材料期刊网

<正> 前言 研究氢在金属中的扩散与渗透,定量的方法主要有阴极过程量气法、电化学测量法、高真空测量法和核物理法。电化学测量法的设备简单,灵敏度高,测量方便、快速、准确,因而被广泛用于氢渗透研究,但到目前为止,一般都只用于温度低于100℃的测量;高真空测量法只适用于氢渗透速率大的体系,不宜用于温度低于200℃的测量。因此,对于100～200℃下氢在金属中扩散行为,目前还缺少合适的测定方法。本工作应用电化学测量法的原理,建立了一套测试装置,研究了100～200℃下氢在碳钢中的扩散行为。

An electrochemical set-up was devised to measure the diffusion and permeation rates of hydrogen in cardon steel at elevated temperatures on the principle of Devanathan cell. The optimum parameters for the set-up were obtained as follows: The electrolyte in measuring room was 0.1N NaOH solution; The reference and appendix electrodes were made with pure nickel; The thickness of palladium plating on the measuring side was 0.2μm; The anodic polarized potential to oxidize permeated hydrogen atoms was +300mV (relative to the nickel reference electrode). The diffusion coefficients and diffusion rates of hydrogen in carbon steel at temperatures 100～200℃ were measured with the above mentioned set-up. The activation energy ot diffusion by means of diffusion coefficients was 8.61kJ/mol, The mechanism of H~+ reduction on carbon steel was discussed. The results showed that the mechanism was "fast charging,slow coupling electrochemically".