Research on weld formation of SUS 304 stainless steel by laser oscillating scanning welding

In order to investigate the underlying mechanism of how process parameters in galvanometer-scanned laser welding affect weld formation, the galvanometer-scanned laser welding technology was applied to SUS304 stainless steel under different oscillating frequency and amplitude. The finite element analysis was used to predict the effect of oscillation parameters on the temperature field of SUS304 stainless steel weld joint. The results indicate that compared to conventional laser welding, laser oscillating scanning welding significantly improved the quality of weld formation and suppressed defects such as burn-through, undercut and overlap. With the increase of scanning amplitude or scanning frequency, the weld forming quality is improved. However, with the further increase of scanning amplitude or frequency, undercut defects will occur on the front side of the weld, and spatter/overlap defects will occur on the back side of the weld. This is because laser oscillating scanning welding changes the energy deposition path. The simulated temperature field is in good agreement with the actual weld geometry. Compared with conventional laser welding, laser oscillating scanning welding reduces the peak temperature and temperature gradient in the welding process.