PH1500热成形钢电阻点焊焊接性能研究

Research on resistance spot welding performance of hot stamping steel PH1500

研究PH1500热成形钢的电阻点焊焊接特性,探讨该工艺下钢板的焊接电流窗口、焊点的微观组织、显微硬度和力学性能等方面的特点,分析其焊接特性。结果表明,1.2 mm厚的该钢种焊接窗口为1.6 kA,最小和最大焊接电流分别为7.2 kA和8.8 kA。在最小和最大焊接电流下,焊点的热影响区都存在软化点。最小焊接电流下焊点焊缝的硬度值波动较小,焊缝硬度略高于最大焊接电流下焊点焊缝的硬度值。相对来说,焊接电流对抗剪力的影响较小,对抗拉力的影响较大。

The resistance spot welding characteristics of hot stamping steel PH1500 is investigated in this paper. The welding lobe,the microstructure,microhardness and mechanical properties of the spot welds on this steel are analyzed. The results show that the welding lobe of this steel with 1.2 mm thickness is 1.6 kA,and the minimum and maximum welding current is 7.2 kA and 8.8 kA respectively. There are softening regions in weld HAZ both under minimum and maximum welding currents. The hardness fluctuation of the weld under minimum welding current is smaller than the one under maximum welding current,but the hardness value is higher. Relatively, the welding current change has less effect on shearing resistance ,while has bigger influence on tensile resistance.