MEASUREMENTS OF FRICTION DURING HOT-ROLLING OF ALUMINUM STRIPS

In order to establish the dependence of the coefficient of friction on rolling speed and the reduction, commercially pure aluminum strips we re rolled at 500 degrees C, using a 2% oil/water emulsion as the lubri cant. The roll separating forces, roll torques, the forward slip, the roll pressure and the interfacial shear stress were measured as a func tion of the reduction and the rolling speed. The coefficient of fricti on was determined from the shear stress and the roll pressure distribu tions and its magnitude was validated independently. The coefficient o f friction was found to increase with reduction and, in general, decre ase with rolling speed. The adhesion theory of friction has been used to explain the observations.