Effect of seawater corrosion on the mechanical behaviour of S690 steel

The marine environment poses significant challenges to metallic engineering structures, not only due to the exposure to wave and wind action and logistic challenges related to transport and maintenance, but also due to the constant exposure to seawater, which makes them vulnerable to corrosion. Typically, protective strategies, such as coatings, are used in marine structures, allowing the base material to retain its properties. However, these protections have limited lifespans which can lead to damage of the base material before maintenance. Structural steels with a higher mechanical strength, such as S690 steel, are object of increasing interest for offshore structures applications due to weight reduction advantages. However, its mechanical behaviour in a corrosive medium is not yet well reported in literature. Thus, this work intends to characterize a S690 steel under marine environment conditions. As such, a methodology for inducing accelerated pre-corrosion is developed and applied to quasi static tensile specimens. Its effect on the tensile mechanical properties is evaluated through testing in accordance with the ASTM E8 standard.