The effect of scaling on interfacial friction in hot rolling of steels

Hot oxidation and hot rolling experiments were undertaken in order to inves tigate scale formation and its effect on the frictional conditions in the h ot flat-rolling of steels. The effect of scale thickness on the coefficient of friction in the hot rolling of a low carbon and a microalloyed steels i s examined. A model of scale growth is presented, predicting the magnitude of the scale index as well as the thickness of the scale as a function of t he temperature and time. The coefficient of friction is inferred from a fin ite-element code as a match between the measured and calculated roll force, torque, and forward slip. It is shown that the coefficient of friction inc reases with decreasing scale thickness. The break-up of the scale and surfa ce defects are discussed. (C) 1999 Elsevier Science S.A. All rights reserve d.