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Hydrogen permeation reduces a material’s properties and increases the risk of brittle fracture, which causes a potential safety hazard. A workpiece’s hydrogen permeation resistance could be improved by improving its surface integrity through surface processing. This paper studies low-alloy steel’s surface integrity and its hydrogen permeation resistance in a hydrogen production reactor, using the electrochemical cathodic hydrogen-charging method to carry out electrochemical hydrogen-charging experiments. After the specimens were pretreated using different surface-grinding methods and shot peening pressure strengthening, they were hydrogen-charged on a self-designed and built electrolytic hydrogen charging platform. Before and after hydrogen charging, the specimens’ section hardness and tensile strength were tested, and the fracture morphology of the specimens was observed. The influence laws of surface roughness and surface residual compressive stress on the distribution of material hardness along the depth, the variation in material hardness, the fracture morphology, and the decline in the tensile properties of the low-alloy steel specimens after 5 h of hydrogen charging were analyzed. The reasons for the influence of surface integrity indexes on the hydrogen permeation resistance of the specimens were also analyzed. Based on the experimental results, a series of mechanical processing parameters were proposed to improve the material’s permeation resistance, which provides a theoretical and practical basis for the processing of materials with high surface integrity and hydrogen permeation resistance. Through the experiments, it was found that the hydrogen permeation resistance of the Ra 0.17 μm surface roughness specimen was the best of all specimens with different surface roughness values, and its hydrogen embrittlement sensitivity index was 20.96%. The specimen had the best hydrogen permeation resistance under 336 MPa surface residual compress stress, and its hydrogen embrittlement sensitivity index was 16.45%.

Corrosion can hurt the quality and service life of a workpiece, which could create potential safety hazards. However, improving the workpiece’s surface integrity through surface treatment could improve the effect of corrosion resistance. To study the effect of surface integrity on the corrosion resistance of low-alloy steel for hydrogen reactors, electrolytic corrosion experiments were carried out on specimens that were processed using different grit sandpapers or using different shot peening pressures using a self-built electrolytic platform. The influence regulation of initial surface roughness and surface residual stress on the corrosion rate of the low-alloy steel for a hydrogen reactor under different lengths of corrosion time, surface roughness after corrosion, and the tensile property degradation of the specimens after 4 h of corrosion were analyzed, respectively. In this paper, based on experimental research, we obtain the influence regulation of the processing parameters on the corrosion resistance of low-alloy steel for hydrogen reactors and provide processing parameters that could improve the corrosion resistance of low-alloy steel, which guides the corrosion resistance processing of hydrogen production reactors. It was found through experiments that with an increase in the initial surface roughness of the specimens, the corrosion rate of the specimen tends to decrease with the increase in corrosion duration; the surface roughness of the specimen after corrosion first increases and then decreases with the increase in corrosion time; and the tensile strength of specimen with the initial surface roughness of Ra 0.168 μm is relative good after 4 h of corrosion. With the increase in residual compressive stress on the surface of the specimen, the corrosion rate of the specimen decreases with the increase in corrosion time; the surface roughness of the specimen after corrosion first increases and then decreases with the increase in corrosion time; and the tensile strength of specimen with the surface residual stress of −335.64 MPa is relative good after 4 h of corrosion.

In order to study the influence of workpiece surface topography on deformation and residual stress during shot peening, the paper built a rough surface single-shot peening simulation model and designed a rough surface workpieces shot peening experiment to verify the correctness of the built simulation model, which differed from the smooth surface simulation model and was closer to the actual processing situation. Based on the W-M fractal dimension theory, the shot peening model of the target with a rough surface is established, and the simulation analysis is carried out by finite element software. The effect of different impact positions of the pellet on surface residual stress and surface displacement were also simulated. The simulation found that with the increase of surface complexity, the surface deformation and residual stress would both increase after shot peening. Through shot peening tests on workpieces with different surface roughness, it is found that the error between simulation and experiment results on surface deformation and residual stress are both less than 20%, which verifies the validity of the rough surface single-shot peening model and that the established model could provide a new method on shot peening simulation analysis.