SU954866A1

SU954866A1 - Magnetic noise checking method

Info

Publication number: SU954866A1
Application number: SU802989881A
Authority: SU
Inventors: Владимир Васильевич Волков; Владимир Федорович Кумейшин; Валентин Васильевич Лаптев; Михаил Юльевич Черниховский
Priority date: 1980-10-08
Filing date: 1980-10-08
Publication date: 1982-08-30

Description

, 1 . , one .

Изобретение относитс к средствам магнитошумового контрол ферромагнитных материалов и может быть использовано дл дефектоскопии сварных соединений и проката.The invention relates to magnetic noise control of ferromagnetic materials and can be used for the inspection of welded joints and rolled products.

Известен способ магнитошумового контрол ферромагнитных сталей, заключающийс в том, что образец стали перемагничивают линейно измен ющимс магнит ным полем и регистрируют возникающие ,Q при этом магнитные шумы, по которым определ ют зернистость структуры стали 1. . ..The known method of magnetic noise control of ferromagnetic steels is that the steel sample is re-magnetized with a linearly varying magnetic field and the resulting Q, magnetic noise, which determines the grain size of the steel 1 structure, is recorded. ..

Однако достоверность контрол этим способом не достаточна , так как спектр магнитных шумов не всегда соответствует характеру дефектов в структуре стали.However, the reliability of control by this method is not sufficient, since the spectrum of magnetic noise does not always correspond to the nature of defects in the steel structure.

Наиболее близким к йзобретешю вл етс способ магнитошумового контрол , заключающийс в том, что объект контро- 20 л перемагничивают накладным электретмагнитом и регистрируют спектр возникающих при этом магнитоакустических шумов, по которому определ ют состо - .The closest to the invention is the method of magnetic noise control, which consists in the fact that the object of the control 20 lm reversal is overlaid by an applied electretmagnet and the spectrum of the magnetoacoustic noise arising in the process is determined.

ние структур. материала объекта по заранее вы вленным коррел ционным зависимост м 2..structure the material of the object according to previously determined correlation dependences m 2.

Однако точность послойного контрол структуры материала недостаточна , так как. перемагничивание привод т синусоидальным полем, а врем регистрашга рпектра шумов не стробируют.However, the accuracy of layer-by-layer control of the structure of the material is insufficient, since. The magnetization reversal is driven by a sinusoidal field, and the time of the register of the noise spectrum is not strobed.

Цель изобретени - повышение точности послойного контрол структуры материала ..The purpose of the invention is to improve the accuracy of layer-by-layer control of the structure of the material ..

Эта цель достигаетс тем, что перемагничивание провод т линейно измен к шимс магнитным полем, а при регистрации спектра стробируют врем , соответ ствующее интервалу изменени указанного пол , создак дего в заданном слое объекта магнитоакустические шуМы.This goal is achieved by the fact that the magnetization reversal is carried out linearly by changing the magnetic field, and when registering the spectrum, the time corresponding to the change interval of the specified field is strobe; the magnetoacoustic noise is created in a given layer of the object.

На чертеже приведена блок-схема устройства дл реализации предлагаемого способа..The drawing shows a block diagram of a device for implementing the proposed method ..

Claims

The device contains in series a linearly varying generator 1, a power amplifier 2, a remagnetization node 3, as well as a well connected acoustic noise converter 4, a signal amplifier 5, a recorder 6 and a time gate 7 connected between it and the generator 1. The device works by speed and in the image. The reversing unit 3, executable in the form of a laid on (attached) electromagnet (not shown), contacting the poles with the surface of the control object (not shown), excites the node 3 from generator 1 by a linearly varying current, as a result of which the controlled object is remagnetised by a linearly changing magnetic field In this case, magnetoacoustic noise arises, the spectrum of which is determined by the error of the structure of the material of the control object / acoustic component of these noise is received by the transducer. 4 n through the amplifier 5 and further are transmitted to the recorder 6. The change in the nepeMiririroaKraero field in the control object from its top to the depth occurs at a speed proportional to the period of the generator signal 1. In this case, magnetoacoustic noise is generated in a certain interval of the field intensity. By means of a cascade 7 of time gating, the recorder 6 is opened to receive signals just at the time when the specified field strength interval has reached a certain layer of material 4 of the control object, thus performing layer-by-layer control. The application of the proposed method improves the accuracy of control in several p & s, as it allows to determine the discrepancy between the structure of the material of the object and its depth in relatively thin layers. Claims The method of magnetic noise control, comprising. that the control object is remagnetized by a superimposed electromagnet and the spectrum of the magnetoacoustic noise arising in the process is recorded, from which the state of the structure of the material of the object is determined by the previously determined correlation dependencies, so that In order to improve the accuracy of the layer-by-layer control of the structure of the material, the remagging is carried out with a linearly varying magnetic field, and when registering the spectrum, the time corresponding to it is sampled. This means that the specified field creates magneto-acoustic noise in a given layer of the object. Sources of information taken into vn1maniye during examination 1, the Federal Patent of Germany No. 2141751, cl. Q 01 N 27/80, 1972.

2.E4) Barkgausen effect and its use in engineering. Abstracts of the NTS. Izhevsk, Udmurt region NTO Council, p. 165-169 (prototype).