Dislocation sweeping model for hydrogen assisted subcritical crack growth

Mobile dislocation sweeping transport of hydrogen in crack tip plastic zones can explain recent observations of time delayed hydrogen induced plastic zone development in a high strength steel. These findings appear to have received further confirmation from the derivations reported on dislocation sweeping in crack tip plastic zones. An expression was developed for the crack growth rate in terms of the stress intensity factor, K/sub I/, based on a dislocation transport model. Theoretical plots of da/dt versus K/sub I/ agree remarkably well with previously well documented experimental data.