LONG-TERM CREEP-BEHAVIOR OF AUSTENITIC STEEL S-590 (X 40 COCRNI 20 20)

Typical data from discontinuous long-term stress rupture tests were adapted for a differentiated creep analysis. A test series of more than 200000 h (23 years) single test time was available for austenitic steel S-590. This alloy was formerly used for high temperature applications. Various factors influence the creep behavior and cause anomalies from classical three-stage creep division. These phenomena are: microstructural instability, early creep damage (cavitation, microcracks) and corrosion. Typical features of diffusion creep were not observed. The procedure used in this examination and the principal findings can be applied to other high temperature materials.