SU1350607A1 - Method of determining flaw coordinates at ultrasonic check of articles - Google Patents

Abstract

This invention relates to the field of acoustic non-destructive testing methods. The aim of the invention is to improve the accuracy of determining the coordinates of a defect of a product with plane-parallel surfaces during ultrasonic (US) monitoring of the swinging beam by eliminating the influence of the input angle measurement error on the accuracy of determining the coordinates due to the measurement of the propagation time of the reflected signals on the forward and once reflected beam. The ultrasonic beam is transmitted by the transducer 1 and the oscillations reflected by the defect 6, ultrasound propagating at an angle oi.,, And reflected by the defect 6 and the bottom surface 5 of the product 3 ultrasonic vibrations propagating at an angle otg- are measured. on it, taking into account the thickness H of the product 3, the coordinates of the defect 6 are determined. 1 Il. S (L /

Description

The invention relates to acoustic methods of non-destructive testing and can be used to determine the coordinates of a defect in ultrasonic (US) testing of products by a swinging beam.

The purpose of the invention is to improve the accuracy of determining the coordinates of a defect of a product with plane-parallel surfaces when testing with a swinging beam due to the elimination of the influence of the error in measuring the angle of entry on the accuracy of determining the coordinates.

The drawing schematically shows the determination of the coordinates of a defect when the components are controlled by the oscillating beam.

In the drawing, an ultrasonic transducer 1 with a constant insertion point of the ultrasonic, a flaw detector 2 and a controlled product 3 G plane-parallel input surfaces 4 and a bottom 5

and defect 6. I.

The method for determining the coordinates of the defect during ultrasonic inspection of products is as follows.

Radiating ultrasound pulses into the product. During radiation, the angle at which ultrasonic vibrations are introduced in the back-end range is smoothly changed, the pulses reflected by and reflected by the defect and the bottom surface of the ultrasonic product are received, and the times t ,, and to, of the propagation of reflected pulses, respectively, are measured. The defect coordinates are determined from the expressions

four

21}

C tl- Y; cftln -. 4lT

de X is the distance from the insertion point to the projection of the defect on the input surface;

Y is the depth of the defect;

C is the speed of propagation of ultrasonic vibrations in the material of the product;

C is the time of propagation of oscillations reflected by the defect;

t is the propagation time of the oscillations reflected by the defect and bottom surface;

H is the thickness of the product:

The method for determining the coordinates of the deject is carried out as follows.

thematically varying angle, measures in the range of 40-65. Ultrasound

An ultrasonic transducer is installed on the input surface of the product 3 with thickness I from the material with the speed C of ultrasonic oscillation, capable of controlling the oscillating beam with a constant insertion point, and electrically connected to the flaw detector 2. The ultrasonic transducer 1 is emitted under continuous and automatic radiation oscillations propagating at an angle L2 are reflected only by defect 6, and ultrasonic vibrations propagating at an angle ix are reflected both by defect 6 and the bottom surface 5 of product 3.

Using flaw detector 2, the time of propagation of ultrasonic vibrations from transducer 1 to defect 6 and vice versa is measured by monitoring on the tri direct beam and monitoring on a single reflected beam tj Defect coordinates, expressed in terms of the distance X from the ultrasonic input point to the projection of the defect 6 on the input surface 4 and the depth Y of the bed 6, is determined by the formulas

X

Y

sc

- Sch :.

+ 4H

4H

five

0

five

When the defect 6 is sounded by multiply reflected ultrasonic pulses, the number of reflections from surfaces 4 and 5 of product 3 is determined, with the help of flaw detector 2, the time ti, and tn, of the propagation of ultrasonic pulses that have undergone an even and odd number of reflections, are measured. In this case, the coordinates of the defect are determined by the formulas

 4 t - Y

L, 1,

,one. g

Y 5-bL: .tkti5t ™ tUlH

--- 2 ()

- nH,

where n and m

the number of even and odd pulse reflections, respectively. The range of the swing angle of the ultrasound beam is chosen so as to ensure that the angle of intersection of the direct and once-poisoned rays, or even and odd reflections within 60-100, is found, because in this case

The area of the error ellipse, which characterizes the accuracy of the method, is the smallest, which makes it possible to achieve the accuracy of determining the coordinates of a defect in the case of ultrasonic inspection of products using a swing beam in the order of 3%.

Claims (1)

Invention Formula The method of determining the coordinates of a defect in ultrasonic testing of products, which implies that ultrasound pulses are emitted into the product, accept oscillations reflected by the defect, measure the propagation time of the reflected oscillations, and determine the distance from the defect coordinate, using the measured time, increase the accuracy of determining the coordinates of the defect of a product with plane-parallel surfaces; during radiation, an acoustic beam is pumped, additionally with Editor P.Geershi Compiled by V. Gondarevsky Tehred M. Morgental Proofreader M. Maksimishinets Order 5281/46 Circulation 776, Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4 the vibrations reflected by the defect and the bottom surface of the product are understood and their propagation time is measured, and the coordinates of the defect are determined from the expressions X ten where X is the distance from the entry point to the projection of the defect on the entry surface; the depth of the defect; the speed of propagation of ultrasonic vibrations in the material of the product; the propagation time of the oscillations reflected by the defect; the time of propagation of oscillations reflected by the defect and bottom surface; product thickness. Y WITH t t ", n