High temperature compatibility of 25/20 type austenitic stainless steel with carbon dioxide

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Date
1962-09
Journal Title
Journal ISSN
Volume Title
Publisher
Australian Atomic Energy Commission
Abstract
The 25% Cr, 20% Ni type stainless steel has been proposed for use in the Australian High Temperature Gas Cooled Reactor in core structures, and in hot gas ducting. Thus a knowledge of the compatibility of this steel with high pressure carbon dioxide was required. Rates and mechanisms of corrosion were investigated for machined, vapour blasted, and etched pretreated samples of this steel, exposed to carbon dioxide up to 5,000 hours in the temperature range 650ºC to 800ºC at gas pressures from 3 p.s.i.g. to 280 p.s.i.g. Oxide film flaking was apparent at all temperatures investigated, but was only severe for pre—ground samples at 710ºC and above, and for pre—vapour blasted samples at 760ºC and above. However, severe intergranular penetration was observed in preetched samples on exposure to carbon dioxide at 650ºC and above. Pressure of the gas appeared to have no systematic effect on the corrosion rate, at least in the temperature range investigated. The maximum useful temperature for which the steel could be used would be limited by the amount of oxide flaking permissible. In reactor gas circuits where a small amount of scale flaking could be tolerated, the steel is satisfactory up to 750ºC.
Description
Keywords
Carbon dioxide, Stainless steels, Austenitic steels, Compatibility
Citation
Lee, E., & Draycott, A. (1962). High temperature compatibility of 25/20 type austenitic stainless steel with carbon dioxide. (AAEC/E98). Lucas Heights, NSW: Australian Atomic Energy Commission.