Аннотация:This paper presents a generalization of the popular approach of Orowan for calculating the roll pressure in flat rolling of homogeneous strips on three-layer sheets. In contrast to the original approach, the approach for three-layer sheets requires the analysis of the velocity field for determining the shape of the bi-material interface. The present paper employs the solution for compression of a three-layer block of rigid perfectly plastic materials for finding the through thickness distribution of stress and velocity. It follows from this solution that the regime of friction at the bi-material interface (sticking or sliding) depends on the ratio of yield stresses of two materials, the ratio of the current thicknesses of two materials and the friction factor at the friction surface between the strip and rolls. On the other hand, the regime of friction at the bi-material interface controls the shape of this interface.