40Cr钢棒材冷拔断裂原因分析与改进

Analysis and Improvement for Cold Drawing Fracture of 40Cr Steel Bar

采用扫描电镜能谱仪、光学显微镜、光谱仪、硬度计等,检测分析40Cr样品冷拔断裂原因;通过宏观分析、化学成分分析、金相检验以及断口分析等方法对40Cr冷拔断裂的原因进行分析。结果表明,40Cr钢冷拔断裂原因为表层组织异常。该异常组织源于棒材轧制过程中控冷工艺不当,冷速过快。

Cold drawing fracture of 40Cr samples were analyzed by using EDS,Optical Microscope,Spectrometer,Micro hardness tester,to test and analyze the reason of cold drawing fracture.By means of macroscopic analysis,chemical composition analysis,metallographic examination and fracture analysis,the reason of cold drawing fracture is further studied.The results show that the reason of cold drawing fracture of the 40Cr steel is due to the abnormal structure on the surface of the samples,which were from unreasonable rolling and cooling process.The cooling rate is too fast,which results in abnormal structure such as bainite.