采用化学成分分析、宏观检验、显微硬度测试、金相检验及工艺分析的方法，对CF-8M铸钢材料攻丝加工过程中丝锥断裂的原因进行了分析。结果表明: 钻孔加工过程中产生的冷作硬化层和不恰当的热处理，是导致无法攻丝及丝锥断裂的主要原因。可通过优化钻孔切削参数及固溶处理参数，有效解决CF-8M不锈钢铸件攻丝工序中丝锥断裂及效率低下的问题。

Through the chemical compositions analysis, macrographic inspection, microhardness testing, metallographic inspection and process analysis, the causes of the fracture of strew tap during the tapping process of CF-8M casting steel were analyzed. The results show that the cold hardening layer generated during the drilling process and the improper heat treatment process were the major causes. The problems of strew tap fracture and low efficiency could be solved effectively through optimizing the parameters of the drill process and the solution treatment.