A mixed lubrication model of the cold strip rolling process

Abstract

Le regime de lubrification mixte est le plus frequemment rencontre en laminage a froid. Sa modelisation est le but de cet article. La lubrification, phenomene interfacial, est fortement couplee a la mecanique de l'operation de laminage. C'est pourquoi le modele presente assemble un modele macroscopique de laminage (methode des tranches elasto-plastique) et un modele microscopique de lubrification en regime mixte, lui-meme compose d'une equation de Reynolds entre surfaces rugueuses (formation du film lubrifiant) et d'une equation d'evolution de la rugosite, par conformation de la tole au cylindre. Les principes du modele sont presentes, compares a ceux de la bibliographie, ses hypotheses et ses resultats sont discutes, et quelques applications sont evoquees = The mixed regime of lubrication is most frequently encountered in cold strip rolling processes. A model is presented hereafter. The lubrication at the interface is closely coupled with the mechanics of the rolling process. Therefore, the proposed model combines a macroscopic model of rolling (elastic-plastic slab method) with a microscopic mixed lubrication model, consisting of a Reynolds equation for rough surfaces (describing the formation of the lubricant film) and an equation for the evolution of roughness, describing the conformation of the strip surface to the roll. The bases of the model are presented and compared to models in the literature; its hypotheses and results are discussed, a few applications are given.