## 1 Introduction  
As a high-energy clean fuel, hydrogen is widely used in aerospace, energy, and other application domains [1]. During hydrogen generation, storage, and transportation, the hydrogen production reactor's inner wall surface contacts with the produced hydrogen. In the presence of concentration differences, the hydrogen atoms penetrate the hydrogen production reactor material surface through adsorption and diffusion. The hydrogen atoms are enriched within the lattices of the steel of the hydrogen production reactor, leading to hydrogen embrittlement and the performance degradation of the material, resulting in the degradation of various hydrogen reactor steel properties [2, 3], which increases the risk of material cracking, gas leakage, explosion, and other major safety accidents associated with the equipment. The hydrogen production reactors, hydrogen containers, and hydrogen-chemical facilities are conventionally manufactured using low-alloy steel due to its excellent machinability, mechanical strength, and low manufacturing costs. Currently, the hydrogen permeation resistance of the materials used can be enhanced by elemental ratio adjustment [4; 5; 6], surface plating [7; 8], and other processing methods. Meanwhile, decreasing the surface unevenness of the material, majorizing the surface micro-topography, and modifying the residual stress variation on the material surface to improve its integrity could also enhance the material's hydrogen permeation resistance, reducing the reduction in the mechanical properties of the material caused by hydrogen permeation [9; 10; 11]. Finally, these approaches can improve the reliability of the equipment and prolong the service life of the equipment. At present, many scholars take surface roughness as the evaluation index of surface integrity and carry out research related to the influence of laws of the surface roughness of materials on the hydrogen permeation resistance and material performance after hydrogen permeation. [PERSON] et al. [12] analyzed the effect of pre-charging hydrogen on the mechanical behavior of melt-blown amorphous Ni-Nb-Zr alloy and found the larger surface roughness specimens had a higher hydrogen absorption capacity, resulting in a higher hydrogen content within the specimens. [PERSON] et al. [13] conducted an electrolytic water experiment and found that the amount of dissolved hydrogen produced during water electrolysis varied according to the roughness factor of the electrode. [PERSON] et al. [14] analyzed the stress corrosion behavior of steels with different degrees of plastic deformation. The experiments found that the steel with more significant deformation promoted the permeation and absorption of hydrogen in the steel due to its higher surface roughness, resulting in higher hydrogen content in the steel. [PERSON] et al. [15] studied the hydrogen embrittlement sensitivity of AISI 304 and 310 austenitic stainless steels with different surface finishing and found that the hydrogen embrittlement process accelerated with the increase in the specimens' surface defects and surface hardness. [PERSON] et al. [16] studied the effect of surface roughness on the fatigue life of specimens in a hydrogen environment and found that the rough surface of the specimen was more conducive to hydrogen permeation, resulting in the shorter fatigue life of the specimen. [PERSON] [17] and [PERSON] et al. [18] investigated the effect of surface roughness on the hydrogen permeation rate of Ti-6 Al-4V alloy and found that the hydrogen capacity at the initial stage of hydrogen charging was directly related to the surface quality of the specimens. [PERSON] [19] analyzed the interaction of different states of surface materials with hydrogen and found that the surface of unpolished specimens absorbed more hydrogen due to having a greater contact surface area. [PERSON] et al.