Effect of Cr Doping on Oxidation Resistance and Oxidation Mechanism of TiC Reinforced Steel Matrix Composites: Experiments and First-Principles Calculations

Oxidation is an inevitable problem and accelerates the wear of materials under high temperature wear conditions. To enhance the oxidation resistance of TiC particle–reinforced steel matrix composites (TiC-SMCs), the role of Cr on the oxidation mechanism of TiC-SMCs at 600 °C was investigated through experimentation and first-principles calculations in this work. The results indicated that the addition of 3 wt% Cr could induce a transformation from internal oxidation to external oxidation because the diffusion energy barrier of O atoms was increased from 0.66 to 0.91 eV. Furthermore, The adsorption of the Fe and O atoms was reduced via Cr addition. Consequently, the oxidation resistance of TiC-SMCs was improved and internal oxidation was inhibited with increasing Cr content, where the oxidation rate coefficients of TiC-SMCs with 3 wt% and 0.3 wt% Cr content were 3.79 × 10⁻⁴ and 4.84 × 10⁻¹ mg² cm⁻⁴ h⁻¹, respectively. The present study would not only provide the basic understanding for the role of Cr on oxidation behavior, but also contribute to the design of TiC reinforced steel matrix composites with excellent oxidation resistance. Graphical Abstract: [Figure not available: see fulltext.]