Hot rolling of an aluminum alloy using oil/water emulsions

The effects of the rolling speed, reduction and emulsion composition on the roll separating forces, roll torques, forward slip and the surfaces after hot rolling of commercially pure aluminum strips are studied. The roll separating forces, roll torques and forward slip are measured and compared with the predictions of two mathematical models, a finite element model and a one-dimensional technique. By matching the measured and calculated roll separating forces, roll torques and the forward slip, the coefficient of friction as a function of the process parameters is obtained also. The coefficient of friction reduces when the rolling speed or the emulsion concentration is increased but it is not strongly dependent on the reduction. At higher rolling velocities the forward slip is negative, indicating that the lubricating regime approaches hydrodynamic conditions.