CO_2激光焊接车身拼焊板

CO_2 Laser Welding of Vehicle Body

利用CO2激光对汽车车身拼焊板进行了焊接实验,并对焊缝进行了显微组织分析和机械性能分析。采用Ar气作为焊接保护气体,能获得比采用N2气时更好的深冲性能;侧吹保护气体的方法能有效地控制焊缝中的锌含量。研究了焊接熔深和焊缝宽度随激光功率和焊接速度变化的规律。实验结果表明,在优化的工艺参数下,激光焊接车身拼焊板的焊缝中没有出现气孔、裂纹和热影响区(HAZ)软化等缺陷,拼焊板的深冲性能优良;拼焊板的成形性能取决于两种材料的强度比和厚度比,焊缝易于向高强度镀锌钢板一侧偏移;普通钢板越薄,焊缝的偏移量越大。

Based on experiments of CO2 laser welding to vehicle body, joint microstructure and mechanical property of specimen are analyzed. The deep punching performance of laser welding adopting Ar as protective gas is better than that acquired by adopting N2. Meanwhile the percentage of zinc in welding seam can be effectively controlled by the side protective gas blowing. Welding depth and width varying with laser power and speed of welding were also investigated. The result indicates that it does not appear some flaws, such as gas hole, crack and softening of heat affect zone （HAZ） in laser welding seam of tailor-welded blanks through optimizing technology parameters. The deep punching performance of tailor-welded blanks is of very high quality. Forming property of tailor-welded board depends on strength ratio and thickness ratio of two materials, welding line mainly locates at high strength galvanized steel sheet, the offset of welding line tends toward thin general steel.