Effect of asymmetric material entrance on lubrication in cold rolling

Theoretical Analysis of Rolling Force during Cold Rolling with Roll Crossing and Shifting System

“…Hsu et al established a rigid-plastic FE code combined with a realistic friction model to analyse the lubricant flow and determine the hydrodynamic friction stress within a billet-roll interface. Their work developed predictions of the rolling force, rolling torque and outlet velocity ratios which could be obtained with high accuracy during a lubricated cold rolling process [21]. For the hot rolling of aluminium, Shahani et al applied a coupled thermal visco-plastic finite element code to estimate the effects of initial slab thickness, thickness reduction ratio, friction coefficient and rolling speeds on the hot rolling process [22].…”

Experimental and numerical study of pinching phenomena in sheet metal rolling processes

“…The efficacy of the lubrication depends on several factors, including the lubricant's chemical composition [77] and properties, particularly its viscosity, as well as the surface roughness of the strip and the roll. Furthermore, process conditions such as the rolling speed, temperature, and geometry of the deformed roll bite [78] also influence the thickness of the lubricant film. To achieve optimal lubrication conditions, it is necessary to supply a sufficient amount of lubricant, which must be drawn into the roll bite.…”

“…It was found that this elastic entry zone significantly impacts the amount of lubricant that enters the roll bite and, consequently, the thickness of the lubricant film. Jacobs et al [78] have recently observed that an uneven strip feed into the roll bite, with unequal top and bottom contact, can cause significant variations in the film thickness. This asymmetry has been identified as the cause of the mismatch between the calculated film thickness using the equation derived by Wilson and Walowit [80] and the measured film thickness.…”