Effect Of Inhibitor On Corrosion Behavior Of Metals In Hydrochloric Acid Medium

The corrosion inhibitor have a good inhibition effect on metal corrosion in a variety acidic environments,and does not change the characteristics of metal.In this paper,the corrosion behavior of N80 steel and Cu in 15%hydrochloric acid was studied and discussed by means of electrochemical experiments,infrared spectroscopy and X-ray photoelectron spectroscopy(XPS).The results of surface detection and experimental results show that the adsorption of single Mannich base and sodium tungstate on the surface of N80 steel has some certain defects after being added into the corrosive medium.The content of chloride ion on the surface of N80 steel was decreases greatly and the binding energy of Fe2 p was increases rapidly after compounding.When the concentration of Mannich base was 0.00013~0.02mol/L,the concentration of sodium tungstate was 0.0002mol/L and the concentration ratio was 1:1(both 0.0002mol/L),the inhibition efficiency was the highest up to 84.92%.When the 0.01mol/L vanillin and 0.02mol/L cinnamaldehyde were added to 15%HCl corrosion solution,the inhibitor molecules replaced the water molecules at the metal-solution interface to form an adsorption layer,which reduced the contact area between copper and corrosion particles.The corrosion current density on the metal surface was decreased and the charge transfer resistance was increased.In the experimental range,the longer the immersion time,the higher the experimental temperature,the more complete the corrosion inhibitor film is,and the more obvious the corrosion inhibition efficiency is.The corrosioninhibitor solution of0.01mol/L vanillin and0.015mol/L cinnamaldehyde compound can effectively reduced the corrosion of N80 steel in 15%HCl solution,decreased the corrosion current density,film capacitance and double layer capacitance of metal surface.The charge transfer resistance was increased and the content of Cl~-was decreased rapidly.The adsorption of the complex corrosion inhibitor on the metal surface was spontaneous and followed langmuir adsorption.