Study of expander segment wear for calibrating large diameter pipes

In metallurgical industries, expensive tools are used, which often have complex geometries. The performance of such tools directly affects the economic performance of the production. One of these tools is the expander segment. This tool is used in the process of calibrating large diameter pipes obtained according to the JCOE, UOE, RB-forming schemes. The calibration process is the last stage of shaping, which consists of the gradual deformation of the pipe billet using segments that have a certain set of mechanical and geometric properties. At each stage, the segments give a rounded shape to the pipe, correcting straight sections, ovality and other geometric irregularities of the billet. The main load of the process falls on the expander segments. In this paper, we study the wear of segments in the process of calibration of large-diameter electric-welded pipes. To predict wear, CAE models of the calibration process were built in a specialized software package MSC-Software, with the help of which an analysis of possible wear, its magnitude, position and nature was carried out. A technique is proposed for assessing the wear of expander segments using 3D scanning, digitizing the data obtained and constructing a 3D map of deviations from the reference model. An analysis of finite element modeling and experimental studies showed that CAE models with high convergence predict zones and features of the wear distribution of expander segments. It is shown that modeling with a high degree of certainty can be used to assess the performance of tools, both new and already in operation. Based on the experimental data, an equation was obtained to determine the wear of the expander segments. According to the obtained equation, a nomogram was constructed, which makes it possible to predict the wear of the expander segments depending on the stresses that arise in the tool during calibration and the number of processed pipes. Evaluation and accounting for the wear of the working surface of the expander segments make it possible to predict deviations in the geometric parameters of pipes in the process of expanding.