MAGNETIC-PULSED TREATMENT TO IMPROVE THE STRENGTH PROPERTIES OF DEFECTIVE SECTIONS OF OIL AND GAS PIPELINES

Abstract

Link for citation: Schipachev A.M., Mohammed Aljadly. Magnetic-pulse treatment to improve the strength properties of defective sections of oil and gas pipelines. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 5, рр.7-16.In Rus. The relevance. During the operation of oil and gas pipelines, continuity defects (including point and linear defects such as delamination, cracks of various nature, etc.) occur in their structure. The peculiarity of material continuity defects is caused by the fact that in the process of loading the defects cause stress concentration near their tops, which leads to a rapid increase in their number and geometric dimensions, followed by the merging of the latter and the formation of large discontinuities, and as a consequence, the strength properties of pipelines decrease. Consequently, early detection of metal continuity defects and their elimination before they reach a critical size are urgent tasks. The solution of which will significantly improve the operational and strength properties of the working elements of pipelines and extend their lifespan. The main aim of the research is to study the effectiveness of magnetic-pulse treatment to improve the strength properties of used oil and gas pipelines by reducing the defects size. Objects: defective sections of main oil and gas pipelines. Methods: magnetic pulse treatment of samples on a magnetic-pulse unit MPU-10-SSAU 10, determination of temperature changes caused by magnetic-pulse treatment, testing samples for impact strength on a pendulum-testing machine, comparison of the obtained results for treated and untreated samples, determination of the effect of magnetic-pulse treatment on the strength properties of gas pipeline metal, study of the fracture surface of samples after impact tests. Results. It was established experimentally that the impact strength of the treated samples increased by 14 % compared to the untreated samples. Snapshots of the temperature distribution during the magnetic-pulse treatment showed a significant increase in temperature near the crack tips. It was found that destruction of the metal subjected to magnetic-pulse action acquired more viscous character.