SU1511676A2 - Method of ultrasonic built-up inspection of articles - Google Patents

Abstract

This invention relates to acoustic methods of non-destructive testing. The aim of the invention is to expand the information content and improve the accuracy of control by determining the thickness of the product in the control zone and the speed of propagation of ultrasonic (US) oscillations in the material of the product by measuring the distance between the positions of the receivers when they are coaxially mounted with the radiators in the absence and presence of the product. . An acoustically coaxially paired combined emitter 1 and receivers 2 and 3 are installed, product 4 is inserted between them, receivers 2 and 3 are shifted to achieve acoustic coaxiality again, and the displacement is measured. Artificial defects 5 and 6 are placed on opposite sides of the product and move it. During the movement, the time of detection of defects 5 and 6 by each of the receivers 2 and 3 is recorded. Using the measured parameters, the thickness of the product and the velocity of propagation of ultrasonic vibrations in it are determined. Defects 5 and 6 are removed, product 4 is sounded in a similar way, and the time of detection of defect 7 by each of receivers 2 and 3 is recorded. The measured depth for the defect 7 and length are determined by the measured parameters. 1 il.

Description

1H

This invention relates to acoustic methods of non-destructiveness, its control and is complementary to auth. No. 1320742.

The purpose of the invention is to expand the information content and increase the accuracy of control by determining the thickness of the product and the speed of propagation of ultrasonic vibrations in its material,

The drawing shows a diagram of the ultrasonic control products,

Ultrasonic control method

The products are as follows. I

A pair of emitters combine and install them acoustically coaxially to a pair of receivers. Install the product between the emitters and receivers so that the bisector of the angle oL between the acoustic axes of the emitters is perpendicular to the surface of the product. Ultrasonic vibrations are emitted into the product and the last vibrations are received. The receivers are shifted in a plane parallel to the surface of the product until the amplitude of the received oscillations reaches its maximum value and the value 1 of the displacement of the receivers relative to the initial position is measured. Artificial defects of known length are placed on the opposite surfaces of the product and move the product in the plane of the acoustic axes of the emitters and receivers to the bisector of the angle cL. During the movement of the product, the amplitude of the received oscillations is determined and the time of detection of artificial defects by each receiver is determined to reduce the amplitude of the received that signal. Using measurements carried out on artificial defects, as well as measurements of displacement magnitude 1, the parameters determining the angle oi, the distance between the surface of the product and the combined emitters, the thickness of the product and the propagation velocity in its material of ultrasonic vibrations are carried out. the way the product is sounded without artificial defects, in the event of defects, the time of defect detection is recorded by each receiver to reduce the amplitude of the received signal. From the difference in the time of defect detection each From the receivers, taking into account the parameters found by artificial defects, the depth and length of the defect are determined.

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The method of ultrasonic-shadow monitoring of products is realized in a sweet manner. Combined guy) 1H emitter 1 s and two receivers 2 and 3 are set acoustically coaxially, between emitter 1 and receivers 2 p; 3 enter the controlled article 4, positioning it so that the bisector of the angle cxL between 0 acoustic axes of the emitter 1 is perpendicular to the surface of the product 4. The emitters emitted by the emitter 1 into the product 4 are received by the 5 receivers 2 and 3, Since the acoustic path between the emitter 1 and receiver-n-2 si 3 changed with the introduction of product 4, the acoustic coaxiality of emitter 1 and receivers 2 and 3 was disturbed. Each receiver 3 and 3 are displaced parallel to product 4 until the amplitude of the received ultrasonic vibrations reaches a maximum value of 10 °, which again achieves acoustic alignment. Measure the magnitude of the displacement of the receiver 2 or 3 relative to the initial installation. An artificial defect 5 is placed on the side of the product 4 facing the radiator 1 and the artificial defect 6 is on the opposite side of the product. 4 They are moved with defects 5 and -b of known length in the plane of the acoustic axes of the emitter 5 and receivers 2 and 3 of the normal bisector of the angle oi . In the course of moving along the reduction of the amplitude of the received signal, the time of detection of artificial defects 5 and 6 is recorded. The thickness H of the product 4 is determined from these 0 measured parameters

 j

0

H

where d t

(. Ky-2 .. 2-T

- the time difference between the detection of a defect 6 receivers 2 and 3, s; .t - time difference between the detection of a defect 5 receivers 2 and 3, s; Ku - factor proportional to speed: movement of the product 4, mm / s; K is the coefficient determined by the angle i (),

Using certain values of L1, R and R, calculate the angle jb between the acoustic axes in article 4 and

5151

velocity with the propagation of ultrasonic vibrations in it

WITH

WITH . ° sinc6 / 2

where C is the propagation velocity

Ultrasonic vibrations in the medium between the emitter 1 and the receivers 2 and 3 and the product 4, for example in the air.

Similarly, the sounding of the product is carried out after the removal of defects 5 and 6, and the detection time of the defect 7 is measured by each receiver 2 and 3,. The depth h of the defect is determined from the expression

h

 H,

where t is the time difference between

defect detection 7 receivers 2 and 3, s,

From the duration tn of the time of detection of the defect 7, its length L can be found according to

L - Ku t g, FQ - arithmetic average time 1LGG r-lf h Q t-ЧТГ «/ а« 1Л СТ ПО ЦЗК-ТД f

m defect detection by rivets 2 and 3,

etc

16766

The ultrasonic monitoring method of the product, LIU, during the sounding of the product, makes it possible to determine the actual thickness 5 of the product in the control zone and the speed of propagation of ultrasonic oscillations in its material, as a result of which the accuracy of determining the depth of the defect is ensured.

ten

15

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25

thirty

Claims (1)

Invention Formula The method of ultrasonic shadow control of products according to autor. St., No. 1320742, characterized in that, in order to expand the information content and control accuracy, emitters and receivers are installed acoustically coaxially in the absence of the product, after installing the product between radiators and receivers, displace receivers in the plane parallel to the surface of the product until the amplitude of the received oscillations reaches its maximum value, the magnitude of the displacement of the receivers is measured and is additionally determined using the measured maximum the displacement of the thickness of the product and the speed of propagation of ultrasonic vibrations in its material.