LOW-TEMPERATURE EMBRITTLEMENT BEHAVIOR OF DIFFERENT FERRITIC-MARTENSITIC ALLOYS FOR FUSION APPLICATIONS

In the last few years a lot of different low activation Cr-WVTa steels have been developed world-wide. Without irradiation some of these all oys show clearly a better low temperature embrittlement behaviour than commercial Cr-NiMoV(Nb) alloys. Within the MANITU project a study was carried out to compare, prior to the irradiation program, the embritt lement behaviour of different alloys in the unirradiated condition per forming instrumented Charpy impact bending tests with sub-size specime ns. The low activation materials (LAM) considered were different OPTIF ER alloys (Forschungs-zentrum Karlsruhe), F82H (JAERI), 9Cr-2WVTa (ORN L), and GA3X (PNL). The modified commercial 10-11% Cr-NiMoVNb steels w ere MANET and OPTIMAR. A meaningful comparison between these alloys co uld be drawn, since the specimens of all materials were manufactured a nd tested under the same conditions.