Influence of the welding process technology on metallurgical and mechanical properties of DP600 steel welded joints

The aim of this study was to evaluate the effect of different welding technologies on metallurgical and mechanical properties of DP600 steels joints. Arc, plasma and electron beam welding were analysed. Such technologies are characterized by a different heat input which can be considered the main parameter affecting the microstructure and the softening in the heat-affected zone. The degree of softening was found to be stronger in the arc and plasma welded joints than in the electron beam welded samples. Accordingly, in a tensile test perpendicular to the weld axis, all the electron beam welded joints failed at the base metal while the other samples failed at the softened zone. All the analysed samples showed a yield strength higher than those of the raw material but a lower elongation. The hardness of the weld zone was increased compared with that of the base metal.