IDENIIFICATION OF RADIATION EMBRITIEMENT CENIERS IN PRESSURE VESSEL STEELS

电阻率和显微硬度的测量已被用来阐明压力容器钢的脆化机制。用高能质子辐照Fe-Cu模型合金，并通过退火实验，讨论了各种缺陷的产生、生长和湮灭模型。还研究了估算辐射效应的辐照相关性。1.电阻率测量研究建立了高精度电阻率自动测量系统。已经发现，由于铜或其它杂质与辐射诱导缺陷的缔合，Fe-Cu合金在质子辐照后电阻率降低。对初步退火实验的再分析表明，存在缺陷、铜原子和碳原子的成簇过程，以及伴随这些杂质释放的缺陷湮灭过程等，并提出了辐照后过程的模型。 关于我们 怨恨为了进一步证实该模型，有必要获得这些阶段的激活能和频率因子以及这些阶段与杂质浓度的关系。2.用显微硬度测量方法研究Fe-Cu合金的时效过程。合金表现出典型的时效硬化。最大硬度取决于铜的浓度，表明硬化是由铜浓度在时效温度下的过饱和解释。在讨论铜对辐射脆化的影响时，应考虑铜在溶液中的浓度，而不是总浓度，从达到最大硬度的时间得到的表观激活能为154 kJ/mol，远小于铜在铁中扩散的激活能。这似乎表明存在淬灭的空位或铜与空位的关联3.辐照相关性辐照相关性是一种基于机理的方法来估计辐射效应。作为辐照相关性研究的一部分，本文对缺陷成簇机理、高能重离子辐照损伤原位观测的应用、辐照相关性的层次结构和模型化进行了研究。少

Electical resistivity and micro-hardness measurements have been applied to elucidate the embrittlement mechanisms of pressure vessel steels. Fe-Cu model alloys were irradiated with energetic protons and from annealing experiments, models of production, growth and annihilation of various defects were discussed. Irradiation correlation to estimate radiation effects has also been studied. The results are summarized as follows :1.Studies with electrical resistivity measurementsAutomatic measurement system of electrical resistivity with high precision has been established. It has been found that the resistivity decreases after proton irradiation in Fe-Cu alloys due to association of copper or other impurities with radiation induced defects. Re-analysis of preliminary annealing experiments suggests the presence of clustering process of defect, copper and carbon atoms, defect annihilation processes with liberation of these impurities and so on. A model of post irradiation processes has been p … More resented. To further confirm the model, it will be necessary to obtain activation energies and frequency factors for these stages and the dependence of the stages on impurity concentrations.2.Studies of ageing processes of Fe-Cu alloys by means of micro-hardness measurements.To elucidate the behavior of copper atoms in Fe-Cu, age-hardening experiments have been performed. The alloys show typical age-hardening. The maximum hardness depends on copper concentration, indicating that the hardening is explained by supersaturation of copper concentration at the ageing temperatures. It is important to note that copper in solution, not the total concentration should be considered in discussing the effect of copper in radiation embrittlement.Apparent activation energy obtained from time to reach maximum hardness is 154kJ/mol, which is much less than the activation energy of diffusion of copper in iron. This seems to indicate the presence of quenched-in vacancies or association of copper with vacancy3.Irradiation correlationIrradiation correlation is a mechamism-based methodology to estimate radiation effects. As a part of irradiation correlation, defect clustering mechanisms, application of in-situ observation of radiation damage with energetic heavy ions, hierarchical structure of irradiation correlation and modeling have been studied. Less