PARTICIPATION OF HYDROGEN IN SLOW BENDING BEHAVIOR OF 304L STAINLESS-STEEL

Three point bending test studies on 304L austenitic stainless steel at 293 and 77 K demonstrated that hydrogen charging promoted the formati on of brittle fracture features at 293 K; promoted the formation of la rger and shallower microvoids at 77 K; and reduced the energy absorbed by the material at both temperatures, although to a greater degree at 77 K. These observations suggest that although hydrogen redistributio n during testing can affect the failure mode of this material, it is n ot a necessary requirement for hydrogen induced degradation. Furthermo re, the observation that embrittlement is more severe at liquid nitrog en temperatures indicates that the effects of low temperatures and hyd rogen may interact synergistically. The data presented in this paper a re consistent with a model in which the embrittlement process is affec ted by local hydrogen concentrations.