An Experimental Study of Boundary Conditions in Hot and Cold Flat Rolling

Abstract

The significance of heat transfer during hot rolling and of the interfacial forces during warm and cold rolling at the roll/strip contact surface is considered. The techniques used for the determination of the coefficients are given briefly and the heat transfer and frictional coefficients are established experimentally as functions of the process and material parameters. The dependence of both coefficients on those parameters is discussed. Average coefficient of friction results, obtained by the embedded-pin technique, are shown to be similar to those, obtained by measuring the forward slip. It is shown that the frictional forces depend on the reduction, the rubbing velocity, the temperature and the presence of a lubricant. The heat transfer coefficient, while affected by these, is much more strongly dependent on the condition of the surface, that is, the presence of scaling or a lubricant. © 1990 CIRP.