Experimental Study of Hydrogen Diffusion Behaviors in Stress Fields

Hydrogen diffusion behavior in a given stress field was studied for two high-strength, low-alloy (HSLA) steels using the electrochemical method. In unidirectional tensile stress fields, the apparent diffusion coefficient increased with increases in the linear stress gradient parallel to the direction of diffusion. Steady flux (J_∞) increased similarly. The ideal diffusion coefficient (D₀) increased with the stress gradient. D₀ and J_∞ decreased when the direction of diffusion was opposite to the stress gradient. Experimental results were consistent with the theoretical solution.