Friction and Forward Slip in Cold Strip Rolling

Forward slip, interfacial normal and shear stresses, roll separating forces, and roll torques are measured during cold rolling of commercially pure aluminum strips. The validity of the measured contact stresses in the deformation zone is substantiated by comparing roll forces and torques obtained through mathematical modeling, via the force and torque transducers and by integration of the normal pressure and shear force distributions over the contact surface. The usefulness of previously published forward-slip coefficient of friction formulae is examined. After comparing the predictions of five of these relationships, their unreliability is pointed out.