以Cu箔为填充金属, 采用碟片激光器对厚度为2 mm冷轧TA2/409不锈钢层状复合板进行了拼接焊接实验, 研究了不同热输入(50～150 J/mm)对焊接接头宏观形貌、显微组织及力学性能的影响。实验结果表明, 随着热输入的增加, 焊缝横截面的熔宽、熔深及凹陷量均逐渐变大, 热输入为60～150 J/mm可以获得完全焊透的接头, 焊缝的横截面形貌由“漏斗状”变成“沙漏状”; 不同热输入条件下, 焊缝区的显微组织以Fe基固溶体为主, 随着热输入的增加, Cu基固溶体含量逐渐减少, TiFe2含量逐渐增加, 导致焊缝区中部的平均显微硬度逐渐增加; 拉伸试样的断裂位置均在焊缝区, 断裂方式为脆性断裂, 其抗拉强度先增大后减小。当热输入为75 J/mm时, 焊接接头的抗拉强度可达到基材的88.6%。

Using Cu foil as filler metal, 2 mm cold rolled TA2/409 stainless steel laminated composite plates were butt welded by disk-laser. The effect of different heat inputs(50～150 J/mm)on macroscopic morphology, microstructure and mechanical properties of welded joints were researched. The experimental results show that as the heat input increases, the weld width, depth and deboss of welded seam cross-section gradually increase, and the full penetration welded seam is gained when heat put is 60～150 J/mm. The welded seam cross-section morphology changes from “hopper-shape” to “hourglass-shape”. The microstructures of welded seam is dominated by Fe-based solid solution under different heat inputs. With the increase of heat input, the content of Cu-based solid solution gradually decreases, TiFe2 content gradually increases, resulting in the gradual increase of the average microhardness in the middle of the weld zone. The fractures location of the tensile specimen is in the weld zone and the fracture mode is brittle fracture. The tensile strength first increases and then decreases, when the heat input is 75 J/mm, the tensile strength of the welded joint can reach 88.6% of the substrate.