Suppression Mechanism of Strain-age Hardening in Carbon Steel Associated with Hydrogen Uptake

Abstract

We investigated the suppression mechanism of strain-age hardening in a ferritic carbon steel associated with hydrogen uptake. We considered hydrogen-related three factors suppressing the strain aging: 1) solution softening, for instance, arising from a reduction in Peierls potential of screw dislocations and a change in Young’s modulus, 2) suppression of dislocation-carbon interaction through hydrogen/carbon site competition, and 3) change in plastic strain evolution behavior by hydrogen-enhanced localized plasticity (HELP). According to the present experiments under in-situ hydrogen charging, it was concluded that the solution softening (factor1) and the site competition (factor2) by hydrogen did not significantly suppress the strain aging but the change in the pre-straining behavior (factor3) did.