Improvement of Mechanical Properties and Wear Resistance of Direct-Quenched Wear-Resistant Steel by Deformed Austenite

Herein, thermomechanically controlled processing (TMCP) and direct-quenching (DQ) process are investigated to improve the mechanical and wear properties of wear-resistant steel, compared to the reheating-quenching (RQ) process. Scanning electron microscope, electron backscatter diffraction, transmission electron microscope, and X-ray diffraction are employed to characterize the microstructures of the DQ and RQ specimens, and the mechanical and wear properties are investigated using the Vickers hardness, impact, tensile, and stirring wear tests for both processes. The results show that DQ steel exhibits strong plasticity, impact toughness, and wear resistance; the DQ process also retains the deformed austenite formed by rolling in the nonrecrystallization region. The compressed austenite reduces the size of the martensite lath and block structure, increases the density and proportion of the high-angle grain boundaries, and improves the plasticity and toughness of DQ steel. Meanwhile, DQ steel also inherits the high-density dislocations created during the rolling process, which is its primary strengthening mechanism. The deformed grains in DQ steel reduce the Schmid factor, improve resistance to wear deformation, and enhance its wear performance.