铁素体-马氏体P92钢在600℃/25MPa超临界水中的氧化特性
摘要
The oxidation behavior of ferritic-martensitic P92 steel was studied in supercritical wa- ters containing different dissolved oxygen of 0, 100 and 300 μg/L at 600 ℃ under 25 MPa. The re- sults show that a typical double-layered oxide scale is formed on all the samples, which consists an outer layer Fe-rich magnetite and an inner layer Cr-rich Fe-Cr spinel. Cracks on the surface of ox- ide scales are found at the initial oxidation stage, which is different from the experimental phenom- enon in supercritical water at 550 ℃. A distinct gap between inner oxide layer and substrate alloy is observed in some regions of the sample which is exposed to the supercritical water containing 300 μg/L dissolved oxygen. The mechanism concerning the influence of dissolved oxygen on oxi- dation behavior and the gap formation is further discussed.