Tribocorrosion of nanocrystalline 42NiSiMo8-3-7-F steel

This paper presents the influence of a nanobainitising (N-B) and bainitising, quenching and partitioning (B-Q&P) heat treatments on corrosion resistance and wear resistance in corrosive environment on carburised 42NiSiMo8-3-7-F steel, as compared to steel after quenching and tempering (Q&T). Nanobainitizng leads to produce nanobainitic microstructure and the B-Q&P treatment resulted in ultra-fine, multiphase microstructure composed of nanobainite, martensite and temperature-stable austenite. It was revealed that steel after novel heat treatments, despite multiphase microstructure, large number of grain boundaries and high residual stress showed similar corrosion resistance in 3.5% NaCl solution and better wear resistance in dry sliding conditions as well as in corrosive environment. In addition, volume loss due to wear in corrosive environment was almost twice as low as in dry sliding test. Obtained results show that novel heat treatments of steel may be successfully applied instead of traditional Q&T without the risk of lowering corrosion resistance.