不锈钢薄板T形接头激光穿透焊工艺

采用YLS-6000型激光焊接系统对304不锈钢进行穿透焊，研究激光功率和离焦量对T形接头焊缝成形、显微组织和显微硬度的影响。结果表明，随着激光功率的增加，焊缝的熔深、熔宽和搭接处焊缝宽度都增大；焊缝搭接处焊缝宽度在离焦量为-2 mm时达到最大，同时考虑深宽比，离焦量为0 mm时焊缝成形较好；焊缝区组织为以奥氏体柱状晶为基体，间隙中分布着网状δ铁素体；焊缝区硬度略低于母材，且随着激光功率的增加，焊缝区组织粗化，硬度降低。创新点：对不锈钢T形接头进行了激光穿透焊接，较为系统的分析了激光功率、离焦量等对焊缝成形的影响。综合考虑搭接处焊缝宽度和熔深，离焦量为0 mm时，焊缝成形最好。

Laser full-penetration welding technology for T-joint of stainless steel sheet

Laser full-penetration welding of 304 stainless steel was carried out by YLS-6000 laser welding system.The effects of laser power and defocusing amount on formation of weld,microstructure and microhardness of T-joint were studied.Results showed that with the increase of laser power,weld penetration,weld width and lap weld width increased.The weld width reached the maximum when the defocusing amount was -2 mm.Also taking penetration-to-width ratio into consideration,formation of weld was better when the defocusing amount was 0 mm.The microstructure of weld zone was based on austenitic columnar crystal,and the network δ ferrite distributed in the gap.The hardness of weld zone was slightly lower than that of base metal,and with the increase of laser power,the microstructure of weld zone got coarsened and the hardness decreased.Highlights:Laser penetration welding was carried out on stainless steel T-joint,effect of laser power and defocusing amount on formation of weld was systematically analyzed.Considering weld width and penetration of lap joint,formation of weld was best when defocusing amount was 0 mm.