The Hydrogen Diffusion Behavior Of10CrSiNiCu Steel Under Tensile Stress

For the exploration and development of marine resources, there are more stringentrequirements for material properties needed in the related fields, which require ensuring highstrength and high anti-failure ability.10CrSiNiCu steel is a kind of HSLA steel which iswidely used in the field of marine engineering and naval equipment. Hydrogen embrittlementis one important failure form of this type of steel. Therefore, it is of great significance thatresearching the diffusion behavior of hydrogen at the crack tip and other regions underdifferent stress of high strength steel in the environment of simulated acid salt water. Theresearch in this field is important for the material design and researching related protectivemeasures in the marine environment.In this paper, by combining the electrolytic double cell technology and micro electrolyticcell technology, we establish an equipment which can be successfully used for in-situ testingthe hydrogen diffusion behavior of metal in the micro region of the crack tip. The testconfirms that three tensile stresses significantly promote the diffusion capabilities of hydrogenas well as the concentration of hydrogen atoms in the metal at the crack tip region (diffusionsource area of sub-surface). And by exploring the mechanism of the concentration ofhydrogen atoms in the metal at the crack tip region, we confirm the mechanism thatstress-induced diffusion of hydrogen play an important role in this process, but thismechanism is not the only factor. To solve this problem we creatively put forward thepromotion mechanism of tensile stress: we find the tensile stress could improve the hydrogentrap effect on the metal surface which can be communicated by the method of contact angletesting. And the hydrogen trap can block the process of the desorption of hydrogen atomsbecoming hydrogen molecules. This kind of effect acts a part of hydrogen embrittlementpromoters such as arsenite and hydrogen sulfide. And this kind of promotion can reduce themechanical capability of metal.By studying this the promotion mechanism of tensile stress, we successfully made akind of inhibitor with strong adsorption performance. By adding this kind of inhibitor in thesolution of hydrogen permeation, we successfully inhibit the promotion effect of tensile stressin the hydrogen permeation process and the reducing of the mechanical behavior. That willprovide design direction of materials for reducing the occurring of the hydrogen induced cracking failure.