Multi-factor coupling system characteristic of the dynamic roll gap in the high-speed rolling mill during the unsteady lubrication process

• A multi-factor coupling system dynamic model for dynamic roll gap was developed.
• Interface friction model based on the unsteady lubrication process was obtained.
• The rolling force, interface friction and work roll movement models were considered.
• The friction and pressure at different surface roughness and times were analysed.

In the present work, a multi-factor coupling dynamic model of a rolling mill system for a dynamic roll gap during an unsteady lubrication process was developed on the basis of the rolling theory, lubrication and the friction theory, and the mechanical vibration theory. The multi-factor coupling model of interfacial film binding was coupled with the rolling force model, dynamic roll gap interface friction model and work roll movement model. The corresponding distributions of friction and pressure at varying surface roughness and times were systematically analyzed during the unsteady mixed lubrication process. The effects of the main processing parameters on the critical speed and amplitude for self-excited vertical vibration were investigated.