All-Russian Scientific and Research Institute of Tube Industry — RosNITI (Chelyabinsk, Russia):

A. V. Vydrin, Dr. Eng., Prof., Deputy General Director on Scientific Work, e-mail: vydrinav@rosniti.ru
E. A. Shkuratov, Cand. Eng., Deputy Head of the Laboratory of Longitudinal Rolling, e-mail: shkuratov@rosniti.ru

The features of metal biting capacity for rolls in the finishing three-roll stands of continuous elongating mills are considered. Mathematical description of the angles during primary and secondary metal biting is realized taking into account the features of forming of tube wall and cross section in the finishing passes. It is shown that friction coefficient of the contact between tube internal surface and a mandrel should be decreased maximally to provide stable filling of interstand space. It is established that reduction procedure has substantial effect on the conditions of metal filling of the continuous elongating mill, and the more is the pass out-of-roundness, the larger reduction can be preset. Metal filling of the continuous elongating mill depends also on friction conditions between tube and rolls, and increase of the friction coefficient provides more easy filling of interstand spaces. The new mathematical models of metal biting are developed; they allow to optimize the rolling technology and the modern continuous elongating mills.

1. Starchenko D. I. Longitudinal rolling kinematics. Kiev: Uchebnometodichesky kabinet vysshego obrazovaniya (UMK VO), 1992. 276 p.
2. Druyan V. M., Gulyaev Yu. G., Chukmasov S. A. Theory and technology of tube production: tutorial. Dnepropetrovsk: «Dnepr-VAL», 2001. 544 p.
3. Grudev A. P. Catching capabilities of mill rolls. Moscow: «SP Inzhiniring», 1998. 283 p.
4. Potapov I. N., Kolikov A. P., Druyan V. M. Theory of tube production: tutorial for institutes for higher education. Moscow: Metallurgiya, 1991. 424 p.
5. Kirichenko A. N., Slavin V. B., Bisk M. B. et al. Methods to improve catching conditions during longitudinal plug rolling of tubes. Collection «Longitudinal rolling of tubes». 1980. pp. 93–94.
6. Polyakov M. G., Nikiforov B. A., Gun G. S. Metal deformation in multiple-roll grooves. Moscow: Metallurgiya, 1979. 240 p.
7. Vydrin A. V., Struin D. O., Chernykh I. N., Shkuratov E. A., Bunyashin M. V. Theoretical and practical issues of the process for rough tubes rolling-off at the state-of-the-art continuous rolling mill. St. Petersburg: Izdatelstvo SPb PU, 2015. pp. 72–82.
8. Vydrin A. V., Chernykh I. N., Struin D. O., Shkuratov E. A., Khramov E. V. Comparative analysis of the tubes longitudinal plug rolling process using grooves formed by different quantity of rolls. “Tubes–2014” Conference Proceedings, Part. 2. pp. 143–150.
9. Yue Sh., Liu Y., Guo H. Design and Development of ø382 mm Pass of PQF Mill. Steel Pipe. 2009. Vol. 38, No. 3. pp. 46–49.
10. Shkuratov E. A., Vydrin A. V. Improvement of the technology for hollow shell longitudinal rolling in continuous rolling mills. Chernye metally. 2017. No. 3. pp. 42–46.
11. Chen B. Development and Comparative Analysis of 3-roll Mandrel Pipe Mills. Steel Pipe. 2010 (6). Vol. 39, No. 3. pp. 60–62.
12. Zhong X. PQF & FQM three-roll mandrel mill. Steel Pipe. 2009(5). pp. 13–20.
13. Savkin I. P. Study of metal deformation and forces during tubes rolling in the continuous plug mill: thesis of inauguration of Dissertation … of Candidate of Engineering Sciences. Dnepropetrovsk, 1966. 25 p.
14. Struin D. O., Chernykh I. N., Korol A. V., Sherkunov V. G., Zinchenko A. V., Verkhoglyad S. B., Kutepov V. A. Tubes accuracy monitoring along the tube production line with PQF mill. “Tubes–2012” Conference Proceedings, Part. 2. 2012. pp. 9–10.
15. Shkuratov E. A., Strunin D. O., Chernykh I. N. et. al. Study of the effect of the finishing gage out-of-roundness value of the 3-roll continuous plug FQM mill on rough tube forming. Vestnik YuUrGU. Seriya Metallurgiya. 2015. Vol. 15. No. 3. pp. 139–147.
16. Shkuratov E. A. Optimization of the rough tube continuous rollingoff process to improve hot-rolled seamless tube accuracy: Dissertation … of Candidate of Engineering Sciences. Chelyabinsk, 2017. 166 p.
17. Tselikov A. I., Nikitin G. S., Rokotyan S. E. Theory of longitudinal rolling: tutorial. Moscow: Metallurgiya, 1980. 320 p.
18. Grudev A. P. Theory of rolling: tutorial for institutes for higher education. Moscow: Metallurgiya, 1988. 240 p.
19. Nikitin G. S. Theory of longitudinal rolling: tutorial. Moscow: Izdatelstvo MGTU im. N. E. Baumana, 2009. 399 p.