共查询到16条相似文献,搜索用时 859 毫秒
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在分别采用光学显微镜和辉光放电光谱仪获得S22合金钢的金相显微组织和元素成分的基础上,利用已经过氘渗透速率定量标定的渗透实验装置,研究了S22合金钢在400~600℃下的氘扩散渗透行为,得到了氘在S22合金钢中的渗透率和扩散系数。对比分析了500℃时纯D2和He+1%D2下S22合金钢的氘渗透数据,结果表明,随氘分压的降低,氘在S22合金钢中的扩散渗透孕育期增加,氘渗透速率降低,但即使在较低氘分压下依然有氘渗透现象。该结果可为高温气冷堆、快堆等先进反应堆在使用S22合金钢时进行必要的氚渗透防护及其安全分析提供理论与数据支持。 相似文献
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低活化铁素体/马氏体钢(RAFM钢)是聚变堆产氚包层的优选结构材料。氢同位素在结构材料中的扩散渗透特性关系到产氚回收率、燃料循环及运行安全。本工作对国内研发RAFM钢之一的CLAM钢进行了气体驱动的氘渗透实验,得到573~873 K温度范围内氘的宏观溶解度S(mol/(m3•Pa0.5))为0.264exp(-22 447/RT),扩散系数D(m2/s)为1.38×10-7exp(-17 271/RT),渗透率Φ(mol/(m•s•Pa0.5))为3.64×10-8exp(-39 718/RT)。还进行了氕氘气体混合物的渗透实验,确认了渗透同位素效应;探索了钢中溶解氘的真空热释放去除。 相似文献
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Flibe具有熔点低、中子性能好、沸点高等特点,是未来大型氟盐冷却高温堆的主要候选氟盐冷却剂之一,在堆芯中与中子相互作用后会导致一定量的副产物氚产生。根据哈氏N合金的成分,钍基熔盐堆核能系统(TMSR)发展了GH3535合金,作为未来大型熔盐堆的主要候选结构材料。本实验中采用GH3535合金为试样,通过使用压力差驱动原理搭建的氢同位素扩散渗透装置,试验测得了400~800℃的温度下氢气、氘气在该合金中的渗透系数、扩散系数、Sieverts常数等主要参数。实验结果表明,氢气与氘气在GH3535合金中的扩散渗透机理均属于基体扩散控制过程,扩散渗透过程中氢气、氘气的主要参数与相应温度关系均符合阿累尼乌斯公式。对于不同质量数的氢同位素原子,拟合后渗透系数和扩散系数的指前因子之比分别为1.4:1和1.2:1,扩散和渗透过程中的激活能也非常接近,符合经典扩散理论的同位素效应,可以估算得到氚在GH3535合金中扩散渗透时的主要参数大约为氢的1/3(1/2),并可能用于氚在熔盐堆中的分布计算。 相似文献
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研究了氚在金属材料、陶瓷材料、玻璃、弹性材料和聚合材料中的溶解度系数、扩散系数和渗透率;介绍了国外一些作者关于氢同位素在一些材料中的溶解度系数、扩散系数和渗透率及这些参数随温度变化的经验公式;论述了氚在金属材料、陶瓷材料和玻璃中的扩散渗透机理;总结了氚和氢在316L不锈钢中的扩散系数和渗透率。 相似文献
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研究了氚在金属材料、陶瓷材料、玻璃、弹性材料和聚合材料中的溶解度系数、扩散系数和渗透率;介绍了国外一些作者关于氢同位素在一些材料中的溶解度系数、扩散系数和渗透率及这些参数随温度变化的经验公式;论述了氚在金属材料、陶瓷材料和玻璃中的扩散渗透视理;总结了氚和氢在316L不锈钢中的扩散系数和渗透率。 相似文献
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采用气相渗透方法,开展了国产低活化铁素体/马氏体钢(RAFM钢?)之一的CLAM钢的氚渗透实验,研究了影响渗透的关键因素,建立了可靠的实验方法。在573~823?K温度范围内,得出氚的渗透率FT为2.57×10-8exp(-38639/RT),氚溶解度ST为2.2×10-1exp(-38639/RT),扩散系数DT?为1.17×10-7exp(-22011/RT)。另外,氘氚混合渗透时存在明显的正同位素效应,在实验温度范围内,推导得出的氘氚渗透分离系数αDT为1.42,氕氚渗透分离系数αHT为3.76。 相似文献
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低活化铁素体/马氏体钢(RAFM钢)作为聚变堆结构材料中最有前景的候选材料,其氢同位素渗透行为备受关注。采用氢同位素气相驱动渗透的方法,对中国低活化铁素体/马氏体钢CLF-1的氢同位素渗透行为进行了研究,研究了温度、气体压强、样品表面状态等因素对其渗透行为的影响。结果表明:氢、氘在RAFM CLF-1钢中渗透扩散过程为体扩散控制,渗透率与温度的关系式均遵循Arrhenius关系;在实验测试过程中,由于样品表面发生氧化现象和缺陷捕获造成H2和D2渗透实验中渗透通量出现下降的现象。 相似文献
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Kun Jie Yang Peng Shao Xu Zhang Quan-Fu Han Yuming Ma 《Journal of Nuclear Science and Technology》2013,50(11):1014-1028
We systematically carried out first-principles simulations to study H diffusion and permeation in molybdenum (Mo) and found that their activation energies are the temperature dependence and exhibit the compensation effect. The H migration is primarily via two nearest neighbor tetrahedral sites and its migrating energy raises notably with increasing temperature, which is caused by vibration free energy alteration with the temperature. The H permeation activation energy is also dependent strongly on the temperature since it is the sum of solution energy and migrating energy of H. Our predicted H diffusivity/permeability with the temperature is in quantitative agreement with the experimental result in Mo. The impurity capturing effect can cause the alteration of H diffusivity/permeability with the temperature. Despite the diffusion/permeation activation energy and pre-factor depending strongly on the temperature, the diffusivity/permeability still follows the Arrhenius curve with rising temperature. This attributes to the compensation effect between activation energy and pre-factor, i.e. the increment of the pre-factor compensate directly the modification of diffusivity/permeability in the case of a variation in the activation energy with rising temperature. 相似文献
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《Journal of Nuclear Science and Technology》2013,50(2):143-151
The permeation time-lag method have been used to determine the permeabilities, diffusion coefficients and solubilities of hydrogen and deuterium in type 304 stainless steel of three kinds of surface treated specimens; with oxide film, reduced by H2 gas and Pd coated. For the specimen with a thin oxide film the permeability increased abruptly at the temperature higher than 1,050 K owing to reduction of the oxide film by H2 gas introduced. The permeability and diffusion coefficient for hydrogen-reduced specimens agreed with those for Pd-coated specimens showing the data of bulk diffusion limited. The isotope effects for permeability ΦH/ΦD, diffusion coefficient D H/D D and solubility were about 1.4, 1.2 and 1.1, respectively. From these values θ(=hν/k)=1,530±50K and θ′(=hν/k)=2,740±20K were obtained by the quantum effect of a harmonic approximation. 相似文献
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PdY合金膜因其具有良好的透氢性能与机械性能,有望应用于聚变堆氢同位素纯化工艺。基于PdY合金膜的服役参数及氚安全要求,有必要研究在低氢压下PdY合金膜的氢同位素渗透特性,为后续设计氢同位素纯化组件提供数据支撑。本工作基于直管外压式PdY扩散器,研究了低氢压(<50 kPa)、工作温度为350~450 ℃条件下,厚度为80 μm的PdY合金薄膜管的氢渗透速率与膜两侧压力、工作温度的关系。结果表明,低氢压下,PdY合金膜的氢渗透规律符合J=ΦpnH-pnLd,且压力指数n等于0.9,渗透速率控制机制主要表现为表面过程控速;提高工作温度使得合金膜的渗透通量增大,且温度对扩散过程的影响更大,使渗透过程更加趋于表面控速。此外,计算了该工作温度范围下的渗透系数,并通过阿伦尼乌斯公式推导求得渗透活化能约为24.54 kJ/mol,渗透常数Φ0为5.86×10-6 mol/(m·s·kPa0.9)。低氢压下,该厚度膜的渗透系数可由5.86×10-6e-24.54/(RT) mol/(m·s·kPa0.9)进行计算。 相似文献
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Yasuhisa Oya Makoto Kobayashi Junya Osuo Masato Suzuki Akiko Hamada Katsushi Matsuoka Yuji Hatano Masao Matsuyama Takumi Hayashi Toshihiko Yamanishi Kenji Okuno 《Fusion Engineering and Design》2012,87(5-6):580-583
Effect of surface oxide layer on the hydrogen isotope permeation was studied. Iron oxide was uniformly formed in the oxide layer, although chromium was limited at the interface between the oxide layer and bulk SS-316. The permeation behavior of deuterium for oxidized SS-316 was compared with that for unoxidized SS-316 at temperature range of 333–673 K. The deuterium permeability for the oxidized SS-316 was reduced 1/10–1/20 times as high as that for unoxidized one. However, the activation energy of deuterium permeation as gas form for oxidized SS-316 was almost the same as that for unoxidized SS-316 and was 0.64 eV, which was almost consistent with the sum of activation energies for diffusion and solubility. This fact indicates that the deuterium permeation is diffusion limited. The permeability of deuterium as water form was almost constant even if heating temperature is high, showing that the deuterium was permeated through bulk SS-316 and react with oxygen at the oxide layer as water desorption, which is controlled by the permeation flux of deuterium and oxygen concentration on the surface of oxide layer in downstream side. 相似文献
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