LOCAL OXIDATION PENETRATION OF HYDROGEN-CHARGED 308L STAINLESS STEEL CLADDING IN DEAERATED PWR PRIMARY WATER

摘要

The properties of the oxide films formed on non-charged and hydrogen-charged 308L cladding stainless steel in deaerated pressurized water reactor (PWR) primary water at 290 °C were investigated. The oxide films were mainly composed of the Fe-rich outer oxide layer and the Cr-rich inner oxide layer. Ni-enrichment at the oxide/ferrite and oxide/austenite interfaces was observed. The content of Ni at the interface of ferrite matrix/oxide was higher than that at the austenite matrix/oxide interface in both uncharged and hydrogen charged specimen. Charged hydrogen reduced the general corrosion resistance of 308L SS cladding layer. In uncharged specimen, the corrosion resistance of the ferrite is higher than that of the austenite. In hydrogen-charged specimen, locally accelerated oxidation of ferrite was observed with a thicker oxide on the ferrite than that on the austenite.