采用300 W准连续脉冲光纤激光器对1 mm厚304不锈钢进行拼焊试验, 分析了激光峰值功率、脉宽、频率、离焦量以及焊接速度等主要焊接工艺参数对焊接质量的影响规律。结果表明, 对于1 mm厚304不锈钢准连续脉冲光纤激光焊接, 在高功率且大离焦量的情况下焊接得到的焊缝成型和力学性能均优于低功率且小离焦量下的焊接效果。在优化的工艺下进行焊接时, 焊接过程中几乎无飞溅, 并且可以得到表面均匀一致, 无裂纹和气孔且成形优良的焊缝。拉伸试验结果表明, 焊缝力学性能优良, 其抗拉强度可达682.32 MPa, 优于母材。

304 stainless steel with thickness of 1 mm was welded by 300 W quasi-continuous (QCW) pulse fiber laser. The influence of main welding parameters (Peak power, pulse width, repeat frequency, defocus length and welding velocity) on welding quality was analyzed. The results show that appearance and mechanical property of weld acquired under welding with high power and high defocus length were better than that acquired under low power and low defocus length. With optimized welding technology parameters, the welding process was almost no splash, uniform and high quality weld joint without any cracks and porosity was acquired. Tensile test indicated that tensile strength of weld could reach 682.32 MPa. Mechanical property of weld was better than that of base metal.