Corrosion Protection of Mild Steel in Petroleum Industry Saline Medium

Abstract

Corrosion is major problem with metals. When they come in contact of surrounding corrosive medium to construct a corrosion cell on their interface, metals undergo in corrosion reactions. Such environments metals can be exhibited uniform, galvanic, pitting, stress, crevice, embrittlement, intergranular corrosion etc. The corrosion of phenomenon of rebar steel studied in saline water. It creates corrosive medium for rebar steel due to availability of chloride ions. Rebar steel is used for the construction of bridge, road, airport and building. These components interact with saline medium producing corrosion reactions. Saline water chloride ions attack on rebar steel to form corrosion cell and corrode metals. Rebar steel is covered with concrete and that structure is dipped into saline water by the process of osmosis chloride ions are entered inside the structure creates dissolving and swelling chemical corrosion with nonmetallic components and electrochemical corrosion with metal. For this work synthesized electron rich organic compounds 2-(propan-2-ylidene) propane-1,3-diamine. The corrosion rate of rebar steel was calculated before and after coating by gravimetric method at different temperatures in presence different concentrations of saline water. Potentiostat technique used for the measurement of corrosion potential, corrosion current and corrosion current density in various concentrations of saline water and coating compound.

The surface coverage area and coating efficiency were determined by corrosion rate uncoated and coated rebar steel. The coating compound adhered on the surface of base metal by chemisorptions and it confirmed by thermodynamical parameters like activation energy, heat of adsorption, free energy, enthalpy and entropy. The surface adsorption phenomenon completed by Langmuir, Frendlich and Temkin isotherms. The results of thermodynamical parameters and surface adsorption confirmed that coating compound formed stable passive barrier which increased physical, chemical and mechanical properties of rebar steel saline environment.