Effects of Surface Roughness on Lubrication in Cold Rolling of Metals

Experiments were conducted on a laboratory rolling mill to assess the effects of surface roughness on lubrication in the cold rolling of thin steel and aluminum strips by measuring the forward slip, frictional power, roll force, and change in surface roughness. Adverse lubricating conditions indicated by higher forward slip and frictional power were found when a strong longitudinal directionality was present on the initial strip surface. Favorable lubricating conditions were found when the initial strip surface had strong transverse directionality because of the ease of bringing lubricant into the roll gap and formation of oil pockets on the strip surface.