New limit condition for steady-state rolling process

Abstract

Maksimenko O. P., Nikulin A. V., Loboiko D. I. New limit condition for steady-state rolling process. Material working by pressure. 2020. № 1 (50). Р. 266-271.

Improvement of existing and creation of new progressive machines and technologies for metal processing requires from designers, developers and researchers a comprehensive, systematic approach to the object under study. The interacting rolls and the strip in the deformation zone, as well as in the inter-stand gaps, are considered as a developing dynamic system, in which it is necessary to maintain stability and stability (permissible region), ensuring that the rolling process does not fall into the instability region by controlling the parameters-criteria. Following the principle of consistency, based on the study of contact and longitudinal normal stresses, as well as current horizontal forces, an analysis of the limiting conditions of rolling in a steady state is carried out. The current longitudinal forces and the average resultant of these forces are determined. A new limiting condition for rolling in a steady state is obtained as the equality to zero of the resulting current longitudinal forces, which is more adequate to the experimental and production data than the known criteria in the theory of rolling. The calculated nature of the determination of the signs of the numerical values of the criterion allows its use in assessing the longitudinal stability of the strip in rolls during rolling with tension. It is recommended to use this boundary condition when adjusting the technological parame-ters of rolling in energy-saving processing processes.