XPS Analysis of nanolayers obtained on AISI 316L SS after Magnetoelectropolishing
In the present paper, the passive layers' chemical compositions of AISI 316L austenitic stainless steel samples after three treatments, such as mechanical/abrasive polishing (MP), standard electropolishing (EP) and magnetoelectropolishing (MEP) are displayed. For the surface studies after each treatment, XPS analysis was performed. It has been noted that after MP treatment the Cr/Fe ratio in the passive layer is the lowest and equals to about 1, whereas after the MEP it is close to 3.
... ly, it has to be reported that the passive layers after MP consist mainly of Cr 2 O 3 and Fe 2 O 3 , after a standard EP treatment-of CrOOH and FeOOH, and after MEP-of Cr(OH) 3 and FeOOH compounds. Concerning the surface layer compositions, in the passive layer formed after MP the detected iron consisted partly of Fe 0 (46.5 at %) and partly of iron compounds Fe 2+ and Fe 3+ (53.5 at %), whereas the detected chromium consisted of Cr 0 (16.5 at %) and mostly of chromium compounds Cr 3+ (80.8 at%), with a small amount of Cr 6+ (2.7 at %). In case of the nanolayer after EP treatment, the detected iron consisted of Fe 0 (39.5 at %) and iron compounds Fe 2+ and Fe 3+ (60.5 at %), whereas the detected chromium consisted in a small amount of Cr 0 (6.6 at %), and mostly chromium compounds Cr 3+ (83.8 at %) with some Cr 6+ (9.6 at %). The XPS analysis of nanolayer formed on AISI 316L after MEP indicates that the detected iron consisted partly of Fe 0 (27.1 at %) and mostly of iron compounds Fe 2+ and Fe 3+ (72.9 at %) whereas the detected chromium contained Cr 0 (18 at %) and chromium compounds of Cr 3+ (76 at %) and Cr 6+ (6 at %).