氢在金属中的扩散——（Ⅲ）硫脲及其衍生物在盐酸介质中对钢铁渗氢影响的研究

氢在金属中的扩散——（Ⅲ）硫脲及其衍生物在盐酸介质中对钢铁渗氢影响的研究 DIFFUSION OF HYDROGEN IN METALS（Ⅲ） Study on the effect of Thiourea and its Derivative on Hydrogen penetration rate in Iron—Steel in Hydrochloric Acid 顾弘 first-author 周仲柏 陶映初 姚录安 <正> 众所周知,铁在盐酸介质中的腐蚀是以氢去极化为特征的。过去,人们在评选这类缓蚀剂的功效时,通常习惯于测定金属阳极溶解过程和与其共轭的阴极过程受抑制的程度,由此判断缓蚀剂的缓蚀效率。但仅考虑这一方面显然是不够的,特别对阴极型缓蚀剂更是如此。若是这些添加剂对氢析出过程的影响主要是减慢氢原子脱附速度,则加入后可能会增大金属表面的氢原子浓度,有可能造成一种比金属溶解损失更为严重的后果——氢损伤。但是,由于测量钢铁中的渗氢行为比较复杂,使这方面的研究受到一定限制。自从M.A.Devanathan等人提出用电化学渗氢技术测定氢在钯中的扩散后,由于该方法具有简便、灵敏、准确等优点,为这方面研究提供了一个有效的实验手段。 In this work, the rates of hydrogen penetration in iron—steel in 1N HC1 containing thiourea and its derivative（Phenylthiourrea and Propenylthiourea） have been measured by electrochemical technique. According to the results of corrosion test, the corrosion rate changes with concentration of thiourea. Only in certain concentration range, thiourea is cathodic corrosion inhibitor. While at all concentrations studied, thiourea accelerates hydrogen penetration in iron—steel in HC1. This phenomenon attributes to the presence of H 2 S, which forms when the thioureas are dissolved in aqueous acidic solutions. In addition, the present study showed that the thiourea molecule is also a accelerater of hydrogen penetration. The mechanism by which thiourea and its derivative accelerate hydrogen penetration in iron—steel in HC1 is discussed on the basis of experimental results. It may be the result of increase surface adsorption energies of hydrogen atom cursed by adsorption of the thiourea compounds, and the increase in concentration of surface hydrogen atom due to inhibition of the recombination step of hydrogen evolution. 1982-02-01 2021-04-01 2