预涂导电密封胶的轨道车辆不锈钢车体电阻点焊工艺试验

Process Test of Resistance Spot Welding Based on Conductive Sealant for Stainless Steel Carbody of Railway Vehicle

根据某不锈钢车辆上下侧墙板搭接结构形式,采用涂导电密封胶的电阻点焊技术,实现结构连接的同时保证了车辆密封。为验证该工艺的可靠性,采用预涂导电密封胶的电阻点焊技术分别对三种搭接结构试件进行焊接试验。焊后根据相关标准分别对三种搭接结构进行电阻点焊接头试验,包括外观检验、剥离试验、剪切拉伸试验和金相检验,并对点焊接头的表面凹陷尺寸、熔核直径、拉剪载荷、熔核内部裂纹、缩孔缺陷等进行分析。结果表明,电阻点焊接头性能满足结构要求,基于导电密封胶的电阻点焊技术在不锈钢车体上的应用是可行的,可用于项目生产;同时验证了所设定的点焊参数是合理的,为基于导电密封胶的电阻点焊技术在不锈钢车体中的应用提供了数据支持。

According to the lap joint structure of the upper and lower sidewall panels of a stainless steel vehicle, the spot welding technology based on conductive sealant is adopted to realize the structural connection, and ensure the vehicle sealing. To verify the reliability of the procedure, the three types of lapping structure were carried out welding tests respectively by resistance spot welding based on conductive sealant. Then, tests on spot welded joint were carried out for the three types of lapping structure according to the product standard after welding,and the visual testing, shear testing, shear tensile testing,metallographic examination are included.Moreover, the test results of the dent size on the spot welded joint surface,nugget diameter,tensile shear force,cracks inside nugget,shrinkage hole were analyzed. The test results show that performance of resistance spot welded joint can meet the demands for the structure,and the resistance spot welding technology based on conductive sealant applied in the stainless steel carbody is feasible;and the spot welding parameters are verified reasonable,which can provide the data support for the resistance spot welding technology based on conductive sealant applied in the stainless steel carbody.