Preparation method of simulation stress corrosion cracks for eddy current testing

Abstract

The invention provides a preparation method of simulation stress corrosion cracks for eddy current testing. The method comprises the following steps: processing a flat plate test piece and leading in fatigue cracks with same size to real stress corrosion cracks ; obtaining a fatigue crack flat plate test piece; utilizing a four-point bending on-line loading device to conduct bending loading on the fatigue crack flat plate test piece to enable the fatigue crack to close opening; conducting eddy current testing experiment at the same time; acquiring eddy current detection signals under different loading states, wherein the closed-opening fatigue cracks under the loading state anastomotic to the real stress corrosion crack eddy current testing signals are equivalent to real stress corrosion cracks in eddy current testing meaning, and can be taken as the simulation cracks of the stress corrosion cracks. The stimulation test piece prepared according to the method can effectively replace stress corrosion crack test pieces which are complex in actual shapes and difficult to prepare, has the advantages that the simulation test piece is simple to operate, easy to realize, low in cost, and known in size of cracks, and can be extensively applied to a testing capability certification system of the stress corrosion crack quantitative eddy current testing method.

Description

technical field

[0001] The invention relates to the field of preparation of a stress corrosion crack simulation test piece, in particular to a preparation method of a simulated stress corrosion crack for eddy current testing. Background technique

[0002] Stainless steel materials sensitive to stress corrosion are widely used in nuclear power plants, and the existence of tensile stress and corrosive environment in nuclear power structures makes stress corrosion cracks widely exist in key parts of nuclear power plants, such as the heat exchange tube sheet expansion part of steam generators , Welding part of the main cooling tube platform, etc. The existence of stress corrosion cracks poses a huge threat to the safe operation of nuclear power structures, and considering economic benefits, it is necessary to evaluate the size of cracks, so the quantitative nondestructive testing of stress corrosion cracks is extremely important. At present, the testing ability certification sy...

Examples

Embodiment Construction

[0029] Such as figure 1 As shown, the principle of the present invention is to use the jack 14 to load the fatigue cracked plate specimen 12 through the four-point bending loading device 11, so that the fatigue crack located in the central part of the fatigue cracked specimen is closed to a certain extent, and the two crack surfaces occur Partial contact produces a conductivity weaker than that of the base material, thereby simulating a real stress corrosion test piece in the sense of eddy current testing.

[0030] Such as figure 2 As shown, the structure of the four-point bending online loading device 11 designed by the present invention includes a lower cover plate 4, side plates 2 arranged on both sides of the lower cover plate 4, and a chute 3 is opened on the inner side of the side plate 2, and the slider 5 passes through the two sides of the lower cover plate 4. The slider guide rail 10 on the side is loaded into the chute 3, the center of the slider 5 is a groove, and...

technical field

[0001] The invention relates to the field of preparation of a stress corrosion crack simulation test piece, in particular to a preparation method of a simulated stress corrosion crack for eddy current testing. Background technique

[0002] Stainless steel materials sensitive to stress corrosion are widely used in nuclear power plants, and the existence of tensile stress and corrosive environment in nuclear power structures makes stress corrosion cracks widely exist in key parts of nuclear power plants, such as the heat exchange tube sheet expansion part of steam generators , Welding part of the main cooling tube platform, etc. The existence of stress corrosion cracks poses a huge threat to the safe operation of nuclear power structures, and considering economic benefits, it is necessary to evaluate the size of cracks, so the quantitative nondestructive testing of stress corrosion cracks is extremely important. At present, the testing ability certification sy...

Examples

Embodiment Construction

[0029] Such as figure 1 As shown, the principle of the present invention is to use the jack 14 to load the fatigue cracked plate specimen 12 through the four-point bending loading device 11, so that the fatigue crack located in the central part of the fatigue cracked specimen is closed to a certain extent, and the two crack surfaces occur Partial contact produces a conductivity weaker than that of the base material, thereby simulating a real stress corrosion test piece in the sense of eddy current testing.

[0030] Such as figure 2 As shown, the structure of the four-point bending online loading device 11 designed by the present invention includes a lower cover plate 4, side plates 2 arranged on both sides of the lower cover plate 4, and a chute 3 is opened on the inner side of the side plate 2, and the slider 5 passes through the two sides of the lower cover plate 4. The slider guide rail 10 on the side is loaded into the chute 3, the center of the slider 5 is a groove, and...

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