The influence of in-situ alloying of electro-spark deposited coatings on the multiscale morphological and mechanical properties of laser welded Al–Si coated 22MnB5

During laser welding of Al–Si coated 22MnB5 steel, the melted Al–Si coating alloys with the molten weld pool promoting α-ferrite phase formation during the heat-treatment stage of hot-stamping, which results in a fusion-zone (FZ) microstructure consisting of α-ferrite islands disbursed through a martensitic matrix. The presence of the softer ferrite phase is the main cause for premature failure of laser-welded 22MnB5 joints in the hot-stamped …