• Dry–wet cycles promote corrosion and increase the hydrogen permeation current. • Macrofouling effects on corrosion and hydrogen permeation are tide‑level dependent. • Dry–wet cycles and macrofouling can increase the SCC susceptibility of steel. • Cathodic protection can decrease the SCC susceptibility of steel, and HE risk remains. Herein, the hydrogen permeation and stress corrosion cracking (SCC) behavior of high-strength steel under the effects of dry–wet cycles and macrofouling were studied by field exposure tests. The dry–wet cycles can increase the hydrogen permeation current density and SCC susceptibility of steel in the natural corrosion state by promoting corrosion. Owing to the failure of cathodic protection caused by dry–wet cycles, the increase in the dry–wet cycle ratio resulted in a U-shaped variation in the SCC susceptibility of steel under cathodic protection, with the hydrogen permeation rate also decreasing. Macrofouling adhesion can increase the susceptibility of high-strength steel to SCC in both natural corrosion and cathodic protection states, and increase the hydrogen permeation current density on the MTL steel surface under cathodic polarization. A schematic was provided to visually illustrate the effects of dry–wet cycling and macrofouling adhesion on high-strength steel.
Cai et al. (Fri,) studied this question.