780MPa级DP钢点焊焊接性能与失效分析  

Spot welding properties and failure analysis of 780 MPa grade DP steel

作　　者：汪小培[1] 张永强[1] 王威[1] 杨建炜[1] 章军[1] 

机构地区：[1]首钢技术研究院,北京100043

出　　处：《电焊机》2016年第4期75-78,共4页Electric Welding Machine

摘　　要：高强度DP钢在汽车制造生产中得到了广泛的应用。研究780 MPa级别的DP钢点焊后焊点的性能,并分析焊点失效情况。结果表明,1 mm厚的该级别钢种的焊接窗口为3.4kA,最优焊接电流为11kA;增加预热脉冲后,能够有效防止和改善高强钢点焊焊核上的焊接冷裂纹;焊接电流较小时,点焊后的汽车前纵梁容易造成轴向失稳,使得其吸收碰撞能量的能力减弱。High strength DP steel has been widely used in auto manufacture. The spot welding properties of 780 MPa grade DP steel and the failure of the welds are studied. The results show that the welding lobe of the steel with lmm thick is 3.4 kA,and the optimal welding eurrent is 11 kA. The welding cold crack in weld nugget can be prevented or improved by preheating treatment. The front rail is likely to cause axial instability in low welding current, which decreases the ability to absorb impact energy.

关 键 词：DP钢 点焊 性能 失效 

分 类 号：TG457.11[金属学及工艺—焊接]