Multifunctional pressure difference type method for testing compatibility of high-pressure hydrogen and materials

Abstract

The invention relates to the field of development of material mechanical property testing devices, and aims at providing a multifunctional pressure difference type method for testing the compatibility of high-pressure hydrogen and materials. The method includes a bursting test method, a variable-hydrogen-pressure fatigue test method and a constant-hydrogen-pressure fatigue test method. By means of the method for applying loads on a disc sample through the pressure difference of the upper surface and the lower surface of the disc sample, complex servo test mechanisms are avoided, the device size is greatly reduced, the device input is reduced, operation is easy and convenient, and the test efficiency is improved; in the test process, parameters such as strain and displacement of the disc sample can be conveniently measured, and corresponding tested elements are not influenced by high-pressure hydrogen.

Description

technical field [0001] The invention relates to the field of development of testing equipment for mechanical properties of materials, in particular to a testing method for compatibility between multifunctional differential pressure high-pressure hydrogen and materials. Background technique [0002] Hydrogen is an important part of the clean utilization of fossil energy and the development of new energy. Hydrogen is usually stored and transported in gaseous form under high pressure. In recent years, due to the development trend of higher pressure of high-pressure hydrogen system and complex service environment, the compatibility problem of materials used in high-pressure hydrogen system and hydrogen (ie hydrogen embrittlement problem) has gradually become prominent. Hydrogen embrittlement will reduce the toughness of the material and increase the crack growth rate, which will cause a sudden and serious failure of the high-pressure hydrogen system during service, causing grea...

AI Technical Summary

Problems solved by technology

[0004] (1) The equipment structure is complicated, the cost is high, and the operation is complicated

[0005] Most of the hydrogen compatibility test devices currently developed are based on traditional material testing machines, plus an environment box that can provide a high-pressure hydrogen environment. The samples and their fixtures are contained inside the environment box. Therefore, the internal volume of the environment box Large, coupled with its usually high pressure (up to 100MPa), resulting in expensive equipment

In addition, a large-volume environmental chamber also needs to be equipped with a corresponding hydrogen gas supply system. The operation of the entire equipment is complicated, and the cost of hydrogen and labor is high.

Such as the test device proposed in the patent [201110259252.2], not only the cost of the equipment itself is high, but each test requires multiple people to operate the equipment, and the hydrogen consumption is also large

[0006] (2) There is a high-pressure hydrogen pneumatic sealing structure, which is prone to leakage

Practice has shown that the existing dynamic seal structure has a very short service life, and often fails suddenly due to wear and hydrogen dissolution and expansion after a short period of use, resulting in hydrogen leakage and posing a major safety hazard

[0008] (3) It is difficult to measure various parameters of the sample in a high-pressure hydrogen environment

[0009] In a high-pressure hydrogen environment, due to the influence of hydrogen on the measuring elements such as sample strain and force, the signal will drift seriously, resulting in inaccurate measurement

[0010] (4) There is a big difference between the stress state of the sample and the stress state of the actual component

However, the existing testing machines usually test the failure behavior of samples under unidirectional stress, and there is still a certain gap between them and the actual service conditions of components.

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