Evaluation of the Effect of Steel Microstructural Features on Corrosion Resistance Under Conditions of Processing Gas Containing Co2.

One of the main corrosive environments in gas processing is the moisture condensation condition in the vapor phase and variable wetting on the inner surface of equipment. In this case, steel microstructure and non-metallic inclusion content affect formation and development of corrosion defects of carbon and low alloy steels. It is shown that localization of carbon dioxide corrosion within a welded seam of X65 steel proceeds more intensively than within basic metal. Tests conducted in a specially designed stand under variable wetting conditions show that at the surface of 09Mn2Si steel local defects in the form of corrosion pitting occur in places where corrosion products are carried away. The morphology (density, continuity, etc.) of corrosion products (FeCO3) formed affects their potential barrier properties with respect to carbon dioxide corrosion of steel. Use of corrosion inhibitors prevents generation of local damage on steel under the action of media containing CO2. [ABSTRACT FROM AUTHOR]