Lateral variation of the native passive film on super duplex stainless steel resolved by synchrotron hard X-ray photoelectron emission microscopy

Abstract

A native passive film on 25Cr-7Ni super duplex stainless steel was analyzed using synchrotronhard X-ray photoemission electron microscopy, focusing on variations between individualgrains of ferrite and austenite phases. The film consists of an oxide inner layer and anoxyhydroxide outer layer, in total 2.3 nm thick. The Cr content is higher in the outer than theinner layer, ca. 80% on average. The Cr content is higher on ferrite than austenite, whereas thethickness is rather uniform. The grain orientation has a small but detectable influence, ferrite(111) grains have a lower Cr content than other ferrite grains.Corrosion science 174, 108841 - (2020). doi:10.1016/j.corsci.2020.108841Published by Elsevier Science, Amsterdam [u.a.]