Loboiko D. Improving the technology of continuous rolling through the simulation process using the strip`s criterion of longitudinal stability

Object of research - Cold continuous rolling processes with thin flat rolled tension. The purpose of the work is to increase the stability and reliability of sheet rolling processes on the basis of the further development of theoretical foundations and methods for estimating the longitudinal stability of the thin sheet rolling process with tension. Research methods – the theoretical studies were based on the methods of plasticity theory, which include numerical recurrent solutions of finite-difference forms of conditions of static-dynamic equilibrium of isolated elementary volumes of deformation zone, simulation mathematical modeling, engineering approaches, as well as the development of practical recommendations for improving the modes of tension and reduction on tandem mill; physical modeling of the investigated technologies and equipment in the laboratory, measurement of geometric characteristics. Theoretical and practical results – the method of assigning rational modes of tension on continuous states is developed on the basis of the estimation of longitudinal stability of the sheet in the deformation zone with tension taking into account the action of internal longitudinal forces of plastically deformed metal; the method of determining the maximum magnitude of the tension on the passes at different parameters and rolling conditions on tandem mill; a laboratory unit designed to investigate the effect of the back tension on the longitudinal stability of the rolling process; method of rolling flat products in hot or cold state: sheets, strips, tapes, foil and can be used on tandem or reversible mills; rational tension modes are developed on continuous sheet states of cold rolling. Novelty – for the first time, the criterion for evaluating the longitudinal stability of the roll and the rolling limit conditions is the use of the average resulting internal longitudinal forces; for the first time, the effect of tension on the limit of longitudinal stability of the metal in the deformation zone was established, as well as on the average resultant value of internal longitudinal forces, and it was found that with increasing tension the longitudinal stability of the roll decreases; model of smooth change of the specific friction forces along the length of the deformation zone, which corresponds to the boundary conditions of the rolling process and takes into account the position of the neutral section, kinematic conditions in the plastic zone, was further developed; for the first time, it is found that with increasing stripes in the intracellular gap, the stability of the process decreases as the average resulting internal longitudinal forces in absolute magnitude decreases, this makes it possible to develop rational modes of tension. Introduction – the method of determining the longitudinal stability of the rolling process, proposed in the paper has practical value and can be used in the production of existing and developing new modes of tension and squeezing thin sheets on continuous states of cold rolling, which is confirmed by the act. Scope – metalforming.