CO_2激光焊接高强度镀锌板的试验研究

Experimental study about CO_2 laser welding of galvanized sheet

为了研究汽车专用高强度镀锌钢板的CO2激光焊接性能,采用侧吹保护气体的方法,进行了大量的焊接试验,并对焊缝进行了显微组织分析和相关的机械性能试验。在试验的基础上,选择了焊接保护气体的种类,分析了热输入工艺参数对材料深熔焊接熔化特性的影响,解决了因锌的蒸发及环境中水分等因素的影响下,在激光焊接时焊缝中易于形成气孔的问题。结果表明,在侧吹保护气体的条件下,激光深熔焊接能有效地避免高强度镀锌钢热影响区的软化和控制焊缝气孔及焊接接头裂纹的产生。

Based on many experiments of CO2 laser welding of zinc coated high strength steel to vehicle body, joint microstructure and stress-strain curve of specimen were acquired. In the course of experiments, the sort of welding protective gas was selected, the influence of technological parameter on material melting characteristic of deep penetration welding was analyzed. By adopting blowing side protective gas ,the problem that gas hole was easy to form owed to evaporation of zinc and moisture of circumstances in laser welding was solved. The experimental result indicated that deep penetration laser welding could effectively avoid softening heat affecting zone, control the gas hole and restrain joint flaw of welding of zinc coated high strength steel by blowing side protective gas.