Experimental investigation on the hydrogen embrittlement characteristics and mechanism of natural gas-hydrogen transportation pipeline steels

Abstract

Hydrogen blended with natural gas is one of the best ways for large-scale hydrogen transportation; however, pipeline steels exploited for transferring natural gas have the risk of hydrogen embrittlement. Therefore, the hydrogen damage mechanism and resistance property of different steel pipelines should be carefully examined to select suitable materials for the task mentioned above. The common X42, X52, X70, and AISI 1020 are taken into account as research objects. Their mechanical properties and hydrogen absorption properties in a hydrogen environment are investigated to explore further factors affecting the hydrogen embrittlement of material. Dynamic slow strain rate tensile test results show that these materials exhibit varying hydrogen embrittlement sensitivity in a hydrogen environment. AISI 1020 has the highest hydrogen embrittlement susceptibility, then X70, and X42 presents the lowest one. Generally, hydrogen embrittlement behaviours are strengthened by increasing the current density. As the current density grows, the fracture mode of pipeline steels transforms from the ductile fracture to the quasi-cleavage fracture and finally turns into the cleavage fracture. The hydrogen embrittlement fracture of the tensile specimen results from the action of the HEDE and HELP in various zones. TDS test results indicates that the content of C and Mn significantly influence on the hydrogen solubility in metal materials.

Effects of pressure on hydrogen diffusion behaviors in MgO

“…have attracted great attention from researchers. [1][2][3][4][5][6][7][8][9][10][11][12] There are numerous studies on hydrogen diffusion behaviors on the surface of magnesium 4 and MgO, 2,5 and on hydrogen diffusion behaviors in solid SiO 2 , 6 Al 2 O 3 , [7][8][9]13,14 and steel. 3,12,15 On one hand, hydrogen is a clean energy fuel material, and the search for high-efficiency and lowcost hydrogen storage materials has promoted studies on hydrogen adsorption and diffusion on the surface of materials.…”

“…[1][2][3][4][5][6][7][8][9][10][11][12] There are numerous studies on hydrogen diffusion behaviors on the surface of magnesium 4 and MgO, 2,5 and on hydrogen diffusion behaviors in solid SiO 2 , 6 Al 2 O 3 , [7][8][9]13,14 and steel. 3,12,15 On one hand, hydrogen is a clean energy fuel material, and the search for high-efficiency and lowcost hydrogen storage materials has promoted studies on hydrogen adsorption and diffusion on the surface of materials. 4,11,[16][17][18] On the other hand, hydrogen, as an atom with the smallest radius, can penetrate into materials in various forms (e.g., atomic, ionic, and molecular states), which has significant effects on the structural, electrical, and optical properties of materials.…”