Effect of Dissolved Oxygen and Amino Acid Corrosion Inhibitor on Corrosion of Carbon Steel Firewater Pipeline

This paper investigates the effects of dissolved oxygen and an amino acid corrosion inhibitor on the corrosion of 20# carbon steel in tap water and deionized water. The corrosion behavior was systematically analyzed using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, weight loss measurements, and scanning electron microscopy (SEM). The results show that deoxygenation is the most effective way to inhibit the carbon steel corrosion in two media, and the increase in dissolved oxygen concentration will make the carbon steel in the tap water corrosion resistance decline, but additional oxygen will enhance its corrosion resistance compared with the natural state without deoxygenation and oxygen addition in deionized water. Moreover, the effectiveness of the corrosion inhibitor in inhibiting carbon steel corrosion in tap water is significantly lower than that in deionized water. These results offer valuable insights for the operation of carbon steel firewater pipelines in media containing dissolved oxygen and serve as a practical guide to enhancing their service life.