Test specimen for high-temperature strength and notch sensitivity of welding seam

Abstract

The invention relates to a test specimen for high-temperature strength and notch sensitivity of a welding seam and belongs to the technical field of material science. The test specimen comprises an elongated specimen which is thick at both ends and thinner in the middle, wherein the two ends are clamping ends and the middle is a test section; an inwardly recessed smooth transition section is arranged in the direction from the clamping ends on the two ends of the specimen to the middle test section, and a notch is arranged on the test section. According to the invention, since a variable cross-section notch is added to the specimen, the specimen can be broken in the weld metal, the welding seam metal strength and the sensitivity of the notch to the welding seam can be tested, and the problems that the welding seam strength and the welding seam notch sensitivity and the like cannot be tested by the traditional specimen can be solved. The specimen is simple to process, and the test process is basically the same with the conventional tension test method. The test specimen fills in the gap in the technical field and has great social and economic benefits.

Description

technical field [0001] The invention relates to a test sample of weld seam high-temperature strength and its notch sensitivity, belonging to the technical field of material science. Background technique [0002] With the development of my country's electric power industry, many high-parameter and large-capacity thermal power units have been put into operation one after another. High-temperature and high-pressure steam pipes in power stations are widely used in high-alloy steel, such as P91, P92, etc. The strength and safety of the weld seams of these high-alloy steel steam pipes , reliability and service life have always been a matter of great concern to domestic and foreign design, manufacture, operation, maintenance, supervision and inspection personnel. With the long-term operation at high temperature, the safety problem of weld metal has become increasingly prominent. It is mainly manifested in the decrease of its high-temperature strength and the sensitivity of the weld...

AI Technical Summary

Problems solved by technology

[0004] For the weld, the test section should include the weld, the heat-affected zone and the base metal. Since the metal strength of the weld is much higher than that of the base metal and the heat-affected zone, especially for P91 steel welds, conventional tensile specimens are generally broken at In the weld heat affected zone, the measured strength of the welded joint is actually the strength of the weld heat affected zone, but the real properties of the weld metal are difficult to measure

The weld performance of high-temperature and high-pressure steam pipelines in power stations affects its safe operation. In order to study the weld metal performance, it is usually necessary to perform performance testing on the weld metal. Conventional stretching, including normal temperature stretching, high temperature stretching and durable strength test methods, The cross-sectional area of ​​the test section is generally constant. Since the strength of the weld is much higher than that of the base metal and the heat-affected zone, most of the samples are broken in the heat-affected zone, and the transverse properties of the weld metal cannot be known.

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