Study on Pb-Bi Corrosion of Structural and Fuel Cladding Materials for Nuclear Applications, 4; Corrosion investigation of steels at 550 and 650C after 800, 2,000 and 5,000 h of exposure to stagnant liquid Pb-Bi containing 10 and 10 wt% of oxygen

Muller, G.*; Schumacher, G.*; Weisenburger, A.*; Heinzel, A.*; Zimmermann, F.*; Furukawa, Tomohiro  ; Aoto, Kazumi 

This is the fourth report on the compatibility of structural and fuel cladding materials that has to be investigated for a possible advanced heavy metal cooled reactor system. The first three reports considered the behavior of 316FR, P122 and ODS steels during 800, 2,000, 5,000 and 10,000 h in stagnant LBE between 500 and 650 degrees centigrade containing 10 sup-6 wt% of oxygen. This report describes experiments of 800, 2,000 and 5,000 h duration in liquid Pb-Bi containing 10 sup-4 and 10 sup-8 wt% of oxygen for 316FR, P122 and ODS steels at 550 and 650 degrees centigrade. 1. No significant dissolution attack occurred on 316FR and P122 steels at 550 degrees centigrade with 10 sup-4 wt% oxygen in LBE. They have Protective oxide layers at the surface, like in the experiments with 10 sup-6 wt% oxygen. At the high oxygen concentration (10 sup-4 wt%) thick oxide multilayers develop on 316FR instead of thin spinel layers at 10 sup-6 wt%, in both experiments LBE is enclosed in the oxide layer. With 10 sup-8 at% oxygen in LBE, however, there is no protective scale formation but strong dissolution attack (up to 120 um) occurs at the 316FR specimen.At the P122 only very little dissolution attack (2um) is observed at the surface.