Effects of hydrogen on disorder of passive films and pitting susceptibility of type 310 stainless steel

The effects of hydrogen in type 310 stainless steel on the disorder of pass ive films and pitting susceptibility have been investigated. II is found th at hydrogen decreases the breakdown potential, facilitates the pitting init iation and increases the pit density and growth rate. The passive films are found to exhibit n-type semiconductivity. Observed hysteresis in the capac itance-potential curve and Urbach rail in the photocurrent spectra indicate that the passive films are highly defective. Hydrogen increases the disord er of the passive films, which is one of the reasons that hydrogen increase s the pitting susceptibility. (C) 2000 The Electrochemical Society. S0013-4 651(99)12-048-2. All rights reserved.