Corrosion investigations of P235 carbon steel in deionized water

Abstract

In this paper results of the corrosion behavior of steel P235 used for pipes in the water softening plant with ion exchangers were reported. Investigations were carried out in deionized water without and with the addition of commercial biocides and corrosion inhibitors, using mass loss measurement method and electrochemical methods (linear and potentiodynamic polarization method). After potentiodynamic polarization investigations, the surface of the steel was examined by optical microscopy. It has been found that general corrosion of steel occurs in deionized water. The addition of the commercial biocide (Chemtec BI01) does not alter the corrosion behavior of the steel while application of commercial inhibitor (Chemtec FI30) reduces the corrosion rate of the steel in deionized water to an acceptable value acting as an anodic type of corrosion inhibitor. However, anodic polarization on steel sample in deionized water causes the appearance of pitting corrosion, and surface damage is considerably lower in inhibited solutions.