Corrosion and electrochemical properties of the steel of exploited oil tanks in bottom water

We have detected a distinction in the corrosion and electrochemical behavior of St3sp steel of different parts of an oil storage tank in under-product water of different oil refineries depending on preliminary contact between the metal and working media of different corrosiveness. Due to long-term contact of the steel with a corrosive working medium (under-product or condensed water), its corrosion resistance decreases substantially. We have established that a medium with an oil-water interface has the greatest corrosiveness, and oil-water emulsion has the lowest. The intensity of electrochemical processes is higher on the steel of those domains of the oil storage which contacted with under-product or condensed water as compared with the metal contacted with oil. The least mineralized under-product water is also the least corrosive.