SU903758A1 - Device for ferromagnetic material magnetic noise structuroscopy - Google Patents

Description

I

The invention relates to a means of JsaM electromagnetic structuroscopy and can be used to control the structural and mechanical characteristics of ferromagnetic materials.

A device for monitoring the physicomechanical state and structural properties of ferromagnetic materials is known, comprising a generator, a converter, a phase-sensitive unit, a filter, a broadband amplifier, a second detector, and an automation unit. The device allows for a combination of a magnetic noise signal and a fundamental frequency signal to extract a signal characterizing the fitness of item ij.

However, measuring the distribution of pulses in amplitudes or durations and using the results of these measurements to control the material is associated with a significant complication of the instrument of the struktroscope. The control of the same structural state

metal by a single.-only integral parameter — the number of Barkhausen jumps — has a low confidence due to the influence on this parameter of changes in the structural properties of the material.

The closest to the invention to the technical essence is a device for magnetic-noise structuroscopy of ferromagnetic materials, containing a series-connected generator, a magnetic-induction converter, an amplifier, an amplitude selector, a switch and a pulse counter.

15

The switch transmits EMF pulses to the meter; from the Barkhausen jumps during the half cycle of the magnetization reversal, and the phase of the switch controlling the switch is due to

20 control 2,

Claims (2)

A disadvantage of the known device is low reliability of the control due to the low information content of the one-dimensional measuring signal, the magnitude of which is affected by the influence of various structural and mechanical properties of the material. The purpose of the invention is to increase the dignity of monitoring the structural and mechanical characteristics of ferromagnetic materials. The goal is achieved by the fact that the device for the super-noise-free strugroscopy of ferromagnetic materials, containing a series-connected magnetic induction converter, amplifier, amplitude selector, switch and pulse counter, is equipped with a processor, operational and permanent storage blocks, a comparison unit and a gate generator, the comparator inputs are connected with generator outputs and a permanent storage unit connected to the generator, and the output through the gate driver is the switch, the processor outputs are connected to the inputs of the counter, operational and permanent storage units, and the input to the output of the operational storage unit, the other input of which is connected to the output of the counter. The drawing shows a block diagram of a device for magnetic-noise structuroscopy of ferromagnetic products. The device contains sequentially connected generator 1 of sawtooth current, magnetic induction converter 2, amplifier 3, amplitude selector, switch 5, counter 6 pulses. The generator 1 is made according to the digital-to-analog converter circuit (DAC) and contains a controlled clock pulse generator, a reversible counter and the DAC itself (not shown). Selector 4 is equipped with a scheme for adjusting the threshold of amplitude selection, and this scheme is also based on the DAC. The device contains a comparison unit 7, a gate driver 8, an operative storage unit 9, a permanent storage unit 10 and a processor 11. The inputs of the comparison unit 7 are connected to the outputs of the generator 1 and a permanent storage unit 10 that is connected to the generator 1 and the output through the gate driver 8 to the switch 5 The outputs of process 11 are connected to the inputs of counter 6, operational and standby storage units 9 and 10, and the input with output of operational storage unit 9, the other input of which is connected to the output of counter 6 , Devices o works as follows. Since the analog output of the generator 1 to the transmitter 2 is fed symmetric linearly varying (sawtooth) current namagnichivaniYao arise in the test material irreversible magnetization jumps create a magnetic induction converter 2 EMF stream of pulses which are amplified in an amplifier 3 and through amplitude selector 4 and the switch 5 provided to the counting the input of the counter 6. The threshold value at which the pulse is cut off is set by the digital input of the selector from the persistent storage unit 10. In the Codes of the coordinates selected for measuring the points of the hysteresis loop, the boundaries of the neighborhood of each of these points, and the values of the magnetization reversal rates used in the control are also stored in it. The switch 5 transmits pulses to the counter 6 only Yb of the time of action of the strobe produced by the shaper 8 according to the output signals of the comparison unit 8, the beginning and the end of each strobe being set by the moments of coincidence of the magnetisation current value with numerical values that correspond to the boundaries of the neighborhood of each measuring point. These numerical values are fed to the comparator unit 7 from the permanent storage unit 10 by a processor command 11. During one cycle of the magnetization reversal, the device measures the number of EMF pulses from magnetic noise at all previously selected points of the hysteresis loop, with the measurement results at each point following a command from processor 11 is copied from counter 6 to the operational storage unit 9. Then this measurement cycle is repeated for all predetermined combinations of amplitude selection threshold values and remagnetization speed After the completion of the specified measurement program, the accumulated set of results is used to calculate the quantitative characteristics of the structural state and mechanical properties of the material under test. To this end, the processor 11 produces the solution of multifactor regression equations. The use of a multidimensional measuring signal generated by measuring the current value of the number of pulses at several points of the hysteresis loop with various combinations of amplitude selection and the rate of magnetization reversal allows selective, control of such structural and mechanical characteristics of the ferromagnetic material as the surface layer after heat treatment, the depth of the nitrated layer - the magnitude of the residual internal stresses in the metal, which, ultimately, The reliability of material control is higher. Claims An apparatus for magnetic noise restructuroscopy of ferromagnetic materials, containing a series-connected generator, a magnetic induction converter, an amplifier, an amplitude selector, a switch and a pulse counter, characterized in that, in order to increase the control reliability, it is equipped with a processor, operational and permanent memory blocks, by the comparison unit and the gate driver, the inputs of the comparison unit are connected to the outputs of the generator and the permanent storage unit connected to the generator, and the output, via the gate driver, to the switch, the processor outputs are connected to the inputs of the counter, the operational and fixed storage units, and the input to the output of the operational storage unit, the other input of which is connected to the output of the counter. Sources of information taken into account during the examination 1. USSR author's certificate No: 532802, cl. G 01 N 27/86, 1975. 2. USSR author's certificate №, cl. G 01 N 27/86, 1976 (prototype).