The lubricity of oil-in-water emulsion in cold strip rolling process under mixed lubrication

A mixed lubrication analysis of strip rolling has been developed to investigate the lubricity of oil-in-water emulsion. The combination of rolling speed and supply concentration determines the pattern of pressure distribution in the inlet zone. For emulsions of very low concentration, considerable hydrodynamic pressure still can be generated by transforming the emulsion into pure oil in the work zone; the lower concentration yields the higher peak of hydrodynamic pressure near the outlet. In addition to the rolling speed, the asperity adhesion is the dominant factor to augment the hydrodynamic pressure and the oil concentration by confining the lubricant flux with smaller film thickness. The bigger oil droplet, which plays the secondary role, also helps pressurize the lubricant.