闪光焊焊接过程热效率与接头落锤试验性能研究

Study on Thermal Efficiency of Flash Welding Process and Drop Weight Test Performance of Joint

为降低脉动闪光焊接过程中的能量消耗,减少母材损失,本文以U71MnG钢轨为研究材料,在对照组参数的基础上通过正交试验、极差分析和参数微调设计了试验组参数。采用UN-200脉动闪光焊机对钢轨焊接过程中的热效率和接头落锤试验性能进行研究。结果表明:焊接过程热效率与钢轨损耗量成显著负相关关系,热效率依次是中期≥前期>末期;试验组前期、中期、末期热效率比对照组分别增加2.5%、5.7%、11.3%,整个焊接过程母材损耗量共减少34.6%,试验组总热输入值为对照组的56.6%;15个试件承受2锤未断后使用切割机开口再落锤,7个试件断口未见明显缺陷,8个试件断口仅有一个灰斑,且灰斑面积小于规范限值。试验组参数降低能耗效果显著,其与U71MnG钢轨的匹配度良好。

In order to reduce the energy consumption in the process of pulse flash welding and reduce the loss of base metal,this paper took U71 MnG rail as the research material,and designed the parameters of the test group through orthogonal test,range analysis and parameter fine adjustment based on the parameters of the control group. Un-200 pulse flash welder was used to study the thermal efficiency during rail welding process and drop weight test performance of joint. The results show that there is a significant negative correlation between the thermal efficiency of welding process and rail loss,and the order of thermal efficiency from large to small is middle stage,early stage,and late stage.Compared with the control group,the thermal efficiency of the test group in the early,middle and late stage is increased by 2.5%,5.7% and 11.3% respectively,and the loss of base metal in the whole welding process is decreased by 34.6%.The total heat input value of the test group is 56.6% of that of the control group. After 15 test pieces were subjected to 2 hammers without breaking,the cutting machine was used to open and then the hammer was droped. No obvious defects were found on the fracture of 7 test pieces,and there was only one gray spot on the fracture of 8 test pieces,and the area of gray spot was less than the specification limit. The parameters of the test group have a significant effect on reducing energy consumption,and their matching degree with U71 MnG rail is good.