Experiment and simulation on testing steel plate with corrosion defects via magnetic flux leakage method

The testing of corrosion defects of steel components in engineering is critical to ensure the service safety of structures in civil engineering. Although some research of the corrosion of steel components using magnetic flux leakage (MFL) testing has been carried out, the quantitative evaluation of corrosion parameters has not been achieved due to the lack of quantitative analysis on the relationship between corrosion parameters (action zone, corrosion amount) and the MFL signal. In this paper, the steel plate is taken as the specimens of nondestructive testing. The MFL testing technology was used to measure the change laws of the MFL signal and its characteristic with under different lengths of the action zone and corrosion amount. The finite element simulation of the corrosion testing shows a good correlation with the MFL testing experiment. Combined with finite element simulation and experimental data, a detailed process for quantitative evaluation of the corrosion length and corrosion amount is established based on the corrosion signal characteristic. Based on the analysis of the signal characteristics measured by the experiment, it is confirmed that the evaluation accuracy of the corrosion amount of the steel plate can be guaranteed to be about 1.0 g, which demonstrates the feasibility of quantitative evaluation of corrosion parameters based on the MFL signal.