Sensitivity Study of Typical Pipelines and Station Pipes in Hydrogen Environment

ABSTRACT This article selects a certain gas pipeline system, the director of the line on material X60 steel and typical process pipeline structure of 20 # steel elbow, yard by the metallurgical structure observation of the typical sampling position and hardness tests, hydrogen permeation test compared the hydrogen and hydrogen content of X60 steel base, girth weld and hydrogen embrittlement sensitivity of 20 # steel elbow position size. The risk of hydrogen embrittlement at sensitive sites in hydrogen environment was studied by notch tensile test. The results show that the hydrogen diffusion coefficient of base metal and weld of X60 steel is higher, and the hydrogen concentration adsorbed on the surface is lower. The hydrogen diffusion coefficient of 20# steel is low, and the concentration of hydrogen adsorbed on the surface is high, which indicates that the hydrogen trap content in 20# steel is high, and it is easier to capture hydrogen atoms, and the possibility of hydrogen embrittlement exists. The notch tensile test of 20# steel at a sensitive position was carried out in a medium with a total pressure of 6 MPa and a volume fraction of 3% hydrogen. Compared with the similar experimental results in the air, the strength and plasticity of 20# steel have no obvious changes. The results show that the risk of hydrogen embrittlement of 20# steel is low in the mixed hydrogen transportation environment.