SU1093958A1 - Method of electromagnetic checking of ferromagnetic material physical mechanical parameters - Google Patents

Abstract

A METHOD OF THE ELECTROMAGAITO CONTROL OF M13IKO-MECHANICAL PARAMETERS OF FERROMAGNETIC MATERIALS, which consists in the fact that the control gnNun section of the material is magnetized on one side of it by an external magnetic field of a rod electromagnet and it can detect the amount of nymptoma, it can detect the amount of nymprostomy, and it can detect the amount of nymptoma, it can detect it, and it can be able to detect it. yu u and so that, in order to increase the reliability of the control, after magnetizing and the external constant magnetic field is gradually reduced to zero, in the process of decreasing it is fixed the strength of the intensity And, the external constant magnetic field at the moment when the intensity of the constant magnetic field reaches zero, the field on the other side of the material and the strength of Novo, the residual magnetic field on the other side of the material at the moment when the external constant magnetic field is zero, and controllable parameters are judged by the expression H X NOVR. 7 ////// //////// L о: О:; о D1 eo

Description

figure 1

The invention relates to non-destructive electromagnetic control of materials and products and can be used to control the physicomechanical parameters of ferromagnetic materials and products in the metallurgical and engineering industries.

There is a method of electromagnetic control of physicomechanical para- meters of a moving ferromagnetic material, which consists in the fact that the controlled section of material is magnetized by a pulsed magnetic field formed on one side of it, on the opposite side of the material pho, the second pulse field directed towards the first one is read, the gradients are residual magnetization from opposite fields, summarize both gradients and, based on the obtained value, judge the physicomechanical parameters of the controlled material iala 1,

The disadvantage of this method is that it can be used only to control the physicomechanical parameters of thin-carbon steels.

The closest to the invention in its technical essence is a method of electromagnetic control of the physicomechanical parameters of ferromagnetic materials, which implies that it is controlled. the area is material, and magnetized on one side of it by an external constant magnetic field of ste1 | The magnet magnet is measured and the intensity of the constant magnetic field on the other side of the material is measured. The hardness of the steel tape is determined by the degree of weakening of the magnetic field, which is then calculated from the ratio of the magnitudes of the constant magnetic field strengths on opposite sides of the material {2}.

The disadvantage of this method is its lack of reliability due to the low sensitivity of the monitored parameter to changes in the mechanical properties of materials.

The aim of the invention is to increase the reliability of the control.

This goal is achieved by the fact that according to the method of electromagnetic control of physicomechanical parameters of ferromagnetic materials, the fact that the controlled section of material is magnetized, on one side of it, by an external constant magnetic field of a rod-shaped electromagnet and a constant magnetic field is measured on the other side of the material, after magnetization the intensity of the permanent magnetic field is smooth

reduced to zero, in the process of decreasing the magnitude of the intensity Hi of an external constant magnetic field is fixed at the moment when the intensity of a constant magnetic field on the other side of the material reaches zero and the magnitude of the strength of the residual magnetic field on the other side of the material Hegp is equal to zero external constant magnetic field, and the controlled parameters are judged by the expression H v Hpgo.

FIG. 1 shows a diagram of one of the variants of the device that implements the method; in fig. 2 -, the dependence of the magnetic field strength on the back side of the material on the strength of the increasing and decreasing external magnetic field (H) for a sample 10 mm thick made of ZOHGSA steel.

The device contains (Fig. 1} a DC stub electromagnet 1 with a core 2, an adjustable DC source 3, an ammeter 4, a magnetically sensitive element 5, for example, a Hall transducer, a constant magnetic field indicator b. The magnetically sensitive element 5 is connected to the indicator b magnetic field and installed on the same axis with the electromagnetic 1 on the side of the controlled product 7 opposite the core.

The increase in the reliability of control is based on the use of the physical phenomenon of premature magnetization reversal of the upper layers of the ferromagnet in a decreasing external magnetic field. When a ferromagnetic sample is magnetized by an external constant magnetic field of a rod electromagnet on one side of the sample, the magnetic field on the reverse side with increasing external magnetic field H changes according to the OA curve (Fig. 2). If, after reaching an external magnetic field of a certain magnitude (for example, point A), the LF is reduced, then HOBP varies along the ABC curve and reaches zero at point B with an external magnetic field that is not equal to zero (segment OV). With a further decrease in H, N. changes its sign and at N., 0 reaches a certain value (segment OC), and the direction of the residual magnetic field is opposite to the direction of the applied external magnetic field.

The method is carried out as follows.

The controlled sheet, 7 (Fig. 1), is placed by the electromagnet and the magnetically sensitive element 5. The sheet is magnetized by an external constant magnetic field caused by the current flowing through the electromagnet coil. The magnitude of the direct current, which determines the intensity of the external constant magnetic field, is controlled by the source 3 and measured by an ammeter 4. The magnetically sensitive element 5 measures the intensity of the field passing through the material and is fixed by the indicator 6. Increase the constant magnetic field by means of the source 3 the field of an electromagnet is up to a certain value, e.g. The field with the reverse side of the sheet, registered by the indicator 6, changes in this case along the curve OA (Fig. 2), reaching a certain value (point A). Using a source 3, the current is reduced, which means that the constant magnetic field of electromagnet 1 (curve ABC, figure 2 and ammeter 4 fixes the current at which the field on the back of the sheet, recorded by indicator 6, becomes zero (point B). Continue to reduce the field of the electromagnet 1 to 6 zero and using the indicator b measure the intensity of the residual magnetic field on the back side of the sheet 7 (cut OC). Multiply the intensity of the residual magnetic field from the reverse side of the sheet to the intensity of the field of the electromagnet H, ( current), in which the field on the reverse side of the sheet becomes equal to zero, and the magnitude of the expression N x Nov defines the mechanical and mechanical parameters of ferromagnetic materials. The invention improves the reliability of the control of the physical and mechanical parameters of ferromagnetic materials by using simultaneously two sufficient sensitivity to changes in the mechanical properties of materials.

Fi & 2

Claims (1)

METHOD OF ELECTROMAGNETIC CONTROL OF PHYSICAL AND MECHANICAL PARAMETERS OF FERROMAGNETIC MATERIALS, which consists in the fact that the controlled section of the material is magnetized on one side of it with an external constant magnetic field, the magnitude of the strength H, the external constant magnetic field at the moment of reaching zero, the strength of the constant magnetic field, and the other the magnitude of intensity H 0 _OB residual magnetic policy other side of the material at the time constant equal to zero external magnetic Nogo-W fields, and about control- | Our parameters are judged by the expression x But _b p. (L sl I