Defect feature extraction and recognition of buried pipeline based on metal magnetic memory

The surfaces of metal pipelines are always susceptible to various types of defects and damages, including corrosion defects and early stress concentration defects. Metal magnetic memory detection technology is the only non-destructive testing technology that can diagnose the early damage of ferromagnetic components. However, the metal magnetic memory original signal itself cannot directly recognise and distinguish corrosion defects and stress concentration defects. To solve this problem, this paper establishes a multi-characteristic statistical recognition method for the two defect types based on the metal magnetic memory technology and the magnetic memory test data obtained from pipeline test pieces. Next, this method is used to identify the defect types of four pipelines in the oil field environment; the results demonstrate that the established defect type recognition method is effective for the identification of pipeline corrosion defects and early stress concentration defects.