SU1527564A1 - Apparatus for inspecting mechanical properties of articles of ferromagnetic materials - Google Patents

Abstract

THE INVENTION IS RELATED TO NON-DESTRUCTIVE TESTS OF FERROMAGNETIC PRODUCTS. THE PURPOSE OF THE INVENTION IS THE IMPROVEMENT OF THE CONTROL RELIABILITY. FOR THIS CHART 9 sample and hold control signal, the generated zero-BODY 8, a memory VOLTAGE U _H @ proportional to the coercive force and supplied to the input of the circuit 9 with a resistor 6. Output voltage from the circuit 9 is supplied to a first input of the computing unit 10. From the output of the integrator 17, a signal proportional to the magnitude of the magnetic induction B is applied to one of the inputs of the multiplier 13, to another input of which a signal is proportional to the speed DH / DT of the change in the magnetic field. Thus, the output signal of the multiplier 13 is proportional to the value of B _x (DH / DT). This signal, the passage through the serially connected switch 14, the integrator 15 and the amplitude detector 16, is converted into a signal proportional to the area of the hysteresis loop limited by the selected values of H ₁ and H _{2 of the} magnetic field strength. The detector output signal 16 is supplied to the second input of the computing unit 10, wherein signal processing is performed according to the expression U _a = A ₀ + A ₁ / U _ns + A ₂ (1 / U _p) + A ₃ (U _ns / U _p ) where U _{to is the} output voltage

U _p , - nap proportional to the part of the hysteresis loop

A ₀ , A ₁ , A ₂ , A ₃ - normalization factors. 4 il.

Description

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From the output of the integrator 12, a signal proportional to the magnitude of the magnetic induction B is applied to one of the inputs of the corner 13, to another input of which a signal is proportional to the speed dH / dt of the magnetic field change. Thus, the output signal of the multiplier 13 is proportional to the value of B (dH / dt). This signal, the passage through the serially connected key 14, the integrator 15 and the amplitude detector 16, is converted into a signal, proportionally. The invention relates to the field of non-destructive testing of ferromagnetic materials and products and is used to determine the mechanical properties of the products, such as their hardness after tempering .

The aim of the invention is to increase the reliability in the control of steel after high-temperature tempering by optimizing the choice of the control parameter.

FIG. 1 shows a block diagram of the device; in fig. 2 is a null-organ block diagram; FIG. 3-6 are timing diagrams explaining the work of the / 1 unit; in fig. 7-diagrams of the change in the magnetic state of the controlled product. Gt15 RP with the change in the magnetizing field,

A device for controlling the mechanical properties of products made of ferromagnetic materials contains successively connected synchronizer 1, generator 2 and inductive transducer 3, consisting respectively of exciting and measuring windings 4 and 5, resistor 6 connected in series with exciting winding 4, connected in series - libie, the first integrator 7, the input of which is connected to the output of the converter 3, the zero-organ 8, the sample-storage circuit 9, the computing unit 10, the indicator 11, are connected in series to the second integration or 12, the first and second inputs of which, respectively, are connected to the output of the converter 3 and the second output of the synchronizer 1, multiplication unit 13, key 14, the third integrator 15 and the amplitude detector 16, the output of which is the subfield of the hysteresis loop, limited by the selected values of IC and Ufi eg magnetic field. The output signal of the detector 16 is supplied to the second input of the comp.) 1-unit block 10, in which the signal processing is performed in accordance with the expression 1 AO + A

UH. + +), Where l is the output voltage-, I p voltage proportional to the part of the loop gi ..: theresis {A, A, A, A, - H (world coefficients. 7 ill.

0

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0

3

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to the second input of the computing unit 10, the differentiation unit 17, the output of which is connected to the second input of the multiplication unit 13, and two comparators 18 and 19, the outputs of which are connected to the second and third inputs of the key 14, respectively. The connection point of the exciting winding 4 and the resistor 6 is connected to the second input of the sampling-storage circuit 9, and the inputs of differentiation unit 17 and comparators 18 and 19. Third output of synchronizer 1 is connected to the second inputs of first integrator 7, zero organ 8, third integrator 15 and amplitude detector 16.

The null organ 8 consists of the second amplitude detector 20, the adder 21, the comparator 22 and the pulse forger 23, and the third amplitude detector 24, the output of which is connected to the second input of the adder 21, connected in series. The first inputs of the amplitude detectors 20 and 24 are combined The input of the null organ 8, the second inputs of the detectors 20 and 24 and the comparator 22 are also combined and are another input of the null organ 8, the output of which is the output of the pulse former 23.

The device works as follows.

The control consists in measuring the coefficient of force and the area of the part of the hysteresis loop of the part being monitored by changing the magnetizing field in a given interval Hd-H (contour area E-E-K in Fig. 7a) and determining the control parameter K by the ratio

five

To AO -t-A, He + Ai- (l / P) A.J- (НС / Р)

where not coercive force;

Р is the area of a part of the hysteresis loop with a change in the reversal field in the interval H (- H (2i AO, A, A and A J, are the normalization coefficients

According to the value of the parameter K, the mechanical properties of the controlled part are judged. In this case, the interval of the field H (-Hg is determined in each specific case of control so that the parameter K best correlates with the controlled property.

For this, from the first output of the synchronizer 1, the control signal 43 is fed to the input of the generator 2, which begins to produce a current of 25 pn-like form, and the second inputs of the synchronizer 1 receive the second inputs of the integrator 7 and 15, the zero-body 8 and the amplitude detector 16 26, which embed integrators 7 and 15 and amplitude detectors 20, 24 and 16. The output current 25 of generator 2 enters the first winding 4 of converter 3 and re-magnetizes the monitored product located in it. The signal 27 in the secondary winding 5 of the converter 3, proportional to the first rate of change of magnetic induction, is fed to the input of integrator 7. The latter integrates the measuring signal, and the output signal 28 of integrator 7, which is proportional to the magnetic induction in the product being tested, may be asymmetric with respect to zero , since the magnetization reversal of the product can begin with an arbitrary magnetic state, not necessarily corresponding to the demagnetized state (for example, from point A, Fig. 7).

The signal 28 is fed to the second inputs of the amplitude detectors 20 and 24 of the zero-body 8, which form the positive and negative constant signals 29 and 30, respectively, equal to the amplitude values of the output signal 28 of the integrator 7. The signals 29 and 30 are fed to the adder 21, at the output which produces a signal 31, equal to the half-sum of the input signals 29 and 30. The output

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the signals of the adder 21 and the integrator 7 are received respectively at the first and second inputs of the comparator 22, and the state of its output signal 32 at the instants Tr and T coincides with the magnitude of the input signals.

The output signal of the comparator 22 is fed to the input of the imager 23

Q pulses, at the output of which, a negative pulse is formed at the negative edge of the input signal 32, which arrives at the first input of the sample-storage circuit 9, and the second input receives a signal from a resistor 6 proportional to the current value of the magnetic field in the primary winding. At the moment Ta, when the control pulse 9 arrives at the first input, an output signal 34 is generated at its output equal to a constant voltage 11 proportional to the current value of the magnetic field at time Tj equal to the coercive force

25 controlled product.

The control signal 35 arrives at the second input of the integrator 12 and zeroes it in the intervals O T and above T7. Integrator 12 integrates

30 signal 27 in the interval T (-T / g, and its output signal 36, proportional to A. magnetic induction B in the controlled product, nocTynaet to the first input of multiplication unit 13. The signal from the resistor 6, proportional to the current 25 B winding 4 goes to block 17 differentiation, and after differentiation, the signal 37, proportional to the rate of change of the field dH / dt, supplies the second input of block 13. The output signal 38 of the multiplier 13, proportional to B (dH / dt), goes to the first input of the key 14, which opens at intervals In, - TD and

45 T5 - Tg, when the second and third

the inputs of the key 14 simultaneously receive, respectively, the output signals 39 and 40 of the positive level from the comparators 18 and 19. At the same time, in the interval Tj — Tc, the induction of the upstream branch of the hysteresis loop changes as the magnetic field increases from H to TQ , the induction of the downward branch changes as the magnetizing

floor from H 4. to H. The comparator 18 changes its state at times T, and Tfc, when the magnitude of this input signal is proportional to the current

35

the value of the field reaches a predetermined level Nc, and the comparator 19 changes its state at the time of TC and Td when the value of its input signal reaches a predetermined level N. The output signal 41 of the button 14 is fed to the input of the integrator 15. The integral of the signal 41 in the TQ interval - T / | corresponds to the contour area HI, -D-E-He. (Fig. 7a), and the signal integral 41 in the Tg-Te interval corresponds to the area of circuit H (-D-E-H (Fig. 7a). Therefore, the constant voltage Up of the output signal 42 of the integrator 15 corresponds to the area of the circuit D-E- And (Fig. 7a). The signal 42 is fed to the amplitude detector i6, and the constant voltage IJ p from the output of the detector 16 is fed to the second input of the computing unit 10, the first input of which receives the signal UH from the output of the storage sampling circuit 9, Bj: numerical unit 10 realizes the formation of the output signal Tj according to the indicated relation. Signal U. Indicator 11.

Claims (1)

When performing pre-testing for parts with known properties, the output signals of Hz, Up, and Ufv of blocks 9, 16, and 10 are measured. According to the obtained least-squares data, the results of the coefficients AO, A, Aj, and Lree are intervals. ting the field H, -H (j is determined experimentally in such a way that the azan relation with the found magnitudes of the coefficients gives the minimum root-mean-square error, i.e., that the parameter and h correlate best with the controlled properties. Formula of the invention the property for controlling the mechanical properties of the product: HF from a ferromagnet five 0 five 0 five 0 45 ; shh. materials containing serially connected oscillator, inductive transducer consisting of exciting and measuring windings, ifflTerpaTop and null organ, a resistor connected in series with the giving winding of the inductive converter, serially connected multiplication unit, a key and a second integrator, comparator, included between the connection point, the exciting winding, the inversion (the body and the resistor and the second key input, and the indicator, characterized in that, in order to increase the reliability during control one, drink after the high-temperature otpug.ka, it is equipped with a third integrator, connected between the output of the inductive-r and the first transformer and the input of the multiplier unit, connected in series with the AMG; 1HNm ds 1 ect; pa, and a computational unit whose output is soy; nen with the indicator input, the second km of parameter, the enabled input of the first comparator, and the TpeTifViM BxoiTQM key, the differential unit1. G: -) ianip, included between the junction point of the HHJvyKTKBHHoro transducer and the second block turn at the knob of the sampling unit-xy.anen, input: .. which corresponds to the BeTci Demio gyyugene to the switch Organ L is the input of the first comparator, and the output is connected to the second input of the computational unit, and a synchuator, the port and the second outputs of which are respectively connected to the generator input and the input 1 of the integrator, and the third output is connected to the first and second inputs second integrator, 1gul-organ and amplitude de.tector J 25 HI Hi n t, t 26 PHIC CPU r. 2  t Gw Fig.z one 4/0 l trisrig .B