Minimum Quantity Lubrication MQL~R Substitutes Traditional Emulsion Lubrication in Tandem Cold Mill

摘要

The growing demands of steel producers for optimized processes to increase product quality, to reduce operational costs and to extend their product mix require new roll-gap lubrication solutions, which are more efficient, less oil consuming and more flexible. Especially, the rolling of high-strength steels poses enormous demands on coolants and lubricants. The applied medium must be optimized to meet the targeted quality requirements for various steel grades. Based on these customer demands, Primetals Technologies Austria has been working since many years to extend the knowledge and expertise on lubrication and cooling to better understand the complex tribological phenomena in the roll-gap and to support customers with leading-edge innovations. Resulting from these efforts, an innovative technology package for highly efficient, robust and flexible roll-gap lubrication for cold rolling mills could be developed [1].Minimum Quantity Lubrication MQL~R represents a new generation of roll-gap lubrication technologies for cold rolling, which applies minimum amounts of pure rolling oil atomized with pressurized air directly onto the work roll surface. MQL~R overcomes the existing limitations of classical emulsion technology in terms of flexibility (rapid change of highly different lubrication requirements) and ensures the adjustment of a proper lubrication level with reduced oil consumption.After several successful prototype tests, MQL~R has recently been permanently installed and successfully commissioned in a batch tandem cold mill of a major European steel producer. Since installation, MQL~R replaces the conventional roll gap lubrication system with emulsion in mill stands 1 and 2. Additionally, Primetals has modernized the work roll cooling on mill stands 1 to 3, which resulted in improved cooling performance and drastically reduced emulsion flow rates.The successful commissioning of MQL~R proved that this new lubrication technology works flawlessly in the industrial field and delivers high potential to overcome the existing limitations of classical emulsion technology in terms of lubrication performance and flexibility. The new system shows potential to reduce the overall oil consumption in the pickling line and the tandem cold mill.