Abstract
The DOE/OCDO sponsored Ultrasupercritical (USC) Steam Boiler Consortium is conducting thermal shock tests on austenitic and nickel-based materials to assess their use in thick-section boiler components. The paper describes the tests on CCA617 and Super 304H thick-walled tubes, the metallurgical analyses of the observed cracking in the bore and on the OD of the samples, and the thermal-mechanical analyses to explain the results in terms of creep and fatigue failure modes. Elastic-plastic and elastic-plastic-creep analyses are used to calculate damage based on rupture life and creep strain accumulation. Fatigue calculations are based on total strain range, inelastic strain range and plastic strain range, where appropriate. The results of the metallurgical and mechanical analyses are compared and conclusions drawn as to the accuracy and effectiveness of available analysis techniques