Analysis Of Current Corrosion Situation And Study On Protective Measures Of The Diesel Tank In Daxie Oil Depot

This paper researches the corrosion status and the anti-corrosion measures of the two diesel oil tanks in Daxie oil depot including tank roof, tank wall and tank bottom by macro inspection, ultrasonic thickness and magnetic flux leakage testing. Through the analysis of detection images and data, it finds that the differences in different parts of tank corrosion degree, and tank bottom corrosion is serious. Using corrosion mechanism of the relevant theory, from the corrosion morphology, type, location, etc. analysis of the factors that affect oil tank corrosion, and through the experiment and theoretical calculation of Q235 A in the average corrosion rate of oil tank bottom water.The result shows that Q235 A steel has good corrosion resistance. In addition, combined with measured water ion composition in the bottom of the tank, using electrochemical corrosion test produce the polarization curves and impedance spectroscopy of Q235 A in different concentrations of Cl-, SO42- solution. Through the analysis, it finds that Cl- on the corrosion rate of Q235 A is not always increasing with the rising of concentration, when more than a certain critical value, there will be the trend of decrease. SO42- on the corrosion rate of Q235 A is increasing with the rising of concentration. Through the investigation and test analysis, formulate the painting scheme of each part of the tank,the combined protection scheme of coatings and sacrificial anode cathodic protection for the bottom of the tanks, the replacement of the 301 cans of floor plan, the partner replacement of the 303 cans of floor plan, and puts forward some improving measures. It greatly improves the effect of the oil tank protection, prolong the service life of the tank, in order to reduce or avoid tank corrosion perforation and leakage accidents, it provides scientific basis and prevent methods.