Screening And Performance Evaluation Of Solid Corrosion Inhibitor With Five Membered Heterocyclic Containing Nitrogen

In order to find solid corrosion inhibitor with slow release performance and good corrosion inhibition,two kinds of corrosion inhibitors were selected from six kinds of nitrogenous fiveelement heterocyclic compounds(BZL ATB JXZ JMZ KKJ NNS)by electrochemical measurement,weight loss test and quantum chemistry calculation.Finally,the solid corrosion inhibitor was prepared by cementation bonding method,and its properties of slowing release and corrosion inhibition were evaluated.The electrochemical measurement showed that six kinds of nitrogenous five-element heterocyclic compounds have a certain inhibition effect on N8 steel in 1M hydrochloric acid.Relatively speaking,the corrosion inhibition efficiency of BZL,ATB,JXZ and JMZ is higher,and the corrosion inhibition efficiency of KKJ and NNS is poor.Therefore,BZL,ATB,JXZ and JMZ are selected as the main inhibitors and go into one step.The results of weight loss test showed that the corrosion inhibition efficiency of BZL,ATB,JXZ and JMZ increases with the increase of concentration,and the corrosion inhibition efficiency of BZL and ATB is obviously higher than JXZ and JMZ,and the effect of corrosion inhibition is good.Therefore,BZL and ATB are more suitable as the main inhibitors.The adsorption isothermal fitting of weightless test data showed that BZL and ATB molecules adsorb on the surface of N80 steel by physical adsorption and chemical adsorption to inhibit the corrosion in the acid solution,and the adsorption of corrosion inhibitors follows the adsorption isotherm of Langmuir.Quantum chemistry calculation showed that BZL and ATB have multiple active adsorption centers.The highest occupied orbital(HOMO)and the lowest unoccupied orbital(LUMO)energy distribution and Mulliken charge showed that the active adsorption centers are mainly concentrated around N and O atoms.BZL and ATB are likely to adsorb on the surface of N80 steel through these active centers,thus inhibiting the dissolution of metals in acid solutions.The main corrosion inhibitor,corrosion synergistic agent,and curing agent were prepared by solid cementation.The results of iodide concentration titration showed that the effective components of the solid corrosion inhibitor can be released evenly,and the weight loss test showed that the corrosion inhibition efficiency of the solid corrosion inhibitor is better,the maximum can reach 83.5%,the corrosion inhibition performance is good,and the action time is 15 days.