Effect of Heat Treatment on the Microstructure and Wear Resistance of NiCrMoV Steel

Abstract

Abstract The effect of an applied load within a 50-200 N range, speed of 10-45 mm/s, and sliding of 10-120 min on the wear behavior of a NiCrMoV low alloy steel quenched in air at 1123-1323 K, followed by tempering at 873 K, was investigated. The material’s microstructure was further studied. The wear was measured using a ball-on-disc type wear machine at room temperature under dry sliding conditions. The micromorphology, worn surface and debris were investigated using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The results indicate that all the tempered specimens’ microstructure of the NiCrMoV low alloy steel consists of ferrite and carbide and that the grain size increases with an increase in quenching temperature. The friction coefficient and mass loss increased with an increase in the applied load, the sliding speed and time, as well an increase in quenching temperature. The friction coefficient and mass loss significantly increased at a load of 200 N. The worn surface of all the specimens revealed a discontinuous adherent layer. Furthermore, the microstrucure revealed that the specimens underwent a combination of delamination, plastic deformation, fatigue, and oxidation. The wear mechanism involves predominantly adhesion with a mixture mode of abrasive, adhesion, and oxidation.