In this study, the hot rolled medium manganese steel containing titanium was solution treated at 1,000 °C and followed by aging treatment at 500, 550, and 600 °C. The influence of aging treatment on mechanical properties and wear resistance of medium manganese steel reinforced with Ti(C,N) particles was investigated. It was found that the matrix of medium manganese steel was austenite. The austenite grain size was refined, and Ti(C,N) particles were precipitated after aging treatment. Compared to that of the as-hot rolled sample, the initial hardness of 500 °C aged sample increased by 9.5% to 312.86 HV, whose impact energy was more than doubled to 148.5 J. As the aging temperature raised to 600 °C, the initial hardness changed slightly. However, the impact energy dropped significantly to 8 J due to the aggregation of Mn at the grain boundaries. In addition, the main wear mechanisms of the samples were fatigue wear and abrasive wear. It was worth noting that 500 °C aged sample exhibited the best wear resistance under a 300 N applied load, whose wear loss was just half of the as-hot rolled sample. The relationship between wear loss and mechanical properties indicated that the wear resistance of medium manganese steel was independent of the initial hardness. The large difference in the wear resistance was predominately due to the outstanding work hardening ability of 500 °C aged sample, whose strengthening mechanisms were contributed from transformation induced plasticity (TRIP) effect, dislocation strengthening, twinning induced plasticity (TWIP) effect, and precipitation strengthening.

The study aims to investigate the influence of environmental media on the friction and wear behavior of low-alloy wear-resistant steels and to provide practical references for their application. This article conducted sliding wear tests on NM500 wear-resistant steel under different loads under air atmosphere, deionized water, and 3.5 wt% NaCl solution conditions. Someone quantitatively measured the friction coefficient and wear amount of each friction pair. The present study employed scanning electron microscopy, energy dispersive spectroscopy, and a white light interference three-dimensional surface profiler to analyze the surface structure, cross-sectional morphology, element distribution, and wear mechanism of the wear scars under various experimental conditions. The results show that: In deionized water, NM500 has the best wear resistance, while the dry state is the worst. The lubricating and cooling effect of the liquid, as well as the corrosive effect of the NaCl solution, play an essential role in the wear behavior of NM500. Under dry friction conditions, the wear mechanism of NM500 is principally adhesive wear, fatigue wear, and oxidation wear. In the case of wear testing in deionized water, the researchers characterized the dominant wear mechanism as adhesive wear in conjunction with fatigue wear and abrasive wear. In contrast, when they carried out the wear testing in NaCl solution, the wear mechanism was primarily driven by corrosion wear and adhesive wear, with only a minor contribution from fatigue wear.