不锈钢水下激光焊接焊缝成形与力学性能

摘要： 采用水下局部干法激光焊接技术对1 mm厚SUS304不锈钢进行了焊接试验，重点分析了水深及保护气体流量对焊缝成形与力学性能的影响.实验结果表明：通过适当的水深与保护气体流量匹配，可以获得成形良好、剪切拉伸强度与母材相当的焊缝.在水深一定时，随着气体流量的增加，焊缝熔宽变宽，熔深变浅，深宽比减小.在气体流量一定时，随着水深的增加，焊缝熔深和熔宽也表现出类似的变化规律.与普通激光焊接相比，水下激光焊接改变了焊缝的散热方向以及散热速度，因此同一焊接工艺参数下，水下激光焊接的熔深变浅，熔宽变宽.
关键词： 水下焊接； 激光焊； 奥氏体不锈钢； 焊缝成形； 力学性能
中图分类号： TG 456.7文献标志码： A

Weld Forming and Mechanical Property of Stainless Steel Underwater Laser Welding

Abstract： The local dry underwater laser welding was applied on 1mm thick SUS304 stainless steel. The effect of water depth and shielding gas flow rate on the weld forming and weld mechanical property was investigated. The results show that when the water depth and shielding gas flow rate is appropriate, the weld with good shaping can be obtained. Meanwhile, the tensile shear strength of weld is similar with that of base metal. At a given water depth, when the gas flow rate increased, the weld width increased, and when weld penetration decreased, the depth-to-width ratio decreased. When the gas flow rate was constant, the variation of weld width and weld penetration is similar when the water depth increases. Compared with the traditional laser welding, the underwater laser welding changes the direction and rate of heat dissipation, resulting in the lessening of weld penetration and widening of weld width.