Test data for uniaxial creep on material ALLOY 800H at 950 Celsius and a stress of 16.47 MPa

The creep rupture data in this collection were determined for the high temperature reactor projects (the direct cycle helium turbine project, the nuclear process heat project and the district heating project) of the Federal Republic of Germany and the State of North Rhine Westphalia, the aim being to qualify the candidate constructional alloys for service at temperatures up to 950°C. Several batches of each alloy were investigated and special attention was given to the effects of the service environments (helium containing different impurity gases, such as hydrogen, water vapour, carbon monoxide and methane, all at microbar levels, and methane reforming gas mixture) on the properties. In the test machines, these test environments led to carburisation of test pieces. However, analysis of the data showed that the stress rupture data for tests in air, in impure helium and in methane reforming gas lay in the same scatterband at each temperatures tested.

The data were used for the formulation of draft nuclear design rules for the high temperature reactor systems, which are summarised in 'Proceedings of the Workshop on Structural Design Criteria for HTR', G Breitbach, F Schubert, H Nickel, Jül-Conf-71, April 1989, Berichte der Kernforschungsanlage Jülich GmbH, ISSN 0344-5798.