Design Of High Temperature Components Research Articles

Aspects of design codes for metallic high temperature components

High temperature component design is very important in different industrial fields. This paper discusses work done in Germany on the design of metallic components for the Helium Cooled High Temperature Reactor. Candidate materials for application at the different temperature regions are presented. Criteria are developed to specify the allowable strength values of the materials (S m, S t) for use in design codes. The following typical relevant phenomena are treated and discussed: • —creep under uniaxial and multiaxial conditions up to temperatures of 1000° C; • —creep fatigue interaction, where holding times during the stress strain cycles have a great influence on the life time; • —creep buckling for pressure loaded shells with initial imperfections; • —creep ratcheting as a phenomenon, where cyclic secondary stresses produce enhanced deformations; • —fracture mechanics at high temperatures with the aspects of creep crack growth and fatigue crack growth.

Multiaxial loading tests of high temperature reactor components

This paper provides background information on the theory and tests to develop stress and strain analysis procedures employed in the high temperature component design of the helium cooled reactor prototype plant THTR.

High temperature component design

Abstract High temperature component design requires the consideration of constructive aspects prior to design and dimensioning work. In the high temperature range of more than 800°C special importance is attached to the failure modes “creep fatigue”, “ratcheting” and “creep buckling”. Comprehensive examinations of existing design rules considering these failure modes with regard to possible applicability for HTR-conditions have been completed. Corresponding calculations have pointed out that there is a promising potential for safe component design even for extreme temperature load conditions. These results have additionally confirmed that available elastic methods often cannot be used and would lead to very conservative approximations. Thus the improvement of simplified verification methods as well as the improvement of relevant constitutive equations is required in view of further development work in the field of high temperature component design.