镀锌钢板点焊焊接接头组织与性能

Microstructure and properties of resistance spot welded joints of galvanized steel sheet

采用了合理的电阻点焊焊接参数对镀锌钢板进行焊接,研究了点焊参数对焊接接头组织和性能的影响,分析了焊接接头的硬度分布和拉伸断口断裂机理。结果表明,焊接接头的抗拉强度随着焊接电流和焊接时间的增加均呈先增大后减小趋势;焊缝区铁素体组织随着焊接电流的增大现象明显,而焊缝区铁素体组织却随着焊接时间的增加而变得细密;焊接接头的焊缝区的硬度均匀,且高出母材很多;焊接接头断口表现出明显的延性断裂特征。

The galvanized steel sheet is welded with reasonable resistance spot welding parameters to study the influence of resistance spot welding parameters on microstructure and properties of welded joints.The results show the following：when the welding current and welding time increases,the welding joint tensile strength increases and then decreases;weld zone microstructure of ferrite extends obviously when the welding current increases;weld zone microstructure of ferrite become dense with the increase of welding time;the hardness of weld zone distributes evenly and higher than that of the parent material;welded joint fracture shows obvious ductile fracture characteristics.