PDF(Pubmed)
Abstract：
Hydrogen diffusion and uptake in nickel Alloy 625 under cathodic protection potential (-1050 mVAg/AgCl) and temperature (10 °C) were studied using electrochemical permeation tests. It is the first time hydrogen permeation of nickel alloy at a temperature lower than room temperature was investigated. The results revealed that the effective diffusivity of hydrogen D eff at -1050 mVAg/AgCl varied from 1.81 to 2.86 × 10-15 m2/s across the temperature range of 10-23 °C. The effective subsurface hydrogen concentration C s u b was influenced by both the applied temperature and overpotential. Particularly, the change in C sub at 10 °C is dependent on the hydrogen absorption efficiency affected by the surface coverage fraction of hydrogen. Furthermore, the hydrogen fugacity on the sample surface f H 2 , the applied overpotential, and the temperature have been successfully cross correlated to interpret hydrogen evolution and adsorption. It was demonstrated that f H 2 primarily changed with the applied overpotential, while the temperature affected the gradient of f H 2 during the potential increment. The current study provides valuable insights for industries, assisting in the prediction of hydrogen absorption and hydrogen-assisted failures in subsea nickel alloy components.
摘要：
使用电化学渗透测试研究了在阴极保护电位（-1050mVAg/AgCl）和温度（10°C）下镍合金625中的氢扩散和吸收。这是首次研究镍合金在低于室温的温度下的氢渗透。结果表明，在10-23°C的温度范围内，氢Deff在-1050mVAg/AgCl时的有效扩散系数在1.81至2.86×10-15m2/s之间变化。有效的地下氢浓度Csub受施加的温度和过电势的影响。特别是,在10°C下Csub的变化取决于氢的表面覆盖分数影响的氢吸收效率。此外，样品表面的氢逸度fH2，施加的过电势，和温度已经成功地交叉相关来解释氢的析出和吸附。结果表明，fH2主要随施加的过电势而变化，而电势增加期间，温度会影响fH2的梯度。当前的研究为行业提供了宝贵的见解，协助预测海底镍合金部件的氢吸收和氢辅助故障。
