Comparison of wear performance of bainitic and martensitic structure with similar fracture toughness and hardness at different wear conditions

Abstract

The high-stress and low-stress abrasive wear behaviors of carbide-free bainitic and tempered martensitic steels with similar fracture toughness and hardness were comparatively investigated. The results indicate that for the steels with similar hardness and fracture toughness, the wear performance of the carbide-free bainitic steel outperformed the tempered martensitic steel at both high-stress abrasive and low-stress wear conditions. Typical microcutting, microploughing, microfatigue and microcracking were observed in all samples under high-stress abrasive wear condition, and different predominant microfatigue morphologies were shown in the bainitic and martensitic samples. For low-abrasive wear condition, microcutting, microploughing were predominant wear mechanisms, and microcracking was also observed in samples with lower fracture toughness. In addition, for the bainitic and martensitic structure of the same steel, the bainitic samples exhibited a better wear performance at high-stress abrasive wear condition, while the martensitic samples showed a better wear resistance during low-stress abrasive wear. Moreover, the higher stability of retained austenite improved the wear performance at high-stress abrasive wear condition, while it had a limited influence on the wear performance when the stability of retained austenite was sufficient to retard the transformation of retained austenite into martensite at low-stress abrasive wear condition.