Revealing the role of micron-sized in situ TiC particles on tensile properties and fracture mechanism of martensitic wear-resistant steel at elevated temperature

In order to improve the performance of the TiC ceramic reinforced wear-resistant steel at medium and high temperatures, such as slag transportation and cement production, its high-temperature tensile properties need to be well understood. In this paper, an in situ micron-sized TiC ceramic particle reinforced wear-resistant steel with 1 vol% TiC particles was fabricated. The tensile behavior and fracture mechanism of the TiC ceramic reinforced steel at 25-600 degrees C were investigated. The role of micron-sized TiC particles on tensile properties and fracture mechanism at elevated temperature was studied. Results indicated that the high temperature strength of TiC ceramic reinforced wear-resistant steel was enhanced by improving the thermal stability of the matrix. In the low and medium temperature range (25-500 degrees C), micron-sized TiC ceramic particles played a role in improving the strength, but had little effect on the elongation to failure. However, the micron-sized TiC ceramic particles greatly reduced the elongation to failure of the experimental steel when the temperature exceeded 500 degrees C. In the range of 25-600 degrees C, the fracture mechanism matched the typical ductile fracture. However, the mechanism of cavity formation varied at 500 degrees C. At 25-500 degrees C, the micro-cavities mainly formed due to fracture of the micron sized TiC particles with sizes in the range of 1-9 mu m and defects of the matrix. Above 500 degrees C, the interfacial debonding between the micron-sized TiC and the matrix was the main mode of crack initiation.