SOME ASPECTS OF THE CORROSION OF A 20°/oCr/25°/oNi/Nb STAINLESS STEEL AT ELEVATED TEMPERATURES

摘要

Work is reported on three aspects of the corrosion of a 20%Cr/25%Ni/Nb stainless steel at temperatures within the range 600-1100 C, namely the exchange of carbon between a carbon dioxide environment and the metal, the influence of minor alloy additions of yttrium on corrosion by carbon dioxide, and the influence of fission neutron and fission fragment irradiation on corrosion by carbon dioxide and oxygen respectively.nThe majority of the work on the behaviour of carbon has been concerned with a pure carbon dioxide atmosphere over the temperature range 650-850 C. Under these conditions the steel initially picked-up a small amount of carbon, but subsequently, at least up to 722 h exposure at 850°C, it was slowly decarburised in accordance with thermodynamic predictions.