Microstructural and crystallographic features of hydrogen-related fracture in lath martensitic steels

摘要

This paper summarised the microstructural and crystallographic features of hydrogen-related fracture under tensile deformation in martensitic steels. The specimens with relatively low strength exhibited quasi-cleavage fracture. Crystallographic orientation analysis demonstrated that the quasi-cleavage fracture occurred on {011} planes. On the other hand, the macroscopic fracture surface morphologies of the specimens with relatively high strength appeared to be intergranular-like. However, nature of the fracture was somewhat different from a typical intergranular fracture, and the fracture surfaces consisted of facets parallel to {011} planes on a microscopic level. Based on the experimental results, we concluded that the crystallographic feature of {011} plane itself had an important role on the hydrogen-related fracture.