Hydrogen enhanced fatigue crack growth in an HSLA steel

Fatigue crack growth rate (FCGR) for an HSLA steel was studied with in-situ hydrogen charging. The effects of different parameters, like stress intensity range (ΔK), frequency, load ratio (R), stress values and crack length have been investigated. The hydrogen contribution to FCGR decreased with increasing ΔK. FCGR was inversely dependent on frequency. The role of loading strain rate on the hydrogen enhanced FCGR was explained. The effect of load ratio on hydrogen enhanced FCGR was not monotonic. A dependence of FCGR of hydrogenated samples on crack length was observed and explained.