An in situ AFM study of the first steps of localised corrosion on a stressed 304L stainless steel in chloride media

By Martin, Frantz; Fréchard, Sophie; Bataillon, Christian & Cousty, Jacques
Published in NULL Elsevier Science 2006

Abstract

Publisher Summary This chapter presents a study in which the pitting corrosion of an austenitic 304L stainless steel in chloride borate buffer solution was monitored by using an in situ electrochemical AFM. The set-up used was an AFM Picoscan II from Molecular Imaging, mounted in a #stand-alone# configuration. The samples were prepared by mechanical polishing with diamond paste, then submitted to at least 20 hours of chemical-mechanical polishing with colloidal silica, and finally rinsed and sonicated in distilled water and ethanol. The results emphasize the effect of sample preparation, particularly mechanical polishing. Mechanical polishing induces local strain-hardening of the material, which substantially modifies the local electrochemical properties on the surface. It can be concluded that when the sample contains superficial strain-hardened zones, induced by a mechanical polishing treatment, pits initiate preferentially in these areas.

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