Romanyuk R. Enhancement of sheet gauge rolling process longitudinal steadiness based on development of theoretical representations of sheet and roll interaction

The thesis includes new, well-grounded scientific results in the field of rolling process longitudinal steadiness. The method of rolling process longitudinal steadiness assessment has been enhanced. The method is based on using contact stress plots to determine diagrams of current horizontal contact force resultant changes. The last plot is used to determine the deformation process steadiness indicator. Its positive value means the process is steady, while any negative value shows the steady process is impossible and a threshold deformation mode occurs at zero value of the indicator. The theoretical condition of capturing metal by rolls in the steady mode has been formulated more exactly. The ratio of maximum capture angle, in the steady mode, to average friction coefficient has been shown to depend on friction conditions at the contact with its value in the range of 1,43 to 1,44 when rolling with no lubrication and equal to 2 in the hydrodynamic friction mode. Validity of the rolling process longitudinal steadiness assessment using the proposed method was confirmed when analyzing experimental plots of contact stresses and existing deformation modes on cold and hot sheet and slab rolling mills. The existing deformation modes have been enhanced for the 1500 PAT "Module" cold rolling mill resulting in lower power consumption. Dependence of rolling steadiness and power consumption parameters of the process on tension was studied. The results were accepted for use at 1500 PAT "Module" and at the Metal Pressure Processing Department of Dniprodzerzhynsk State Technical University.