The Effect of the Slip Transition in the Rolling Deformation Zone on the Wear Behavior of Hot Rolling Work Rolls

Abstract

High speed steel work rolls in hot rolling are subjected to severe conditions involving high temperature, heavy load, and complex sliding behaviors, where surface damage affects roll service life and strip surface quality. The coexistence of forward and backward slip zones within the deformation region leads to periodic reversal of friction direction during rolling process. However, its influence on wear behavior has not been fully clarified. In this study, two simulation experiments were designed to investigate, on an exploratory basis, the work roll wear behavior under reciprocating and unidirectional friction conditions. The results show that under unidirectional sliding, a continuous oxide layer forms on the surface, and the wear process is characterized by repeated formation and spallation of the oxide film, corresponding to typical oxidative wear and delamination. In contrast, under reciprocating friction, the formation and retention of the oxide layer are suppressed, resulting in reduced interfacial protection. Consequently, severe spalling accompanied by pronounced ploughing grooves is observed, and the dominant wear mechanism shifts to abrasive wear and fatigue induced delamination. It is demonstrated that friction reversal plays a key role in governing the transition of wear mechanisms by affecting the formation and stability of the tribo-oxide layer. Based on these findings, in industrial hot rolling processes, the distribution of reduction, the magnitude of front and back tensions, and the length ratio between forward and backward-slip zones can be optimized (avoiding symmetric distributions) to promote the formation and retention of protective oxide films, thereby reducing the friction coefficient and mitigating roll surface damage.