RU2273848C1 - Universal control sample for fault detection - Google Patents

Abstract

FIELD: the invention refers to the field of nondestructive control.

SUBSTANCE: the sample has a plate with an opening and a bushing of the same material installed in it. The opening and the bushing are fulfilled in a stepped form in the shape of several coaxial cylinders with diameters d₁ , d₂ ...d_n decreasing in accord with the depth of the plate and fulfilled on the depth t_1, t_{2 ...}t_n correspondingly from the surface of the sample. The conjugation of steps forms subsurface defects. The sample may be fulfilled of ferromagnetic material or of nonmagnetic material conducting electricity.

EFFECT: allows to control defects.

2 cl, 3 dwg

Description

The invention relates to the field of non-destructive testing and can be used for metrological support of flaw detection equipment with magnetic and eddy current methods of non-destructive testing of products.

Control samples are known (copyright certificates of the Russian Federation No. 1562835, No. 1467488, No. 1698732 and auth. Certificate. GDR No. 258077) with surface defects such as crack, slit, designed to verify and determine the sensitivity of magnetic flaw detectors, the disadvantages of which are that the depth of the surface defect of these samples is determined by the thickness of the hardened layer, which is difficult to set with the required accuracy. The possibility of manufacturing a sample containing a number of defects of various depths is also excluded, and in these samples there are no subsurface defects with known dimensions and depth, which does not allow to provide the necessary reliability and accuracy of control.

The closest technical solution is a control sample for magnetic flaw detection (a positive decision to grant a patent dated 08/09/2004 according to application No. 2003116886 dated 06/05/03), consisting of a plate with a hole and a sleeve made of the same material installed in it, the interface of which forms a surface defect and a through hole in the sleeve, located at a distance t from the surface of the control sample, forms a subsurface defect. It is desirable to magnetize the control sample so that the direction of the magnetic field is perpendicular to the direction of the defect, otherwise powder deposits from the subsurface defect will not form. Also, the physical properties (geometry and magnetic properties) of an artificial defect in the form of a hole in the sleeve are far from the physical properties of a subsurface defect that arises as a result of real fatigue processes. There is a need to develop a universal control sample, which allows to simultaneously determine the sensitivity of flaw detectors and indicator materials to surface and subsurface defects, which ensures the necessary reliability and accuracy of control.

The aim of the invention is to increase the reliability, accuracy of control, by improving the physical properties (geometry, magnetic properties) of subsurface defects, increasing the accuracy of setting the depth of a subsurface defect, and also expanding functionality by working with both magnetic and eddy current flaw detectors.

This goal is achieved in that a universal control sample for flaw detection, consisting of a plate with a hole and a sleeve of the same material installed in it, the interface of which forms a surface defect, the hole and sleeve are made in a step form in the form of several coaxial cylinders with diameters d ₁ , d ₂ , ..., d _n , decreasing along the plate depth, and made to a depth t ₁ , t ₂ , ..., t _n , respectively, from the surface of the control sample, the conjugation of the steps of which forms subsurface defects. For working with magnetic flaw detectors, the universal control sample is made of ferromagnetic material, and for working with eddy current flaw detectors, the control sample is made of non-magnetic electrically conductive material.

Figure 1 presents a General view of the control sample.

Figure 2 is a cross section of a control sample with a number of subsurface defects.

Figure 3 is a cross section of a control sample with one subsurface defect.

Universal control sample for magnetic and eddy current flaw detection (1, 2) contains a plate 1 with a thickness of H with a hole. A sleeve 2 is installed in this hole. The conjugation of the plate 1 and the sleeve 2 forms a surface defect 3. The sleeve 2 and the hole are stepped in the form of coaxial cylinders with diameters d ₁ , d ₂ , ..., d _n decreasing in depth of the plate, and made to a depth, respectively, t ₁ , t ₂ , ..., t _n , the conjugation of the steps of which forms subsurface defects 4, 5, 6.

Figure 3 shows a cross section of a control sample with one subsurface defect 4. The conjugation of the plate 1 and the sleeve 2 form a surface defect 3. The sleeve 2 and the hole are made stepwise in the form of two coaxial cylinders with diameters d ₁ and d ₂ decreasing along the depth of the plate. The conjugation of the steps of the hole with a diameter of d ₁ and the sleeve d ₁ forms a subsurface defect 4 at a depth of t ₁ . This control sample can be made of both ferromagnetic and non-magnetic conductive material for working with both magnetic and eddy current flaw detectors and will determine the sensitivity of flaw detectors to subsurface defects occurring at different depths.

The depth of the subsurface defect t ₁ is set during machining of the upper surface, which will allow for higher control accuracy. The roughness parameter Ra _a 2.5 μm according to GOST 2789-73.

The control sample for defectoscopy (figure 1, 2) works as follows. This control sample contains a plate 1 of thickness H with a hole. A sleeve 2 is installed in this hole. The conjugation of the plate 1 and the sleeve 2 forms a surface defect 3. The sleeve 2 and the hole are stepped in the form of coaxial cylinders with diameters d ₁ , d ₂ , ..., d _n decreasing in depth of the plate, and made to a depth of t ₁ , t ₂ , ..., t _n , the conjugation of steps of which forms subsurface defects 4, 5, 6. In the case of magnetic particle inspection, a control sample can be magnetized in any direction. Deposits of magnetic powder from surface defect 3 will be sharper and have the shape of two crescents, in contrast to subsurface defects 4, 5, 6, which will give deposits of magnetic powder also in the form of two crescents, but with lower contrast deposits, and the image contrast will decrease with increasing depth t ₁ defect. In the case of eddy current flaw detection, the signal from the surface defect 3 in amplitude will be larger than that from the subsurface defects 4, 5, 6, since the signal amplitude from the subsurface defects 4, 5, 6 decreases with increasing depth of the defect. This control sample can be made of both ferromagnetic and non-magnetic conductive material for working with both magnetic and eddy current flaw detectors and will determine the sensitivity of flaw detectors to subsurface defects occurring at different depths. The implementation of a number of artificial defects in the form of several cylinders with diameters decreasing along the depth of the plate will allow for greater reliability of control. The physical properties of artificial subsurface defects of the proposed control sample are not far from the physical properties of real subsurface defects resulting from real fatigue processes, which will also improve the accuracy and reliability of control.

Therefore, a positive effect has been achieved, since the universal control sample contains a surface defect and a number of subsurface defects with a given burial depth, which will ensure reliability and accuracy of control, and the execution of the control sample from different materials will expand the functionality of use due to work with magnetic, so with eddy current flaw detectors.

Claims (3)

1. A universal control sample for defectoscopy, consisting of a plate with a hole and a sleeve installed in it from the same material, the interface of which forms a surface defect, characterized in that the hole and sleeve are made in a step shape in the form of several coaxial cylinders with diameters d ₁ , d ₂ , ..., d _n , decreasing along the depth of the plate, made to a depth of t ₁ , t ₂ , ... t _n, respectively, from the surface of the control sample, the conjugation of the steps of which forms subsurface defects. 2. The universal control sample according to claim 1, characterized in that it is made of ferromagnetic material. 3. The universal control sample according to claim 1, characterized in that it is made of a non-magnetic electrically conductive material.

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