氢在金属中的扩散——（Ⅱ）常温下测定钢铁中氢扩散系数的研究

氢在金属中的扩散——（Ⅱ）常温下测定钢铁中氢扩散系数的研究 DIFFUSION OF HYDROGEN IN METALS （Ⅱ） Study on the Measurement of Diffusion Coefficient of Hydrogen in Iron—Steel at normal temperature 顾弘 first-author 周仲柏 陶映初 姚录安 <正> 一前言自从M.A.Devanathan和Z.Stachrski 1962年提出应甩电化学方法研究氢在钯中的吸收和扩散[1]以来,由于这种方法具有简便、灵敏等特点,很快引起了科研工作者的关注,并广泛地用来研究在不同条件下、氢在不同材料中的吸收和扩散行为。鉴于钢铁在国民经济中的重要地位和使用过程中遇到的许多与氢有关的问题（例如氢脆等）,故试验工作主要集中在钢铁材料上进行。但从很多作者发表的氢扩散系数来看,即使应用纯铁作试样,数据分散性仍然很大[2],有的甚至达到几个数量级之差[3]。对这问题曾有不少学者在各自实验事实的基础上加以讨论,以求得相应的解释[3-12]。但还未见到这方面工作的系统报导。常温下应用电化学方法测定钢铁中氢扩散系数时数据分散性大,表明在测试过程及数据 There is obvious diversity of published data of diffusion coefficients of hydrogen in iron—steel at normal temperature。 The causes of this phenomenon were investigated by comparing the result of different data—processing techniques of electrochemical measurement and test condition （e. g. surface condition, internal structure of sample and medium composition）. It has been discovered that the measured apparent diffusion coefficient of hydrogen varies with concentration of hydrogen within the sample, which is in contradiction with the basic supposition（D=const. ）of the Fick’s Second law. Then the diversity of data could be explained to a certain extent. It was also found that all factors which could alter the internal structure and surface condition of sample may affect the measured apparent diffusion coefficient of hydrogen to the extent as much as 1—2 orders of magnitude. For reason given above it is apparent that the diffusion of hydrogen in ironsteel can not be treated as the simple case of homogeneous bulk diffusion. It is a rather complicated physicochemical process. It seems necessary to point out that, when the diffusion coefficient of hydrogen through ironsteel samples is quoted or measured, source of samples and test conditions should be described in detail. 1981-03-01 2021-04-01 3