Experimental Study on Corrosion of Unstressed Steel Strand based on Metal Magnetic Memory

Aimed at the corrosion problem of the commonly used steel strand in the structure engineering, the Metal Magnetic Memory (MMM) was adopted as the non-destructive detection method in this paper. Firstly, based on the magnetic dipole model, the theoretical equations of the Self-Magnetic Flux Leakage (SMFL) for the trapezoidal corrosion section were derived, and the trend of the SMFL was depicted by the software of MATLAB. Then, the experiment of the corrosion detection for the unstressed steel strand based on the MMM was carried out. Ultimately, combined with the above theoretical model, the experimental data were analyzed. The results show that the corrosion of steel material can be relatively precisely calculated by the Faraday's first law of electrolysis. Via the horizontal scanning, the length of the corrosion region can be effectively obtained by the intersections of the x-Bx curves, and the theoretical model is verified. And via the vertical scanning, the inverse point x-z curve presents an inverted U-shape for the corroded steel strand and becomes a new means to determine the range of the corrosion areas. The findings have extensive prospects for the non-destructive detection in civil engineering.