【摘要】 研究了60Si2Mn弹簧钢半固态电磁搅拌工艺和凝固过程,分析电磁搅拌对60Si2Mn弹簧钢凝固组织的影响规律。结果表明:电磁搅拌可以消除60Si2Mn弹簧钢的凝固组织中发达的柱状枝晶层,随着电磁搅拌的功率的增加,60Si2Mn弹簧钢凝固组织从枝晶或短枝晶向等轴晶转变,随着搅拌时间增加,60Si2Mn弹簧钢凝固组织更为圆整。制备合格的60Si2Mn弹簧钢半固态流变浆料的工艺参数:搅拌功率应不低于8.5 kW,搅拌时间应不少于5 min,连续搅拌终止温度应不高于1 460℃。理论分析认为:在60Si2Mn弹簧钢凝固过程中进行电磁搅拌,引起熔体的强烈流动,使液相区的温度场和溶质含量趋于均匀,晶核数量增加,并减慢了奥氏体的一次臂生长速度,最后发展成细小的等轴晶的凝固组织。更多还原

【Abstract】 The semisolid electromagnetic stirring technology and solidification process of 60Si2Mn spring steel have been studied in this paper, and the influence of electromagnetic stirring parameters on the solidification microstructures of the 60Si2Mn spring steel has been investigated. Results have shown that electromagnetic stirring can eliminate the thick layer of columnar dendric austenite formed in conventional castings. The higher electromagnetic stirring power and the longer electromagnetic stirring time, the more spherical or dedendritic the austenite formed. The proper parameters of electromagnetic stirring for preparation rheological semisolid slurry of 60Si2Mn spring steel is that the power of electromagnetic stirring had better not less than 8.5 kW, the stirring time had better longer than 5min and the temperature of stopping stirring had better not above 1 460℃ . During the solidification of liquid 60Si2Mn spring steel, the rapid motion of melt which caused by electromagnetic stirring make the temperature gradient of melt become more smooth than that of melt of conventional and solute gradient of freezing interface become more . The amount of austenite nucleation increased and the growth speed of the first arm of austenite dendric decreased. So the austenite grain become finer in stirred castings.更多还原