Corrosion behavior of cold-rolled metastable Cr–Mn–Ni–N austenitic stainless steel in acidic NaCl solution

Abstract

The microstructure and corrosion behavior of metastable austenitic stainless steel (MASS) 14Cr10Mn in acidic 1 wt.% NaCl solution were investigated by X-ray diffraction (XRD), electron back scatter diffraction (EBSD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and electrochemical measurement techniques. Cold rolling deformation noticeably increases the contents of martensites and microdefects in the steel. All specimens show active–passive transition during the anodic polarization process. With changing the cold rolling reduction from 0% to 20%, the active corrosion rate markedly increases about 55%, whereas the pitting potential slightly decreases about 80 mV. The cold rolling deformation clearly facilitates the preferential dissolution of Fe and Cr as well as the enrichment of Cu on the metal surface in the corrosion process. The small shallow grooves and pits form at the deformation band regions.

Keywords

• Cr–Mn–Ni–N MASS
• Cold-rolling
• Microstructure
• Active corrosion
• Pitting