Effect of Chromate Inhibitor on the Mechanical and Electrochemical Components of Erosion-Corrosion in Aqueous Slurries of Sand

Abstract

Abstract Both weight loss and electrochemical measurements have been made to study the effects of chromate inhibitor on the erosion-corrosion of carbon steel specimens in a 5 cm diameter slurry pipeline carrying a 20 Vol% aqueous slurry of silica sand (size range 0.3 to 0.6 mm) over a velocity range 2–3.5 m/s. In the absence of inhibitors the total wear rate of a 5 cm long × 1 cm wide specimen located at the 4 o'clock position in the pipe wall was 2.7 to 17.5 mm/year. In the presence of inhibitor, the wear rate was reduced to values in the range 0.48 to 0.82 mm/year. The electrochemical measurements showed that erosion was the major mode of metal loss. However, there is a major interaction between the erosion and the corrosion components and a reduction in the corrosion component, which leads to much smoother surfaces, greatly reduced the erosion losses.