Local corrosion morphology analysis and simplification of low carbon steel plates

This paper focuses on the surface morphology of low carbon steel plates with local corrosion. Copper-accelerated acetic acid salt spray tests were carried out on 24 steel plate specimens with different corrosion parameters, and then the 3D morphology of the steel plate surfaces after corrosion was observed, extracted and analyzed. Ac-cording to the statistical analysis of the surface depth of the corrosion morphology, the local corrosion surface can be divided into the central flat corroded zone and edge corroded zone, and the width of the edge corroded zone almost keeps constant regardless of the corrosion area. The 3D morphology of the corroded specimens was imported into ABAQUS software to develop finite element models, and the numerical results were compared with the tensile test results of the corroded steel plates, showing good agreement. Finally, based on the finite element analysis, it is suggested that local corrosion of steel plates can be simplified into a region with uniform depth, whose depth is determined as the average corrosion depth of the locally corroded region. The maximum errors of prediction results of yield strength, ultimate strength and ultimate strain between the simplified model and the actual morphology model were 0.03%, 1.8% and 20%, respectively.