARBIDE PRECIPITATION OF M2 HIGH SPEED STEEL

采用立式连铸机生产135 mm×135 mm M2高速钢,并利用金相显微镜和扫描电镜分析了不同拉速、过热度、电磁搅拌参数对铸坯碳化物的分布、形貌、厚度的影响。结果表明:M2钢连铸坯横截面上平均碳化物面积分数约0. 20,改变连铸工艺对其影响不大;拉速和过热度分别从1. 5 m/min、50℃降低到1. 0 m/min、30℃,碳化物网的厚度降低29. 4%,碳化物均匀性明显提高;结晶器电磁搅拌可以有效降低M2钢连铸坯中心碳化物含量和碳化物网厚度,提高碳化物均匀性。

135mm×135mm M2 high speed steel was continuously cast in a pilot laboratory using a vertical continuous casting machine.The effect of different pulling speeds,superheat and electromagnetic stirring parameters on carbide distribution,shape and thickness were analyzed by metallographic microscope and scanning electron microscopy.The results show that the average carbide area of M2 steel continuous casting billet is about 0.20,and the continuous casting process has little effect on it.The pulling speed and superheat are respectively reduced from1.5m/min,50℃ to 1.0m/min,30℃,carbide mesh thickness is reduced by 29.4%,and carbide uniformity is obviously improved;mold electromagnetic stirring can effectively reduce the central carbide content and carbide network thickness of M2steel billet,and improve the carbide uniformity.