RU2262689C1 - Method and device for testing rolled stock - Google Patents

Abstract

FIELD: analyzing or investigating materials.

SUBSTANCE: method comprises irradiating an irregularity by Relay wave, recording the ultrasonic wave transformed by the irregularity, applying the magnetic field to the object to be tested, recording the magnetic flux scattered by the irregularity and modulated by the ultrasonic wave, and determining depth, orientation, and divergence of the irregularity from the amplitude and polarization of the transformed ultrasonic wave and alternative component of the scattered magnetic flux. The device comprises electromagnetic acoustical converters, amplifier, unit for measuring information parameters that is connected with the non-distractive testing instrument, and computing unit. Additionally, the device has a pulse laser generator for exciting Relay waves and at least one light guide that transmits the laser radiation to the working zone of the electromagnetic acoustical converters.

EFFECT: enhanced sensitivity and reliability.

3 cl, 6 dwg

Description

The invention relates to the field of non-destructive testing of the surface layer of metal and can be used to detect surface defects of sheet, long products and pipes from ferrous and non-ferrous metals.

A known method of ultrasonic flaw detection of cylindrical products and a device for its implementation [1], including the excitation of an ultrasonic wave pulse in the product, the implementation of the multiple passage of this pulse along the perimeter of the cross section, the reception of signals due to reflection and transformation processes using electromagnetic-acoustic transducers.

The disadvantage of this method and device is the low sensitivity when receiving, since the energy of the probe pulses does not provide in the controlled object the excitation of acoustic waves with a sufficiently high amplitude [2].

In addition, a disadvantage of the known method and the device implementing it is the inability to detect defects with very little opening or filled with fluxes or oxides that are transparent for ultrasonic testing.

A known method and device for generating surface waves using a laser [3].

It includes the excitation of surface waves, the reception and registration of signals using an interferometer.

The disadvantage of the method and the device that implements it is its limited sensitivity due to the use of an interferometer when receiving signals, which is a rather complex device that is sensitive to vibration [2].

This drawback does not allow sufficiently efficient use of laser radiation, which excites ultrasonic pulses with a significant amplitude in the surface layer of the test object.

The aim of the invention is to increase the sensitivity, reliability and effectiveness of control.

This goal is achieved by the fact that in the known method, including the use of the interaction of Rayleigh waves with discontinuities, the Rayleigh wave is irradiated with a discontinuity, an ultrasound wave transformed by discontinuity is recorded, a magnetic field is applied to the control object, and the magnetic flux modulated by the ultrasound wave is recorded by amplitude and polarization the transformed ultrasonic wave and the variable component of the scattered magnetic flux judge the depth, orientation and disclosure discontinuities.

The achievement of this goal is also facilitated by the fact that the known device comprising electromagnetic-acoustic transducers, an amplifier, a unit for measuring informative parameters, a flaw detector and a decision unit, further comprises a pulsed laser generator for exciting Rayleigh waves and at least one optical fiber delivering radiation laser into the working area of electromagnetic-acoustic transducers.

In addition, the laser and electromagnetic-acoustic converters are mounted on a common platform equipped with a drive, with the possibility of movement along the horizontal axis of the control object, and electromagnetic-acoustic converters are mounted on a frame equipped with a drive, with the possibility of movement along the vertical axis of the control object.

The use in the known method of ultrasonic testing of laser radiation and the use of ultrasonic surface Rayleigh waves as probing pulses (ZI) can significantly increase their amplitude compared to electromagnetic radiation generated by electromagnetic-acoustic transducers (EMAT), and therefore, increase the sensitivity and monitoring efficiency quality metal.

The use in the known device of an additional pulsed laser generator allows you to create Rayleigh waves in the surface layer of metal and register ultrasonic waves transformed by discontinuities using EMAT or piezoelectric transducers (PES).

The use in a known device of a platform with a drive allows you to install the device strictly along the axis of the object of control (OK) and, if necessary, roll it aside during repairs and maintenance.

The use in the known device, in addition to installing the transducers of the frame, equipped with a drive, allows you to move the EMAT unit vertically to combine their geometric center with the geometric center OK (i.e., Fig. 5).

Figure 1 shows the structural diagram of the device.

Figure 2 shows the location of the points of generation of the probe pulses (ZI) and the converters in the plan.

Figure 3 shows a diagram of the relative position of the transducers and the ZI around the circle OK relative to each other.

Figure 4 shows three possible cases of applying the method:

Case 1 - Detection of a large crack with dimensions in the plan of more than 0.1 mm and a depth of 0.3 mm.

The Rayleigh wave is partially transformed into a transverse wave, recorded using a probe.

Case 2 - Simultaneous registration of small and large discontinuities (that is, defects) of the surface layer of metal using EMAT and PEP.

Case 3 - Detection of a shallow crack with plan dimensions less than 0.1 mm and depth less than 0.3 mm using EMAT.

Figure 5 shows a view In the device (front).

Figure 6 shows a view A of the device (side).

The device contains (Figs. 1, 5, 6) a block of converters (electromagnetic-acoustic or piezoelectric) - 1, a block of amplifiers 2, a block for measuring informative parameters 3, a flaw detector 4, a decision block 5, a two-channel laser wave generator Rayleigh 6, optical fibers 7 , a control unit 8, a platform 9, a frame 10 on which transducer blocks 1 are mounted on both sides, a cabinet 11 in which an amplifier unit 2, an informative parameter measurement unit 3, a flaw detector 4, a decision unit 5, a two-channel laser generator 6 are installed, from which about to OK the optical fibers 7, the control unit 8, the drive 12 of the platform 9, the drive 13 of the frame 10, the pneumatic drive 14 of the transducers for their supply or removal from the surface of the OK are laid.

The device operates as follows.

Using the drive 12, the platform 9 with the laser 6 and the converter unit 1 is moved to the operating position and mounted on the OK axis. From accidental movements of the platform captures are provided (not shown conditionally). Using the drive 13, the geometric center of the frame 10 is combined with the geometric center of OK (i.e., O, FIG. 5). Using drives 14, the converters 1 are brought to the surface OK. On the optical fibers 7 to the surface of the OK are sent pulses of laser radiation (FROM) (figure 2, 3).

When the surface of the diagnosed OK interacts with the radiation pulse of laser 1, an intense Rayleigh wave occurs (Figs. 3, 4). When this wave interacts with a discontinuity located on the propagation path (for example, a crack, Fig. 4), it partially transforms into a transverse wave (Figs. 3, 4), which are recorded by EMAT or PED transducers 1 both in amplitude and polarization of the transformed ultrasonic wave and the variable component of the scattered magnetic flux is judged on the depth, orientation and opening of the discontinuity.

Changing the relative position of the converters 1 and the optical fibers 7, diagnose near-surface defects of any configuration.

The method is very effective in practical application, since it allows you to increase the EMAT resource by providing an increased gap between the EMAT and OK, as well as detect defects that are not detected by other methods or their detection is substantially difficult.

Sources of information

1. RF patent No. 2146363 A method for ultrasonic inspection of cylindrical products and a device for its implementation.

2. N.P. Aleshin, V.E.Bely, A.Kh. Vopilkin et al. Methods of acoustic control of metals. M .: Engineering, 1989

3. US patent No. 4541280 from 10.17.1985

Claims (3)

1. A method for diagnosing discontinuities in the surface layer of metal rolling, including the interaction of Rayleigh waves with discontinuities, characterized in that they irradiate the Rayleigh wave with a discontinuity, register an ultrasonic wave transformed by a discontinuity, impose a magnetic field on the control object and record the magnetic flux modulated by the ultrasonic wave, modulated by the amplitude and polarization of the transformed ultrasonic wave and the variable component of the scattered magnetic flux judge the depth , orientation and disclosure of discontinuities. 2. A device for diagnosing discontinuities in the surface layer of metal rolling, containing electromagnetic-acoustic transducers, an amplifier, a unit for measuring informative parameters connected to a flaw detector, and a decision unit, while it further comprises a pulsed laser generator for exciting Rayleigh waves and, at least, one optical fiber that delivers laser radiation to the working area of the electromagnetic-acoustic transducers. 3. The device according to claim 2, characterized in that the laser and electromagnetic-acoustic transducers are mounted on a common platform equipped with a drive with the possibility of movement along the horizontal axis of the control object, and electromagnetic-acoustic transducers are mounted on a frame equipped with a drive, with the possibility of movement along vertical axis of the control object.

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