Microstructure, Mechanical Properties and Wear Resistance of Low Alloy Abrasion Resistant Martensitic Steel Reinforced with TiC Particles

The TiC-reinforced low alloy abrasion resistant martensitic steel was developed to improve the wear resistance without increasing hardness through traditional melting and casting technology and subsequent hot rolling and heat treatment processes. The new wear resistant steel was reinforced with micron- and nano-sized TiC particles. The phase diagram calculated by Thermal-Calc software indicated that micron-sized TiC particles precipitates towards the end of solidification. The hot rolling process changed the distribution of initial micron-sized TiC particles and transformed it from a segregated distribution to a uniform distribution. Amounts of nano-sized precipitation was obtained via pre-tempering treatment, which remarkably improved the three-body abrasive wear performance of TiC reinforced steel at the expense of a little ductility and toughness. The steel reinforced with only micron-sized TiC particles, whose wear resistance was 1.35 times that of conventional abrasion resistant steel (NM500). However, the steel reinforced with micron- and nano-sized TiC particles, whose wear resistance increased to 1.5 times that of NM500. The wear mechanism of conventional steel was micro-cutting/micro-ploughing, while the wear mechanism of TiC-reinforced steel was spalling and fatigue, because the micro-cutting was efficiently resisted by TiC particles.