Friction and Lubrication in the Cold Rolling of Thin Sheet Metals

One of the important problems to be solved on the friction and lubrication in the cold striprolling is to know how much amount of lubricant is carried in the interface of the roll and strip. In order to facilitate its estimation, the authors proposed a new parameter ; td=η(U0+U1)/(αp1) where η is viscosity of lubricant, U0 peripheral speed of rolls, U1 entry speed of strip, α angle of bite and p1 yield stress of strip in plane strain. Experimental results on aluminium sheets show that oil quantity dragged in the roll bite increases with the value of tψ and the larger the td the smaller the calculated coefficient of friction. By applying the td on the results of further investigation, some other factors affecting the lubrication are revealed. They are strip thickness, reduction, roll diameter, previous heat treatment of strip, intensity of roll pressure and others.