Simulation of the operation of two-roll screw piercing of steels of the 13Cr type

Abstract

The development of new offshore oil and gas fields is impossible when using pipes made of carbon and low-alloy steel grades, due to their inability to effectively withstand an aggressive environment. Therefore, the urgent task of pipe manufacturers is to develop and master the technology of mass production of seamless pipes from martensitic steels with a high chromium content. This article discusses the peculiarities of the technology for the production of seamless pipes from steel grades of the 13Cr type when piercing a billet on a two-roll screw rolling mill with a non-driven guide tool - a ruler. The results of physical modeling at the MISIS laboratory screw rolling mill are presented. To identify the features of the piercing during physical modeling, the elongation coefficient was changed (due to the use of piercing mill mandrels of different diameters and due to a change in the thickness of the sleeve wall), the feed angle was varied, and the workpieces were pierced at different temperatures. In addition, for a comparative analysis, steel 45 was pierced. During the research, the machine time of the piercing and the force on the roll of the piercing mill were recorded. Underrolls were obtained, on which the pitch of the sleeve was measured, and the area of the contact surface of the pierced metal with the rolls was also determined. The energypower parameters of the piercing were evaluated at various settings of the piercing semi-industrial mill "MISiS -130D". To compare the obtained force values, the piercing process was simulated in the QForm software package. As the material of the billet workpiece, the material C.20Сr13 was chosen with deformation resistance characteristics obtained from the results of testing samples on the Gleeble System 3800.