To study the microstructures and mechanical properties of the welded joints of a dual-phase (DP) steel after laser lap welding, we performed the laser lap welding and laser powder filling with titanium powder lap welding of DP590 steel using a fiber laser with optimized welding parameters. The experimental results show that the microstructures of weld seam region of DP590 steel are mainly composed of martensite. There exists a softening zone in the weld joints, which is mainly originated from the generation of tempered martensite due to the thermal effect during laser welding. The hardness and...
