气门嘴早期失效分析及改进

The Early Failure Analysis and the Improvement of the valve cock

通过对气门嘴宏观检查、化学成分分析、微观检查i、氨熏试验等结果分析,确定了其开裂原因是气门嘴折弯部位内应力较大,在敏感应力腐蚀环境作用下,产生点蚀裂纹并扩展,导致发生应力腐蚀开裂。并提出了相应的改进措施,为质量控制提升提供了思路和方法。

The paper showed that stress corrosion is the reason of valve cock cracking by the macroscopic examination,thechemical analysis,the microscopic examination and the ammonia fumigation test.The pitting crack is generated for thegreater inner pressureof the bending part of valve cock,which is under the stress corrosion sensitivity environment.Thepitting crack is extended,which causes the valve cock cracked.The improvement measures are put forward,which providethe method for quality control promotion.