Design of Wear-Resistant Low-Carbon Cast Steel Through In Situ TiC-MMC Local Reinforcement

Enhancing the local mechanical response of low-carbon cast steels remains essential for improving their performance in wear-intensive environments. In this work, a low-carbon cast steel was locally modified through the in situ formation of TiC particles via melt reaction with pressed Ti–Al–C powders. Advanced microstructural characterization (SEM/EDS, EBSD, and TEM) revealed a heterogeneous TiC-reinforced composite microstructure containing ~36 vol.% TiC with particle sizes between 0.73 and 3.88 μm. The reinforced region exhibited a substantial increase in hardness, from 160 ± 5 HV30 in the base steel to 407 ± 78 HV30, resulting from the synergistic contribution of TiC particles, fine κ-carbides, and a martensitic matrix. Nanoindentation revealed a strong mechanical contrast between phases, with TiC achieving 25.70 ± 7.76 GPa compared to 4.68 ± 1.09 GPa for the base metal matrix. Micro-abrasion tests showed a 24% reduction in wear rate, accompanied by shallower grooves and reduced plastic deformation. These findings demonstrate that in situ TiC formation, combined with κ-carbide precipitation, provides an effective strategy for improving local hardness and abrasive wear resistance in low-carbon cast steels. The results highlight the potential of in situ composite formation as an effective microstructural engineering strategy for next-generation wear-resistant cast steels.