Enhancing wear resistance in CSS-42L gear steel at room and elevated temperatures via electroshocking treatment

Abstract

The high-temperature-resistant CSS-42L gear steel is designed for service temperature of up to 500 °C and is susceptible to failures due to elevated temperature friction. This study applied electroshocking treatment (EST) to enhance the wear resistance of CSS-42L gear steel and investigate its dry friction behavior at room and elevated temperatures. Results demonstrated that EST, applied at 80 A/mm²–0.04 s, reduced the wear rate of CSS-42L at 500 °C under dry sliding wear tests conditions by 50.9 % compared to the control sample, the coefficients of friction (COF) decreasing from approximately 0.58 to 0.35. Electron backscatter diffraction (EBSD) analysis indicated static recrystallization post-EST, with the average ferrite size reducing from 5.889 μm to 5.126 μm, and the plastic deformation layer formed under elevated temperature friction conditions thickened from 10 μm to 20 μm. Scanning electron microscopy (SEM) results showed that EST significantly enhanced specific deformation energy, with the wear mechanism on the contact surface transitioning from plastic shear strain to plastic deformation, and the type of wear evolving from abrasive wear to oxidative wear. These performance improvements were attributed to the synergistic effects of refined structural size, enhanced specific deformation energy, and decreased dislocation density. This study provides novel insights into the use of EST to improve the wear resistance of CSS-42L gear steel, particularly under high-temperature conditions, offering valuable data for aerospace applications.