Effect of microstructure on hydrogen uptake in SA 210 grade A1 steel studied using cyclic voltammetry and hydrogen permeation method

Abstract

Carbon steel piping and tubing can be degraded by hydrogen uptake. The hydrogen permeation method is commonly applied to testing and qualification steel in response to hydrogen atom diffusion. Cyclic voltammetry (CV) has recently been proposed because it is a more straightforward method than permeation. A comprehensive study was conducted to investigate whether these two methods are comparable. A model alloy of SA 210 grade was studied. The study involved preparing specimens with varying microstructures through different heat treatments. Subsequently, metallographic analysis was conducted on each microstructural variation, followed by mechanical testing to evaluate the changes obtained before and after the hydrogen absorption test. The CV method consisted of three steps: CV before H absorption to search for a reference voltammogram, H charging, and CV after H absorption to determine the after-charge voltammogram. Electrochemical hydrogen permeation tests were performed in a Devanathan–Stachursky double cell. A comparison of the CV and permeation methods revealed that they show pretty similar results in evaluating the interaction between steel and hydrogen. Permeation methods provide quantitative results, while CV offers more qualitative insights. Both methods show that the quenched steel has the slowest hydrogen diffusion rate compared with those in normalized and base material conditions.