Mechanistic similarities between hydrogen and temperature effects on the ductile-to-brittle transition of a stainless steel

Abstract

Charpy V-notched impact test studies on an Fe-Mn-Al austenitic stainless steel over a range of temperatures (293 K to 77 K) demonstrated that hydrogen charging promoted multiple crack initiation, reduced the energy absorbed by the material, and shifted the ductile-to-brittle transition curve to higher temperatures. These observations suggest that some stainless steels can exhibit changes in their ductile-to-brittle transition behavior in the presence of hydrogen. Further, the observation that embrittlement exists even at liquid nitrogen temperatures indicates that little or no localized rearrangement of hydrogen during the test is required or that relatively high strain rate effects on hydrogen embrittlement need not be necessarily attributed to enhanced transport of hydrogen atmospheres by mobile dislocations. The data presented in this paper are consistent with a model that predicts the lowering of interfacial strengths in the presence of an environment.