Clamping device for rodlike sample long-time creep test

Abstract

The invention provides a clamping device for a rodlike sample long-time creep test. The clamping device includes clamping units symmetrically fixed to the two ends of a to-be-tested rodlike sample; each clamping unit includes a jig and a pull rod; one end of each jip is fixedly connected with the to-be-tested rodlike sample by threads, the other end of each jip is connected with one end of the corresponding pull rod by a pin, and the other end of each pull rod is connected with a long-time creep tester main body. Threaded connection ensures the coaxiality of the to-be-tested rodlike sample, the existing to-be-tested rodlike sample does not require structural change and can be directly used, and symmetric arrangement also ensures the use flexibility of the to-be-tested rodlike sample; at the same time, through the connection of the jigs and the pull rods by the pins, rapid and flexible clamping can be conducted before and after the test. The clamping device is simple in structure, and the test can be guaranteed to be carried out smoothly on the premise that the coaxiality is ensured; after the test is completed, the upper jig and the upper pull rod are separated smoothly, the lower jig and the lower pull rod are separated smoothly, and the disassembly inconvenience problem is solved.

Description

technical field [0001] The invention relates to a clamping tool for a mechanical performance test, in particular to a clamping device for a rod-shaped sample durable creep test. Background technique [0002] Endurance / creep test is a kind of high-temperature mechanical performance test to measure the fracture resistance / deformation resistance of materials under high temperature and long-term load. For many high-temperature parts, such as boiler overheating and reheater tubes, etc., not only need good short-term tensile properties, excellent oxidation resistance, but also need to bear a certain stress during service, which requires good High temperature durability / creep properties. In order to obtain the durability / creep properties of the material, long-term experiments must be carried out. The heating furnace of the endurance / creep testing machine is generally long, and except for the sample to be tested, most of the entire clamping device is in a state of high temperature...

AI Technical Summary

Problems solved by technology

At present, rod-shaped persistent creep samples are usually clamped and fixed by clamps with thread structure. Although good coaxiality can be guaranteed, it is inconvenient to disassemble, especially after long-term service at high temperature and high pressure, sintering and oxidation will occur. In serious cases, only by destroying the clamping device can the clamp and the sample be removed after the test. This will not only damage the sample during the sample taking process, but also cause irreversible damage to the clamping device, making It cannot be reused, greatly increasing the cost of testing

In addition, this type of experiment has high requirements on coaxiality. Due to various factors such as the design, processing, assembly and use of the upper and lower sample clamping devices of the testing machine, there is inevitably a coaxiality positioning error.

Influenced by the positioning error of coaxiality, in the durability / creep test of materials, additional stresses will be generated due to bending when the test bears normal stress, such as bending normal stress and bending shear stress, etc., thus affecting the accuracy of test results

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