Fundamental Aspects of CO₂ Metal Loss Corrosion. Part II: Influence of Different Parameters on CO₂ Corrosion Mechanism

Abstract

General and localized CO₂ corrosion is influenced by a number of factors which can be divided into materials-related, environment-related and interface-related parameters. Materials-related parameters include alloy composition, microstructure and heat treatment. CO₂ partial pressure, pH, solution chemistry, temperature, presence of hydrocarbons, corrosion inhibitors and the presence of oxygen and other gas phase related impurities constitute major medium-related parameters. Interface-related parameters comprise temperature, flow, heat transfer, condensation, stress and presence of scales. All parameters are interdependent and influence the CO₂ corrosion in different ways. The paper gives an overview on the present day knowledge on the effects of these parameters on CO₂ corrosion. Referencing the reviews produced on this topic at the NACE CORROSION’2006 conference, the focus is put on the progress in understanding CO₂ corrosion mechanisms during the last decade emphasizing investigations and results in dense phase and supercritical CO₂ corrosion systems related to the CCS technology.