Effect of Aging Treatment on Precipitates and Intrinsic Mechanical Behavior of Austenitic Matrix in Ti–V–Nb‐Alloyed High‐Manganese Steel

Abstract

The collaboration of precipitated particles and austenitic matrix plays a significant role in the overall wear performance of high‐manganese (high‐Mn) austenitic steels. The austenitic matrix cannot support micrometer‐sized precipitates because of its poor Young's modulus and hardness before work hardening, and the relative sliding of abrasive particles over the matrix may result in the precipitates detaching from the matrix and deteriorating the overall wear performance of the steels. Herein, a solid‐solution temperature of 1100 °C is applied to balance the size of the austenite grains and precipitates. Different volume fractions of submicrometer V2C are precipitated in the austenitic matrix by aging at different temperatures, and the volume fraction of submicrometer V2C precipitates increases with aging treatment temperature. When the aging temperatures are higher than 450 °C, Young's modulus and nanohardness of the austenitic matrix are significantly enhanced, and the overall Brinell hardness and strength of the specimens are also improved. The improvement in the mechanical properties of the matrix is mostly related to the precipitation strengthening of nanoscale precipitates, and the enhancement in the overall hardness of the steels is mainly related to a sufficient amount of precipitated submicrometer V2C particles in the austenitic matrix.