Preferential dissolution mechanism of ferritic or austenitic phase in crevice corrosion of duplex stainless steels

Aoki, So  ; Nada, Yushi*; Sakai, Junichi*

In any case, duplex stainless steels (DSS) suffer from crevice corrosion. Accordingly, the measure of crevice corrosion is of pragmatic importance. The modes of crevice corrosion on DSS were complex because of its preferential dissolution and distinguishable as some types from the outside to the center of the crevice: the passivity retention region, the region with preferential dissolutions of austenitic phase precipitates, and the region with preferential dissolution of the ferritic phase matrix. It is described the study to elucidate the preferential dissolution mechanism of crevice corrosion on DSS, based on the in-situ observation of crevice corrosion dissolution behavior, and the analysis of dissolution behavior of DSS, ferritic and austenitic phases in a simulated crevice solution.