Designing of fast reactor equipment and pipelines: Normative method for calculation of long-term cyclic strength

The paper deals with the method for calculational analysis of long-term cyclic strength recommended by ''Norms for strength...'' to estimate cyclic damage of equipment items being operated at temperatures which cause creep and loaded by repeated thermal or mechanical forces. The paper gives formulae interrelating amplitude of allowable conditional elastic stresses [σAF] and allowable number [N0] of cycles, as well as calculational fatigue curves for alloyed steels, corrosion-resistant austenitic steels at loading duration of 1·105 hours. The paper describes the method for calculational analysis of long-term cyclic strength for items made from steels with non-metallic inclusions, for items contacting with corrosion-aggressive media, welded joints etc. An example of calculational analysis of long-term cyclic strength by the use of recommended normative method is given. It is shown that the item analyzed as an example (the joint of upper tube sheet of BN-600 intermediate heat exchanger and outer shell) has cyclic strength meeting the requirements of ''Norms for strength...'' valid in Russia. (author). 2 refs, 6 figs, 14 tabs