The kinetics of the oxidation of steels in hightemperature aqueous solutions

Abstract

The corrosion of mild steel, an Fe-1 %Cr alloy and a 5 %Cr steel has been studied in alkaline and Cl − solutions at 250°, 300° and 350°C by a H 2-effusion technique. In most cases the corrosion rate falls exponentially to a final constant value, the rate of fall reflecting the morphology of the oxide produced. There is no correlation between the initial and final corrosion rates and in particular the Cr-containing materials have lower initial but higher final corrosion rates than mild steel. The main influence of temperature is on the initial corrosion rates. Those at 300°C are greater than those at 250° and 350°C.