Effect of Nd-YAG laser pulse shape on welding characteristics of STS 310S stainless steel

This paper describes a study of the effects of pulse shaping on weld dimens ions and weld discontinuities in continuous seam welds of STS 310S stainles s steel using a Nd-YAG laser. Laser weldability tests Soi STS 310S and Inco nel 600 were also carried out. Pulse shapes evaluated in this experiment we re of the type generally applied in YAG laser materials processing, the ram ped up type (three steps), and the ramped down type (three steps). The puls e energy was constant regardless of type of pulse shape. Penetration of las er welds increased as pulse width and peak power increased. The ramped tip type pulse was the most effective Sol deep penetration. With regard to the weld discontinuities (porosity and hot clacking), the general type pulse ga ve poorest results and the ramped down type pulse gave the best.