Tensile Load Characterization of Two‐Point Corroded Steel Wires Via Metal Magnetic Memory Detection

ABSTRACT The detection of corrosion defects and evaluation of stress are important for ensuring the service safety of cable systems in bridge engineering. Although the metal magnetic memory (MMM) technique has been applied to study corrosion problems in metallic materials, most studies have focused on the magnetic signal characteristics of single corrosion defects, whereas studies on adjacent two‐point corrosion defects remain limited. In this study, 1670 MPa high‐strength steel wires were selected as the test specimens. Electrochemically accelerated corrosion tests were conducted to prepare two‐point corrosion specimens with varying defect spacings and severities, followed by MMM signal analysis and verification of the corrosion method's accuracy. A three‐dimensional magnetic charge (MC) model for two‐point corrosion defects was established based on MC theory, providing an explanation for the experimentally observed signal features. A tensile load characterization method combining magnetic feature parameters and Lissajous diagram analysis was developed, with R 2 exceeding 0.9 for all specimens, demonstrating the potential of this method for load evaluation of two‐point corroded steel wires.