Sliding friction properties of austenite-and martensite-based white cast iron containing 8.5% chromium

摘要

In this paper, the wear resistance and track of austenite-and martensitic-based white cast iron (AWCI and MWCI) containing 8.5% chromium have been investigated with micro-fricative wear tester, optical microscopy (OM), scanning electron microscopy with EDS (SEM-EDS), and 3D digital microscope. The results show that significant differences exist in the hardness (AWCI: HRC41.2, MWCI: HRC55.8) and impact toughness (AWCI: 28.6 J cm~(-2), MWCI: 20.3 J cm~(-2)) between as-forged AWCI and forged + heat-treated MWCI samples. At 20 N load, due to AWCIs' low resistance matrices (pearlite and austenite), the wear performance is poor. The depth of the wear track in AWCI sample was 45.479 μm, lower than 70.810 μm in MWCI sample, indicating that the wear performance of AWCI sample was better than that of MWCI at 120 N. Additionally, associating with oxide film and wear debris on the samples' surfaces, the sliding friction coefficient of AWCI increases with load increasing from 20 N to 60 N then decreases with load increasing from 60 N to 120 N, whereas the friction coefficient for MWCI decreases with load in the range of 20-60 N then increases with load increasing from 60 to 120 N.