EUROPEAN STEEL TECHNOLOGY AND APPLICATION DAYS 2017 - ESTAD 2017

In cold strip rolling, the amount of wear generated in the contact zone influences the surface quality of the final product, and, by influencing the coefficient of friction between work roll and strip, the force and power requirements of the mill. Most of this wear is expected to be generated from the strip, as the rolls are generally much harder. In order to study the generation of wear during cold rolling and the impact of important influencing factors, a mathematical model for the prediction of wear extracted from the strip surface was developed. This model is an extension of the modular tribological cold rolling model developed by the authors [1]. The proposed modelling approach utilizes a locally distributed implementation of the well-known Archard’s equation [2] for the prediction of the generated strip wear volume. The wear coefficient in Archard’s equation is determined by a fractional film defect model [3] reflecting the lubrication efficiency of the interface between work roll and strip. The wear model for cold strip rolling was utilized for the prediction of strip wear generated in typical rolling schedules on a production mill. Based on these schedules, the influence of significant rolling parameters (e.g., strip material grade, thickness reduction) on the amount of generated strip wear was examined. Together with the results of the tribological cold rolling model, the interdependence between coefficient of friction and strip wear generated during cold rolling could be investigated. The presented model significantly contributes to a better understanding of the interrelations between friction and wear in cold rolling. It allows for the prediction of strip wear generated in different stands of a rolling mill depending on rolling parameters, lubricant properties, and the rolled product. Furthermore, the presented simulation results allow systematic investigations on the influence of significant rolling parameters on the amount of strip wear generated in typical production mills. [1] M. Bergmann, A. Kainz, K. Zeman, K. Krimpelstaetter, D. Paesold, B. Smeulders and P. Schellingerhout, Enhanced modelling of friction and lubrication in cold strip rolling, Proceedings of the 9th International & 6th European ROLLING Conference (2013). [2] J.F. Archard, Contact and Rubbing of Flat Surfaces, Journal of Applied Physics 24 (1953), 981–988. [3] A. Beheshti, M.M. Khonsari, An engineering approach for the prediction of wear in mixed lubricated contacts, Wear 308 (2013), 121–131.