中文摘要：

研究了在过共晶高铬铸铁板坯凝固过程中脉冲处理时间对碳化物结构形态及对板坯冲击韧性的影响。结果表明．脉冲电流能够细化过共晶高铬铸铁凝固组织中初生碳化物，随着脉冲处理时间的延长，杆状碳化物细化为颗粒状，尺寸进一步减小。在试验参数范围内，脉冲处理时间为5min时细化效果最佳，冲击韧性值为4．75J／cm2。

英文摘要：

The influences of electric current pulse treating time on the carbides microstructure shape and impact toughness of hypereutectic high chromium cast iron slab during the course of solidification were investigated.The results show that electric current pulse can refine the primary carbides of solidification structure of hypereutectic high chromium cast iron.Rod-shaped primary carbides can be refined to granular and the size reduces as the treating time prolonging.The optimal electric pulse treating time is 5 min in the range of test parameters and the impact toughness is 4.75J/cm2.