The role of dissolved oxygen in supercritical water in the oxidation of ferritic–martensitic steel

High Temperature Oxidation Behavior of Fe-Cr Steel in Air at 1000-1200 K

“…During scale growth, it becomes progressively richer in iron, up to the transformation in hematite (Fe2O3). The growth of outer and inner layer is then controlled by outward diffusion of iron and inward diffusion of oxygen, respectively [19]. In addition, from the SEM cross-sectional observation as shown in Fig.…”

“…The irregular and porous morphologies can be observed in the outer part of oxide scale after high temperature oxidation. The pores in the oxide layer are mostly formed due to vacancy coalescent which can act as transport paths for oxygen diffusion [1,7,18,19], leading to a high oxidation rate and the formation of thick oxide layer. In order to obtain more detail information on the microstructural development of the oxide scale on Fe-Cr steel after high temperature oxidation test at 1000-1200 K for 72 ks, the cross sectional observation was carried out by SEM and the elemental distribution across the oxidized sample was analyzed by EDX.…”

“…It can acts as short circuit part of oxygen. Accordingly, oxygen can diffuse easily to the alloy surface [1,7,18,19]. Meanwhile, the reason for gap formation at the inner/outer oxides interface seems to be the same as oxide cracking and spallation which commonly takes place at the oxide/alloy and oxide/coating interface.…”

“…Meanwhile, the reason for gap formation at the inner/outer oxides interface seems to be the same as oxide cracking and spallation which commonly takes place at the oxide/alloy and oxide/coating interface. Several studies have pointed out that oxide cracking and spallation can occur due to thermal stress arising from a different in thermal expansion between oxide and the underlying materials [3,[5][6][7][8]11,19], grow stress [3,7,8,18] and the formation of other nonadhesive oxide/spinel [7]. During heating and cooling, the thermal stress can enhance the oxide crackingand spalling.…”

The role of Cr atom in the early steam oxidation of Fe‐based alloys: An atomistic simulation

“…[10][11][12] The oxide formation is correlated with the thermodynamic properties of the oxide, oxide-metal, and oxide-steam interfaces, [13][14][15] extensive research studies have been carried out to understand oxide formation mechanism on FeCr alloys. [16][17][18][19][20][21][22] Zhu et al [23] investigated the oxidation behavior of ferritic-martensitic steel exposed to deaerated supercritical water at 560-650°C and 25 MPa by oxidation experiment, and the oxidation kinetics at different temperature was analyzed. Furthermore, a large number of models have been put forward for determining the kinetics of the oxide formation.…”