Abstract
Hydrogen diffusivity and permeability in three austenitic iron-based alloys at 200-350 °C were measured using a gas phase permeation technique. The results were compared with those for AISI 300 series austenitic stainless steels. It was found that hydrogen diffusivity and permeability in all these alloys were very nearly the same. The effects of hydrogen gas on the mechanical properties, especially on the fracture mode and the possibility of hydrogen-induced cracking in these alloys, were investigated and compared. Two of the alloys which had a high manganese content were fairly insensitive to hydrogen damage under our experimental conditions, whereas a high CuN substitute for AISI 301 was severely degraded in hydrogen gas near room temperature. The different effects of hydrogen in these alloys are discussed on the basis of hydrogen transport and the stability of their austenitic structure. © 1990.