SU1765762A1 - Device for electromagnetic nondestructive test - Google Patents

Description

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(21) 4841628/28 (22) 06.25.90 (46) 09.30.92. Bul №36

(71) Sverdlovsk Scientific-Research Institute of Technology

(72) L.N.Litvinov, S.V.Sytnik, V.A.Parkov and I.R.Alferova

(56) Instrument for non-destructive testing of materials and products. Handbook ed. VVKlyueva, M .: Mashinostroenie, 1986, p. 64-81.

Melguy M, A. Magnetic control of the mechanical properties of steel. Minsk .: Science and Technology, 1980, pp. 46-70.

Mikheev M.N., Gorkuchov E.S., Antonov A.V. and others. Device for non-destructive magnetic control of the hardness of tempered products from structural and simple carbon steels. Flaw detection, 1980, No. 2, p. 31-34.

(54) DEVICE FOR ELECTROMAGNETIC NON-DESTRUCTIVE TESTING

(57) The invention relates to non-destructive testing of ferromagnetic materials and products, is intended to control the mechanical properties of products after tempering, and can be used on a machine. The invention relates to the field of non-destructive testing of ferromagnetic materials and products, intended to control the mechanical properties of products after tempering, for example, their hardness, and can be used in machine-building, metallurgical and other enterprises.

Nondestructive testing devices are known that contain a block of magnetizing, metallurgical and other enterprises. The purpose of the invention is to increase the reliability of quality control of structural steels by eliminating changes in the amount of residual induction. During the control, the control unit 11 sequentially starts the magnetization and demagnetization unit with a constant field and the magnetization and demagnetization unit 3 with an alternating field, which act on the test piece placed in coaxial solenoids 2 and 4, the Ferrosonde 5 registers the scattered field of the part proportional to the residual values HF and B2 inductions after partial demagnetization by blocks 1 and 3, respectively. The scatter field registration unit 6 converts the measured values into constant voltages AI and A2 which, through blocks 7 and 8, of the sampling and storage, arrive at the first and second inputs of the adder 9, at the third input of which constant voltage A0 is set. The output voltage of the adder 9, proportional to the control parameter K + AiBi + A2B2, is recorded by the indicator 10. 1 cf files, 3 sludge.

vani, electromagnetic transducer, the processing unit of the measuring signal and the determination of magnetic characteristics. The control using known devices consists in measuring the magnetic characteristic and the determinations of the property being monitored in the presence of an unambiguous relationship between the magnetic characteristic and the property being monitored.

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A disadvantage of the known devices is the low reliability of the control of the mechanical properties of structural steels after high-temperature tempering (450 - 650 ° C), due to the absence of an unambiguous relationship between the magnetic characteristics and the monitored property of most structural steels after high tempering.

The closest to the technical essence of the invention is an electromagnetic non-destructive testing device comprising successively connected magnetization and demagnetization unit by a constant field and a solenoid, sequentially connected ferrosonde and a register of scattered fields and an indicator.

The control using a known device consists in measuring the residual induction of the part after partial demagnetization, the value of which determines the properties of the material. A disadvantage of the known device is low reliability due to the fact that for some parts the value of the residual induction after partial demagnetization is non-monotonous or slightly varies with high tempering.

The purpose of the invention is to increase the reliability of quality control of structural steels.

This is achieved by the fact that an electromagnetic non-destructive testing device, containing a series-connected magnetization and demagnetization unit by a constant field and a solenoid, a series-connected ferrosonde and a scatter field detection unit, a control unit, is connected to the control input of the magnetization unit and demagnetized by a constant field, and the indicator is equipped with successively connected demagnetization blocks with an alternating field and a second solenoid, two sampling and storage units, and a summation unit. m, the output of the scattered fields registration unit is connected to the first inputs of the sample and storage blocks, the outputs of which are connected respectively to the first and second inputs of the adder, the third input of which is intended to set a constant voltage, and its input is connected to the indicator input, the second output of the block the control is connected to the control input of a demagnetizing unit by a variable field, and the third and fourth outputs are connected to the second inputs of the first and second sample and storage blocks, respectively.

The magnetizing and demagnetizing unit by a constant field is made in the form of a power amplifier with current feedback.

Figure 1 shows the functional

block diagram of the device; figure 2 - timing charts of the main signals of the device; FIG. 3 shows the change in the magnetic state of the monitored part at

0 change magnetizing and demagnetizing fields.

The device contains series-connected magnetization and demagnetization units by a constant field and the first

5 solenoid 2, alternating field demagnetization unit 3 and second solenoid 4, as well as sequentially connected ferrosonde 5 and scattering field detection unit 6, sampling and storage units 7 and 8, adder 9,

0 indicator 10 and control unit 11.

The output of block 6 is connected to the first inputs of blocks 7 and 8, the outputs of which are connected respectively to the first and second inputs of the adder 9, the third input of which has a constant voltage, and the output is connected to the indicator 10. The first output of the control block 11 is connected to the first the input of block 1, the second output of block 11 is connected to the second input of the block

0 1 and to the input of block 3, the third and fourth outputs of block 11 are connected to the second inputs, respectively blocks 7 and 8.

The unit 1 magnetization and demagnetization by a constant field is intended for

5 of creating a constant excitation current and is made according to the scheme of a power amplifier with current feedback. The demagnetization unit 3 is designed to create a time-varying excitation current and

0 is made according to the generator of a sinusoidal current with a measured amplitude. Solenoids 2 and 4 are designed to magnetize and demagnetize the controlled part and are made coaxially.

5 Ferro probe 5 is intended for registering a field of dispersion of a part proportional to the residual induction after partial demagnetization and is made according to a gradiometer scheme. Block 6 registration

0 scattered fields is designed to convert the measured dissipated field into a constant voltage proportional to the field, and is made according to a known scheme that includes the excitation unit

5 ferrosonde and phase detector. Block 7 and 8 of the sampling and storage are applied according to their intended purpose and are made on KR1100SK2 microcircuits.

The adder 9 is used for its intended purpose and is made according to the known

pattern. Indicator 10 is a voltmeter universal B7-16. The control unit 11 is designed to synchronize the operation of the device, is made according to the pulse distribution scheme, contains a pulse generator, a frequency divider and a decoder.

The device works as follows. From the first output of the control unit 11, the control signal VCxi (Fig. 2a) is fed to the input of the unit 1, which generates a magnetizing current 0 and a demagnetizing current And (fig.2b) in the interval Ti - T2. In this case, the field in the solenoid 2 varies as shown in Fig. 3b, and the magnetic induction of the component changes from a state with an arbitrary induction B0 through the state B: residual induction and partial demagnetization with induction BHi to the state with residual induction Bi after partial demagnetization field Hi (fig.Za).

The flux probe 5 registers the part scattering field, proportional to HF induction, which is converted by block 6 to constant voltage VB-I, fed to the first input of sample and storage unit 7, and at the time T5 of the control signal VCx3 arrives at its second input (Fig .2c) from the third output of block 11, at the output of block 7, a constant voltage VBI is established (Fig. 2d).

The unit produces in the time interval Te - T the magnetizing current 1e and in the time interval Te - Td the demagnetizing current 12 (fig.2b). In the time interval Ts - Td, the control signal VCx2 (FIG. 2d) is fed to the input of unit 3 from the second output of unit 11, and unit 2 produces a sinusoidal current C with varying amplitude in the interval Ta - Td (FIG. 2e). In this case, the field in the solenoids 2 and 4 varies as shown in Fig. 3g, and the magnetic induction of the component changes from the state with induction W through the state with residual induction Bj and partial demagnetization before induction HF2 and through the individual hysteresis loops with a residual induction of Ba after partial demagnetization (Fig. 3b). The flux probe 5 registers the field of the scattered detail, proportional to the induction B2, which is converted by the block 6 into a constant voltage VB2, which is fed to the first input of the sampling and storage unit 8, and at the time of arrival Ty to its second control signal / Cf4 (fig. 2g) a fourth voltage is set at the output of block 11 at the output of block 8

V2 (figs). The voltages VBI and VB2 from the outputs of blocks 7 and 8 are supplied, respectively, to the first and second inputs of the adder 9, the third input of which has a constant voltage VO.H adder 9 realizes the formation of the output signal VK (fig.2i) according to the relation

VK Vo + Al VB1 + A2-VB2

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The invention allows to obtain a positive effect, which consists in increasing the reliability of controlling the mechanical properties of structural steel products after high-temperature tempering by obtaining a control parameter uniquely associated with a change in the properties of steels during tempering. Using a device quantified

assess a controlled property, for example, hardness.

Claims (2)

1. Device for electromagnetic non-destructive testing, containing series-connected magnetization and demagnetization unit by a constant field and a solenoid, a series-connected ferrosonde and a registration unit for scattering fields, a control unit, an output connected to the control input of the magnetization and demagnetization unit by a constant field, and an indicator that, in order to increase the reliability of the quality control steel, it is equipped with serially connected demagnetization blocks by an alternating field and a second solenoid, two sampling and storage blocks and an adder. The output of the scatter field recording unit is connected to the first inputs of the sample and storage blocks, the outputs of which are connected respectively to the first and second inputs of the adder, the third input which is designed to set a constant voltage, and its output is connected to the input of the indicator, the second output of the control unit is connected to the control input of the demagnetizing unit by a variable field, and the third and fourth outputs are connected to the second inputs of the first and second sample and storage blocks, respectively 2. The device according to claim 1, of which is that the magnetization and demagnetization unit with a constant field is made in a current feedback power amplifier. FIG. 2 U Ј-, fa l 4J / l - d Ho Hi ft ".3 at / S f