The effects of the reduction, speed and lubricant viscosity on friction in cold rolling

Abstract

The effects of the reduction, roll speed, lubricant type and viscosity on the roll separating forces, forward slip and resulting specimen surface roughness during the cold rolling of aluminium are investigated. Increasing speed and/or viscosity are found to lower the forward slip and the coefficient of friction. The roll separating force is reduced when lubricants are used. Increased reduction results in increased forward slip. The surface roughness of the rolled strip tends toward that of the roll. The dominant mechanism affecting these changes appears to be the entrapment of the lubricant in the contact zone. The most significant attribute of a lubricant appears to be its viscosity. Both natural and synthetic lubricants affect the rolling parameters to approximately the same extent. The results should aid industry in decision making concerning the choice of natural or synthetic lubricants.