激光焊接镀锌钢/冷轧钢异种板材工艺试验研究

Experimental investigation on laser welding dissimilar materials between galvanized steel and carbon steel plates

为了研究镀锌钢/冷轧钢异种板材间激光焊接性能,采用光纤激光器及其配备的机器人对其进行了焊接试验,并对接头进行了显微组织和力学性能分析。在试验的基础上,分析了激光功率、焊接速度、离焦量等主要工艺参量对焊缝性能的影响。结果表明,在一定范围内,随着激光功率的增大和焊接速度的降低,焊缝宽度和熔深增加;焊缝及热影响区硬度均高于母材,焊接接头的强度与母材冷轧钢板相当;为保证焊接接头强度和性能的有效过渡,克服因其物理性质差异所导致的焊缝与拼接中心间的偏离,激光光斑中心宜向冷轧钢板一侧偏移。

Dissimilar metal plates welding between galvanized steel and carbon steel was investigated experimentally. The fiber laser and equipped robot were used in the experiment. The microstructure and mechanical properties of joints were analyzed. Based on the experiment, the influence of parameters variation such as laser beam power, welding speed and defocusing distance on the width and depth of welding seam was studied. The experimental results indicate that the width and depth of welding seam are inclined to be higher with the increase of laser beam power and the decrease of welding speed, and the surface hardness in the welded joint and heat affected zone are higher than that of base materials, and the tensile strength of the welded joint is reasonable equal to that of the carbon steel under the experimental condition. It is advisible that laser beam center offset a bit to the carbon steel side so as to prevent the uncoinciding between the centerline of joint and butt caused by the material physical properties difference, and to keep the continuity of strength and performance in the joint during the laser welding dissimilar materials between galvanized steel and carbon steel.