EFFECT OF DISSOLVED OXYGEN ON THE CORROSION AND OXIDE MORPHOLOGY OF MATERIALS IN SCW
The SCW corrosion test loop at the University of New Brunswick has been used to examine theeffects of dissolved oxygen in the water on the corrosion behaviour of alloys being consideredfor use in the CANDU?-SCWR. This study includes the exposure of an ODS steel, a novelferritic alloy produced as a base alloy for future ODS development and commercially available304 stainless steel. Duplicate coupons cut from stock of all the steels were exposed tosupercritical water with a dissolved oxygen concentration held constant at less than 5 ppb or at200 ppb. Experiments were carried out at two temperatures, 400°C and 500°C at a pressure of25 MPa for durations of 100, 250 and 500 hours. Direct weight change results indicatedincreased weight gain, on the order of 1.5 to 2 times greater, for the alloys exposed inoxygenated conditions. A comprehensive coupon descaling procedure was also established andreveals a more dramatic effect of dissolved oxygen in the supercritical water leading to overallcorrosion rates five-to-six times higher in some cases than in the deoxygenated condition. Theresults highlight the necessity for sample descaling to elicit the true corrosion of materialsexposed to supercritical water. Weight change data were combined with detailed surfacecharacterization of the samples using SEM and EDX analysis that revealed an increase in theouter oxide porosity at the higher oxygen levels, a finding consistent with the increasedcorrosion rates observed.
W.Cook J.Miles
University of New Brunswick,Fredericton,New Brunswick,Canada
国际会议
3rd China-Canada Joint Workshop on Supercritical Water-Cooled Reactors(第三届中国-加拿大超临界水堆研讨会 (CCSC-2012)
西安
英文
1-11
2012-04-18（万方平台首次上网日期，不代表论文的发表时间）