2016 Volume 65 Issue 9 Pages 369-371
In this paper, the effect of supercritical CO2 on corrosion behavior of stainless steels, mainly 13%Cr steels, was reviewed. Corrosion rate of 13%Cr steels in supercritical CO2 was similar to or less than that in gas CO2. When the pressure of supercritical CO2 became higher than 20MPa, pitting corrosion was more likely to occur in the steels. Under the supercritical CO2 including 45kPa oxygen, crevice corrosion of 13%Cr steels was recognized. When oxygen partial pressure reduced to 4.5kPa in supercritical CO2, no crevice corrosion was recognized in Steel B which was a low C steel with Mo addition. Steel B showed better corrosion resistance than Steel A which did not contain Mo, in all tested conditions, not only CO2 gas conditions but also critical CO2 conditions. Published papers related to effects of impurities such as NO2, SO2 and etc. on corrosion resistance of stainless steels and estimation of phase behavior of supercritical CO2 were reviewed and summarized.