A kind of low-temperature CTOD testing device and method

Abstract

The invention discloses a low-temperature CTOD test device, which is characterized in that the centering adjustment during the sample clamping process can still ensure the centering accuracy when the fixture expands with heat and contracts with cold, and specifically includes a vertical correction system and a horizontal centering system and front and rear centering systems; the vertical correction system includes a base and pressure rollers, the horizontal centering system includes a span plate and an adapter plate, and the front and rear centering systems include a centering adjustment module and a calibration block; the horizontal The centering system is located on the upper edge of the side of the base, and the front and rear centering system is located above the base. The invention also discloses a method for using the low-temperature CTOD testing device. The low-temperature CTOD test device and method provided by the present invention can effectively ensure the alignment and span consistency during the test process, improve the stability and consistency of the test results; at the same time facilitate low-temperature sample change, improve the efficiency of continuous low-temperature testing, and save energy ; The device is suitable for both low temperature and room temperature, and can be widely used.

Description

technical field [0001] The invention relates to the technical field of fatigue fracture research, in particular to a low-temperature CTOD test device and method. Background technique [0002] The CTOD test is one of the commonly used methods to measure the fracture toughness of materials. The CTOD test has high requirements for the device, especially for the neutrality during the test process. Neutrality has a great influence on the dispersion of data test results. During the low-temperature CTOD test, a low-temperature environment chamber is generally used, which greatly increases the difficulty of changing the sample or adjusting the alignment during the low-temperature test, and also affects the test efficiency. [0003] At present, the fixtures in the CTOD test process mainly include the following types: [0004] 1. In the CTOD test process, most of the traditional three-point bending fixtures are used, but when adjusting the centering of the sample in the thickness di...

AI Technical Summary

Problems solved by technology

[0004] 1. In the CTOD test process, most of the traditional three-point bending fixtures are used, but when adjusting the centering of the sample in the thickness direction of the sample, it often stays in visual inspection, and uses a ruler to measure the distance between the two end interfaces of the fixture. side distance, this kind of centering process generally takes a long time and the efficiency is very low

At room temperature, this method can be used barely, but in the process of low temperature testing, especially in ultra-low temperature environments, it will not only be difficult, but also take a long time, and there is also the risk of frostbite

[0005] 2. Although most of the three-point bending fixtures are designed with the function of adjustable span, due to the thermal expansion and contraction of the material in the low temperature environment, there will be gaps in the span fixing device and relative looseness, which makes the test The span will fluctuate during the process, which will affect the test results

[0006] 3. Due to the difficulty of adjusting the centering when changing the sample at ultra-low temperature, most of the current ultra-low temperature CTOD tests cannot test the continuous test well

In many tests, the sample is changed after the sample returns to close to room temperature, which not only greatly reduces the test efficiency, but also wastes energy

[0007] It can be seen that most of the current fixtures and methods for low-temperature CTOD testing remain in the more traditional methods, and the testing process is complicated and inefficient.

Continuous testing cannot be performed during the low temperature test

The symmetry in the test process is difficult to be guaranteed, and the data dispersion is large

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