Study of the effect of the piercing mill plug shape on the axial force and its wear

Most modern pipe-rolling units for producing pipes use the method of screw piercing of billets to obtain pipe shells, which has become widespread due to the high speed of the rolling process, as well as the possibility of obtaining shells with the required surface quality and dimensional accuracy. Improving the screw rolling process is an urgent task. The article presents the results of a study of the screw piercing process of 30KhGSA steel billets using the QForm program. The axial force acting on plugs with and without a nose during piercing of shells of the same size was investigated. The wear of the specified types of plugs under the action of normal and tangential stresses was studied. The distribution of temperature fields on the surface of plugs at the final stage of the piercing process is also considered. It was found that during the piercing process, a smaller axial force acts on the plug without the nose than on the plug with one. It was also found that the plug with the nose is subject to greater wear than the plugs without one.The work was carried out at the Ural Federal University named after the first President of Russia B. N. Yeltsin under the agreement with the Ministry of Science and Higher Education No. 075-03-2023-006 dated 01/16/2023 (topic number FEUZ-2023-0015).