Steel structure for hydrogen which exhibits excellent hydrogen embrittlement resistance properties in high-pressure hydrogen gas, and method for producing same

Abstract

A steel structure for hydrogen, which can exhibit excellent hydrogen embrittlement resistance properties in a high-pressure hydrogen environment and therefore can be used as a pressure accumulator forhydrogen, a line pipe for hydrogen and the like. The steel structure can be produced by: providing a steel composition containing, in % by mass, 0.02 to 0.50% of C, 0.05 to 0.50% of Si, 0.5 to 2.0% of Mn, 0.05% or less of P, 0.01% or less of S, 0.01 to 0.10% of Al, 0.0005 to 0.008% of N and 0.01% or less of O and also containing V and Mo in amounts that meet such requirements that the content ofV is 0.05 to 0.30%, the content of Mo is 0.05 to 1.13% and the (number of atoms of V)/(number of atoms of Mo) ratio becomes 0.6 to 2.0, with the remainder being made up by Fe and unavoidable impurities; and adjusting the average particle diameter of a composite fine carbide composed of V and Mo to 1 to 20 nm.

Description

technical field [0001] The present invention relates to a steel structure for hydrogen such as a hydrogen storage container and a hydrogen pipeline having excellent resistance to hydrogen embrittlement in a high-pressure hydrogen environment, and a method for manufacturing the same. Background technique [0002] In recent years, hydrogen has attracted worldwide attention from the viewpoint of clean energy and diversification of energy sources. In particular, expectations for fuel cell vehicles that use high-pressure hydrogen as a fuel source are increasing, and research related to the development of fuel cell vehicles has been extensively conducted around the world, and some of them have already been tested for practical use. [0003] Fuel cell vehicles run with hydrogen stored in tanks instead of gasoline. Therefore, in order to popularize fuel cell vehicles, it is necessary to replace gas stations with hydrogen refueling stations for refueling. At the hydrogen refueling s...

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Problems solved by technology

However, at a pressure of 15MPa or more, the risk of hydrogen embrittlement fracture during use increases, so low-alloy steel is not used, and austenitic stainless steel such as SUS316L steel, which is less prone to hydrogen embrittlement than low-alloy steel, is used.

[0006] However, due to the high cost of steel materials such as SUS316L steel, but also the low strength

Therefore, in order to withstand the hydrogen pressure of 80MPa, the thickness needs to be greatly increased, and the price of the hydrogen storage container itself becomes very high.

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