600MPa级高AI冷轧双相钢的点焊工艺研究

Research on resistance spot welding technology for 600 MPa high aluminum dual phase steel

基于600 MPa级高Al冷轧双相钢WHT600DP的点焊工艺和力学性能试验,以及接头的宏观金相分析,研究了焊接电流、焊接时间等工艺参数变化对点焊接头压痕深度、焊核直径、焊透率以及拉剪强度等性能指标的影响规律,进而得到了WHT600DP钢的焊接工艺窗口图。研究结果表明:在焊接时间变化较大的情况下,WHT600DP钢的可焊电流范围均大于3 kA,而且在较大的焊接电流范围(平均2.0 kA)内,焊点熔核直径均大于6.0 mm。此外,相对于普通低碳钢,WHT600DP钢的焊接工艺窗口略向低电流方向偏移。

The effects of welding parameters on the weld qualities for 600 MPa high aluminum dual phase steel WHT600DP were revealed,such as press depth,nugget diameter,penetration rate and tensile shear strength,based on the welding experiment,mechanical test and macroscopic metallurgical analysis.The weld lobe diagram of WHT600DP was also plotted.The results show that a minimum 3 kA weld lobe current range can be met under a large variety of welding time and the nugget diameter is larger than 6 mm in a large weld lobe current range of about 2 A.Moreover,the welding lobe diagram of WHT600DP moves slightly to the lower current in contrast to the mild steel.