SU1206678A1 - Arrangement for inspecting mechanical properties of ferromagnetic articles - Google Patents

Description

The invention relates to non-destructive testing of the mechanical properties of ferromagnetic materials and products and can be used in metal. lurgic industry to control the quality of sheet metal, as well as in mechanical engineering to control the quality of heat treatment of thin-walled products made from a wide range of structural steels with a carbon content of over 0.3

The purpose of the invention is to increase the accuracy of control by eliminating the influence of changes in the thickness of the products being tested.

The drawing shows a block diagram of a device for controlling the mechanical properties of ferromagnetic products.

The device contains a magnetizing solenoid 1, the formers 2 and 3 of the magnetization and demagnetization pulses connected to it, consisting, for example, of two charging devices, in which capacitor batteries are used as accumulators of electric energy, and - bit d - thyristors, delay unit 4, the first and second outputs of which are connected respectively to the inputs of shapers 2 and 3 of magnetization and demagnetization pulses, threshold unit 5, the output of which is connected to the input of the shaper 3 pulses The demagnetization switch located inside the magnetizing solenoid 1 is a ferrozond-gradiometer 6 connected to the last measuring unit 7, connected in series switch 8 and amplifier 9 connected to the output of measuring unit 7. The output of amplifier 9 is connected to the first input of the threshold unit 5, the second input which is connected with the second output of the de-magnetization pulse generator 3, the second and third input 1 of the switch 8 are connected to the third and fourth outputs of the delay unit 4, respectively, and the second output of the switch 8 to indicator 10.

The device works as follows

On} an aging solenoid 1 with a ferro probe-gradiometer 6 is installed with an end on the surface of the control 30

ferromagnetic product (not shown). The magnetization pulse generator 2 accumulates electrical energy, is charged

5 capacitor banks. Simultaneously, a delay unit 4 is started, which sequentially, at set intervals, sends signals to the driver 2 of the magnetizing pulses and the switch 8 or to the driver of the 3 demagnetization pulses and the switch 8. When the charging is completed, the capacitor of the driver of the 2 magnetizing pulses discharges

15 through the solenoid 1. At the same time, a current impulse flows through the solenoid 1, the amplitude of which provides for the creation at its end of a pulsed magnetic field sufficient for

20 the introduction of the local area of the controlled product into a magnetic nastia. The magnitude of the normal component of the local magnetic field of the residual magnetization is measured: - 25, which carries information about the thickness of the product under test. Then the signal through the switch 8 is fed to the input of the amplifier 9, and from its output a signal proportional to the measured gradient is fed to the first input of the threshold unit 5. At the same time, the shaper 3 of demagnetizing pulses begins to accumulate electrical energy, i.e. capacitor banks are charged. From the output of the imaging unit 3, the signal enters the second input of the threshold unit 5. When reaching the second input of the unit

5 voltage equal to the voltage at the first input, it works, and

capacitor discharge stops. After that, the capacitors of the demagnetization pulse generator 3 are discharged through the solenoid 1. At the same time, a pulsed magnetic field is created at its end, which partially demagnetizes the local region of the controlled product. The magnitude of the gradient of the local magnetic field of the residual magnetization is measured and is shown on the indicator 10, and the magnitude of the gradient depends on the mechanical properties of the ferromagnetic product and does not depend on the thickness.

40

45

50

VNISHSh Order 8703/45 Circulation

Branch ShSh Patent, Uzhgorod, Proektna St., 4

Subscription

Claims (1)

DEVICE FOR CONTROL OF MECHANICAL PROPERTIES OF FERROMAGNETIC PRODUCTS, containing a magnetizing solenoid, magnetization and demagnetization pulse shapers connected to it, a delay unit, the first and second outputs of which are connected respectively to the inputs of the magnetization pulse shapers and the demagnetization threshold input, the output of the demagnetization pulses, 'located inside the magnetizing solenoid, a fluxgate gradient meter, a measuring unit connected to the latter y, and an indicator, characterized in that, in order to increase the accuracy of control, it is equipped with series-connected switch and amplifier connected to the output of the measuring unit, the output of the amplifier being connected to the first input of the threshold unit, the second input of which is connected to the second output of the demagnetization pulse generator, the second and third inputs of the switch are connected respectively to the third and fourth outputs of the delay unit, and the second output of the switch is connected to the indicator.