Improving sustainability of cold rolling of low-carbon steels via oil free lubricants

The European steel sector is committed to improve sustainability of the whole steel production chain, from decarbonisation of major upstream processes up to all downstream operations, including rolling. In particular, in the cold rolling process, oil-in-water emulsions are usually applied to lubricate the cold rolling process of low-Carbon steel. Such emulsions present some drawbacks mainly related to emulsion bath maintenance, subsequent production stages and waste disposal. Past research works showed that in some application areas, Oil Free Lubricants (OFL) show lubricant properties that are comparable to conventional lubricants, while providing significant environmental benefits. These lubricants are formulated as aqueous dispersions of Polyalkylene Glycols (PAG), a water-soluble synthetic polymer base, combined with various additives for lubrication enhancement, corrosion protection, and oil rejection. The project entitled “Transfer of aqueous oil free lubricants into steel cold rolling practice” (Ref. RollOilFree II – G.A. No 101112433) aims at developing an Oil-Free Lubricant for the cold rolling process of low-Carbon steel for applications in the automotive and packaging sectors by assessing its performance in industrial conditions. To this aim, the project combines tests at laboratory scale and simulations with trials in an industrial pilot cold rolling mill and, finally, field trials at industrial scale. Results demonstrate that OFL01 and OFL02 represent the most promising formulations as substitutes for commercial lubricants. The paper overviews the work undertaken in the first 18 months of the project, including laboratory investigations and part of the pilot trials.