Abstract
In order to model the hydrogen-induced cracking of unstable austenitic stainless steel, three types of stainless steels with different microstructures were studied and compared. The relative order of second-stage crack velocity at room temperature was AISI 301 greater than Ferralium 255T greater than AL 29-4-2 greater than Ferralium 255L. The kinetics of crack propagation were modeled in terms of the hydrogen transport in these alloys. This is a function of temperature and microstructure in the embrittlement region. The relatively high crack growth rate of AISI 301 was shown to be controlled by the stress-induced alpha prime martensite around the crack.