TWO- BODY ABRASION RESISTANCE OF HIGH-CARBON METASTABLE AUSTENITIC STEELS

This study presents the results of two-body abrasion tests on several high-carbon low-alloy steels initially consisting of a dual-phase microstructure containing metastable austenite and thermally induced plate martensite. The wear behavior of these metastable austenitic steels (MAS) is compared to commercial wearresistant steels. Some tested MAS showed specific wear rates (SWR) that are more than three times lower compared to that of a martensitic 30MnB5 (1.5531) and an austenitic X120Mn12 ( 1.3401) steel and even more than five times lower than the SWR of Hardox 450. Pre- and post-wear hardness measurements indicate that low wear rates in MAS are related to hardness increase during wear. MAS with post-wear hardness in the range of 900 - 1000 HV achieved the lowest SWR. A further increased post-wear hardness up to 1250 HV proved to be not beneficial and led to an increasing SWR. XRD measurements show significant changes in the phase fractions of the MAS sub-surface region due to an austenite-martensite phase transformation. SEM micrographs also show severe plastic deformation in the sub-surface layer and the wear tracks.