铜/钢角接激光焊工艺和性能研究

Study on the Process and Performance of Copper/Stainless Steel Fillet Laser Welding

针对铜/钢直连型永久阴极板对其导电性和耐腐蚀性能的较高要求,采用激光不填丝焊接方法研究不同激光功率和预热条件下的铜/钢角接焊接接头的形貌和微观组织。同时测量了接头的名义抗拉强度、电导率及耐腐蚀性能。铜/钢角接头焊缝成形质量随激光功率增大先上升后下降,激光功率3000 W时预热后的接头焊缝质量最优,接头成形良好,无焊接裂纹,熔合区内球状和枝晶状ε-Cu颗粒相均匀分布在γ相为主的(γ+ε)双相固溶体组织中;不同激光功率下接头的力学性能和电导率均表现为:预热3000 W>3000 W>2000 W>4000 W;接头铜侧区域更容易腐蚀失效,熔合区中的ε-Cu相易于腐蚀溶解,接头钢侧区域的耐腐蚀性能较好。

In order to meet the performance requirements of copper/stainless steel direct-connected permanent cathode plate,laser welding without filler wire is used to study the morphology and microstructure of copper/stainless steel fillet welded joint under different laser power and preheating conditions. The nominal tensile strength, conductivity and corrosion resistance of the joint are also measured. The results show that the weld forming quality of copper/stainless steel joints increases and then decreases with the laser power increases. After preheating with laser power of 3 000 W, the quality of welded joint is optimal, the joint is well formed and no welding cracks. Spherical and dendritic ε-Cu particle phase in fusion zone uniformly distribute in(γ+ε) dual-phase solid solution organization dominated by γ-phase. The mechanical properties and conductivity of joint with different laser power are as follows: preheating with 3 000 W>3 000 W>2 000 W>4 000 W. The copper side area of the joint is more prone to corrosion failure, the steel side area has good corrosion resistance, and the ε-Cu phase in fusion zone is easily corroded and dissolved.