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Effects of Hydrogen on Passivity and Stress Corrosion Cracking of Stainless Steels
Last modified: 2013-05-07
Abstract
It is known that the stress corrosion cracking (SCC) susceptibility of austenitic
stainless steel (SS) is dominated by the mechanism of anodic path cracking (APC)
and is enhanced by the passivity degradation. Experimental observations show
that ingress of hydrogen into austenitic SSs reduces the stability of passive films
and enhances the susceptibility to SCC. The hydrogen-promoted SCC is well
demonstrated by lower crack initiation lifetime and higher crack propagation rate,
as well as high frequency of passive breakdown at crack tip. The hydrogeninduced
passivity degradation is indicated by the low breakdown potential, high
passive current density, declined repassivation ability and low critical chloride
concentration to induce breakdown of passive films.
stainless steel (SS) is dominated by the mechanism of anodic path cracking (APC)
and is enhanced by the passivity degradation. Experimental observations show
that ingress of hydrogen into austenitic SSs reduces the stability of passive films
and enhances the susceptibility to SCC. The hydrogen-promoted SCC is well
demonstrated by lower crack initiation lifetime and higher crack propagation rate,
as well as high frequency of passive breakdown at crack tip. The hydrogeninduced
passivity degradation is indicated by the low breakdown potential, high
passive current density, declined repassivation ability and low critical chloride
concentration to induce breakdown of passive films.
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