Fractal characteristic of corroded steel surface and application to the fracture analyses

• Published in: Construction & building materials 2022-07, Vol.340, p.127759, Article 127759
• Main Authors: Songbo, Ren, Song, Gu, Chao, Kong, Shenghui, Zeng, Ying, Gu, Gang, Li, Tao, Yang, Liqiong, Yang
• Format: Article
• Language: English
• Subjects: Corroded steel; Critical corrosion pit; Fractal dimension; Fracture behaviors; Fracture toughness parameters; Morphological characteristics
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2022.127759

•Establishing a synthetic approach to show the corrosive effect on corroded steel.•Fractal character of the critical pit to analyze the performance degradation of corroded steel.•Proposing the influence of the oxide passivation layer on material property of corroded steel.•The changes of corroded morphology and material property to study the fracture behaviors of corroded steel. To analyze the effects of morphological characteristics on fracture behaviors of corroded steel, the morphology analysis, tensile test and corresponding finite element (FE) simulation were systematically performed to investigate the morphological evolution and the degradation of mechanical property of corroded steel. The results indicated that the size parameters (C and W) followed the Chi-square distribution, and the fractal character was obviously observed on corroded steel, especially for critical corrosion pit. The fractal dimension of critical corrosion pit (D*) was a key factor influencing the mechanical property and fracture behavior for corroded steel due to the advantage in systematacially reflecting the morphological characteristics, the agreement with the various mechanical parameters was obvious more than C or W of critical corrosion pit. Comparing the toughness parameters (α and η) among different corroded specimens, the effect of the oxide passivation layer on fracture toughness properties of corroded steel was revealed, and modified. Finally, the characterization of D* on fracture toughness parameters (α, η, effective plastic strain εpcritical and stress triaxiality T) of corroded steel was discussed