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Abstract Due to their superior water-repelling effects, superhydrophobic surfaces have received increasing attention as a promising solution to corrosion of metallic materials. The present article introduces the fundamental theories behind [...]

The corrosion of X70 pipeline steel under a model disbonded coating was studied in a simulated solution of Korla soil by combining in situ electrochemical measurements at different locations in the crevice and stress corrosion cracking (SCC) sensitivity analyses in the corresponding simulated environments. The results from electrochemical impedance spectroscopy showed that the corrosion product resistance R and charge transfer resistance R of X70 steel first increased and then decreased with increasing distance from the opening of the crevice in the disbonded coating. Scanning electron micrographs showed that pitting in the crevice became more severe at deeper locations in the crevice. Slow strain rate tests showed that the lowest SCC sensitivity of X70 steel was found at 15 cm away from the opening, and the highest SCC sensitivity was at the end of the crevice. [ABSTRACT FROM AUTHOR]

Using soft lithography, a superhydrophobic epoxy coating was prepared with lotus leaf-like surface microstructures. Electrochemical measurements were performed to compare barrier properties of the superhydrophobic coating with a regular smooth coating during immersion, wet–dry cyclic immersion and salt spray tests. The results demonstrated that the superhydrophobic coating can act as a much stronger barrier than can the regular coating when immersed because of trapped air films in the surface microstructures. However, the ultrafine electrolyte particles in the salt spray can easily penetrate these microstructures and deposit on the coating surface, which leads to the faster deterioration of the superhydrophobic coating. [ABSTRACT FROM AUTHOR]

This study employs potential-monitoring techniques, cyclic voltammetry tests, alternating current (AC) voltammetry methods, and surface characterization to investigate the AC corrosion of cathodically protected X80 pipeline steel. In a non-passive neutral solution at pH 7.2, a sufficiently negative potential completely protects steel at an AC current density of 100 A/m². In an alkaline solution at pH 9.6, more serious AC corrosion occurs at more negative cathodic protection (CP) potential, whereas without CP the steel suffers negligible corrosion. In addition, the interface capacitance increases with AC amplitude. Based on these results, the AC corrosion mechanisms that function under various conditions are analyzed and described., Competing Interests: No conflict of interest exits in the submission of this manuscript, and all authors have seen the manuscript and approved to submit to materials.