Growth of Austenitic Stainless Steels Oxidised in Carbon and Oxygen Bearing Gases

Abstract

AbstractAbstractSample lengths from A.G.R. (Advanced Gas Cooled Reactor) fuel cans in 20Cr/25Ni/Nb and 18Cr/12Ni/Nb steels and specimens of thin 18Cr/8Ni/Ti foil have been heated in carbon dioxide and other oxidising gases at temperatures between 750 and 900° for periods up to 2500 h. Length increases of up to approximately 2% have been observed, the growth being greater under conditions of thermal cycling than under isothermal conditions. Extensions have been related in part to carbon pick-upand the formation of carbides but the major proportion of the observed extensions has been due to tensile stresses produced in the thin sectioned steels as a result of the oxidation processes.