Effect of Grain Boundary Carbide on Hydrogen Embrittlement in Stable Austenitic Stainless Steels

Abstract

The effect of grain boundary precipitates on hydrogen embrittlement was investigated with a stable austenitic stainless steel, Fe-20Cr-11Ni-5Mn-2Mo-0.5Si-0.3N-0.1C (wt.%). The steels were aged to form M₂₃C₆ along the grain boundaries and electrochemically charged with hydrogen. Based on the fractography and silver decoration results, it was found that hydrogen seemed to be concentrated at M₂₃C₆/austenite interfaces, and have promoted crack initiation and propagation. Accordingly, hydrogen-induced ductility loss was intensified in the aged alloys.