Rotated cage corrosion experiments (4 m/s) were performed with flat coupons of 2 carbon steels
(38Mn6/C75, X65) and 3 Cr-containing steels (X20Cr13, X2CrNiMoN22-5-3 (1.4462) and
X1NiCrMoCu 25-20-5 (1.4539)) in the presence of supercritical carbon dioxide (scCO2) and different
amounts of water at 50, 80, 110 and 130oC. While water-free scCO2 is non-corrosive for C-and Crcontaining
steels, water mist saturated with scCO2 was corrosive for C-steels, however not for 13Cr or
CrNi steels even up to 130°C. Droplets of water mist, saturated with scCO2, caused localized attack
when touching the C-steel surface. Water phases saturated with scCO2 were very corrosive for C-steels
in the whole range of 50 to 130°C (corrosion rates 5-15 mm/y and mesa-type localized attack). Under
such conditions also the resistance of 13Cr steel was not acceptable (corrosion rates 0.3 to 0.8 mm/y).
Even the austenitic-ferritic (1.4462) and the austenitic CrNi steel (1.4539) surpassed the target line of
0.1 mm/y at 110°C when contacted with water saturated with scCO2.
Keywords: carbon steels, 13 Cr steel, duplex steel, austenitic CrNi steel, water; corrosion, supercritical
carbon dioxide, rotated cage,