Explosive forming of 316L(N)-IG for the production of saddle shaped parts for the ITER vacuum vessel

Full text of publication follows: A major challenge in the production of the ITER vacuum vessel sectors are the saddle shaped shell plates. The most promising conventional production technique is hot pressing. It is expected that the necessary calibration after the forming process makes this fabrication route expensive. Secondly the material properties can be degraded by the elevated temperatures. Explosive forming is seen as an alternative process with attractive aspects. Due to a high strain rate the yield stress and ultimate tensile stress of the material are raised, while maintaining the major part of the ductility of the material. In this study, explosively formed saddle shapes of 60 mm thick 316L(N)-IG are analysed. A series of mechanical and dimensional stability tests will be carried out on the explosively formed material. The dimensional stability of the final part will be investigated by water jet cutting of holes and trimming of the sides. The mechanical tests will consist of tensile and fracture mechanics tests at temperatures between 25 and 300 deg. C. The microstructure will be examined by optical and transmission electron microscopy. (authors)