Analysis of the influence of setting parameters washing machine on the change of case wall diameter and thickness

In the production of seamless pipes, a mass method is the use of billet piercing at helical rolling mills with the first rolling at longitudinal rolling mills. At the same time, increased requirements are imposed on the quality and geometric parameters of finished pipes. Geometric parameters include such as wall thickness, diameter, thickness variation. In this case, the difference in thickness mainly affects the quality of the liner. It is known that the same geometric parameters of the sleeve (diameter and wall thickness) can be obtained at different distances between the rolls, the distance between the holding tool, the extension of the mandrel beyond the clamping. However, in this case, the difference in thickness of the liners will be different. In addition to the tuning parameters, the degree of tool wear, in particular, the mandrel of the piercing mill, also affects the thickness difference. It was found that as the mandrel of the piercing mill wears out, the diameter of the liner monotonically increases, which leads to a redistribution of the liner wall, and, accordingly, the difference in liner thickness. This work is devoted to the search for rational tuning parameters in order to minimize the thickness difference. An experimental plan was developed using modeling in the QForm environment. The obtained sleeves were processed according to the geometric parameters. Based on the data, the mean square error coefficient (RSME) was calculated for various models of regression equations. For the selected model, nomograms of the distribution of thickness variation, wall thickness, and sleeve diameter were constructed depending on the tuning parameters. These nomograms can be used in industrial practice for the operational calculation of geometric parameters when the conditions for piercing workpieces change. As a project, recommendations were developed for obtaining liners with a wall thickness of 17 mm with a minimum thickness difference