高温氘离子辐照对低活化钢微观结构的影响

Microstructure changes of reduced activation steel after deuterium ion irradiation at high temperature

材料问题是可控核聚变能否实现商业应用从而解决人类能源问题的"瓶颈"之一。低活化铁素体/马氏体(RAFM)钢具有良好的抗辐照性能,被普遍认为是新一代聚变反应堆的候选结构材料之一。在聚变堆环境下,材料不仅会受到高能中子辐照而且氘氚也可能进入材料中。为了研究氘离子以及辐照对低活化钢的微观结构的影响,采用CLAM钢(一种RAFM钢)和FeCr模型合金,在500℃下进行58keV氘离子辐照,利用高分辨透射电镜对比分析辐照前后材料微观结构的变化,研究辐照及氘离子对低活化钢的影响。结果表明:高温氘离子辐照不仅在材料中产生大量的缺陷和缺陷集团,同时还可能产生辐照诱导析出。而CLAM钢中原有的析出物经高温离子辐照后并没有发生非晶化,对其原因进行了讨论。

A good understanding on the effect of deuterium which exists in the environment of fusion reactions and irradiation is important to develop structural materials in fusion reactors and for a safe design and operation of innovative nuclear systems.Reduced activation ferritic/matensitic (RAFM)steel is considered as the candi-date of structural materials for fusion power reactors due to their excellent resistance to swelling under irradia-tion and low cost.To investigate the effects of deuterium ion and irradiation on the microstructure of RAFM steel,CLAM steel,one kind of RAFM steel,and Fe-10Cr model alloy have been irradiated by 58 keV deuteri-um ion at 500 ℃.The microstructural changes were investigated by high-resolution transmission electron micro-scope (HRTEM).The results show that lots of defects such as dislocation loops have been induced.Precipitates have also been induced after deuterium ion irradiation at high temperature.According to the HRTEM image of M23 C6 in irradiated CLAM steel,no obvious amorphization has been observed.This complex phenomenon was discussed.