Fracture toughness of Friction Hydro-Pillar Processing welding in C–Mn steel

This investigation focuses on the analysis of fracture toughness characteristics of Friction Hydro-Pillar Process (FHPP) welded joints in C–Mn steels. Crack tip opening displacement (CTOD) tests were performed to analyze the influence of axial loads applied during welding on fracture toughness. For this evaluation compact tension C(T) specimens were used with notches located at the bonding line of the welded specimens. The welding process produced a significant reduction of toughness independent of the axial force applied. Fractographic analysis indicated that the fracture process occurred by microvoid coalescence. The variation in the morphology of the prior inclusions resulting from welding was responsible for the observed decrease in toughness.