Symmetrical Billet Hot Rolling of Brittle High-Chromium Cast Iron/LCS Laminates for Enhanced Wear Resistance

This study elucidates the enhancement of friction performance in high-chromium cast iron (HCCI)/low-carbon steel (LCS)laminates via hot rolling. Symmetrical billet hot rolling was used to fabricate HCCI/LCS composites, which boosted HCCI impact toughness from 8.1 to 9.7 J/cm2. Microstructural analysis revealed uniform thermoplastic deformation with refined, dispersed carbides post-dissolution, increasing the average hardness of HCCI from 621.5 to 729.1 HV. The (Fe,Cr)7C3 carbides were hardened to 19.18 GPa through dislocation-mediated work hardening during plastic deformation. Hot rolling reduced HCCI’s friction coefficient, though average coefficients increased with higher loads/reciprocating frequencies. Wear mechanisms shifted from oxidation/abrasion to fatigue/oxidation dominance. The hot-rolled matrix predominantly retained austenite, leveraged friction-induced martensitic transformation, work hardening, and austenite’s low elastic modulus to enhance later-stage wear resistance.