中文摘要：

为了探讨U-2.5%Nb（质量分数）合金的氢腐蚀行为，利用在线显微镜研究了U-2.5%Nb合金氢蚀初期氢化物的生长动力学，研究了U-2.5%Nb合金氢化初期的氢化物形貌、生长速度、氢化反应速度等之间关系。结果表明，利用在线显微镜表征氢化物的生长速度是可行的，氢化物前沿推进距离与时间呈线性关系。在一定温度范围内，氢化物的生长速度与反应温度符合Arrhenius关系，U-2．5％Nb合金氢化物生长激活能为24．34kJ／mol。当温度增加到125℃附近时，氢化物的生长速度达到最大值，之后，随着反应温度的升高，生长速度快速下降。

英文摘要：

To study the behavior of hydrogen corrosion on U-2.5%Nb alloy （mass fraction）, a gas-solid reaction system with an in-situ microscope was designed. The nucleation and growth of hydride of U-2.5%Nb alloy were observed continuously and recorded by the system. The results show that the growth velocity of hydride can be well characterized by the in-situ microscope. The growth kinetics result indicates that the relation between growth velocity of hydride and time is linear. Hydride front velocity increases with the increasing temperature, which follows the Arrhenius law at about 125 ℃. The reaction activation energy is 24.34 kJ/mol. But at high temperature （〉125 ℃）, the growth velocity decreases sharply with the increasing temperature.