Fatigue and hydrogen embrittlement evaluation of AF1410 steel

AF1410 steel subject to lateral one-sided electrolytic hydrogen-charging and tested under fatigue at a stress ratio of 0.4 and at 1 Hz loading frequency displayed up to four times higher crack growth rate than specimens evaluated without exposure to hydrogen. Additionally, the hydrogen-attacked side underwent a change in the fracture mode from ductile to brittle, which can be either of intergranular, transgranular or quasi-cleavage nature. Scanning electron microscope and atomic force microscope studies as well as fracture surface analysis were conducted to correlate the fracture modes with the hydrogen embrittlement effects on the steel. Since hydrogen did not permeate the entire thickness of the specimens, the experiments provided a more realistic approach to the study of large aircraft components in marine service conditions.