Materials for coal gasification plants utilizing nuclear process heat generated in a high temperature reactor

In coal gasification plants based on nuclear process heat, materials are subjected to high temperature corrosion in process gas atmosphere at 750 to 9000C. The process gas consists of steam, CO, CH4, CO2 and, depending on the gasified coal, low or high H2S-concentrations. Materials for heat exchangers must be resistant to high temperature corrosion. They should also have adequate creep rupture strength. Therefore the commercial alloy Incoloy 800 and various model alloys were exposed to a process gas atmosphere to determine the corrosion behaviour and also stressed mechanically to investigate the interaction of high temperature creep behaviour and corrosion. Compared with Incoloy 800, one of the new model alloys (30-32% Ni, 25-27% Cr, and Ce, Fe-balance) exhibits a very good corrosion resistance even when sulphur rich coal is gasified. The creep rupture strength at 9000C is in the range of the creep strength for Incoloy 800. (orig.)