316不锈钢表面对氢同位素透过阻碍作用的功函数及俄歇能谱研究

WORK FUNCTION AND AES STUDY OF SURFACE BARRIER EFFECT UPON HYDROGEN ISOTOPE PERMEATION THROUGH 316 STAINLESS STEEL

用功函数和俄歇能谱方法研究了３１６不锈钢的不同表面状态对氢同位素透过行为的阻碍作用．俄歇能谱分析表明，在真空环境中（１０－４Ｐａ）于１２７３Ｋ加热１小时后不锈钢表面未发现有氧的存在，但有大量的硫偏聚，它对氢同位素的透过没有阻碍作用；对于真空退火后又在室温下暴露于空气中２４小时的不锈钢表面则形成了双氧化层结构——外层为铁的氧化物而内层由铁、铬和镍的氧化物组成，该氧化层对氢同位素的透过有明显的阻碍作用，其实质是该氧化层所发生的还原反应，其中外层的氧化铁在高温下容易被氢气体还原，而内氧化层在本研究条件下只能够产生部分还原，其还原的程度可由功函数的测定结果明显地反映出来．结合气体氚扩散速度的实验结果，对其作用机理作了进一步的探讨．

he work function and auger electron spectroscopy(AES) was carried out to study the surface barrier effect on hydrogen isotope permeation through 316 stainless steel. The result of AES shows that there was not oxygen existing on the surface heated in vacuum (10-4Pa) at 1273K for one hour, but large amounts of sulfur segregated has not barrier effect on hydrogen isotope permeation. The duplex oxide layer was formed on the surface exposed to air at room temperature for 24 hours after vacuum annealing. The top layer consists of iron oxide and inner layer consists of iron, chromium and nickel oxides. The central point at surface barrier effect is the reduction of this oxide layer. The iron oxide on the top layer can be easily reduced but the inner oxide layer can only be partly reduced. The degree of the reduction can be obviously reflected by the result of work function measurement. Combining with the experiment result of our previous work, further discussion on the mechanism of surface barrier effect has been given in this paper.