Abstract
It is impossible to imagine the modern development of technology without the use of metal products, including wire products, which are subject to high requirements in terms of variety and quality, and to the production processes, for example, wire of a fashioned profile, the flexibility of technology, high efficiency and economy, labor safety and automation. One of them is the process of drawing metal in roller dies, which combines the features of two methods of pressure metal processing - rolling and drawing. The main working tool when applying the drawing process in roller dies is a roller die with non-driven working rollers. The main drawback of the roller dies method is the presence of traction force. Stretching stresses in combination with a decrease in the plasticity of the metal during the drawing process can lead to the destruction of the rolled product. This limits the assortment of profiles, the total crimping in one of transition. It is possible to increase the plasticity of metal in two ways - thermal and mechanical. The thermal method, which is widely used in industry, requires significant energy consumption. At the same time, previous studies, which were carried out including in the ISI NASU, showed that it is possible to increase the plasticity of the metal by means of alternating sign deformation of the profiles, using, for example, equipment for straightening profiles or a scale breaker. The purpose of analytical research is to establish the dependence of the influence of the technological parameters of the drawing process in a roller drawing machine combined with the pulling of strips through a device for bending with tension (DBT) on the change of the energy parameters of the process based on the developed mathematical model. Analytical studies of the influence of the technological parameters of the DBT were carried out for the case of deformation of the initial workpiece of round cross-section with a diameter of 5.90 mm from low-carbon steel of the St.08 brand in a double-roll roller die with smooth rolls, combined with DBT in the conditions of the laboratory base of the pressure metal processing department of the Iron and Steel Institute of the Z. I. Nekrasov of NASU. On the basis of the revealed regularities, the dependences of the energy-force parameters of the process of drawing in a roller die, combined with the drawing of strip through the DBT, on the influence of the main technological parameters were obtained. It was established that an increase in the distance between of the axes rollers of the DBT at a constant value of the movement of the axis of the pressure roller of the DBT in the vertical direction leads to a decrease in the angle of coverage of the roller by the strip. It has been established that at a constant distance between the axes of the DBT rollers, when the amount of movement of the axis of the DBT pressure roller increases vertically, on the contrary, the values of the angle of coverage of the roller by the strip increase. It is shown that an increase in the number the rollers of DBR leads to an increase in both the pulling force of the strip and the normal component of the force acting on the trunnion of the rollers of the DBT. It was determined that the most significant influence of the height of the stretched strip and the radius the rollers of the DBT on the pulling force occurs in the range of relations R/h≤10. It was established that an increase in the total degree of preliminary deformation in the roller die and sign-changing deformation in the DBT of the strip leads to an increase in the value of the pulling force.
Published Version
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