Precipitation Refinement via Aging Time Modification for Enhancing Wear Resistance in Ti–V–Nb Microalloyed High-Manganese Steels

Abstract

It is imperative to ensure an even distribution of refined precipitates to enhance wear resistance. Herein, different heat treatments are to control the size and distribution of precipitates. The treatments include water quenching at 1100 °C followed by aging at 400 °C for 24, 60, and 84 h, designated as AT24, AT60, and AT84, respectively. The microstructure, mechanical properties, and impact wear properties of high-manganese steel are investigated under solution and aging conditions using scanning electron microscopy, field-emission scanning electron microscopy, tensile testing, and impact abrasive wear testing. Notably, the absence of nanoscale precipitates largely accounts for the poor wear resistance of as-casting steel, whereas the strengthening effect of larger micrometer-sized precipitates is insufficient. After the solution and aging treatment, nanosized precipitates continuously form within the matrix, conducive to the formation of the deeper work-hardening layer, thereby improving the wear resistance. The fine micrometer-sized precipitates and evenly distributed nanoscale precipitates in AT60 actively contribute to toughness. Additionally, these precipitates interact with slip dislocations, providing stronger strengthening via the Orowan looping mechanism. The wear mechanisms of steel can be transformed from wide, deep pits to shallow grooves and microcutting by extending the aging time.