EUROPEAN STEEL TECHNOLOGY AND APPLICATION DAYS 2017 - ESTAD 2017

Rolling of hard and thin strips is still a challenge for steel industry. For such a configuration, the rolling force could drastically increase and might exceed the tandem mill limit. Flexible lubrication has been developed at ArcelorMittal to cope with the aforementioned issue. It enables controlling effectively the friction condition inside the roll-bite through lubrication process with suitable rolling emulsions. Two important influence factors that control the frictional force between the work rolls and the strip are the amount of lubricant inside the roll-bite as well as its viscosity. In this paper, numerical simulations of cold rolling process are performed to reveal the influences of process parameters, e.g. rolling speed, tension and strip's flow stress, on the oil film thickness formation inside the roll-bite, thus the friction condition. Results reveal complex evolutions of oil film thickness with process parameters, especially for the Advanced High Strength Steels (AHSS). These results would enable adapting process parameters according to rolled products to maintain the feasibility and productivity.