42CrMo钢大型厚壁管裂纹形成原因分析

Cracking cause analysis of 42CrMo steel thick wall pipe

采用金相显微镜、扫描电镜及能谱仪对42CrMo钢大型厚壁管裂纹性质及形成原因进行了分析。结果表明,该大型厚壁钢管内壁裂纹性质为淬火裂纹,其产生原因为厚壁钢管淬火冷却时,内外壁冷却速度不均。将淬火冷却方式改为立淬,及喷油循环冷却可避免淬火裂纹。

Cracking causes of 42CrMo steel thick wall pipe were analyzed by metallographic microscope,scanning electron microscopy and energy spectrum. The results show that is quenching crack,which result from unsuitable cooling way and different cooling rate on inside and outside wall. Using vertical quenching and spray-circulating cooling quenching oil can avoid quenching crack.