First, the cause of oil tank corrosion
Rhenium corrosion is the damage caused by the chemical or electrochemical action of external media. Due to the different environmental conditions, the cause of corrosion is also different.
Due to the structure, composition, stress, and surface unevenness of the steel tank material itself, under the action of surrounding media (water, ion concentration) and environmental temperature changes, it is easy to form macro or micro batteries, and it is easy to cause corrosion. The outer wall of the ground steel oil tank has good anti-corrosion treatment, and the corrosion is light; the inner wall corrosion is mainly electrochemical corrosion, and the severely corroded parts are concentrated on the tank top, the bottom water phase, the water-oil interface, and the oil-gas interface.
Second, anticorrosive measures for oil storage tanks
的 The main methods to prevent oil tank corrosion must be considered from two aspects: metal and medium. There are four common methods:
1 selection. Select low-carbon (carbon content below 0.2%), low-sulfur, low-phosphorus (sulfur-phosphorus content below 0.5%) steel tank materials. This kind of anticorrosive effect is the best, but the cost of the oil tank is higher.
2 Coating anticorrosive. Coating anticorrosion is to protect the metal by separating the steel base from the corrosive medium through the coating. At present, there are many varieties of anticorrosive materials used in domestic oil tanks, such as epoxy resin, polyurethane, inorganic zinc-rich, glass flake coating, etc.
3 cathodic protection. Cathodic protection technology is a kind of electrochemical protection technology. Its principle is to apply an external current to the surface of the metal structure to be corroded, so that the structure to be protected becomes a cathode, so that the electron migration of metal corrosion is suppressed, and corrosion is avoided or weakened happened.
4 thermal spray technology. Thermal spraying is to melt the sprayed metal raw materials at high temperature, use compressed air or other inert gas to blow the molten metal into a mist, and quickly spray it onto the surface of a prepared metal object in succession to form a spray coating. The protective layer can effectively isolate the penetration of the corrosive medium and prevent the electrochemical corrosion of the steel base in the medium.
