Friction Coefficient mu in Rolling Operations in Conjunction with a Method of Calculating the Deformation Moment in Rolling.

The dependence of the friction forces upon the rolling conditions has been determined for the first time as a generally valid relationship governing the hot rolling process. This relationship between the medium tangential stress, necessary for the formability transfer from the roll to the rolled metal, and the rolling conditions depend on the medium stress quotient t//m/k//w//m (where t//m denotes medium tangential stress and k//w//m medium deformation resistance), which again depends predominantly on the relative height reduction and the ratio of the pressed length l//d to the medium rolled metal thickness h//m. With the aid of the stress quotient it is possible to calculate the deformation moment using an exact formula.