Study of Low Activation Materials for Fusion Reactor

为了获得核聚变反应堆结构材料发展的基础数据，采用中子、电子和离子辐照法对Fe-Cr-Mn奥氏体钢、改性316不锈钢、铁素体钢和钒合金进行了辐照。此外，还对与这些合金相关的模型合金进行了辐照处理。实验结果表明：(1)改性后的316不锈钢具有较低的溶胀率，在较低的30dpa剂量下具有较低的放射性活性。因此，改性后的316不锈钢可以用作较短时间的核聚变反应材料。(2)低活化Fe-Cr-Mn钢在500℃以上时相稳定性较低。因此，当这类钢用于核聚变反应堆时，在200℃以下的低温下，作为结构部件的支撑材料是可取的。(3)低活化Fe-(9-12)Cr基铁素体钢将代替奥氏体钢用于ITER后的DEMO。然而，还有一些问题需要解决，那就是由于嬗变而引入的氦导致的脆化。(4)钒合金具有良好的放射性活化特性、耐辐照性和高温强度，是未来核聚变材料的发展方向。目前可以推荐的合金是V-4Cr-Ti基合金，但这些合金对氧、氢等间隙杂质非常敏感。因此，如果将合金用作第一壁材，应避免杂质的影响。(5)随着合金的长期发展，将需要SiC、金属间化合物等新材料。

In order to obtain the fundamental data on the development of fusion reactor structural materials, Fe-Cr-Mn austenitic steel, modified 316 Stainless steels, ferritic steels and vanadium alloys were irradiated by neutrons, electrons and/or ions irradiations. Furtheremore the model alloys related these alloys were also irradiated. From these experimentals facts the following results and suggetion were obtained :(1) The modified 316 stainless steel showed lower swelling, and it is expected that these steels are lower radio-activated at lower dose of 30dpa. Therefore, the modified 316 stainless steels could be used as fusion react-or marerials for shorter periods.(2) Phase stability of low activated Fe-Cr-Mn steels was lower at temperature of above 500ﾟC.Therefore, when this type of steels are used for fusion reactor, it is aveirable as buck-up materials of structure components at lower temperature below 200ﾟC.(3) Instead of austenitic steels, the low activated Fe-(9-12)Cr based ferritic steels will be available for DEMO after ITER.However, there is still psome problems to be resolved, that is embrittlement due to helium introduced as a result of transmutation.(4) Future materials for fusion reactor, vanadium alloys are expected, because of the well characteristics of this alloy for radio-activation, the resistance against irradiation and high temperature strength. At present the alloy of V-4Cr-Ti based alloys can be recommended, but these alloys are very sensitive for interstitial impurities such as oxygen and hydrogen. Therefore, if the alloys will be used as first wall materials, the effect of the impurities should be avoided.(5) As the alloy development for long periods, other new matreials such as SiC and intermetallic coumpound will be needed.