Characterization of dry-sliding wear phenomena in a novel martensitic structure based low-carbon Nb and V alloyed steel

The current study investigated unlubricated dry-sliding wear behaviour of a low-carbon Nb+V stabilized microalloyed steel in various treated states, i.e., as-received, direct-quenched (DQ, martensitic-structure) and tempered (T500) samples. The effects of applied normal load on specific wear-rate, worn-surface and sub-surface characteristics have been discussed, enlightening relevant deformation mechanisms. The specific wear-rate is found to be the lowest (2.91 ×10−5 mm3m−1N−1) for the DQ specimen, primarily due to its better combination of hardness, strength, and toughness. SEM investigation of worn-surfaces confirmed that abrasion (i.e., micro-cutting and ploughing) and oxidative wear mechanisms are the dominant phenomena in all the samples, while the counter-face material remained unchanged. The sub-surface analysis indicates the severely deformed region and bending of martensite is only 1–2 µm and 7 µm for the DQ sample, whereas increases to 3–5 µm and 15 µm, respectively, in the T500 specimen.