A comparative study of the galvanized DP980 steel and 2 GPa PHS welded joint via laser beam welding and cold metal transfer welding.

• Galvanized DP980 steel and 2 GPa press hardened steel were joined. • Characteristics of laser beam welding and cold metal transfer welding joints were analyzed. • The soft weld metal of CMT joint with acicular ferrite improved the plasticity of the joint. Galvanized DP980 steel and Al-Si coated 2 GPa press-hardened steel (PHS) were joined via laser beam welding (LBW) and cold metal transfer (CMT) welding, respectively. The weld metal (WM) of LBW joints contains martensite, acicular ferrite, and bainite. The WM of the CMT joint consists entirely of acicular ferrite. The tensile strength of the LBW joint is 895 ± 5 MPa, slightly higher than that of the CMT joint by 50 MPa due to the presence of martensite. The total elongation is 4.1 ± 0.2 % and 5.0 ± 0.3 % for the LBW and CMT joints, respectively. The enhanced plasticity of the CMT joint was due to the soft WM plastic deformation, which increased the total deformation. [ABSTRACT FROM AUTHOR]