Experimental studies on steel corrosion in Pb-Bi with steam injection

Experimental studies on steel corrosion were performed in simulated PBWFR (Pb-Bi cooled direct contact boiling water fast reactor) coolant environment. Some candidate steels of high Cr contents were immersed in steam-injected liquid Pb-Bi pool to investigate how their Cr contents and oxygen potential in Pb-Bi or (PH2/PH2O) in the steam influence their corrosion behaviors at temperature range of the reactor operation. Test specimens were made from eight types of steel with Cr contents ranged from 8 to 18%. The experiments were conducted by exposing these specimens to Pb-Bi pool where steam was injected. (PH2/PH2O) ratios of the steam were employed as experimental parameter, ranged from < 3×10−7 to 1×10−5 to control oxygen potential of Pb-Bi. Exposure temperatures were studied of 400, 450 and 500°C. It was found that 12Cr steel (HCM12/HCM12A) was the most resistant to corrosion and therefore a candidate reactor material.