CREEP-RUPTURE STRENGTH AND CREEP TESTS ON THE EFR STRUCTURAL MATERIAL 316L(N), DIN 1.4909

The tensile properties in the temperature range from RT-850-degrees-C and the creep and creep-rupture behaviour from 500-750-degrees-C were determined for the structural material of the planned European Fast Reactor (EFR). The test program encompassed two melts from a German and French manufacturer with rupture times up to 16000 h. The test results are added with data from a melt of the fusion program, that has the same chemical composition with maximum rupture times up to 40000 hours. All test results were compared with long-term creep results from the commercial type 1.4919 resp. AISI 316 from German, Japanese and American laboratories. In comparison with the Mo-free structural material 1.4948 (AISI 304), the 1.4909 type shows markable higher creep-strength values and a more creep resistant behaviour. The metallographic examinations demonstrate the complex precipitation behaviour and the creep-resistant structure in connection with high ductility and transcrystalline fracture mode in the temperature range from 500-700-degrees-C.