Behavioral Analysis of Hydrogen in Metals under the Effect of H2S Corrosion Using a Layer-stripping Micro-hardness Technique

  • Lei GU
  • Jing WANG
  • Xiaoyang LI
Keywords: hydrogen distribution, layer-stripping micro-hardness method, terminal solid solubility of hydrogen, hydrogen-saturated layer


In order to study the distribution behavior of hydrogen in metals under the condition of H2S corrosion, a layer-stripping micro-hardness test was designed to analyze the hydrogen distribution along the depth of hydrogen-charged 45 high-quality structural carbon steel at three different hydrogen sulfide concentrations and four corrosion periods in this study. The results show that there is a terminal solid solubility of hydrogen in the metal for hydrogen sulfide solutions over various concentrations and corrosion periods. A hydrogen-saturated layer is produced by hydrogen diffusing through the metal from an unsaturated state to a fully saturated state. The hydrogen-saturated layer is not affected by the concentration of the corrosion, but its thickness increases as the corrosion period increases. In this way, we established a new hydrogen diffusion model in metals.