RU1801208C - Method of ultrasonic inspection of continuity of articles - Google Patents

Abstract

The invention can be used in any industry related to mechanical engineering and metallurgy, where non-destructive testing of cladding, anti-corrosion cladding products is carried out. The purpose of the invention is to increase the information content and reliability of control of products whose defect orientation is known in advance by determining the difference between defects with a solid boundary and defects with a free boundary. 1 ill.

Description

The invention can be used in any industry related to mechanical engineering and metallurgy, for example, for the control of forgings, sheets, pipes, including cladding, anti-corrosion cladding, and the like.

The purpose of the invention is to increase the information content and reliability of control of products whose defect orientation is known in advance by determining the difference between defects with a solid boundary and defects with a free boundary.

This goal is achieved due to the fact that in the product a transverse wave is excited at an angle providing transformation of the type of wave at the defect. Simultaneously with the excitation of a transverse wave in the product, a longitudinal wave is excited by falling a transverse wave at its surface at a subcritical angle, then the longitudinal and transverse waves transformed at the defect are received at an angle

equal to the angle of incidence during synchronous movement of the emitter and receiver, determine the distance H to the reflective surface of the defect, and the distance between the points of entry of the latter is determined from the relation L H. (tg "i + tgat), where a and a are the input angles longitudinally and transverse waves, respectively, the coefficient of transformation of the longitudinal wave into the transverse Ac and transverse into the longitudinal Ati is determined, the difference of which determines the type of defect.

The drawing shows a diagram of the implementation of the method. Here 1 is the base metal, 2 is the surfacing, 3 is the fusion boundary, 4 is the defect, 5 is the emitter, 6 is the receiver.

The proposed method is implemented as follows.

On the surface of the controlled product, the orientation of the defects in which is known in advance, set the emitter and the receiver of ultrasonic waves at an angle

fe

00

about

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ICO

providing the transformation of the type of wave at the defect. At the same time, longitudinal and transverse waves are excited in the product. A longitudinal wave is excited in an article by falling a transverse wave at a subcritical angle onto its surface. The distance H to the reflective surface is determined. The distance between the points of entry and reception of ultrasonic waves is determined by the formula L H (tg a + + tg a t), where H is the distance from the input surface to the reflective surface, and a and a are the input angles of the longitudinal and transverse waves, respectively.

In synchronous scanning by the emitter and the receiver, the amplitude Ait of the received shear wave, which is the result of the transformation at the defect of the longitudinal wave, is measured first, and then the amplitude Ati of the received longitudinal wave obtained from the shear transformation. The difference between these amplitudes is related to the transformation coefficient

Rit

the ratio of L Ac-Ati 20 Ig

Rti

Thus, by measuring the amplitudes AN and Ati, the nature of the reflecting boundary is judged. For the free boundary, D 0, and for the solid border, At, is calculated based on the specific acoustic properties of the materials being monitored. The measured Aism Ait-Ati value is compared with At. With Aism 5: At, a solid boundary is attributed to the defect, and with Aism A t, the free border is attributed.

The proposed method allows to increase the information content of ultrasonic testing due to the difference in the boundaries of defects, for example, to establish the fact of non-metallic inclusion detaching from the base metal, which may occur as a result of heat treatment, the reliability of defect size estimation by taking into account when determining the equivalent area of different coefficients for defects with his

5

0

5

5

0

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solid or solid boundaries, which ultimately can lead to a decrease in the repair volume of defective areas and increases the noise immunity in the control of two-layer materials due to the identification of defects with a free boundary against the background of reflection from the solid boundary of the layers.

Claims (1)

SUMMARY OF THE INVENTION A method for ultrasonic testing the continuity of products, including excitation of a transverse wave into the product at an angle, which ensures the transformation of wave types at the defect and reception of the longitudinal wave transported at the defect according to a separate scheme, determining the transverse wave transformation coefficient into the longitudinal Ati, characterized in that, for the purpose of increasing the information content and reliability of control products, the orientation of defects in which is known in advance by determining the difference between defects with a free border from effects with a solid boundary, determine the distance H to the defect reflecting surface, simultaneously with excitation of the transverse wave in the product, they excite the longitudinal wave by incident on the surface of the longitudinal wave at a subcritical angle, take the longitudinal and transverse waves transformed on the defect at an angle equal to the angle of incidence during synchronous movement of the emitter and receiver, the distance between the entry points of which is determined from the ratio L H (tg a + tg at), where a and t are the angles of entry of the longitudinal and transverse waves, respectively, and determine the coefficient of transformation of the longitudinal wave into the transverse Ait, and the type of defect is determined by the difference of the coefficients AH and AH. / SW