高功率光纤激光焊接SUS 304不锈钢板的过程中,熔池由于受力不平衡出现下掉,并在试件底部流动堆积,从而形成底部驼峰。采用高速摄像和“三明治”试件焊接新方法,分别从不同角度拍摄熔融金属的流动情况并从侧面直接观测小孔和熔池的变化过程。结果表明,孔内熔融金属流动的不连续和小孔前沿孔壁凸起向下移动,以及孔内金属蒸气压力导致小孔底部熔池形成多个熔滴;底部熔池表面张力和熔池的流动导致熔融金属不断向后流动从而汇聚形成驼峰;底部驼峰的形成影响熔池的流动状态,是导致焊缝表面塌陷的原因。 High-power fiber laser welding SUS 304 stainless steel plate process, the pool due to stress imbalance appears off, and flow in the bottom of the specimen pile up to form the bottom of the hump. Using high-speed camera and “sandwich” specimen welding new method, respectively, from different angles, the flow of molten metal is taken and observed from the side of the small hole and pool change process. The results show that the discontinuous flow of molten metal in the pores and the downward movement of the front wall of the small holes and the pressure of the metal vapor in the holes lead to the formation of multiple droplets in the molten pool at the bottom of the small holes. The surface tension of the bottom molten pool, The flow causes the molten metal to flow backwards and converge to form a hump. The formation of the bottom hump affects the flow state of the weld pool, which is the cause of the surface collapse of the weld.