电阻点焊异质DP1000–QP1180钢板的组织和力学性能（英文）

Microstructure and mechanical properties of dissimilar resistance spot welded DP1000–QP1180 steel sheets

研究了焊接参数对电阻点焊DP1000–QP1180异质接头组织和力学性能的影响。QP1180侧的热影响区宽度比DP1000侧的小。热影响区的宽度和压痕深度随着焊接电流增大和焊接时间的延长而增大。熔核尺寸随着焊接电流的增大而增大,但在低电流条件下,熔核尺寸随着焊接时间的延长而增大,在高电流条件下,熔核尺寸随着焊接时间的延长而减小。DP1000侧的硬度最低。在QP1180侧,热影响区中心硬度最高。随着焊接电流的增大,焊缝区硬度降低,拉伸剪切载荷增大。在较低的焊接电流下,焊接时间对拉伸剪切载荷没有影响。伸长率随焊接时间的延长而减小,而焊接电流与伸长率之间没有关系。强度较高的点焊接头具有较强的韧性断裂特性。

In this study,the effect of welding parameters on the microstructure and mechanical properties of the dissimilar resistance spot welded DP1000–QP1180 joints was investigated.Heat affected zone(HAZ)width of QP1180 side was smaller than that of DP1000 side.HAZ width and indentation depth increased with increasing welding current and welding time.The nugget size increased with increasing welding current whereas it increased at lower currents and decreased at higher currents with increasing welding time.The lowest hardness was on the DP1000 side.On the QP1180 side,the center of HAZ had the peak hardness.With increasing welding current,hardness values throughout the weld zone decreased and the tensile shear load increased.At lower welding currents,the welding time did not affect the tensile shear load.Tensile elongation decreased with the increase of welding time,whereas there is no relationship between the welding current and elongation.The spot-welded joints having higher strength exhibited a more ductile fracture characteristic.