焊接参数对轨道交通车辆不锈钢磁控电阻点焊的影响

以轨道车辆用2 mm厚的SUS301L-LDT不锈钢为研究对象，对比分析了熔核形貌和磁控电阻点焊的机械性能，以及不同焊接参数下磁控电阻点焊的剪切强度变化规律。结果表明，同等外加磁场强度条件下，当焊接参数增大或焊接周波增加时，点焊试件的拉剪强度和熔核宽高比变化更加明显。当焊接电流为10 kA、焊接周波为0.50 s时，在外加磁场的作用下，点焊的拉伸强度最大增加16.47%;当焊接电流增加、焊接周波缩短时，点焊的拉剪失效位移增加较为明显；当焊接电流为11 kA、焊接周波为0.44 s时，在外加磁场的作用下点焊的拉剪失效位移最大为4.98 mm。可见，影响电阻点焊磁控效果的主要因素为焊接电流和焊接周波。

Influence of Welding Parameters on Stainless Steel Magnetic Controlled Resistance Spot Welding of Rail Transit Vehicle

Based on the 2 mm thick SUS301L-LDT stainless steel used in rail transit vehicle,the mechanical properties of welding nugget feature and magnetic controlled resistance spot welding,the variation law of magnetic controlled resistance spot welding shear strength in different welding parameter conditions are comparatively analyzed.conditions.Results show that under the same external magnetic field action,the spot welding sample shear strength and the aspect ratio changes of nugget width will be more obvious when the welding parameter or the welding cycle increases.For example,under the external magnetic field action,when the welding current is 10 kA and the welding cycle is 0.50 s,the maximum tensile strength of spot welding increases by 16.47%.When the welding current increases and the welding cycle is shortened,the tension shear failure displacement of spot welding will increase more obviously.For example,when the welding current is 11 kA and the welding cycle is 0.44 s,the maximum tension shear failure displacement of spot welding under the external magnetic field action increases to 4.98 mm.Consequently,the welding current and the welding cycle are detected as the main causes to influence the magnetic control effect of resistance spot welding.