A theoretical analysis of the sandwich rolling process

The rolling of high-strength metal sheets to thin gauges causes excessively high-roll forces which result from the flattening of the rolls. One effective way of reducing the rolling load is to roll the sheet sandwiched between layers of softer metal. The situation is similar to that of the production of clad metal. This paper aims to show how to predict the load to which a mill is likely to be subjected and the effect on the load of the various process parameters. A theory is developed which predicts the roll separating force to the same level of accuracy as that normally obtained from cold rolling theories; it takes account of the thickness of the sheets, the relative yield stresses and the interfacial friction. The results of the analysis are verified by comparison with experimental measurements.