Особливості процесу експандування в технологіях виробництва труб великого діаметра для магістральних нафто- та газопроводів

• Date: 2023
• Main Authors: Проців, Володимир, Григоренко, Володимир
• Format: Article
• Language: Ukrainian
• Published: Physico-technological Institute of Metals and Alloys 2023
• Subjects: магістральні трубопроводи; труби великого діаметра; формування; зварювання; експандування; залишкові напруження; технологічне обладнання; нормативна документація; надійність; пружна і пластична деформація; збільшення діаметра труби
• Online Access: https://www.metalsandcasting.com/index.php/mcu/article/view/78
• Journal Title: Metal and Casting of Ukraine

Pipeline transport systems are dangerous man-made objects. This determines the high level of requirements for pipes for construction and repair of pipelines. Ensuring such a high level of technical requirements may be possible in productions with a full technological cycle and on specialized equipment. After forming the pipes from the sheet and welding the side ends of the sheet residual stresses that reduce the reliability of the pipelines accumulate in the metal. To ensure the regulated geometrical parameters of pipes and the complex of mechanical properties of metal pipes at modern specialized pipe enterprises around the world, a calibration-expansion operation is performed on hydromechanical expanders. Expanders are designed to calibrate pipes by outer diameter and fatigue number at the ends of the pipe, to reduce the curvature of the finished pipes, leveling the final stresses in the main metal of the pipe, additional testing of weld quality, preliminary short-term testing of base metal at tangential stresses above the flow limits. Characteristic features and purposes of using the expansion process are as follows: application, if the pipe is not subject to further normalization, hardening and tempering or further heat treatment; execution only on pipes, where there is a continuous technological weld; increase in the outer diameter of the pipe by 0.3–1.5 percent within the limits set in the regulatory documentation; stepwise increase in the diameter of the pipe along the entire length of the pipe; the location of the weld in the recess of the segment of the expander so that it is not affected by radially directed forces applied to the base metal of the pipe; the ability to process the formed pipes with a weld with a wall thickness of up to 50 mm; execution of the expansion process for each pipe; use in the production of main pipes for the transportation of gas and oil.