Investigation On The Corrosion Inhibition Of Organic Mixtures On Bronze In Formic Acid And Acetic Acid

Bronze relics,as a heritage of ancient culture treasures,is exquisite and has different forms.However,after thousands of years of burial,many bronze relics were corroded by natural environment.In the later excavation and preservation,there are still many factors leading to different degrees of damage to bronze.In order to continue the splendid culture of the Chinese nation,it is particularly important to explore ways to protect bronze.In this paper,the synergistic corrosion inhibition of the traditional bronze inhibitor C6H5N3 and food additive C7H5NaO2 was studied.The protective effects of the two corrosion inhibitors on the three bronze were evaluated by scanning electron microscope,electrochemical method and theoretical chemical calculation.Experimental studies show that for three bronze samples,both corrosion inhibitors can bind on its surface,reducing the contact between the sample and the environment.The electrochemical analysis indicate,for no-rust bronze in formic acid in the solution,when BTA and SB in the proportion of 1:1,the value of corresponding corrosion current density and Cdl is the lowest,and the value of charge transfer resistance is quite high,shows that when the mixed ratio is 1:1,the film layer on the surface of the bronze is the thickest,which can defer the corrosion of bronze;In acetic acid,when the ratio is 4:1,the Icorr is the lowest,the charge transfer resistance is the largest,the film is the thickest,and the corrosion inhibition efficiency is the highest.For bronze with Cu2O in formic acid,when the content ratio of BTA and SB is 2:3,the value of Icorr and Cdl are lower,and the charge transfer resistance is higher,and the mixed corrosion inhibitors shows synergistic effect.In acetic acid solution,when the content ratio of BTA and SB is 1:1,the corresponding corrosion current is very small,the radius of capacitive loop is the largest and the corrosion inhibition efficiency is the highest.For bronze with CuCl in formic acid solution,when the ratio of compound corrosion inhibitor is 3:2,the mixture of benzotriazole and sodium benzoate showed obvious synergistic effect,with the inhibition efficiency as high as 98.8%.In acetic acid solution,when the content ratio is 4:1,it shows higher inhibition efficiency.In general,the mixed corrosion inhibitors can show synergistic effect in a certain proportion.Theoretical calculation results show that compared with SB,BTA has a more stable structure.BTA and SB form coordination bond with copper surface through N and O atoms,respectively,and the coordination bond between Cu and SB is more stable.However,BTA mainly covers on the metal surface by physical adsorption,and the two corrosion inhibitors reduce the contact area between the Cu surface and the corrosive medium by physico-chemical way,thus showing a certain synergistic effect.