Research on Corrosion Detection Test of Load-bearing Steel Strand Based on Metal Magnetic Memory

At present, the method of micro-damage detection, based on the metal magnetic memory self-leakage effect,is widely used. However, in the process of detecting the corrosion of steel strand, the influence of load on test results is unclear, which cannot be ignored due to the stress-magnetization coupling effect. To solve this problem, the steel strand after electrochemical corrosion was tensioned. And after considering the effect of load, the magnetic memory test of steel strand was carried out. The experimental results show that, at the center of the corrosion area, the tangential magnetic flux leakage component (Bx ) of the specimens reaches the maximum, and the normal magnetic flux leakage component (Bz ) is zero. On either side of the corrosion area, the Bx distributes asymmetrically, and the Bz reaches its extreme points. With the corrosion degree increasing, the characteristic indicators of the magnetic flux leakage signal (ΔBx max and | ΔBx min |) increased nonlinearly. With the corrosion load increasing, ΔBx max and | ΔBx min | increases first and then decreased. The normalized ‘peak and valley’ MB increases with the increase of the corrosion rate C. The correlation between MB and C is verified by third-order polynomial fit. MB wasn't sensitive to stress, and thus the detection accuracy can be improved by using the proposed characteristic indicator. © 2022 Cailiao Daobaoshe/ Materials Review. All rights reserved.