Answers are grounded in this paper and cite their sources.
Measurement of the X-ray diffraction patterns of 304L stainless steel after subjecting it to an electrochemically induced surface annealing process in concentrated nitrite solutions shows that the austenite lattice contracts during processing relative to the untreated alloy. The surface annealing procedure, which involves alternate anodic and cathodic potential pulses, thereby induces a small increase in the density of the metal surface. The observations are not due to processes involving ingress of reduced hydrogen. The results of comparative experiments in alternative electrolytes show that ingress of hydrogen into the steel expands the austenite lattice.
No takes yet. Share an insight, caveat, or question.
Burstein et al. (2003) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: