Research on Non-Destructive Testing Technology for Small Defects in Oil and Gas Pipelines Based on Magneto-Electric Composite Field

Pipeline transportation serves as a critical lifeline for modern industry and national economies, with its safety being of paramount importance. However, circumferential weld seam defects are among the primary factors compromising pipeline safety. Traditional non-destructive testing (NDT) methods, such as Magnetic Flux Leakage (MFL) and Eddy Current (EC) testing, are widely used but exhibit limitations in detecting small defects and providing quantitative results.To address these challenges, this study innovatively proposes a magneto-electric composite detection method that integrates MFL and EC testing. By applying an external magnetic field, the depth of eddy current detection is enhanced, enabling precise identification of internal wall defects and buried flaws within pipelines. A simulation model for magnetic-eddy defect detection was developed using ANSYS MAXWELL software, and simulations were conducted to analyze magnetization levels and defects, including pinholes and cracks of varying sizes. The results demonstrate that the magneto-electric composite detection method significantly improves the accuracy of small defect detection, capable of identifying pinholes with diameters as small as 3 mm and cracks with openings as narrow as 0.1 mm. This advancement provides robust support for the safe operation of oil and gas pipelines.