Sulfur induced fracture mode transition of nickel at cathodic potentials

The effect of grain boundary chemistry on the tensile ductility and fracture mode of nickel at cathodic potentials was investigated in the present study. Recent work has shown that the fracture behavior and ductility of iron at cathodic potentials is dependent on the concentration of sulfur at grain interfaces. A threshold sulfur content was identified above which the fracture mode changed from transgranular ductile rupture to intergranular fracture. The existence of this transition in iron supplements the growing amount of evidence linking grain boundary chemistry and intergranular hydrogen embrittlement. Indications that a similar relationship might exist for nickel prompted the present research.