THE INFLUENCE OF THERMAL CYCLIC TREATMENT ON THE SERVICE DURABILITY OF WELDED ELEMENTS WITH SOFT INTERLAYER


Cite item

Full Text

Abstract

The authors studied the influence of structural and mechanical heterogeneity of welded joints on bearing capacity characteristics of high-strength steels of K52 (09G2S and 17G1SU brands), K56 (09G2FB), K66 (10HSND) and K70 (10G2FBYU) grades. The authors identified the topography of mechanical heterogeneity of welded elements having soft interlayers in the welded seam area and (or) the near-weld area, the range of thickness ratio of which varies from 0.6 to 0.8. It is proved that the soft interlayers in the welded joints cause the reduction of strength index up to 30%, and the specific fracture work up to 50%. The influence of mechanical heterogeneity on the resistance to breakage in the result of reaction of aggressive corrosive petroleum products was estimated on the example of environmentat tests of welded elements of connection units. The study showed the corrosion velocity increase and the substantial reduction of plasticity index for the soft interlayer metal (near-weld area) in comparison with the base metal during the whole lifetime.

The significant decline of parameters of fracture toughness during the operating time, which is especially intensively manifested during the first three years of operation, was revealed. The authors estimated the influence of thermal cyclic treatment on the mechanical heterogeneity and the indicators of fracture resistance of welded elements. The quantitative assessment of the influence of thermal treatment on the survivability of welded structure elements as the ability to resist destruction in the presence of damages was fulfilled. The analysis of test results for static and cyclic crack resistance allowed to determine the limiting size of damages and residual life of welded elements, as well as to analyze their changes after the thermal treatment. The transformation of the strain-stress state nature during the thermal cyclic treatment is shown.

About the authors

Lyudmila Sergeevna Dinmukhametova

Orsk Branch of Samara State University of Railroads, Orsk

Author for correspondence.
Email: info@orsksamgups.ru

candidate of technical sciences, head of the laboratories

Russian Federation

Ekaterina Vasilievna Poyarkova

Orenburg State University, Orenburg

Email: sopromosu@rambler.ru

candidate of technical sciences, Associate Professor, assistant professor of the department «Mechanical Engineering»

Russian Federation

References

  1. Vinokurov V.A., Kurkin S.A., Nikolaev G.A. Svarnie konstruktsii. Mekhanika razrusheniya i kriterii rabotosposobnosti [Welded structures. Fracture mechanics and performance standards]. Moscow, Mashinostroenie publ., 1996, 576 p.
  2. Makhutov N.A., Mitrofanov N.V., Barishov S.N. Evaluation of the resistance to breakage and life extension of safe operation of equipment used in Н2S-bearing environment. Materiali V mezhdunar. nauch. konf. “Prochnost i razrushenie materialov i konstruktsiy”. Orenburg, 2008, vol. 2, pp. 5–21.
  3. Shakhmatov M.V., Shakhmatov D.M. Prochnost mekhanicheski neodnorodnikh svarnikh soedineniy [Strength of mechanically heterogeneous welded joints]. Chelyabinsk, Svarka i Kontrol publ., 2009, 223 p.
  4. Serensen S.V., Kogaev V.P., Shneyderovich N.M. Nesushchaya sposobnost i raschet detaley mashin na prochnost [Bearing capacity and calculation of machine parts for strength]. Moscow, Mashinostroenie publ., 1975, 488 p.
  5. Dinmukhametova L.S., Poyarkova E.V. Influence of mechanical heterogeneity on limiting bearing ability of welded connections from steels of the raised durability. Nauchno-tekhnichesky vestnik Povolzhya, 2011, no. 6, pp. 160–163.
  6. Shakhmatov D.M., Shakhmatov M.V., Usmanova E.A. Aspects of determining the strength of mechanically heterogeneous welded joints basing on the results of testing of cut samples. Svarka i diagnostika, 2012, no. 2, pp. 9–12.
  7. GOST 6996–66. Welded joints. Methods of determining of mechanical properties. Moscow, Standartinform publ., 2007, 66 p. (In Russian).
  8. GOST 14771–76. Arc welding in shielding gas. Welded joints. Basic types, structural elements and dimensions. Moscow, Standartinform publ., 2007, 37 p.
  9. GOST 25506–85. Calculations and strength tests. Moscow, Standartinform publ., 1986, 66 p.
  10. Fedyukin V.K., Smagorinsky M.E. Termotsiklicheskaya obrabotka metallov i detaley mashin [Thermal cyclic treatment of metals and machine parts]. Leningrad, Mashinostroenie publ., 1989, 255 p.
  11. Kuzeev I.R., Poyarkova E.V., Dinmukhametova L.S. The evolution of gradient of structural and mechanical conditions of welded connections under thermocyclic influence. Elektronniy nauchniy zhurnal Neftegazovoe delo, 2011, no. 1, pp. 254–267.
  12. Makhutov N.A. Konstruktsionnaya prochnost, resurs i tekhnogennaya bezopastoct. Ch. 2. Obosnovanie resursa i bezopasnosti [Structural strength, resource and technogenic safety. Part 2. Resource and safety argumentation]. Novosibirsk, Nauka publ., 2005, 610 p.
  13. Makhutov N.A. Konstruktsionnaya prochnost, resurs i tekhnogennaya bezopastoct. Ch. 1. Kriterii prochnosti i resursa [Structural strength, resource and technogenic safety. Part 1. Strength and safety criteria]. Novosibirsk, Nauka publ., 2005, 493 p.
  14. Dinmukhametova L.S., Poyarkova E.V. The application of magnetic methods at the quality control of welded designs made from increased durability steel. Elektronniy nauchniy zhurnal Neftegazovoe delo, 2012, no. 4, pp. 352–360.
  15. Morozov E.M., Nikishkov G.P. Metod konechnikh elementov v mekhanike razrusheniya [Finite elements method in fracture mechanics]. Moscow, Nauka publ., 1980, 354 p.
  16. Ponomarenko D.V., Syukasev G.M. Mekhanizm vozniknoveniya svarochnikh napryazheniy i deformatsiy [Mechanism of origination of welding stresses and deformations]. Moscow, UGTU-UPI publ., 2010, 46 p.
  17. Dinmukhametova L.S., Poyarkova E.V. The application of magnetic methods at the quality control of welded designs made from increased durability steel. Elektronniy nauchniy zhurnal Neftegazovoe delo, 2012, no. 4, pp. 361–369.
  18. Metodicheskie ukazaniya po provedeniyu analiza riska opasnikh proizvodstvennikh obyektov [Technical tips for analysis of risk of hazardous industrial facilities]. RD 03-418-01. Moscow, Prombezopasnost publ., 2001, 35 p.
  19. Steklov O.I. Welded structures resource monitoring and forecast with account of their deterioration and corrosion. Svarochnoe proizvodstvo, 1997, no. 1, pp. 16–22.
  20. Kuzeev I.R., Dinmukhametova L.S., Poyarkova E.V. Forecasting the operation safety of welded designs in the conditions of oilcontaining environments. Elektronniy nauchniy zhurnal Neftegazovoe delo, 2011, no. 6, pp. 254–262.
  21. Metodika otsenki potentsialnoy opasnosti i ostatochnogo resursa truboprovodov, imeyushchikh korrozionnie porazheniya i nesploshnosti v svarnikh shvakh i osnovnom metalle, viyavlennie pri vnutritrubnoy defektoskopii [Methods of evaluation of potential hazard and remaining lifetime of pipes having corrosion damages and discontinuity flaws in weld seams and basis metal discovered by smart pigging]. STO 0-13-28-2006. Moscow, VNIIneftemash publ., 2006, 65 p.
  22. Kurkin S.A., Lavryakov Yu.Yu. Evaluation of working capacity of butt welded joints in case of part-through flaws. Zavodskaya laboratoriya, 1981, no. 4, pp. 66–70.

Supplementary files

Supplementary Files
Action
1. JATS XML
Download

Copyright (c)



This website uses cookies

You consent to our cookies if you continue to use our website.

About Cookies