A comparison of hydrogen embrittlement and stress corrosion cracking in high-strength steels

The purpose of this study was to compare the known behavior of hydrogen embrittled highstrength steel to the characteristics of environmentally induced failure where hydrogen is continuously generated at the specimen surface. The incubation time for the initiation of slow crack growth was accelerated by prestressing for a fixed time below the lower critical limit. These results obtained on high-strength steel in a stress corrosion environment were directly comparable to behavior of hydrogenated specimens. These data along with hydrogen diffusivity measurements and the insensitivity of the incubation time and crack growth rate to specimen thickness indicated that the stress corrosion process was controlled by the distilled water-metal surface reaction.