Measurement and Estimation of Mean Flow Stress and Coefficient of Friction in Tandem Mills: A New Adaptive Control Method on Light Metal Hot Strip Mill

Abstract In light metal (aluminum etc) rooling, the coefficient of friction varies due to the use of hot rolling lubricant. The mean flow stress of rolled material and the coefficient of friction between roll and material must be studied precisely, by theoretical analysis of the measured values of rolling force, forward slip and interstand tension. As for the measuring system of forward slip, we have developed a new system using a pulse generator attached to the looper roll (for intermediate rolling stand) of deflector roll (for final rolling stand) and majn roll. Using this method, precise mean flow stress and coefficient of friction can be estimated and adaptive feed forward can be accomplished. We have applied this new method to a 3-andem aluminum hot strip mill, and obtained successful results.