High-temperature endurance test fixture for full pipe sample of small-diameter metal thin-walled pipe

Abstract

The invention discloses a high-temperature endurance test fixture for a full pipe sample of a small-diameter metal thin-walled pipe. The fixture is used for clamping the full pipe sample of the small-diameter metal thin-walled pipe during a high-temperature endurance test. The fixture comprises an outer fixture and an inner fixture; the outer fixture comprises an adapter body, a clamping nut, a front clamping sleeve, a back clamping sleeve, an adapter outer thread and a connecting thread; and the inner fixture comprises a shaft bar and a shaft sleeve. During use, the sample of the thin-walledpipe are sunken inwards by the aid of the front and back metal clamping sleeves, so that external clamping of the pipe is realized; and internal clamping of the pipe is realized through matching of the shaft bar and the shaft sleeve. Compared with the prior art, the fixture has the advantages that the clamping force on the sample is increased through internal and external clamping, and meanwhile,damage caused by machining of threads to the sample is avoided. Besides, the fixture is ingenious in design, is simple and convenient to operate and can be mounted on various common high-temperature endurance test machines in laboratories, the cost is low, and test results are accurate.

Description

Technical field [0001] The invention belongs to the field of metal material experiment research, and specifically relates to a high-temperature endurance test fixture for a small-diameter metal thin-walled tube full-tube sample. Background technique [0002] Metal high-temperature endurance strength test is a material mechanical property test that tests the maximum stress that does not cause fracture within a specified duration when the material is subjected to a constant load at a certain temperature. The high temperature endurance strength provides an important basis for the design and material selection of high temperature components. Conventional high-temperature durability test uses standard durable samples (such as rod-shaped samples and plate-shaped samples given in GB / T 2039-2012, ASTM E139). It is feasible to use this sample type for larger materials. [0003] Small-caliber metal thin-walled pipe components have been widely used in key components of nuclear power and the...

AI Technical Summary

Problems solved by technology

[0004] Small-diameter metal thin-walled pipe components cannot directly process standard samples due to their thin wall thickness. Currently, there are two commonly used methods: one method is to throw away the center of the thin-walled pipe and process it into a boat-shaped sample, and then design related fixtures for high-temperature testing. Mechanical performance test (see Chinese patents: 201320175058.0, 200810167020.2 and 201110230495.3), but the neutrality of the sample in this method often cannot meet the requirements, the measurement of the sample size and the calculation of the cross-sectional area are inaccurate, the deviation of the test results will be large, and the data will be scattered sex big

Another method is to use a full-section thin-walled sample, usually using a straight-inserted inner plug and a lock nut on the outside of the sample to cooperate with each other to provide clamping force, but because the inner plug and the inner wall of the tubular sample cannot achieve Tight fit, so this type of fixture has the problem of insufficient clamping force, and processing the external thread will damage the sample, and the external thread is prone to stress concentration, which may cause the sample to break there, resulting in test failure

In addition, when the metal thin-walled sample tube wall is very thin, it will not be possible to process the outer thread, making this method unfeasible

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