管状样品中高温氢扩散系数的测定

MEASUREMENTS OF HYDROGEN DIFFUSION COEFFICIENT FOR TUBE SAMPLES AT MEDIUM AND HIGH TEMPERATURES

采用气相渗透法测定了Cr18Ni10Ti奥氏体合金管材的氢扩散系数.设计了合适的测试装置,测试温度范围为360-600℃.分别对内表面涂铝及未涂铝的管材样品进行了中、高温度氢扩散系数测试.用有限差分方法计算了管材样品氢渗透曲线和氢扩散系数-特征时间曲线,从而能够处理扩散系数的测试数据.涂铝管材的室温氢扩散系数为5.789×10-20m2/s,氢扩散激活能为8.144×104/mol,分别比未涂铝管材低5-6个数量级和高1倍.

By using a specially designed device and gas permeation method, the hydrogen diffusion coefficients for the tube-shape samples of Cr18Ni10Ti austenite steel were measured. The testing temperature covers the range of 360-600 degreesC. The curves of hydrogen permeation flux and the relation of hydrogen diffusion coefficients and specific time were simulated by finite difference method (FDM). According to the simulated curves the experiment data related to the hydrogen. diffusion coefficients can be treated. The hydrogen diffusion coefficients for aluminum film inner coated tubes at room temperature is 5.789x 10(-20) m(2) /s, its activation energy of hydrogen diffusion is 8.144x 10(-20) J/mol, which are 5-6 orders lower and 1 times higher than those of uncoated tubes respectively.