System kinetics characteristics of multi-parameter coupling of rolling mill based on mixed lubrication process of rolling interface

Based on the theories of rolling, hydromechanics and vibration, a multi-parameter coupling kinetic model was established, in which the interface friction, geometric constraint and stress distribution were modelled for dynamic roll gap. A quantitative analysis was performed on the key parameters affecting the amplitude and critical speed of vertical vibration of the rolling mill. The variation of friction stress and compressive stress in the work zone with time was analysed systematically when the rolling mill was in the mixed lubrication state with a constant reduction rate and surface roughness. The results reveal that the critical vibration speed is directly proportional to the thickness of the workpiece in the outlet zone, the surface roughness of the roll and workpiece, and the roll radius, but inversely to the lubricant viscosity and the thickness of the workpiece in the inlet zone. The amplitude is proportional to the rolling speed, and the compressive and frictional stresses are inversely proportional to the post-tensile stress.