Hydrogen induced cracking sensibility of welded joint based on tensile test with hydrogen pre-charging

Focusing on the TIG welded joint of 30CrMn-SiNi2 steel, a new method of tensile test with hydrogen pre-charging is proposed to evaluate the hydrogen induced cracking sensibility, which was also provededby with experiment data. The results show that fracture path was changed from the parent metal area to heat effect zone after hydrogen pre-charging. The electric current of pre-charging hydrogen had less effect on the yield strength. With the increase of current density of pre-charging hydrogen, the tensile strength, elongation, and shrinkage on the cross section of sample was decreased. Meanwhile, the joint fracture mode varied from a mixed-rupture consisting of quasi-cleavage and dimples to a quasi-cleavage fracture containing transgranular fracture and intergranularfracture. The results of pre-charging tensile test shows this method can simply identify the weak zone of the welded joint in hydrogen environment. It also can effectively evaluate the hydrogen induced cracking sensibility of welded joint.