Non-uniform structure thick plate welding joint low-cycle fatigue performance testing method

Abstract

The invention provides a non-uniform structure thick plate welding joint low-cycle fatigue performance testing method. The non-uniform structure thick plate welding joint low-cycle fatigue performancetesting method comprises the following steps: under the set strain amplitude, a sample is subjected to low-cycle fatigue testing, and the fracture position is observed; the sample is subjected to static stretching testing in a static stretching machine, and the fracture position is observed; a metallographic sample of a welding joint is selected, and the non-uniform structure hardness distribution law of the welding joint is calibrated through a hardness meter; the fracture positions of a low-cycle fatigue test fracture sample and a static stretching test fracture sample are compared and analyzed, and the non-uniform structure hardness distribution law of the welding joint is combined to judge the low-cycle fatigue failure fracture position of the sample; the low-cycle fatigue failure fracture position is taken as a machining center of the low-cycle fatigue sample to remachine the sample, and the scale distance of the remachined low-cycle fatigue sample contains a fracture area; and the remachined sample is subjected to low-cycle fatigue testing again, low-cycle fatigue test results are analyzed, and the strain life equation of the fracture area of the welding joint is obtained.

Description

technical field [0001] The invention relates to the field of low-cycle fatigue evaluation of non-uniform structure welded joints of thick plates, in particular to a low-cycle fatigue performance test method of non-uniform structure thick plate welded joints. Background technique [0002] In the current low-cycle fatigue test standard GB-T 15248-2008 "Metallic Materials Axial Equal Amplitude Low-Cycle Fatigue Test Method", only clear requirements are put forward for the low-cycle fatigue performance test method of homogeneous materials. The low-cycle fatigue performance test of welded joints is also generally carried out with reference to this standard. The welded joints of thick plates generally adopt the multi-layer multi-pass welding method. During the low-cycle fatigue test, the clamping part of the extensometer generally includes the base metal, heat-affected zone and weld seam. Among them, according to different materials, the heat-affected zone of general modulation s...

AI Technical Summary

Problems solved by technology

This method is suitable for ultra-thin plates, but not for thick plate welding

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