Development And Evaluation Of Plant Corrosion Inhibitor

Corrosion is one of the most serious damage factors in modern industry,which has caused serious damage to our country's economy.A variety of Corrosion inhibitors with good performance have been researched to slow down the corrosion.But most of them are poisonous seriously,and the residue they made which has serious pollution to the environment is difficult to be degraded.With the development of protection of the environment and the requirement of the society and economy,the research of the green corrosion inhibitor has brought great economic benefits to our country.This paper mainly explores the natural plant green corrosion inhibitor with good corrosion inhibition effect on carbon steel equipment during the pickling process.With a lot of methods been screened,tomato juice,grapefruit juice and apple juice which has good performance in reducing corrosion of carbon steel has been selected.The performance of these corrosion inhibitors was studied by weightlessness method and electrochemical method.The results showed that the corrosion resistance of tomato juice was the best,and the corrosion rate was 0.4286 g-m'2 h'1,and the corrosion rate was.as high as 98.56%.The conclusion was drawn that these three corrosion inhibitors were mixed corrosion inhibitors by the method of limit curve.In the experimental process,the synergistic effect in Hydrochloric acid and Mud acid of tomato juice,grapefruit juice and apple juice had been found by weightlessness method and electrochemical method.The results were all 3:1 in the best ratio.The corrosion rate of different corrosion inhibitor was measured,and the corrosion inhibition mechanism was discussed by electrochemical method.By mixing of these three plant corrosion inhibitors and more than ten kinds compound with good corrosion-inhibition effect,a great composite inhibitor called JXW had been found in the best ratio eventually.The corrosion inhibition performance was evaluated by weight loss method and electrochemical method.The effects of acidity,inhibitor concentration,time,temperature and other factors on the corrosion inhibition performance were determined.The results showed that the minimum corrosion rate of carbon steel was 0.1659g·m-2·h-1,and The efficiency of the corrosion was up to 99.44%after mixing JXW.The best using concentration of JXW was 2.5%and the soil acid concentration was less than 8%.The corrosion inhibitor was not found in 24 hours.The performance of corrosion inhibition was excellent when the temperature was under 60 ?.The Tafel polarization curves showed that the corrosion potential is shifted and the corrosion current was reduced when compared with the JXW and no JXW.The Tafel slope of the anode and cathode was greatly changed,which indicated that JXW was a mixed type inhibitor.Through repeated experiments,the JXW is a kind of corrosion inhibitor for carbon steel in soil acid medium with excellent performance.