Rolling interface friction dynamics of hot strip continuous rolling and its effect on mill chatter

According to the fluid mechanics and rolling theory, the rolling interface friction dynamic characteristics and their influence on rolling speed, rolling load, roller material, rolling temperature and oil properties were studied respectively with lubrication or without lubrication in hot rolling. The two-dimensional Reynolds equation was established for steady and unsteady rolling friction interface. Through the research of rolling interface friction characteristics influence on the mill vibration, we found that when the lubrication film thickness in the roll gap was thicker, the friction coefficient was lower, its damping effect and system stability was worse. And if the rolling speed is greater than a certain value, the rolling interface friction coefficient will fall sharply with the increase of rolling speed and produces the self-excited vibration caused by negative damping. So the contrast test with different rolling interface has been carried out, such as the emulsion is open or close, high chromium cast iron/high speed steel roller is put to use, high chromium cast iron roller is grinded finely or coarsely, rolling speed is normal/reduced. And the results showed that it had an obvious effect on the mill vibration suppression by the adoption of the emulsion close and high speed steel roller