【作者】 章征柏；

【导师】 叶邦角； 翁惠民；

【作者基本信息】 中国科学技术大学 ， 粒子物理与原子核物理， 2009， 硕士

【摘要】 低活化铁素体/马氏体钢被认为最有希望可用于第一壁/包层的结构材料。本论文的目的主要是探讨中国低活化马氏体CLAM钢的辐照损伤机理,研究的重点集中在CLAM钢辐照前的微观分析;Monte Carlo方法对辐照损伤的模拟分析;以及用慢正电子技术研究质子辐照CLAM钢时所产生的缺陷及其退火回复行为,具体内容如下:1. CLAM钢辐照前的微观分析通过对CLAM钢的金相和电镜观察,可知CLAM钢热处理工艺后得到的是板条马氏体结构,马氏体板条内聚集了大量的位错。根据经验公式以及实验数据估算出CLAM钢位错密度的数量级为109cm-2。用多普勒展宽方法研究了CLAM微结构随退火温度的变化,该钢中含单空位、双空位、位错和小空位团等缺陷,分别经不同温度而退火。2.辐照损伤模拟简要讨论了离子轰击模拟中子辐照对材料辐照损伤影响,利用SRIM程序,讨论了离子种类、能量、辐照剂量等实验参量的选择对候选结构材料的溅射率、溅射原子分布、离子能量损失、入射离子在材料中的分布以及产生的辐照损伤情况进行了分析比较,得到了有意义的结果,为接下来的实验提供了初步的理论依据。3.质子辐照CLAM钢利用慢正电子技术研究了质子辐照CLAM钢时所产生的缺陷及其退火回复行为,发现辐照在材料中产生空位团数密度随质子注量增加而增多,而其尺度增大并不明显。辐照仅产生原子尺度的空位和空位团,400℃退火可以使缺陷很好地消除。此外分析了硅对CLAM钢辐照性能的影响,实验上没有观察到硅的添加抑制了质子辐照缺陷的产生。最后比较了离子辐照与中子辐照,简单讨论了离子辐照实验时一般需要考虑的因素。更多还原

【Abstract】 Reduced Activation Ferritic/Martensitic steels have been considered as the most promising candidate for the structural materials of the first wall/blanket for fusion reactor. In order to investigate radiation damage mechanism of the China low activation martensitic (CLAM) steel, the dissertation concentrated mainly on the microstructure analysis of CLAM steel and the SRIM code had been used to simulate the material radiation damage. Besides, the proton radiation damage of CLAM steel was probed by slow positron beam. They were:1. Microstructure analysis of CLAM steelThe metallographic and electron microscope observation showed that CLAM steel obtains the structures of lath martensite including extensive dislocation. The dislocation density in CLAM steel was estimated to be on the order of 109cm-2. Microstructure of CLAM steel and its thermal annealing behavior had been studied by Doppler technique. There exit mono-vacancies, di-vacancies, dislocations and small vacancy clusters in steel.2. Simulate the material radiation damageThe Monte Carlo code SRIM had been used to simulate the sputter yield, distribution of ions, energy of sputter atom, radiation damage of materials for bombardment by ions at different energy and different species. It would provide elementary theory for experiment.3. Proton irradiation defects in CLAM steelThe proton radiation damage of CLAM steel and the annealing behavior of defect were probed by slow positron beam. It was found that the density of vacancies increased, and the size reached a saturation value, with increasing of irradiation fluence. The whole region of irradiated sample was only slightly damaged. Small vacancies and vacancy clusters were the dominant defects, and were recovered after annealing at 400℃. Besides, the effect of minor additive Si on irradiation behavior for CLAM steel was studied. The experimental results showed that additive Si can not prevent proton irradiation defects.更多还原