Characterization of fretting products between austenitic and martensitic stainless steels using Mössbauer and X-ray techniques

Fretting experiments with an austenitic pin on a martensitic disc were performed. X-ray diffraction revealed that a part of the austenite pin was transformed into a martensite layer. The martensite is covered by a layer of Fe–Cr–Ni oxides, detected by the Mössbauer spectroscopy. Martensite and Fe-oxide, originating from the spinel structure, were identified in the debris powder. Obtained results indicate that the crystal structures of the Fe-oxides produced during fretting are highly defected. This is the cause of the observed superparamagnetic properties, broad diffraction maxima, and differences between predicted and observed Bragg spot intensities. ► We report formation of the martensite layer on the austenitic pin. ► Spinel type oxides are formed during the fretting wear. ► Superparamagnetic behaviour of oxides was detected by Mössbauer spectroscopy. ► Highly defected crystalline phases were identified. ► Hematite is not dominating phase of debris.