Manufacturing method of high-temperature tensile sample

Abstract

The invention relates to a manufacturing method of a high-temperature tensile sample. The manufacturing method includes the steps of firstly, rounding is performed on the nominal diameter D of a threaded connecting section to allow the nominal diameter D to be close to an original sample width a0 and conform to the dimension value regulated in GB / T 196 General Purpose Metric Screw Threads Basic Dimensions; secondly, the original width b0 of a test section is determined, the cross section area of a high-temperature tensile sample clamp section is set as S1, and the cross section area of the test section is set as S0; b0m is not larger than 0.7854D1<2> / 1.1a0 under the requirement that S1 is not smaller than 1.1S0; the value, closest to the b0m, of b0 is taken and rounded off to 0.5mm; thirdly, the threaded connecting sections at two ends of the high-temperature tensile sample are machined into cylinders, and the original rectangular cross section of the middle test section is kept unchanged; fourthly, the threads of the threaded connecting sections at two ends of the high-temperature tensile sample are machined, and the major diameter dimension of the threads is D. The manufacturing method has the advantages that the coaxiality of the manufactured sample and a tensile testing machine and sample centering performance in the thickness direction can be increased, test result accuracy is guaranteed therefore, tensile test operation convenience is achieved, and test safety is increased.

Description

technical field [0001] The invention relates to a metal material high-temperature tensile sample, in particular to a full-thickness rectangular cross-section high-temperature tensile sample that is threadedly connected with a clamp. Background technique [0002] The high-temperature short-term tensile test is mainly to measure the performance indicators such as tensile strength, yield strength, elongation, and reduction of area of ​​metal materials above room temperature. High-temperature tensile specimens of metal materials are generally divided into: circular cross-section screw connection specimens, rectangular cross-section tensile specimens with pin holes (such as Figure 1-Figure 2 Shown), a rectangular cross-section with a headed tensile specimen. In order to test the high-temperature tensile properties of materials more accurately, when the machining and testing machine capabilities allow, full-section or full-thickness samples should be prepared. [0003] When doin...

AI Technical Summary

Problems solved by technology

One solution is to clamp the sample directly on the hydraulic fixture of the tensile testing machine. In order to avoid the impact of high temperature on the hydraulic fixture of the tensile testing machine, the clamping end of the sample should be lengthened, which will increase the weight of the sample. It brings great difficulties to sample processing and inspection, and also causes waste of raw materials

Another solution is to place the manually clamped wedge-shaped fixture in a high-temperature furnace, but the maximum temperature generally cannot exceed 350°C, which does not meet the requirements for high-temperature stretching temperature

Generally, the working temperature of high-temperature lubricating grease is -70℃~350℃. If the temperature exceeds 350℃, the high-temperature lubricating grease fails. invalid result

And because the manual fixture needs to manually turn the runner to apply pre-tightening force to the sample, the temperature of the runner is extremely high and it is easy to burn

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