SU1350587A1 - Method of flaw detection of articles - Google Patents

Abstract

The invention relates to the field of flaw detection and improves the efficiency of the process by increasing the detection accuracy. The product is electrically charged and the resulting luminescence on the dielectric is recorded. For this purpose, a film is prepared from a composition containing, g / l: polyvinyl alcohol 40-130, Ge (C10) s-9E ,, 0 20-200 and water the rest is up to 1 liter, on a glass substrate. Then a glass plate with a film, which should be facing the sample, is placed on the surface of a metal grounded sample, and an electrode is applied on top, which is supplied with alternating voltage. When the circuit is closed, spark channels appear in the discharge gap. At the places of their contact with the film, its charring begins, with the particles of the charred layer arranged in a certain way. 1 il. 2 tab. S SL Conjured About SP 00

Description

1135058

The invention relates to methods for detecting defects using magnetic fields and can be used in various fields of technology.

The aim of the invention is to increase the efficiency of the process by increasing the detection accuracy.

The drawing shows the configuration of the magnetic fields of bit channels ig

fishing arising in the discharge gap.

Examples 1-3. The preparation of the film as a dielectric to detect defects is carried out according to the following technology. First, a solution of polyvinyl alcohol (PVA) is prepared by dissolving dry PVA in hot water (solution ") and a solution of ferrous chloride (III) by dissolving in water at room temperature (solution 6). Then solutions a and 5 are mixed and made up to a certain volume.

The solution thus obtained (the compositions are listed in Table 1) was applied to a glass substrate and dried at room temperature. In order to better adhere the layer to the substrate, the latter is preliminarily laminated by dipping in a 1% aqueous solution of PVA, followed by hardening at 150 ° C for 3 hours.

After preparation of the dielectric film, product defects are detected by subjecting it to electric discharge and registering traces of the discharge channels that develop from the defective places of the surface on the dielectric.

Diameter of the pitting shell, mm 0.05-0.08 0,, 020-0.05 0.04 0.03-0.07

Opening width of the extended defect, mm 0.03

Footprint size on the logging material, mm

The magnetic fields are recorded according to the following scheme: a glass plate with a deposited layer is applied to the surface of a grounded metal sample with or without a gap; In the course of the experiment, the voltage is changed within 3-5 kV at a frequency of 24 kHz. The sample and electrode are flat plates (2x3 cm) made of stainless steel. When the circuit is closed, spark channels appear in the discharge gap. At the places of their contact with the film, its charring begins, covering large areas, and under the influence of the arising magnetic fields, the particles of the charred layer are arranged in a certain way, forming an image.

The results of flaw detection using compositions.

Table 1

Fe (C10j, X

X HjO

20

150

200

Water

Up to 1 l up to 1 l up to 1 l

40

Table 2

0.01 0.015 0.02

-7

5-10

0.2-0.6

During defectoscopy, using the proposed composition, a significant increase in the registration of the trace of the discharge channel is achieved, since it is not its weak luminescence that is recorded, but the associated magnetic field,

The use of the proposed method for detecting defects allows detecting smaller defects due to obtaining many times increased traces of these defects on the recording material. This increases the accuracy of controlling minor defects.

Claims (1)

DETAILED DESCRIPTION OF THE INVENTION Method for detecting defects of products by subjecting them to electric discharge and recording the resulting luminescence on a dielectric, characterized in that, in order to increase the efficiency of the process by increasing the detection accuracy, a film made of the composition is used as the dielectric, l: Polyvinyl alcohol Fe (C10pj day. About Water 40-130 20-200 The rest is up to 1 l. S ---;