On the hydrogen-induced corrosion of AISI 410

The martensitic stainless steel (SS) AISI 410 is prone to sulphide stress cracking (SSC) in "sour" service, such as H2S environments, due to hydrogen (H) embrittlement. The presence of absorbed H within SS makes them more susceptible to pitting, corrosion and environmentally assisted cracking, however the mechanistic aspects of such H-induced corrosion has not been fully elucidated in research to date. Herein, a zero resistance ammeter (ZRA) was used to investigate the impact of absorbed H on the corrosion of AISI 410, by galvanically coupling H-charged and uncharged SS specimens. A mechanism of H-induced corrosion was proposed based on the evidence of hydrogen oxidation, metal dissolution and passive film reduction from the H-charged specimens during such ZRA tests.