Sažetak
Oil tanks are often made from mild steel, and as such, they are subject to corrosion damage that can cause leaks which pose a danger to public health and safety and to the environment. Critical parts of the above ground storage tank such as the bottom plate, the lower part of the shell and the roof are often protected with protective coatings, while the other surfaces in contact with oil are not permanently protected. Special attention should be addressed to such bare surfaces when mild steel is in direct contact with water such as during hydrostatic testing. One possible solution is application of a corrosion inhibiting oil which floats on the surface of the water and, in contact with tank walls, forms a protective layer. Electrochemical testing of mild steel samples protected by corrosion-inhibiting oil in natural sea water at elevated temperature (30±2) °C was performed. The three test mixtures were pure sea water, sea water inhibited by oxygen scavenger, and sea water inhibited by oxygen scavenger and treated with biocide. The study included
determination of corrosion potential, metal resistance and corrosion rate. The tested corrosion-inhibiting oil showed significant prevention of general corrosion of the mild
steel samples.
Ključne riječi
corrosion-inhibiting oil; float coat; temporary protection; mild steel; sea water