ZG20CrNiMoRE牙轮钻头躯体丝扣断裂失效分析

Failure Analysis for Thread Fracture of ZG20CrNiMoRE Cone Bit Body

对失效的ZG20CrNiMoRE牙轮钻头躯体进行了化学成分、力学性能、微观断口、EDS能谱和气体含量的检测分析。结果表明:牙轮躯体N含量、残余Al元素偏高,导致晶界AlN含量偏高,致使部分晶粒粗化,出现混晶现象,从而发生丝扣断裂,基于这个原因提出相应解决措施。

The chemical composition, mechanical properties, micro fracture, EDS spectrum and gas content of the failed body of ZG20CrNiMoRE cone bit were analyzed. The results show that the content of N and residual Al in the cone bit body was high, and the high content of AlN was found at the grain boundary. This caused the coarsening of some grains and the phenomenon of mixed crystal, and finally led to the screw thread fracture. Based on this reason, the corresponding solutions are proposed.