ArticleName |
Investigation of forming of end parts in pipe tension reduction using QForm program |

ArticleAuthorData |
South Ural State University, Chelyabinsk, Russia:
**D. A. Akhmerov**, Postgraduate Student, Junior Researcher of the Laboratory for Modeling Technological Processes, e-mail: **AkhmerovDA@rosniti.ru**
**D. Yu. Zvonarev**, Cand. Eng., Head of the Laboratory for Modeling Technological Processes, e-mail: **ZvonarevDY@tmk-group.com**
Russian Scientific and Research Institute of Tube Industry – RusNITI JSC, Chelyabinsk, Russia:
**A. V. Vydrin**, Dr. Eng., Prof., Chief Researcher, e-mail: **VydrinAV@rosniti.ru**
LLC “Scientific and Technical Center TMK” (LLC “TMK STC”), Moscow, Russia:
**E. V. Khramkov**, Cand. Eng., Deputy Head of Digital Technologies Dept., e-mail: **KhramkovEV@tmk-group.com** |

Abstract |
The paper deals with issues of longitudinal stresses during pipe rolling pipes on a three-roll stretching and reduction mill. Opportunities and problems in pipe reduction under tension are described. A research program aimed on reduction and evaluation of all input parameters that affect the parameters of the end parts of pipes based has been developed on the finite element model (FEM) base. Computer study on the FEM basis of stretching and reduction rolling of pipes using the Qform-3D program was carried out. When setting up the experiment using the FEM, the relative variation of the pipe wall thickness at the end parts of the pipe was chosen as the parameter for examination. Reduction of the pipe in its diameter in the pass, ovality of the pipe, geometric parameters of the initial pipe, front and rear tension of the pipe and friction coefficient were the main factors that determine the studying values. Geometric parameters of the end parts of the simulated pipe were measured after modeling. A statistical analysis of the results of a computational experiment of data on variation of pipe wall thickness was carried out. Regression dependence was built using the MATLAB program, and the most significant factors were selected according to the level of their importance. The model that describes the behavior of wall thickness during rolling in a stand of a stretching and reduction mill has been constructed. |

References |
1. Chumakov L. A. Dynamics of reduction mills: Electronic educational text resource. Ekaterinburg. 2019. 68 p. 2. Vydrin A. V., Akhmerov D. A., Khramkov E. V. Simulation mathematical model of the pipe reduction process. *Chernye metally*. 2021. No. 10. pp. 56-60. 3. Bobarikin Yu. L., Radkin Ya. I., Martyanov Yu. V., Strelchenko A. V. Effect of speed parameters of reduction on the resulting pipe profile accuracy. *Chernye metally*. 2021. No. 11. pp. 35-39. 4. Bayoumi L. S. Analysis of flow and stresses in a tube stretchreducing hot rolling schedule. *International journal of mechanical sciences*. 2003. Vol. 45. No. 3. pp. 553-565. 5. Yu H., Li J. H., Guo H. CEC Control Model for Wall Thickness Thickening of Tube Ends and Simulation. *Advanced Materials Research*. 2011. Vol. 317. pp. 2509-2514. 6. RE S. et al. Numerical design of a hot-stretch-reducing process for welded tubes. *Materiali in tehnologije*. 2010. Vol. 44. No. 5. pp. 243-250. 7. Akhmerov D. A., Vydrin A. V. Study of the process of formation of tubes end sections during longitudinal rolling in grooves formed by a different number of rolls. *Chernye metally*. 2021. No. 1. pp. 44-49. 8. Burkin S. P., Shimov V. V., Iskhakov R. V. et al. Improvement of equipment and technology for multi-pass rolling: a manual. Ekaterinburg : UGTU-UPI. 2010. 362 p. 9. Orlov G. A., Orlov A. G. Pipe quality evaluation using the Harrington’s desirability function. *Chernye metally*. 2022. No. 3. pp. 45-48. 10. Anisiforov V. P., Zeldovich L. S., Kurganov V. D., Shpigelman R. M., Ivobotenko V. A. Reduction mills. Moscow : Metallurgiya. 1971. 256 p. 11. Gulyaev G. I., Ivshin P. N., Erokhin I. N., Zimin A. K., Rukobratskiy V. P. Technology of plugless pipe rolling. Moscow : Metallurgiya. 1975. pp. 55-70. 12. Eriklintsev V. V., Blinov Yu. I., Fridman D. S., Grabarnik L. M. Theory of pipe reduction. Sverdlovsk : Sredne-Uralskoe knizhnoe izdatelstvo. 1970. 230 p. 13. Box G. E., Behnken D. W. Some new three level designs for the study of quantitative variables. Technometrics. 1960. pp. 455–475. 14. Zvonarev D. Yu., Osadchiy V. Ya., Romantsov A. I., Kolikov A. P. Mathematical modeling of sheet billet forming for largediameter welded pipes. *Stal*. 2016. No. 6. pp. 45-48. 15. Zvonarev D. Yu. Program for calculation of pipe geometrical parameters during modeling in the QForm medium. *Certificate about the state registration of a computer program*. 2020. No. 2020662611. 16. Kadyrova G. R. Modification of the method for step-by-step regression for obtaining mathematical models of an object behaviour prediction. *Avtomatizatsiya protsessov upravleniya*. 2016. No. 3. pp. 65-70. |