Analysis of TiO2 nano-additive water-based lubricants in hot rolling of microalloyed steel

Hot rolling tests of microalloyed steel were performed at rolling temperatures of 1050, 950, and 850 °C under different lubrication conditions, including dry, water lubrication, and 1.0 vol.% oil-in-water (O/W) emulsion. The rolling force, surface roughness, and thickness of the oxide scale of the rolled steel were investigated in order to evaluate the lubrication effects of TiO2 nano-additive water-based lubricants. The results show that the rolling force under a rolling temperature of 1050 °C does not vary significantly under all the lubrication conditions. The 4.0 wt.% TiO2 water-based lubricant, however, leads to the lowest rolling force at rolling temperatures of 950 and 850 °C. The application of 4.0 wt.% TiO2 water-based lubricant in hot rolling not only produces the best surface finish, but also results in the thinnest oxide scale of the rolled steels. The lubrication mechanisms of TiO2 nano-additive water-based lubricants in hot rolling were also discussed.