Effect of laser fusion repair on the microstructure and properties of stainless steel laser welds

Abstract

In this paper, the stainless steel laser welding defect weld with 1 mm + 0.6 mm plate thickness combination is taken as the research object, and a new laser secondary remelting repair technology is developed. The technique can effectively repair the surface collapse defect in laser weld. At the same time, due of the recrystallization of laser secondary fusion, the microstructure of the repaired weld is refined, the residual stress is decreased, and the fatigue performance is improved. When the fatigue life is 106, the fatigue strength of the repaired weld is approximately 1.6 times that of the gap-free weld. This study provides a reliable data basis for the feasibility of laser fusion repair process, gives a scientific and reasonable explanation from the repair mechanism, and provides basic data and theoretical basis for the application of this technology in the laser weld repair of stainless steel car body.