钒作中间层的TC4钛合金与316L不锈钢双道激光焊接

Two pass laser welding of TC4 titanium alloy and 316L stainless steel with vanadium interlayer

采用TC4钛合金和316L不锈钢作为母材,纯钒作为中间层材料,进行了双道激光焊接试验。研究了焊接速度、光束偏移量对焊缝成形、显微组织、力学性能的影响,并进行了分析测试。结果表明:在钛合金一侧的钒中间层可发生一定程度的熔化,但界面近域均为固溶体,对接头的力学性能影响较小。在钒与不锈钢一侧,钒中间层与不锈钢呈钎焊界面,钒发生一定程度的溶解与扩散,形成扩散层。随着钢侧光束偏移量的增加,V/Fe界面扩散层的厚度减小,偏移量为0.3 mm时,界面扩散层厚度达到35.8μm,此时抗拉强度最高达到406.9 MPa,断裂位置为钒/不锈钢界面处,断口呈韧性断裂特征。

A two-pass laser welding test was carried out using TC4 titanium alloy and 316L stainless steel as the base material and pure vanadium as the interlayer material.The influence of welding speed and beam offset on weld formation,microstructure,and mechanical properties were studied and analyzed.The results show that the vanadium interlayer on the side of titanium alloy can be melted to a certain extent.Still,all near the interface are the solid solution,and the mechanical properties of the joint are less affected.On the side of stainless steel,the vanadium interlayer is brazed with the stainless steel.Vanadium dissolves and diffuses to some extent,forming a diffusion layer.With the increase of beam offset on the steel side,the thickness of the V/Fe interface diffusion layer decreases.At an offset of 0.3 mm,the thickness of the interfacial diffusion layer reaches 35.8μm,and the maximum tensile strength reaches 406.9 MPa at this time.The fracture location is at the vanadium/stainless steel interface,and the fracture is characterized by ductile fracture.