Influence of stress state on abrasive wear of steels

Abstract

The resistance of materials to abrasive wear depends on many factors that can be generally classified as material-based or operating systembased. In the published wear models, the bulk stress state or stress history of worn material do not appear as influencing factors. Following the analogy with stress corrosion and fatigue, as well as with cyclic softening of steel materials, the possible influence of bulk stress state and stress history on abrasive wear of steels has been examined. Preliminary experiments were carried out using a scratch tester with a diamond indenter. Hypoeutectoid steel specimens were bent to obtain tensile or compressive stress and then scratched in situ under a normal load of 25–40 N. The results of the screening experiments indicate that the depth of grooves and the wear mechanism differ, depending on whether the specimens are under tension or compression. Tensile stress favours micro-cutting, while a compressive state apparently maintains microploughing. The pilot experiments,conducted with a hypereutectoid steel, indicate (with a confidence 80%) the significant influence of stress history, i.e. cyclic stressing, on abrasive wear. Further analyses, combined with detailed observation using scanning electron microscopy, have allowed discussion and explanation of these phenomena.