本文以304不锈钢作为试验材料,采用搭接的方式进行激光点焊试验,研究了激光功率、焊接持续时间、离焦量和间隙对焊点形态及尺寸的影响规律.试验结果表明,在熔透情况下,焊点上表面都呈现明显的下塌,持续时间或者间隙较大时,下表面还会出现内凹.随着焊接持续时间的增加,焊点整体尺寸增长较快,中心的下塌和内凹深度都有明显增加;而随着激光功率的增加,焊点尺寸增长缓慢.当间隙变大时,焊点熔合面出现收缩现象.

Laser spot welding of 304 stainless steel was carried out and the relationship between the welding parameters and the geometry of laser spot welds was investigated. The experimental results indicate that the influence of the laser pulse duration on the geometry of spot welds is more significant than that of the laser power. At the condition of full penetration, the surface concave is obvious, and the concave of the bottom side is found when the pulse duration or the dimension of gap increases. Moreover, the fusion area contracts with the increase of gap dimension.