STRUCTURAL-MATERIALS BY POWDER HIP FOR FUSION-REACTORS

Tokamak blankets have complex shapes and geometries with double curvat ure and embedded cooling channels, Usual manufacturing techniques such as forging, bending and welding generate very complex fabrication rou tes. Hot Isostatic Pressing (HIP) is a versatile and flexible fabricat ion technique that has a broad range of commercial applications. Powde r HIP appears to be one of the most suitable techniques for the manufa cturing of such complex shape components as fusion reactor modules, Du ring the HIP cycle, consolidation of the powder is made and porosity i n the material disappears. This involves a variation of 30% in volume of the component. These deformations are not isotropic due to temperat ure gradients in the part and the stiffness of the canister. This pape r discusses the following points: (i) Availability of manufacturing pr ocess by powder HIP of 316LN stainless steel (ITER modules) and F82H. martensitic steel (ITER Test Module and DEMO blanket) with properties equivalent to the forged one, (ii) Availability of powerful modelling techniques to simulate the densification of powder during the HIP cycl e, and to control the deformation of components during consolidation b y importing the canister design, (iii) Material data base needed for s imulation of the HIP process, and the optimisation of canister geometr y, (iv) Irradiation behaviour on powder HIP materials from preliminary results. (C) 1998 Elsevier Science B.V. All rights reserved.