Study On Inhibition Mechanism And Synergistic Effect Of Corrosion Inhibitors In Oxygen-containing System

The corrosion of metal materials will not only threaten the safety of people's lives and property,but also cause economic losses and waste of resources.Oxygen corrosion is a main type of carbon steel corrosion.At present,the main methods are deoxidization and adding phosphate and zinc salt composite corrosion inhibitors.Therefore,it is of great significance to study the new inhibitor formulation system and synergistic effect of carbon steel in oxygen-containing solution.Adding corrosion inhibitor is a simple,effective and economical method to inhibit metal corrosion,which has been widely used.However,the effect of a single inhibitor is often unsatisfactory,or not very friendly to the environment.Therefore,in view of the above problems,a large number of experiments have been carried out in this paper to study the combination and synergistic effect of corrosion inhibitors in 60? tap water solution.The main research contents are listed as follows:1.The inhibition effects of 12 individual inhibitors were evaluated by weight loss method,electrochemical method and surface morphology observation.Phytic acid and sodium gluconate were selected as the best inhibitors.The inhibition rates of phytic acid and sodium gluconate were 55.80%and 64.02%respectively at the concentration of 100 mg/L.2.The corrosion inhibition performance and synergistic effect of phytic acid and sodium hexametaphosphate,sodium gluconate and dimethylaminopropylmethylacrylamide(DMAPMA)were studied by weight loss method,electrochemical test,SEM,AFM,EDS,molecular dynamics simulation and XPS.The results show that the above two composite inhibitors have good inhibition effect.The inhibition efficiency of phytic acid and sodium hexametaphosphate at 100 mg/L is 89.10%,and that of sodium gluconate and DMAPMA at 100 mg/L is more than 95%.Both of them make the inhibitor film more compact through synergistic adsorption.Among them,the compound inhibitor of sodium gluconate and DMAPMA is the first one found in this paper.It does not contain zinc ions and has good corrosion inhibition effect,so it has a good application prospect.3.The corrosion inhibition effect of plant extract(OPE)was studied by weight loss method,electrochemical test method,FTIR,SEM,EDS and AFM.The corrosion inhibition performance and ratio of orange peel extract,sodium gluconate and zinc chloride were studied.The results show that the composite inhibitor can be adsorbed on the surface of carbon steel and has good inhibition effect.Through the above research,some good and environment-friendly composite corrosion inhibitors were obtained,and their inhibition mechanism and synergistic effect were explored.