We describe here microstructure and mechanical properties of similar and dissimilar weld joints between 1.4 GPa (NM400) and 1.6 GPa (NM500) grade wear–resistant steels processed by laser–arc hybrid welding. The results demonstrated that single –pass laser–arc hybrid welding achieved full penetration with a Y–shaped weld seam and a narrow softening zone. The microhardness gradually decreased from the fusion zone to the intercritical heat–affected zone. The NM400–NM400 joint showed superior impact toughness (91.5 J at −20°C) due to its fine microstructure and uniform grain orientation, while the NM500–NM500 joint displays higher tensile strength (1271 MPa). The dissimilar joint exhibited significant grain orientation differences, leading to uneven strain distribution and reduced toughness. These findings highlight the potential of laser–arc hybrid welding for joining high‐strength wear–resistant steel in demanding applications.
Zhang et al. (Sun,) studied this question.