Investigating the effect of Cu-rich phase on the corrosion behavior of Super 304H austenitic stainless steel by TEM

The precipitation of a fine Cu-rich phase dispersedly distributed in the austenitic matrix can impart the novel properties of Super 304H SS. However, the contributions have not been well understood due to the difficulty encountered in obtaining precise experimental information on the corrosion events introduced by the nano-sized Cu-rich precipitates. In this work, we have applied TEM and clarified the dissolution occurred in Cu-rich phase and the dissolution-induced evolution in structure and chemistry on the surface. This work enabled us glean atomic scale insights on the effect of the Cu-rich phase on the corrosion behavior of the Super 304H SS.