Study on passivation effect of dissolved hydrogen on primary material

In this project, 304L stainless steel, the key material of the boron-free primary circuit system, was selected as the research object, and three passivation process conditions were simulated by high temperature and high pressure circulation loop to study the influence of hydrogenation on the thermal passivation effect. Scanning electron microscope, transmission electron microscope and corrosion weight test were used to study the influence of dissolved hydrogen on the morphology, composition, film thickness and corrosion rate of the oxide film of the primary circuit material. The results show that: (1) the 304L stainless steel has a double-layer oxide film pore structure under the three passivation process conditions, and the corrosion rate is at a low level, and the corrosion rate decreases to a certain extent under the hydrogenation condition; (2) After hydrogenation, the thickness of the oxide film formed on the surface of 304L stainless steel becomes thinner and the surface oxygen content decreases, which may be related to the reducibility formed by hydrogenation.