Comprehensive study of the process of pipe end calibration using QFORM

Currently, every year there is a significant increase in requirements for the accuracy of geometric parameters of pipes. One of the important indicators is the ovality of the pipe ends, to ensure which TPP-3 of VTZ JSC has calibration equipment. One of the most difficult specifications to fulfill are the specifications for main pipes made of carbon steel. The specified specifications spell out the most important requirements for the internal diameter, ovality of pipe ends, local ovality, and wall thickness. These pipes with tightening to the inner oval are quite in demand in the Middle East and North Africa, however, due to the inability to meet the customer’s requirements, we had to refuse a large number of orders. Therefore, this article discusses the operating conditions for calibrating pipe ends using external and internal forming. The main problems were identified in which it was not possible to achieve the required parameters (increased ovality at the ends of the pipes). Using the Q-Form 2D/3D software product, computer simulation was carried out varying the calibration process with different tool calibrations. From the obtained modeling results, parameters were identified, by the value of which one can judge the tendency of the tool to destruction and sticking to the metal: forces acting on the working surface of the rings during the calibration process; contact patch area (tool wear). Based on the results, a new ring calibration has been developed for both external and internal calibration. Practical tests were carried out on rings with different calibrations, namely different angles of the inlet/outlet cones.