Study On The Compound And Mechanism Of Environment-Friendly Corrosion Inhibitor For Metals

In this paper,the four-component corrosion inhibitor mitigation scheme was optimized by orthogonal test to obtain the optimal green gas phase corrosion inhibitor.The inhibition behavior and corrosion inhibition mechanism of the gas phase corrosion inhibitor were studied.Firstly,the corrosion inhibition effect of single component in the solution with mass fraction of 3.5%NaCl was obtained by electrochemical experiment method.Then,according to the principle of orthogonal test,four kinds of corrosion inhibitors were compounded in multiple ways.A new type of green gas phase corrosion inhibitor formulation for metal was obtained,and the corrosion inhibition effect of the optimal formulation of the vapor phase inhibitor was verified by a damp heat test.Finally,the inhibition mechanism of vapor phase corrosion inhibitors on carbon steel in atmospheric corrosion was studied by electrochemical methods,SEM&EDS test techniques.The results of electrochemical measurements showed that:When ammonium molybdate is 3 g/L,sodium benzoate is 8g/L,sodium phosphate is lg/L,phytic acid sodium is 2 g/L,the corrosion inhibition effect of 45#steel in mass fraction of 3.5%NaCl solution is the best.The corrosion inhibition effect is best in the corrosion inhibition efficiency of 92.4%in the electrochemical test and 91.63%in the damp heat test results.There is a synergy between the components of the quaternary compound gas phase corrosion inhibitor,which is more than a single component.The corrosion inhibition effect has been significantly improved.Analyzed and tested on the metal surface,the resistance value of the test group added with the vapor phase inhibitor significantly increased,the resistance of the charge transfer increased,and the vapor phase inhibitor showed a strong corrosion inhibition ability to the metal.The contact angle of the metal surface becomes larger,and the corrosion-inhibiting film exhibits hydrophobicity,which,to some extent,hinders erosion of the corrosion ions and diffusion of oxygen.MoO4 2-in vapor phase corrosion inhibitor reacts with metal ions to form the final product of ammonium molybdate passivated carbon steel Fe-MoO4-Fe2O3;When phytate complexes with Fe The oxygen atom in the group can act as a coordination atom for complexation with Fe2+,which can generate multiple chelate rings and act as a corrosion inhibitor.The 45#steel acting as a vapor phase corrosion inhibitor showed a dense corrosion-inhibiting film,which effectively slowed down the corrosion of the metal surface and was basically free of corrosion products.The inhibitory effect of the vapor phase corrosion inhibitor under acidic conditions is weakened,the corrosion film formed on the metal surface is no longer dense,cracks appear,and pitting occurs on the metal surface;there is a strong corrosion inhibition ability under alkaline conditions,and metal surface formation A dense oxide film prevents metal corrosion from occurring.