Kushnarenko Vladimir Mikhaylovich, Doctor of engineering sciences, professor, sub-department of mechanics of materials, structures and machines, Orenburg State University (13 Pobedy avenue, Orenburg, Russia), E-mail: firstname.lastname@example.org
Repyakh Vitaliy Sergeevich, Candidate of engineering sciences, associate professor, sub-department of materials science and materials technology, Orenburg State University (13 Pobedy avenue, Orenburg, Russia), E-mail: email@example.com
Tavtilov Il'fat Shaydullovich, Candidate of engineering sciences, associate professor, sub-department of materials science and materials technology, Orenburg State University (13 Pobedy avenue, Orenburg, Russia), E-mail: firstname.lastname@example.org
Reshetov Sergey Yur'evich, Candidate of engineering sciences, associate professor, sub-department of mechanics of materials, structures and machines, Orenburg State University (13 Pobedy avenue, Orenburg, Russia), E-mail: email@example.com
Background. The object of research is the clutch of pump-compressor pipes (tubing). The subject of the study is metallographic studies of the areas of crack origin in the metal of clutches. The purpose of this work is to determine the causes of damages of pump-compressor pipe clutch during operation.
Materials and methods. Investigation of the crack formation causes because of the impact on the tubing clutches of a corrosive environment and mechanical damage that occurred during operation, as well as analysis of fractographic and metallographic destruction methods.
Results. Considered the destruction of the clutches of the tubing when exposed gray-and-hydrogen-containing environment, correlation of microcracks with mechanical damages of the clutch and formation of dents-scratches from installation Toolkit when a certain torque is required for the formation of a sealed threaded connection.
Conclusions. Comparison of the considered fractures allowed us to conclude that the main causes of failure of tubing couplings are stress concentrators - dents-risks on the outer surfaces of the couplings. The impact of unregulated assembly stresses and a hydrogen sulfide-containing working medium on the area of the dents-marks of the coupling leads to the appearance of microcracks of hydrogen cracking under conditions of a complex stress state.
damage, corrosion medium, stress, clutch, tubing, chemical composition, metallographic examination, metal microstructure, tension, impact bending, hardness
1. Kushnarenko V. M., Repyakh V. S., Chirkov E. Yu., Kushnarenko E. V. Defekty i povrezhdeniya detaley i konstruktsiy [Defects and damage to parts and structures]. Orenburg: OGU. OOO «Russervis», 2012, 531 p. ISBN 978-5-904627-16-4. [In Russian]
2. GOST 633-80. Truby nasosno-kompressornye i mufty k nim. Tekhnicheskie usloviya. Vved. 01.01.1983. Vzamen GOST 633-63 [Tubing pipes and couplings for them. Technical conditions. Introduction 01.01.1983. Instead of State Standart 633-63]. Moscow: Standartinform, 2010, 107 p. [In Russian]
3. GOST R 54918-2012 (ISO/TR 10400:2007). Truby obsadnye, nasosno-kompressornye, buril'nye i truby dlya truboprovodov neftyanoy i gazovoy promyshlennosti. Formuly i raschet svoystv. Vved. 01.10.2013 [Casing pipes, pump-compressor-not, drill pipes and pipes for pipelines of the oil and gas industry. Formulas and calculation of properties. Introduction 01.10.2013]. Moscow: Standartinform, 2014, 252 p. [In Russian]
4. ANSI/NACE MR0175/ISO15156-3:2015. Petroleum and natural gas industries — Materials for use in H2S-containing environments in oil and gas production — Part 3: Cracking-resistant CRAs (corrosion-resistant alloys) and other alloys. Mezhdunarodnyy standart ANSI/NACE MR0175/ISO15156-3:2015. 91 р.