Corrosion behavior of three heat‐resistant steels for turbine system in steam at 600°C and 20 MPa

Abstract The corrosion behavior of KT5916, 2Cr11Mo, and Co3W3 in high‐temperature and high‐pressure steam at 600°C, and 20 MPa were investigated. The kinetic weight gain curves of KT5916 and Co3W3 nearly followed a parabolic law. Oxide scale exfoliation was found in all steels. The oxide layer structural distribution of the three heat‐resistant steels was Fe 3 O 4 layer and FeCr 2 O 4 layer from the gas side to the substrate side, and the critical criterion for the formation of Fe 2 O 3 oxide was 509.3°C. Under the influence of growth stress, the oxide film of the three heat‐resistant steels experienced a stable oxide layer, coarsening of oxide, pulverization of oxide, and exfoliation of oxide in high‐temperature and high‐pressure steam environments.