The assessment of the individual resource of the welded joint during repairs of the technological pipeline

• Published in: IOP conference series. Materials Science and Engineering 2020-01, Vol.734 (1), p.12215, Article 012215
• Main Authors: Naumkin, E A, Rubtsov, A V, Kulakov, P A, Berdin, A R
• Format: Article
• Language: English
• Subjects: Automatic welding; Edge joints; Fragments; Magnetic signals; Mechanical properties; Nondestructive testing; Pipelines; Tensile tests; Ultrasonic testing; Welded joints; Welding
• ISSN: 1757-8981; 1757-899X; 1757-899X
• DOI: 10.1088/1757-899X/734/1/012215

The relevance of research is due to the necessity to develop recommendations for assessing the "individual" resource of welded joints of technological pipelines using non-destructive testing methods for the timely detection of welds with the smallest resource to ensure reliable operation of equipment and the inadmissibility of premature failure in the weld zone. The task is to develop recommendations for determining "individual"resource of welded joints of technological pipelines with a different level of edge displacement and imperfection by introducing correction factors into the modified Coffin-Manson equation based on the mechanical characteristics of the yield strength and strength, determined as a result of static tensile testing of samples of various sections of welded joints with maximum acoustic and magnetic signals according to the results of flux-probe and ultrasonic non-destructive testing. For research, 6 pipe fragments were selected made of steel 20 with dimensions of 159×7 mm and a length of 45 mm each. Fragments were welded together by different types of welding with different displacements of the edges of the welded elements. The authors developed recommendations for assessing the "individual" resource of welded joints of technological pipelines. It is shown that the introduction of correction factors depending on the amount of offset of the edges of the welded joint allows to increase the accuracy of the predicted durability of individual welds by 4% for manual and 11% for semi-automatic welding, respectively.