Effect of Vibratory Peening on Surface Integrity, Strain Hardening, and Tribocorrosion Wear Behavior of Cast X120Mn12 Austenitic Manganese Steel

Abstract

Austenitic manganese steels are relatively soft after casting operation but exhibit the unique capability of significant strain hardening under dynamic loading conditions. They are widely used in critical engineering applications subjected to impact or adhesive wear. In the present study, cast X120Mn12 steel was subjected to vibratory peening at a vibration frequency of 50 Hz for 1, 2, and 3 h, respectively. The effects of this process on surface integrity, microstructure, hardening, dislocation density, and wear resistance were investigated. Wear tests were conducted against an alumina ball ( & empty;\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\emptyset$$\end{document}6 mm) under dry sliding, 3.5% NaCl solution, and 10% HCl solution conditions. The results demonstrated that vibratory peening caused severe plastic deformation on the steel surface, increasing surface roughness by creating peak-valley structures. Surface hardness increased by more than 100%. The wear tests revealed reduced coefficients of friction in the treated specimens, independent of the wear test environment. Wear resistance improved significantly in 10% HCl, although some pitting was observed on the worn surfaces. Similarly, in 3.5% NaCl, wear resistance was enhanced, but grain boundary corrosion additionally occurred. Wear mechanisms were exacerbated with longer treatment durations. These results indicate that vibratory peening has the potential to improve the wear resistance of austenitic manganese steels under dry sliding, 3.5% NaCl, and 10% HCl conditions, thereby extending their service life in demanding applications.