Study On Corrosion Behavior Of Epoxy Polyamide Coating And Aluminium Alloy In Seawater

Epoxy polyamide coating and 5083 aluminum alloy materials are widely used in shipsand marine engineering structures.Ships and marine engineering structures are subject to the combined effects of structural mechanical response,temperature,and cathodic protection during their service,which aggravates the accumulation of corrosion damage,shortens the service time,and causes serious economic losses.This paper mainly uses electrochemical impedance spectroscopy(EIS),linear polarization and potentiodynamic polarization techniques to study the corrosion behavior of stress,solution temperature and cathodic protection on epoxy polyamide coating and 5083 aluminum alloy in artificial sea water solution Impact,the main research work is as follows:1.1.Using EIS and linear polarization resistance measurements to study the failure behavior of epoxy polyamide coatings under different tensile stresses in artificial seawater solutions.The research results show that stress has a significant weakening effect on the blocking performance of the coating.As the stress increases,the pores of the coating increase,the blocking performance decreases,and the protective performance of the coating weakens.2.Using EIS measurement to study the failure behavior of epoxy polyamide coating under different stress and temperature in artificial sea water solution.The results show that under the combined effect of stress and temperature,the temperature increases,the corrosion reaction rate increases,the physical and chemical structure of the coating is destroyed,the retardation performance of the coating decreases,and the protective performance of the coating weakens.3.Using EIS measurement to study the failure behavior of epoxy polyamide coatings under different stresses and different cathodic protection in artificial seawater solutions.Studies have shown that under the combined action of stress and cathodic protection potential,with the negative shift of the polarization potential,the hydrogen evolution reaction gradually increases,causing significant damage to the coating,causing cathodic peeling,and the protective performance of the coating decreases.4.Using polarization characteristic curve and EIS measurement to study the failure behavior of 5083 aluminum alloy under different tensile stress in artificial seawater solution.The results show that with the increase of stress,the corrosion current increases,the anodedissolution of aluminum alloy increases,and the corrosion resistance decreases;the mechanochemical effect caused by stress can promote local corrosion of aluminum alloy.5.Using the polarization characteristic curve and EIS measurement to study the failure behavior of 5083 aluminum alloy in artificial sea water solution at different temperatures.The results show that as the temperature increases,the passivation film formation speed is accelerated,which plays a certain role in protecting the aluminum alloy.At the same time,the corrosion tendency of the aluminum alloy increases,the corrosion rate increases,and the corrosion resistance decreases.6.The failure behavior of 5083 aluminum alloy under different polarization potentials in artificial seawater solution was studied by EIS measurement.Studies have shown that with the negative shift of the polarization potential,a large amount of hydroxide ions appear,destroying the passivation film,accelerating the corrosion reaction,and the corrosion resistance of the aluminum alloy is significantly reduced.