A method to evaluate the critical hydrogen concentration for hydrogen-induced crack propagation

A fast fracture approach to assess hydrogen embrittlement (HE) susceptibility and mechanism(s) of high strength martensitic steels

“…This observation implies that in this range of strength level, there is another first order effect, which could be the critical H concentration; this can be defined as the concentration at which the H induced cracking triggers macroscopic fracture of the material. Earlier, the concept and evaluation methodology of critical H concentration have been reported by several researchers [65][66][67]25] with a consensus that there is a ductile to brittle transition, particularly in steels, when a certain H concentration level is reached. Hence, based on the concept of critical H concentration, 4340L has the same or lower level of critical H concentration requirement than 4340.…”

Effect of grain size on mechanical electrochemical and hydrogen embrittlement behaviour of a micro-alloy steel

“…For HE, a local accumulation of hydrogen at microstructural heterogeneities is considered to trigger crack nucleation, and some authors [35][36] have calculated the critical hydrogen concentration (CHC) in the plastic zone for crack initiation. The precharging and later on testing not indicating HE suggest that the charging without accompanying deformation has not affected the enhanced 1 Current density, mA/cm 2 Potential, mV vs SCE 1 S1-AR 2 S1-1050-1h FC 3 S1-1050-2h AC 4 S1-1050-2h FC Fig.…”

Strength of spot‐welded steel sheets in corrosive environment

“…[21][22][23]. Local accumulation of hydrogen at microstructural heterogeneities is considered to trigger crack nucleation [24][25][26]. The higher the pre-strain, the higher is the microstructural heterogeneity for hydrogen accumulation, and thus higher is the damaging effect.…”