  A rapid fracture test in four-point bending is proposed to assess hydrogen
embrittlement (HE) susceptibility of high strength martensitic steels. The
novelty of this technique is the rapid rate of loading, whereas conventional
approaches require prolonged slow strain rate testing. The essential
fractographic features required to identify the mechanisms of HE failure remain
evident, despite the fast loading conditions. To demonstrate these attributes,
two quenched and tempered steels at two different strength levels were tested,
with and without pre-charging of hydrogen. Stress coupled hydrogen diffusion
finite element analysis (FEA) was performed to calculate both stress and
hydrogen concentration distributions. In addition to fractographic analysis, a
mechanistic description rooted in hydrogen enhanced decohesion (HEDE) mechanism
was used to corroborate the mechanical test data. The study shows that the
approach is capable of quantifying HE susceptibility by being responsive to key
factors affecting hydrogen induced fracture, thus developing further
understanding on the HE of martensitic steels.
