Abstract:

ESDU 05008 presents stress-response data and cyclic stress-strain data for austenitic type 316 stainless steels at temperatures between -269 and 800°C (-452 and 1472°F). The results of tests carried out on type 316 stainless steels, including the low carbon and high nitrogen variants, are reported. The low cycle fatigue data are examined using the methods described in ESDU 04022 "An introduction to low-cycle fatigue phenomena".

The evolution of stresses per cycle during testing, or the stress response, is discussed in terms of the initial and peak stress amplitude and the number of cycles to failure. The effect of temperature, applied strain amplitude and nitrogen content of the steels tested on the stress response is examined. The degree of hardening, which is calculated as the percentage difference between the initial and peak stress, is considered with an examination of the hardening and softening behaviour of the steels.

The Item presents half-life cyclic stress-plastic strain curves from tests carried out at temperatures between room temperature and 800°C (1472°F); those curves are analysed to determine the cyclic strength coefficient K'_sc and the cyclic strain-hardening exponent n'. An analysis of the effect of test conditions on K'_sc and n' is provided as are methods to calculate these constants using fatigue strength and ductility constants ( σ'_f , ε'_f , b and c) from ESDU 05007 "Strain-life data for type 316 austenitic stainless steel at temperatures between -269 and 816°C (-452 and 1501°F)".

Two worked examples illustrating some of the methods described in the Item are provided.