Effect of (Ti, Mo)xC Particle Size on Wear Performance of High Titanium Abrasion-resistant Steel

TiC is a widely used reinforcement in wear-resistant materials. In recent years, many researchers have studied the effect of TiC on wear resistance, and the size of TiC particles is often perceived to influence the wear resistance. However, when the size of TiC particles changes, the composition or hardness of the experimental steel also changes. In this study, (Ti, Mo)(x)C-reinforced steels with the same composition were prepared though melt solidification processing using stepped molds of variable thicknesses to exclude the influence of the composition and hardness of the steel on the abrasion resistance. The solidification rate was varied by the thickness of billets, which directly affected the nucleation and growth rates of the (Ti, Mo)(x)C particles. The size of the (Ti, Mo)(x)C particles in the (Ti, Mo)(x)C-reinforced steels varied between 1.88 and 3.20 mu m. The three-body abrasive wear behavior of the (Ti, Mo)(x)C-reinforced steels was determined using a wet sand/rubber wheel testing machine and the wear morphology was observed using scanning electron microscopy. The results indicated that the three-body abrasive wear mechanism of the (Ti, Mo)(x)C-reinforced steels was mainly pits and micro-cuttings. As the size of the (Ti, Mo)(x)C increased, the wear resistance of the (Ti, Mo)(x)C-reinforced steels decreased. Larger stress occurred owing to different thermal expansion coefficients between the coarse particle and the surrounding matrix, which was more conducive to crack initiation and propagation. The optimum abrasion resistance of the (Ti, Mo)(x)C-reinforced steel was 1.76 times that of traditional low alloy wear-resistant steel with similar hardness.