The corrosion damage of an organic coating accelerated by different AC-DC-AC tests

Study on the evolution of impermeability and mechanical properties of epoxy composite coatings

“…The coating experiences only a certain degree of swelling when the NaCl solution permeates at the beginning, and the internal structure is damaged less, which is similar to the phenomenon observed in the experiments. 3,14 The indentation force after permeation of Gr/EP coatings is lower than that of pure EP coatings due to the deformation and movement of Gr during the permeation process, which prevents the enhancement effect. Comparing Figure 6B,E, after the permeation of the Gr/EP coating, the Gr moves to the left by a certain distance…”

“…5,6 Graphene (Gr) 7,8 and its derivative graphene oxide (GO) 9,10 have been used to enhance epoxy coatings due to their unique mechanical and physical properties. 11 Previously, researchers measured the electrochemical impedance in salt spray experiments 12,13 and accelerated corrosion experiments 14 to investigate the corrosion resistance of epoxy composite coatings. 15,16 The enhancement of corrosion resistance of epoxy coatings by twodimensional materials such as Gr and GO was investigated at a macroscopic level to summarize the antipermeation mechanism of polymer composite coatings.…”

Prediction of long-term service life of an organic coating based on short-term exposure results

“…Nowadays, coating protection performance is usually evaluated according to the following coating characteristics: The physical and chemical changes, such as the gloss loss (Guseva et al , 2003; Evans, 2012), the color change (Lee and Chang, 2016), the emergence of rust (Kim and Itoh, 2007), the adhesion failure (Zhang et al , 2020a; Zhang et al , 2020b; Meng et al , 2017) and the occurrence of blistering (Latif et al , 2017; Chuang and Nguyen, 1997; Bethencourt et al , 2004; Xu et al , 2021; Zheng et al , 2021). The electrochemical resistance reduction, such as the decreased coating resistance (Cmaitland and Mayne, 1962; Deflotian et al , 2008; Yong et al , 2021) and the reduced low frequency modulus (Bierwagen et al , 2001; Shreeoathi et al , 2011; Su et al , 2015).…”

“…The physical and chemical changes, such as the gloss loss (Guseva et al , 2003; Evans, 2012), the color change (Lee and Chang, 2016), the emergence of rust (Kim and Itoh, 2007), the adhesion failure (Zhang et al , 2020a; Zhang et al , 2020b; Meng et al , 2017) and the occurrence of blistering (Latif et al , 2017; Chuang and Nguyen, 1997; Bethencourt et al , 2004; Xu et al , 2021; Zheng et al , 2021).…”

“…Particularly, electrochemical methods (Rodríguez et al , 2004), e.g. the AC–DC–AC tests (Hollaender, 1997; Xu et al , 2021; Zheng et al , 2021), can significantly speed up the corrosion and delamination of organic coatings at the coating/substrate interface. However, all these methods more or less change the coating deterioration mechanism while they are speeding up the coating degradation process.…”