Calculation of the parameters of the roll forming with the purpose of minimizing the uniformity of deformation in the cross section

Currently, the market for large diameter pipes (LDP) is developing in an environment of overcapacity, which puts pipe manufacturers in this segment in a highly competitive environment. Sea crossings, zones of increased seismic activity, high operating pressure of pipelines determine stringent requirements for the strength, geometric and operational characteristics of pipes. Improving the dimensional accuracy of large-diameter pipes is an urgent task for most manufacturers of these products. One of the ways to improve the accuracy of pipes is to minimize the non-uniformity of deformation in the cross-section of the pipe after shaping operations. The roll forming process (TRB) has an advantage over the most common step forming process (JOE) in factories in terms of energy intensity and consistency of curvature of the main part of the perimeter. In the production of LDP by the roll forming method, the uneven deformation is localized in the area of transition from the flat area to the main perimeter. To reduce the unevenness of deformation, the rotation of the rolls at the beginning of the pass is carried out simultaneously with the movement of the upper roll. When implementing this technology, a method is required for calculating the amount of immersion at a given radius at the stage of moving the upper roll. The article presents the results of a numerical experiment to determine the curvature of the workpiece at the stage of moving the upper roll. Based on the results of the experiment, a regression model for the formation of curvature is built and an algorithm for calculating the displacement is presented. The resulting regression model, with sufficient accuracy, allows you to calculate the amount of immersion, which is confirmed by the results of finite element modeling. The results of the work can be useful for practical implementation and are used both for drawing up technological maps of molding, and for building finite element models.