Abstract
Since the fluid flow behavior in the weld pool is closely associated with the mechanical properties of the joint, the analysis and regulation of welding temperature and flow fields are of great practical importance. In this work, numerical simulation technique was used to calculate the welding temperature and flow fields. The results show that weld pool stirring produced by an oscillating laser beam helped to make the heat transfer easier and thus reduce the temperature gradient of the weld pool. In addition, oscillating laser beam stirs the weld pool to drive the fluid to flow in the same direction and form vortices, increasing the stability of the weld pool. Furthermore, degassing the weld pool, refining the grain size of the weld, and promoting the precipitation of β phase in the weld can be achieved by virtue of oscillating laser beam to stir the weld pool.