镀锌钢板电阻点焊涂层电极研究

Research on coated electrode in resistant spot welding of galvanized steel sheet

文中采用焊点熔核直径标准测定了涂层电极的寿命并分析了点焊过程中电极端面的形貌及成分分布。试验结果表明,镀锌钢板电阻点焊时,在相同条件下,涂层电极抗塑性变形能力明显高于普通电极,涂层电极在焊接过程中所受到的损坏程度要比普通电极小;无涂层电极的使用寿命不少于800点,而涂层电极的使用寿命不少于2 200点,相比无涂层电极,涂层电极的使用寿命提高了2.5倍以上;电极表面的涂层能有效防止镀锌钢板电阻点焊过程中Zn在电极表面的粘连、剥离。

The life of coated electrode was tested by the standard of spot nugget diameter,and the appearance of electrode end and its distribution of composition were analyzed.The experimental results show that at the same conditions,the coated electrode has higher ability to prevent the electrode from plastic deformation in welding compared with the ordinary electrode.The extent of damage of coated electrode is much smaller than that of the ordinary electrode.The life of uncoated electrodes is more than 800 times,while that of the coated electrodes is more than 2,200 times,which is increased by 2.5 times or so.The coatings on the surface of electrode can effectively prevent the adhesions,stripping due to Zn diffusion in the resistant spot welding process of galvanized steel sheet.