On the relative efficacy of electropermeation and isothermal desorption approaches for measuring hydrogen diffusivity
On the relative efficacy of electropermeation and isothermal desorption approaches for measuring hydrogen diffusivity
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DOI：
10.1016/j.ijhydene.2022.10.025
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发表时间：
2022-10
影响因子：
7.2
通讯作者：
A. Zafra;Z. Harris;E. Korec;E. Mart'inez-Paneda
中科院分区：
文献类型：
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作者：
A. Zafra;Z. Harris;E. Korec;E. Mart'inez-Paneda
以冷轧纯铁为例，研究了电化学渗透(EP)和等温脱附光谱(ITDS)方法测定氢扩散系数的相对有效性。用传统的滞后法和突破时间法计算了13次瞬变和8次瞬变EP实验的扩散系数，并与10次ITDS实验的结果进行了比较。结果表明，第二次EP瞬变时的平均扩散系数与第一次EP瞬变时的平均扩散率相似，但相对于第一次EP瞬变时，ITDS的平均扩散系数明显增大。然而，与第一次和第二次EP瞬变相比，ITDS实验的变异系数减少了2倍和3倍，证实了ITDS扩散率测量的重复性得到了改善。系统地评价了极压测量误差增大的来源，揭示了假定的电化学边界条件对极压实验分析和解释的重要影响。
The relative efficacy of electrochemical permeation (EP) and isothermal desorption spectroscopy (ITDS) methods for determining the hydrogen diffusivity is investigated using cold-rolled pure iron. The diffusivities determined from 13 first transient and 8 second transient EP experiments, evaluated using the conventional lag and breakthrough time methods, are compared to the results of 10 ITDS experiments. Results demonstrate that the average diffusivity is similar between the second EP transient and ITDS, which are distinctly increased relative to the first EP transient. However, the coefficient of variation for the ITDS experiments is reduced by 2 and 3-fold relative to the first and second EP transients, confirming the improved repeatability of ITDS diffusivity measurements. The source of the increased error in EP measurements is systematically evaluated, revealing an important influence of assumed electrochemical boundary conditions on the analysis and interpretation of EP experiments.