用扫描电镜 /能谱分析、X射线萃取相分析和Thermo -Calc热力学相计算等方法 ,分析了 4Cr9Si2阀门钢丝在冷拔过程中发生脆断的原因。结果表明 ,钢丝脆断是由于中间退火温度选择不合理 ,使 (Cr,Fe) 7C3 相大量析出造成的 The causes of brittle fracture of 4Cr9Si2 valve wire during cold drawing were analyzed by scanning electron microscopy (SEM) / energy dispersive spectroscopy (XRD), X-ray phase analysis (XRD) and ThermoCalc thermodynamic calculation. The results show that the brittle fracture of steel is caused by the large amount of (Cr, Fe) 7C3 precipitates due to the unreasonable choice of intermediate annealing temperature