对内燃机曲轴磁粉探伤磁痕的分析

Analysis on Magnetic Powder Detection on Internal Combustion Engine Crank

材料中Mn和Sn含量较多、表面感应淬火时加热温度较高导致淬火层组织中存在大量块状残余奥氏体。大块状奥氏体与回火马氏体磁导率差异较大造成磁粉探伤时大量磁痕显现。通过工艺改进,避免了大块状残余奥氏体的产生,从而避免了此类磁痕的产生。

A great deal magnetic trace emerged on s.g.cast iron crank of which neck had been quenched by MF,Rounded and rolling grooved,which has been suggested by analysis due to over amount of Mn and Tin existing in crank blank and remains of volume bulk of austenite produced in neck surface after MF quenching.