SU1298621A1 - Device for nondestructive checking of ferromagnetic articles - Google Patents

Abstract

The invention provides an increase in accuracy in controlling the hardness of products made from steels having a non-linear dependence of magnetic parameters on mechanical properties. The test article (AI) 16 is placed between two induction converters (PIs) I, 9, which have field-creating windings 2, 10 and measuring windings 3, 11, respectively. The signal injected into the measuring winding 3, through a band-pass filter 4, separating the MpPleshaya harmonica of the secondary EMF, and the detector 5, rectifying and scaling signal, is fed to the comparator 6. The signal from the measuring winding 11 is fed to the phase compensator 12, on the other input of which receives a signal from the polishing box of the winding 10. Phase compensator I2 adjusts the phase and signal level so that the voltage at the output part is zero. If the AI 16 is different from the reference, the difference signal through the detector 13 and the scaling amplifier 15 is fed to the comparator 14. The comparator 6 is triggered by the min. And the comparator 14 by max. acceptable hardness values of AI. From comparators 6, 14, signals are sent to a command generation unit 7, which forms solid fault commands (by a signal from comparator 6), soft marriage (by a signal from comparator 14) and a norm (in the absence of signals from comparators 6, 14). Formed commands arrive at indicator 8. 2 Il. ts (L to from 00 O5 to

Description

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The invention relates to the technique of destructive testing of mechanical properties of ferromagnetic products by the electromagnetic method using sensors with distributed parameters and can be used for screening publications by hardness.

The purpose of the invention is to increase the accuracy in controlling the hardness of products from steels having a non-linear dependence of the magnetic parameters on the meanic properties.

Figure 1 shows the structural electrical circuit of the device for non-destructive testing of ferromagnetic products; Fig. 2 shows the dependence of the third harmonic voltage of the output signal of the first induction converter and the differential voltage and, from the measuring winding of the second induction converter, on the hardness of steel products 45 x 1.

A device for non-destructive testing of ferromagnetic products — combines the first induction transducer 1 with field structures 2 and measuring 3 windings, the band-pass filter 4, the first detector 5, the first comparator 6, the command generation unit 7, the indicator 8, the second induction transducer 9 with field-shedding winding 10 and measuring winding P, phase compensator 12, the second detector 13, the second comparator 14, the scaling amplifier 15.

The device non-destructive testing of ferromagnetic products works as follows.

The test article 16 is placed between two overlaid induction converters 1 and 9. The current of the master oscillator (not shown), which flowed through the wooded winding 2 of the first induction converter 1, induces in the test article 16 an alternating magnetic field, which in the measuring winding 3 induces a secondary EMF. The signal from measuring winding 3 is fed to a band-pass filter 4, in which, for example, the third harmonic of the secondary emf is released. From the output of the band pass filter 4, the third harmonic voltage is fed to the input of the first detector 5, which rectifies it and scales it. DC signal from the output of the first detector

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5 is fed to the input of the first comparator 6.

Simultaneously, the signal from the measuring winding 11 of the second induction

5 converter 9 is fed to the first input of phase compensator 12, the second input of which receives the signal from the secondary winding S. The phase compensator 12 adjusts the phase and signal level so that the exemplary, (suitable) part of the voltage at the output of phase compensator 12 is zero . In the presence of the test product 16, which is different from the model

15

parts differential voltage with 25

phase compensator 12 is fed to the input of the second detector 13, from the output of which the signal is fed to the input of the scaling amplifier 15, the amplified amplitude of the signal is fed to the input of the second comparator 14.

Thus, in the process of monitoring, the input from the first detector 5 is fed to the input of the first comparator 6, and to the input of the second comparator 14 via the scaling amplifier 15 from the output of the second detector 13. Setting the trigger voltage of the comparators 6 and 14 according to the specified hardness limits the test subjects are manufactured from voltage sources E mouth (not shown), the setting of the response limit of the comparator 6 is made according to the minimum allowable hardness value (point A, Fig.2), and the setting of the response limit Parator 14 - the maximum allowable value

40 hardness (point A, figure 2). The limits of operation are set in accordance with the standard heat treatment of products on model products, also used in tuning and calibrating the devices by means of work and testing.

From the outputs of the comparators 6 and 14, the signals arrive at the input of the block 7, executed on the digital microcircuits

Logic, for example, AND-NOT or OR-HE, in which Marriage commands are produced

hard and scramble soft, and in the absence of signals from comparators the command Norma.

Thus, the proposed device makes it possible to reliably inspect the tested products 16 from STSHTI 45 X I, as well as

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other steels having ambiguous dependence of magnetic parameters on mechanical properties and heat treatment conditions. This is provided by the operation of induction converters 1 and 9 on linearly varying portions of the curves and and and, (Fig 2) in accordance with the established boundaries of suitable products (point A, and A, Fig. 2), i.e. the first induction transducer I rejects the hard marriage, and the second induction transducer 9 - the soft marriage. When testing the tested products 16 with normal hardness, which are within the range of suitable ones (Fig. 2), both comparators 6 and 14 are closed, the circuit of the NOT unit 7 is turned on and the indicator 8 receives the signal Norm. Indicator 8 is, for example, a three-color scoreboard, each color of which corresponds to a demarcation group: Normal, Marriage soft, Solid marriage, activated according to the corresponding signals from block 7.

In addition, when a second induction transducer 9 is used in the proposed device, the magnetic core of which is tungsten in the form of a thin rod with a point contact on the test article 16, allows local control of hardness over its entire surface, for example, when it is rotated. At

significantly increases the accuracy of contro-5 l, allows for heat treatment of products, etc.

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Claims (1)

Invention Formula A device for non-destructive testing of ferromagnetic products, containing a first induction transducer equipped with a measuring winding and a polishing field winding connected via a serially connected band-pass filter, a first detector and a first comparator to the first input of the output unit to the command, the output of which is connected to the indicator input, and the second input is with the release of the second comparator, the second detector is different. In order to improve the accuracy in controlling the hardness of products made from steels that have non-linear the dependence of the magnet, 1x parameters on the mechanical properties, a scaling amplifier, connected between the output of the second detector and the inputs of the second comparator, a phase compensator and a second induction converter, equipped with a ground winding, connected in parallel with the ground winding of the first induction converter, and the measuring winding of the ground point , while the measuring winding of the second induction converter is connected to the first input of the phase compensator, the second input of which connected to a second induction coil polesozdayuschey converter, and the output - to the input of the second detector.