Experimental Study on Roll Wear Behavior and Fractal Modeling Under Hot Rolling Conditions

To investigate the wear behavior of work rolls under hot rolling conditions, an experimental wear-testing apparatus capable of controlling load, slip ratio, cyclic temperature variation, and cooling was developed. The evolution of the friction coefficient and surface damage during rolling was systematically examined, while fractal theory was employed to characterize the evolution of surface morphology. The results reveal that abrasive wear and surface mechanical damage dominate during the initial stage, whereas oxidation-assisted and adhesive wear gradually become more significant with increasing rolling time because of the repeated formation and fracture of oxide layers. The formation of the oxide film may help reduce direct metal-to-metal contact and alleviate material removal. However, repeated cracking and spallation under coupled thermal and mechanical loading progressively weaken its protective effect. Under intensified thermo-mechanical loading, unstable oxide layers tend to undergo severe spallation, which is associated with accelerated surface degradation. A coupled wear model incorporating thermal, mechanical, and oxidation effects was established to describe the wear evolution, and the predicted results show reasonable agreement with the experimental observations. Sensitivity analysis further indicates that the fractal parameters D and G play important roles in wear evolution, while thermal and oxidation-related parameters also affect the wear process through coupled interactions. These findings provide useful insights into the wear evolution of work rolls under hot rolling conditions.