Corrosion Protection of Epoxy-Coated Stainless Steel by Organic-Coating and Filler Materials

Abstract

Epoxy coating uses for the corrosion protection of stainless steel. Epoxy-coated stainless steel surface has possessed lots of porosities so pollutants and particulates materials are entered inside by osmosis and diffusion process. Pollutants like oxides of carbon, oxides of nitrogen, and oxides of sulphur form acids and they make hostile environment for base metal and epoxy polymer. These acids develop chemical reaction with epoxy-coated stainless steel. They develop corrosion cell with metal and start corrosion reaction. They can produce several forms corrosion like galvanic, pitting, stress, crevice, blistering and embrittlement. Epoxy polymer is shown swelling corrosion. Such types of pollutants are disintegrated metal and polymer and change their physical, chemical and mechanical properties. Weather changes can affect the corrosion rate of materials because the compositions of corrosive substances increase or decrease temperatures of atmosphere, concentration of pollutants, moisture, humidity and acids. They initiate the corrosion of materials. The corrosion protection of epoxy-coated stainless steel was controlled by the application of synthesized decahydrobenzo [8] annulene-5, 10-disemicarbazone and this compound was nanocoated on the surface of epoxy-coated stainless steel. Nanocoating and filler materials were formed composite a thin barrier on the surface of epoxy-coated stainless steel and studied their action in corrosion in hostile environment. Nanocoating work can be completed by the use of nozzle spray and chemical vapor deposition. Thermal parameters like activation energy, heat of adsorption, free energy, enthalpy and entropy were used to study composite film formation. The corrosion rates of materials were calculated by gravimetric method. Surface coverage areas and coating efficiencies were obtained by the help of corrosion rate. Potentiostat used to determine corrosion potential, corrosion current and current density. Experimental observations indicated that composite film barrier was formed decahydrobenzo [8] annulene-5, 10-disemicarbazone and Tin which physical, chemical and mechanical properties did not change easily in ambient environment. Keywords: Hostile environment; corrosion; nanocoating; filler; thermal parameters; composite film barrier;