Wear properties of high-manganese steel strengthened with nano-sized V2C precipitates

In this study, the nano-sized V2C precipitations were introduced in the high-manganese steel (Fe–17Mn-0.9C) matrix to improve the wear-resistance under low-impact abrasive wear. To control the size and distribution of nano-sized V2C precipitations, the different heat treatments (quenching at 1100 °C, and tempering at 400, 450, and 500 °C) were applied. The microstructure, strengthening mechanisms, and wear properties were investigated. The untempered steel presented low wear-resistance, owing to the small amount of nano-sized V2C precipitates, and the strengthening effect of the micro-sized precipitates with small sizes was not remarkable. With the increase in the tempering temperature, the increase in the size and density of the micro-sized and nano-sized V2C precipitates were much more advantageous due to the thicker and harder work-hardening layer formed, thus improving the wear-resistance. The tempering at 500 °C led to excellent wear-resistance, owing to the sizes of the micro-sized precipitates being approximately three times larger than those in the untempered steel, with a significantly increased amount of nano-sized V2C precipitates. The latter led to the formation of a work-hardening layer with a thickness of 3.9 mm on the worn surface, which had work-hardening index values up to 0.643. The results proved that the formation of the work-hardening layer substantially enhanced the wear-resistance, and the strengthening mechanism of the high-manganese steel was dependent on the tempering temperature. Concurrently, the wear mechanisms of the tested steels were transformed from micro-cutting to plastic deformation with increasing tempering temperature.