Effects of average lubricant velocity and sliding velocity on friction behavior in mild steel sheet forming

摘要

A series of experiments was carried out using a rolling-type tribometer to investigate the frictionaldependence on the average velocity of the lubricant V at the contact zone inlet and the relative slidingvelocityΔV between the roll and workpiece during deformation. Experiments using mild steel stripswith a dull surface of 0.63μm Ra showed that the friction coefficient decreases with increasingforming velocity, especially at high forming velocity. This variation in the friction coefficient may bedue to the increase inΔV derived from the increase of the forming velocity, because the frictioncoefficient decreases with increasing ΔV but varies hale with increasing V ft was also confirmedthat an increase ofΔV or a decrease in V promotes flattening of the workpiece asperities.