The effect of Ti addition on the wear resistance of Nb-containing cast steel

Abstract

ABSTRACT In this study, the dry sliding friction and wear tests of low-carbon microalloyed steel containing Nb and Ti were performed by using MFT-5000 universal friction and wear tester. An analysis was conducted on the effect of Ti on the wear behaviour and mechanism of experimental steel containing Nb. The morphology exhibited by the worn surface and the microstructure of the plastic deformation layer was characterised under scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). In addition, the phase distribution in the experimental steel was identified with electron back scatter diffraction (EBSD). As indicated from the experimentally achieved results, the wear rates of the two types of experimental steel samples were upregulated with the increase in the load and the rotational speed; with the addition of Ti element, the chain segregation of NbC could be obviously facilitated, the grain uniformity could be promoted, and the chain NbC could be prevented from cracking and damaging the matrix in the wear process. Moreover, with the introduction of Ti element, the strength and hardness exhibited by the matrix were improved, the oxide layer adhered to the matrix better, and the wear mechanism varied from abrasive-adhesive wear to oxidation-adhesive wear, thereby effectively improving the wear resistance of the experimental steel.