Effect of strain-induced ε- and α′-martensitic transformations on the sliding wear resistance in austenitic Fe-Cr-C-Mn alloys

The effect of strain-induced ε- and α′-martensitic transformation (SIMT) on the sliding wear resistance was investigated in austenitic Fe-Cr-C-Mn alloys as a function of the Mn concentration. As the Mn concentration increased, the stacking fault energy (SFE) of Fe-12Cr-0.4C-xMn (x=5, 10, and 20) decreased and the SIMT type changed from γ→α′ to γ→ε+α′ and γ→ε. The sliding wear resistance of the γ→α′ type alloy was superior compared to those of the γ→ε+α′ and γ→ε type alloys. SEM images of the worn surfaces showed that α′ martensite more effectively hindered the formation of disturbed layers. The disturbed layers are generated by plastic deformation on the surface and cause wear loss during the sliding wear test due to the high hardness of α′ martensite, thereby resulting in a low adhesion tendency.