Abstract: In order to study the difference of welding properties between hot-formed steel and dual-phase steel for automobile, 1.5 mm hot-formed steel HS1300T and 1.5 mm dual-phase steel DP590T were respectively used for resistance welding with 1.9 mm cold-rolled steel plate CR1180T, and the weldability interval, weld consistency and macroscopic morphology of welds were studied. Studies have shown that dual-phase steels have a larger weldability current range than hot-formed steels. Continuous welding of 500 welds, hot-formed steel plate are more prone to spatter, and the weld numbers of spatter is 3.72 times that of duplex steel. Under the optimal welding parameters, the indentation depth of the hot-formed steel is deeper, which is 2.62 times that of the dual-phase steel and the hot-formed steel is easier to form shrinkage cavity. Under the same welding conditions, the weldability of dual-phase steel is better than that of hot-formed steel.

Key words: Hot-formed steel; Dual-phase steel; Resistance spot welding; Weldability

摘要： 为研究汽车用热成型钢和双相钢的焊接性能差异，采用 1.5 mm 热成型钢 HS1300T、 1.5 mm 双相钢 DP590T 分别与 1.9 mm 冷轧钢板 CR1180T 进行电阻点焊焊接，对两种板材可 焊性窗口、焊点一致性以及焊点宏观形貌进行研究。研究表明，双相钢比热成型钢可焊性电 流窗口更大。连续焊接 500 个焊点，热成型钢板更容易发生飞溅，飞溅点数是双相钢的 3.72 倍；最优焊接参数下热成型钢焊点压痕深度较深，为双相钢的 2.62 倍；热成型钢焊核更易形 成缩孔。在焊接工况一致的情况下，双相钢相较于热成型钢可焊性更好。

关键词: 热成型钢；双相钢；电阻点焊；可焊性