Macroscopic and nanoscale investigation of the enhanced wear properties of medium-Mn steel processed via room-temperature quenching and partitioning

High-manganese austenitic and high hardness martensitic steels are widely used in wear-related applications. However, their abrasive wear performance is unsatisfactory because of the insufficient twinning induced plas-ticity effect of the former and the weak strain hardening and low crack resistance during wear of the latter. Here, novel wear-resistant steels were developed via alloy design and simple room-temperature quenching and par-titioning (RT-Q&P) of medium Mn steels (0.3C-10Mn and 0.3C-10Mn-0.25V). Their microstructure and sliding abrasive wear behavior were compared to those of conventional Hardox400 and Hadfield steels. The two medium-Mn steels had better wear properties than conventional wear-resistant steels. Moreover, the V -con-taining steel with a multiphase microstructure of tempered martensite, retained austenite, and nano-vanadium carbide precipitates, possessed 2.98 and 3.45 times higher abrasive wear resistance than the Hardox400 and Hadfield steels, respectively. Besides the stimulated transformation-induced-plasticity effect in RT-Q&P steels, the enhanced abrasive wear resistance of V-containing steel was attributed to microstructural refinement and improved strain hardening during wear imparted by V element. The main wear mechanism of RT-Q&P wear -resistant steels was cutting, while it was grooves and pits for Hadfield steel, and peeling pits and delamina-tion for Hardox400 steel. This study can guide the design of structural materials with excellent wear resistance through multiphase microstructural and nano-precipitate regulation to overcome the wear challenges of components.