Studies On The Corrosion Inhibition Performance Of Plant Extractives In Acid Medium

Carbon steel equipment existed in natural environment has super corrosion resistance,because of its low cost,strong practicability,which was wildly used in machine manufacturing,petroleum,chemical industry,life,and other fields.But in practical application,the carbon steel equipment always generates deposit impurities on account of environmental medium.It is easily corroded,which will reduce the operational efficiency and cause huge losses.The best method to clean the depositing is using chemical cleaning,and acid solution is the most universal freshener.Carbon steel could react with acid easily when it is cleaned.The key is to add the valid corrosion inhibitor.And the plant extractives used as a green corrosion inhibitor has the vital significance.Plant extractives are mainly extracted from various green plants of effective corrosion composition.The final production is not only non-poisonous and harmless,but also has good corrosion inhibition effect on the cleaning of carbon steel equipment.This experiment mainly studies corrosion inhibition performance effect of plant extract on carbon steel in acid solution.The paper selects from hundreds of plant extractives by weight-loss method,which filter out the corrosion inhibition of plant extractives on carbon steel in the hydrofluoric acid,hydrochloric acid,mud acid medium.Inspect the corrosion rate of carbon steel and the corrosion inhibition of inhibitor in change watermelon,pawpaw extractives,acid concentration,time,and temperature conditions.It was shown by the results of weight-loss method that two kinds of plant extractives both have good inhibitive efficiencies,the corrosion rate of carbon steel fells to g·m^-2·h^-1,and the corrosion inhibition efficiency of the inhibitor is greater than 94%.It was shown by the results of electrochemical method that watermelon,pawpaw extractives is both the electrochemical mixed type inhibitor.The five extractives of garlic,pawpaw,watermelon,spinach and lemon in hydrochloric acid and citric acid were carried out in two groups and select the corrosion inhibition.It was shown by the results that the synergistic effects in the hydrochloric acid among the watermelon and garlic,lemon and garlic,watermelon and spinach as well as pawpaw and spinach are the best.The synergies in the mud acid among the watermelon and spinach,lemon and spinach,garlic and spinach,lemon and watermelon have the inhibition effect.Using the weight-loss method and the electrochemical method,the best optimum proportion and the type of the eight synergistic extractions are determined.The synergistic extractions combined with many chemical compounds design to develop composite corrosion inhibitor J-XY which has good corrosion inhibition effect for carbon steel in the mud acid.Using the orthogonal test,the best optimum proportion is determined.At the same time,the paper researches the corrosion inhibition performance of the corrosion inhibition and its anti-interference ability to acid rate,temperature and time.It was shown by the results of weight-loss method that the inhibitor has the best corrosion inhibition on carbon steel when the quantity of the corrosion inhibitor is 3%,the temperature is below 50 degrees and the concentration of mud acid is under 6%.The corrosion rate of carbon steel is under 0.4000 g·m^-2·h^-1 and the inhibition rate increases 97%.It was shown by the results of electrochemical method that the J-XY is a kind of electrochemical mixed type inhibitor.The J-XY is non-poisonous and harmless,is a kind of environmentally friendly efficient mud acid cleaning composite corrosion inhibitor for carbon steel equipment.