The Effects of Hydrostatic Pressure on Corrosion of Coated Stainless Steel

Abstract

Underwater steel structure such as Remote Operated Vehicle (ROV) unit was exposed to corrosion element during its operated working hours and at different depth of sea level depending on its operational requirement. The different depth of each operational indicates the different pressure effects under water. The coated material was affected by the corrosion and may have changed in its micro substructure thus decreases the corrosion resistance. The aim of this study was to analyse the corrosion rate of the pressure effects on the coated materials through several testing. The type of coated material used is Commercial Anti-Corrosion spray. The tests done by pressurized the specimen at 2, 6 and 10 atm. The corrosion rates are determined by using immersion and weight loss. The specimens were soaked in the sea water with timeline of 24 hours. Scanning Electron Microscope (SEM) and microstructure observation are used to observed and determine the corrosion morphology of the specimen changes before and after immersion test. As a result, the pressure plays a major role on the corrosion effect and coating materials. The increments of pressure will deteriorated the corrosion resistance of the specimens. However, the coating materials can only slow down the deterioration process of the specimen.