深孔熔咀电渣焊补技术及其接头性能研究

Deep hole repairment molten electroslag welding technology and properties of joint

在轨道车辆装配和检修过程中,转向架经常因螺纹孔牙型受到损伤而报废。利用深孔熔咀电渣焊补技术对受损的螺纹孔进行焊补,然后将焊补试样重新加工螺纹孔。通过宏观金相、显微组织和冲击断口SEM观察,以及拉伸性能、弯曲、冲击性能、硬度和疲劳试验等手段对焊补试样进行测试,研究其最佳深孔焊补深宽比以及修复后螺纹孔的性能与原始材料的性能变化情况。结果表明,熔咀电渣焊技术焊补的试样以及修复的螺纹孔性能均高于原始母材,最佳的深宽比为1∶1~2∶1。

The screw thread of rail vehicles bogie is often damaged during the process of installation and repairment,which results in the failure of bogie. To avoid unnecessary loss,the molten electroslag welding technology for deep hole repairment was used to amend the threaded hole and remanufacture the screw thread. The macrostructure,microstructure and fractured morphology were observed,and tests of tensile,bending,impact,hardness and fatigue were conducted to choose the optimum depth width ratio and analyse the differences between the original samples and repaired parts. The results show that the mechanical properties and fatigue strength of the repairment welded samples are higher than those of the base metal. The best depth-width ratio of 1∶1-2∶1 is to be recommended.