Effect of heat treatment on the microstructure and mechanical properties of high-manganese steel for mining grinding applications

This study investigates the effect of heat treatment on the microstructure and mechanical performance of high-manganese steel intended for mining crusher applications. The applied heat treatment consists of austenitization at 1050°C followed by ice quenching (AQ), and subsequent tempering at 200°C (QT200), 400°C (QT400), and 600°C (QT600). Microstructural characterization was performed using scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and X-ray diffraction (XRD). In addition, microhardness measurements, impact toughness tests, tribological analysis using a tribometer, and surface roughness evaluations were conducted to assess the mechanical and surface properties of the material. The results show that heat treatment significantly modifies the microstructure by promoting phase transformations and the precipitation of secondary carbides. Among the investigated conditions, QT400 leads to a refined martensitic structure with M₃C-type carbide precipitation at grain boundaries. This condition provides the best balance between wear resistance and impact toughness. The minimum wear rate recorded is 0.072 mg/s for the QT400 sample.