Wet oxidation of stainless steels: New insights into hydrogen ingress

It is well established that hydrogen derived from water vapor can penetrate oxidizing alloys with detrimental effect. However, the complexities of tracking hydrogen in these materials have prevented the direct profiling of hydrogen ingress needed to understand these phenomena. Here we report hydrogen profiles in industrially-relevant alumina- and chromia-forming steels correlated with the local oxide-metal nano/microstructure by use of SIMS D₂O tracer studies and experimental protocols to optimize D retention. The D profiles unexpectedly varied markedly among the alloys examined, which indicates mechanistic complexity but also the potential to mitigate detrimental water vapor effects by manipulation of alloy chemistry.