Mechanical properties data needs in Type 316 steel for fast reactor application

The design of high-temperature components has become much more sophisticated in the last decade, demanding considerably more materials data. Data requirements for Type 316 steel are discussed in this paper in relation to the Commercial Demonstration Fast Reactor. Although guidance can be obtained from ASME Code Case N47, there are many areas where additional information is considered necessary. The present data position is given and areas for further work identified. Particular emphasis needs to be given to obtaining additional data on creep/fatigue, strain-controlled high-cycle fatigue, fracture toughness and low temperature deformation. Further information is also required on long-term stress rupture, creep deformation, stress relaxation and crack growth. Although the paper is centred on the properties of solution-annealed Type 316 steel, for a full design endorsement it will also be necessary to establish the effects of thermal aging, sodium and irradiation environment and the properties of weld metal. (author)