电极端面尺寸对IF钢镀锌板点焊性能的影响

Effect of Electrode Tip Size on Spot Welding Performance for IF Galvanized Steel Sheet

对DX54D冷轧IF钢镀锌板进行点焊试验,研究了焊接工艺参数及电极端面尺寸对镀锌板点焊性能、焊点拉剪性能及熔核尺寸的影响。结果表明:随着焊接电流的增加,焊点的拉剪强度和熔核尺寸均增大,当电流过大而发生飞溅时,焊点的拉剪强度和熔核尺寸开始降低。随着电极端面半径的减小,电极与工件的实际接触面积减小,引起电流密度升高,导致在相同焊接时间条件下得到相同熔核尺寸和焊点拉剪强度所需焊接电流降低。

The spot welding test for the cold rolled DX54D IF galvanized steel sheet is carried out. The effect of welding parameters and the electrode tip size on the spot welding performance for a galvanized steel sheet, the tensile shearing property by spot welding and the nugget size is studied. The experimental results show that both the tensile shearing strength of welding spots and the nugget size increase with the increase of welding current. The tensile shearing strength and the nugget size will tend to decrease when welding spatters occur due to the excessive current. The current density will increase with the decrease of the radius of the electrode tip as well as the decrease of the actual contact area between electrode and workpiece, which can lead to decrease the welding current for the same nugget size and the tensile shearing strength of welding spots under the same welding time.