基于铝元素含量控制的E级钢机车车钩钩舌断裂失效问题研究

Research on Fracture Failure of Locomotive Coupler Hook Tongue of E-grade Steel Based on Aluminum Content Control

文中通过一起典型的E级钢机车车钩钩舌静载拉力检测不合格、断裂失效现象,从宏观形貌检查、化学成分分析、微观形貌检查、金相分析、机械性能测试等5方面全面分析了钩舌失效的原因,提出了改进铝元素含量控制的工艺措施,以提高钩舌质量。对实施质量控制措施后的E级钢机车车钩进行型式试验,结果表明,调整钩舌基体中铝元素含量在0.02~0.08 wt.%范围内,同步施加相关质量控制措施,可以有效避免钩舌断裂,提高机车车钩的生产质量。

The coupler hook tongue of E-grade steel locomotive belongs to castings.The traditional failure reasons mainly include the structural defects formed during the casting process of the coupler hook tongue and the stress concentration caused by impact and friction and wear during the application process.In the actual production process,it is difficult to directly identify whether the casted hook tongue contains internal organizational defects through appearance,so it is necessary to strictly control its casting process.At present,there are still limitations in mastering the process control of aluminum content,and there are neither standards nor clear technical requirements.In this paper,through a typical E-class steel locomotive coupler hook tongue static load tensile test unqualified,fracture failure phenomenon,from the macro morphology inspection,chemical composition analysis,micro morphology inspection,metallographic analysis,mechanical performance test and other five aspects of a comprehensive analysis of the causes of the failure of the coupler hook tongue,put forward the improvement of aluminum content control process measures to improve the quality of the coupler hook tongue.The type test of E-grade steel locomotive couplers after the implementation of quality control measures was carried out.The results show that by adjusting the aluminum content in the hook tongue matrix in the range of 0.02 wt.%-0.08 wt.%and applying relevant quality control measures simultaneously,the fracture of the hook tongue can be effectively avoided and the production quality of locomotive couplers can be improved.