旋转磁场对Zn-7Cu-0.25Mn合金水平连铸坯组织性能的影响

对Zn-7Cu-0.25Mn合金在有无旋转磁场下水平连铸坯横截面宏观组织、微观组织的形貌及铜元素的分布进行比较分析,探讨旋转磁场对Zn-7Cu-0.25Mn合金水平连铸坯组织和性能的影响。结果表明,当拉坯速度保持为53.3mm/min时,施加频率为30Hz、电流强度为100A的旋转磁场,可以消除铸坯因为重力作用导致下部凝固速度大于上部凝固速度、最终凝固位置偏离中心线上移的现象;旋转磁场对水平连铸坯的凝固组织具有明显的细化作用,并且使铸坯的铜偏析现象得到明显改善;施加旋转磁场后铸坯的平均硬度较施加前略有提高。

Effect of rotating magnetic field on structure and properties of horizontal continuous casting billet of Zn-7Cu-0.25Mn alloy

Macrostructure, microstructure and copper distribution of horizontal continuous casting billet of Zn-7Cu-0.25Mn alloy with and without rotating magnetic field were investigated,and the influences of rotating magnetic field on the microstructure and property of the casting billet were discussed in detail. The results show that when the casting speed is 53.3 mm/min, rotating magnetic field with 30 Hz current frequency and 100 A current intensity can effectively eliminate the phenomena of the solidification rate of bottom billet larger than that of upper billet and terminal solidification zone drifting upward the geometrical center due to gravity.Rotating magnetic field can markedly result in refining of the solidification microstructure of casting billet,and efficiently reduce copper segregation in the billet.The average Vickers hardness of the billet can be improved slightly by applying rotating magnetic field to the casting process.