The Preparation And Lubrication Model Of Water-based Nano Liquids For Rolling

The development of steel rolling production towards to the direction of continuous, automation, high efficiency, energy saving and environmental protection, which has made the lubrication technology of rolling process be put more attention and get well applied. With the global energy crisis and environmental pollution becoming more and more serious, the iron and steel industry is also required to put forward to implement energy-saving emission reduction and clean production.Oil-based lubricants have problems of harsh operating environment, emulsion easily spoilage, oil sludge refractory, and also difficult to meet the increasingly harsh production conditions. Therefore water-based rolling liquids were paid more and more attention. The rapid developments of water-based rolling liquids have advantages of excellent cooling and cleaning performance, economy and security, etc. However, water-based rolling liquids also have shortcomings of poor lubrication and antirust properties. The new rolling lubricants and lubrication theory should be in-depth study to solve the above problems of oil-based and water-based lubricants.The introduction and development of nano lubrication provides a new way of solving the problems of oil-based lubricants and shortcomings of water-based liquids. In this paper, the combination of physical and chemical dispersion achieved a stable dispersion of nano-TiO2in rolling liquids. Then a new water-based nano rolling liquids were prepared after adding other function water-soluble additives according to a certain process. The antiwear properties, wetting and viscosity, rolling lubrication and surface quality of the strip after rolling were systematic studied. The research provides integrated technical ways and conditions to solve the problems of traditional lubricants and has very important significance of promoting the development of rolling lubrication technology and water-based rolling liquids.The results of the tribological, friction and wear properties of nano TiO2water-based rolling liquids shown that, compared with traditional water-based liquids and emulsions, nano-TiO2can improve the PB value of the water-based rolling liquids, reducing the coefficient of friction and wear scar diameter, and the friction wear surface was significantly improved. Hot rolling and cold rolling tests showed that the use of water-based nano rolling liquids can effectively reduce the rolling force, improve the surface quality after rolling, meanwhile, the addition of nano TiO2improved the corrosion performance of the rolling liquids and the annealing detergence was better than that lubricated by emulsion.Hot compression experiments shown that nano-TiO2had excellent high-temperature lubrication properties. Theoretical analysis and experimental results of TGA shown that nano TiO2lubricated in the state of solid particles at high temperatures. After the EDS analysis of the strip surface, a two-phase liquid and solid of hot rolling lubrication model was proposed. Nano-TiO2not only can improves the bearing capacity of water-based rolling liquids, but also fills the cracks, repairs surface defects, while reduces the direct contact of oxide scale and roller, improves the surface quality of the hot rolled strip.It is defined that lubrication of water based nano liquids for cold rolling is in mixed lubrication state. A theoretical model of lubricant film for nano TiO2water-based rolling liquids in inlet region was developed considering the solid nanoparticles and the roughness of the work piece. Calculation and analysis of mass fraction of nano-TiO2, integrated surface roughness effects on the inlet lubricant film thickness. Film thickness model of cold rolling was established considering the viscosity of water-based nano rolling liquids and deformation of surface asperity. The viscosity of water-based rolling liquids, characteristics of surface roughness, reduction ratio and other parameters were researched on reflection of the pressure of lubricant film in deformation zone, the contact area ratio and the film thickness ratio.