Oxidation of Austenitic Steel TP347HFG Exposed to Supercritical Water with Different Dissolved Oxygen Concentration

Abstract

The oxidation of austenitic fine-grained steel TP347HFG exposed to supercritical water at 550 °C and 25 MPa with the dissolved oxygen concentration of 100 ppb, 300 ppb and 2000 ppb was investigated. The results indicated weight gain increased with the dissolved oxygen increasing. The herpes-shaped oxides were formed on the sample surface. The oxide layer was a typical dual-layered structure with a Fe-rich outer layer and a Fe-Cr-Ni-rich inner layer. The influences of the dissolved oxygen concentration and grain size on oxidation behavior were discussed finally.

Effect of Iron Ion on Corrosion Behavior of Inconel 625 in High-Temperature Water

“…The EDS results suggested that high levels of niobium element accumulated in the corrosion pits. It seemed that the corrosion pits might be determined by inclusions of NbC [ 31 , 38 , 39 ]. In high-temperature water, pitting may be associated with Nb-rich precipitates (likely the γ '-phase) [ 4 , 40 ] and induced by local potential difference between the matrix and the inclusions [ 2 ].…”

Environmentally assisted crack growth rate of an austenitic steel TP347HFG in high‐temperature medium

“…Austenitic steel TP347HFG, a modified form of TP347H, having a fine grain structure, has been developed for use in the finishing stages of reheater and superheater boiler tubes . Several separately studies on oxidation and creep rupture properties of TP347HFG can be found in the literature .…”