Abstract
Effects of Cr content and environmental factors, pH and dissolved oxygen concentration, on removal rate of carbon steels due to flow accelerated corrosion have been examined by experiments. Cr content holds a strong impact on the FAC rate regardless of pH values from 6.84 to 10.4. Addition of 1% Cr to carbon steel reduces the FAC rate by one order of magnitude under the environmental conditions, where magnetite forms. Detailed characterizations of oxide film formed on the specimen have been carried out by using SEM and TEM. Preferential corrosion of pearlite phase has been observed at specimen surface of low Cr content steel in early stage of FAC. It has been suggested that oxide structure and porosity were obviously different between low and high Cr content steels.
