氚在不锈钢中的体扩散行为  

BULK DIFFUSION OF TRITIUM IN STAINLESS STEEL

作　　者：陈长安[1] 武胜[1] 倪然夫[1] 柏朝茂[1] 

机构地区：[1]中国工程物理研究院,四川绵阳621900

出　　处：《核化学与放射化学》2000年第3期144-150,共7页Journal of Nuclear and Radiochemistry

基　　金：中国工程物理研究院科学基金!资助项目 (990 337)

摘　　要：采用酸液蚀刻法和液体闪烁计数法测量了在 6 73K和 1 0 1 3K下分别充氚 8h、室温空气中时效 1～ 3a后 ,31 6L型和 2 2 1 3 5型不锈钢圆柱样品中氚浓度的分布。运用扩散方程的有限差分数值解法 ,计算了样品中氚和氦 3的体浓度分布 ,结果与实验结果符合较好。研究结果表明 ,室温时效期间 ,氚在不锈钢中的扩散缓慢 ,主要通过衰变成氦 3后发生浓度变化 ;由于氧化层的影响 ,表面附近的氚只是部分逸出 ;样品中存在“固溶”和“非固溶”两种形式的氚 ,前者所占份额较小 ,蚀刻时进入溶液 ,后者所占份额较大 ,为缺陷俘获 ,以分子或多个原子簇的形式存在 ,蚀刻时以气体形式释放。The distribution of tritium in 316L and 22 13 5 types of stainless steel cylinders after being exposed to tritium gases at the temperature of 673K and 1 013K and aged in air at room temperature for one to three years is determined with the liquid scintillation counters through etching the samples. The bulk distribution of tritium and helium 3 concentration in these samples is calculated, based on the diffusion equation and finite difference method. The calculation is in good agreement with the determination. According to the results of calculation and experimental determination, it can be concluded that the decaying of tritium to helium 3 is the main cause that has changed tritium concentration during the aging procedure due to the very low diffusion rate at room temperature. And because of the oxide layer on the surface, which can slow the diffusion of tritium, tritium near the surface only partly escapes from the samples. There are two forms of tritium——the “dissolved”and the “non dissolved”. The former is usually less than the latter, which enters the solution while the samples are being etched. The latter is captured by the crystal defects as molecules or clusters of many tritium atoms, and released as gases while being etched.

关 键 词：不锈钢 扩散 液体闪烁计数法 浓度分布 测定 

分 类 号：TG142.71[一般工业技术—材料科学与工程] O613.2[金属学及工艺—金属材料]