Clamp for tensile test of small-pipe-diameter steel pipe in high-pressure hydrogen environment

Abstract

The invention relates to the field of material mechanical property testing, and aims to provide a clamp for a tensile test of a small-pipe-diameter steel pipe in a high-pressure hydrogen environment. The clamp comprises a chuck seat, a chock plug, a belleville spring, at least one pressing plate and a pressing flange, the chock plug is arranged at the end part of the steel pipe to be tested, and the steel pipe to be tested sequentially penetrates through the pressing flange, the pressing plate and the belleville spring; the pressing flange is installed on the outer side of the counter bore of the chuck seat in a fastening mode, and the pressing plate, the bearing steel ball and the belleville spring are sequentially pressed in the counter bore. The bearing steel balls are used for generating clamping force on the pipe wall of the steel pipe, the stress area is small, the clamping force is concentrated, and the steel pipe to be tested is not prone to slipping off. In the clamping process, the bearing steel balls can be automatically and symmetrically distributed along the central axis, it is guaranteed that the steel pipe to be tested cannot be eccentric in the stretching process, meanwhile, the pipe wall at the clamped position is evenly stressed in the circumferential direction, and tearing of the pipe wall cannot be caused. In the stretching process, the bearing steel balls generate clamping force on the pipe wall to form self-locking; the belleville spring can ensure continuous clamping all the time and does not slip off.

Description

technical field [0001] The invention belongs to the field of testing mechanical properties of materials, and in particular relates to a fixture for tensile testing of small-diameter steel pipes in a high-pressure hydrogen environment. Background technique [0002] Small-diameter steel pipes (nominal outer diameter <26mm) are key hydrogen delivery equipment in hydrogen refueling stations and vehicle-mounted high-pressure hydrogen systems, but their materials (especially welding parts materials) may appear due to the joint action of high-pressure hydrogen gas and loads. The degradation of mechanical properties caused by high-pressure hydrogen embrittlement seriously threatens the safety of high-pressure hydrogen systems. Carrying out in-situ tensile test under high-pressure hydrogen environment is an effective means to obtain the anti-hydrogen embrittlement performance of materials, which has been introduced into the relevant standards of high-pressure hydrogen systems at h...

AI Technical Summary

Problems solved by technology

[0005] The technical problem to be solved by the present invention is to provide a fixture for tensile testing of small-diameter steel pipes in a high-pressure hydrogen environment with convenient clamping, high reliability, and reasonable design, so as to solve the problem of tensile testing of small-diameter steel pipes in a high-pressure hydrogen environment. The problem of low success rate of clamping method in tensile test

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