GOST 12119.5-98
GOST 12119.5−98 electrotechnical Steel. Methods for determining magnetic and electrical properties. Method of measurement of magnetic induction amplitudes and magnetic field
GOST 12119.5−98
Group B39
INTERSTATE STANDARD
Electrotechnical steel
METHODS FOR DETERMINING MAGNETIC AND ELECTRICAL PROPERTIES
Method of measurement of magnetic induction amplitudes and magnetic field
Electrical stell. Methods of test for magnetic and electrical properties.
Method for measurement of magnetic induction amplitudes and magnetic field intensity
ISS 77.040.20
AXTU 0909
Date of introduction 1999−07−01
Preface
1 DEVELOPED by the Russian Federation, the Interstate technical Committee for standardization MTK 120 «steel Products from ferrous metals and alloys"
INTRODUCED by Gosstandart of Russia
2 ADOPTED by the Interstate Council for standardization, Metrology and certification (minutes N 13 dated 28 may 1998)
The adoption voted:
The name of the state |
The name of the national authority for standardization |
| The Republic Of Azerbaijan |
Azgosstandart |
| The Republic Of Armenia |
Armastajad |
| The Republic Of Belarus |
Gosstandart Of Belarus |
| Kyrgyz Republic |
Kyrgyzstandart |
| Russian Federation |
Gosstandart Of Russia |
| The Republic Of Tajikistan |
Tajikistandart |
| Turkmenistan |
The main state inspection of Turkmenistan |
| The Republic Of Uzbekistan |
Standards |
| Ukraine |
Gosstandart Of Ukraine |
3 Resolution of the State Committee of the Russian Federation for standardization and Metrology dated December 8, 1998 N 437 inter-state standard GOST 12119.5−98 introduced directly as state standard of the Russian Federation from July 1, 1999
4 REPLACE GOST 12119−80 in section 5
5 REISSUE
1 Scope
1.1 this standard specifies method of determination of the amplitudes of the magnetic induction at a given maximum value of the magnetic eld in the dynamic mode of magnetization reversal. The method used in the testing of samples in a closed magnetic circuit at the frequency of the alternating magnetization of not more than 50 Hz and the amplitude of the magnetic field of at least 100 models for anisotropic steel, and 1000 A/m for isotropic.
1.2 it is allowed to apply the method at lower values of magnetic field intensity and a higher frequency. The values of magnetic quantities can significantly differ from those measured in static mode.
2 Normative references
The present standard features references to the following standards:
GOST 8.377−80 State system for ensuring the uniformity of measurements. The soft magnetic materials. Methods of measurement in the determination of static magnetic characteristics
GOST 8711−93 Devices showing analog electrical measuring direct action and auxiliary parts to them. Part 2. Special requirements for ammeters and voltmeters
GOST 12119.0−98 electrotechnical Steel. Methods for determining magnetic and electrical properties. General requirements
GOST 13109−97 Electrical energy. Compatibility of technical equipment. Quality norms of electric energy in power supply systems of General purpose
GOST 21427.1−83 cold-rolled anisotropic electrotechnical Steel sheet. Specifications
GOST 21427.2−83 cold-rolled isotropic electrotechnical Steel sheet. Specifications
3 General requirements
General requirements for methods of tests GOST 12119.0.
Terms used in this standard — GOST 12119.0.
4 Preparation of samples for testing
4.1 Samples for testing shall be insulated.
4.2 Samples with ring shape is assembled from stamped rings with a thickness of 0.1 to 1.0 mm or is wound from a tape thickness of not more than 0.35 mm and placed in cassettes of insulating material with a maximum thickness of 3 mm or non-ferrous metal thickness of not more than 0.3 mm. Metal cassette should have the clearance.
The ratio of outer diameter to inner of sample should be not more than 1.3; the cross-sectional area of the sample not less than 0.1 cm.
4.3 samples for the Epstein apparatus are manufactured from strips with a thickness of 0.1 to 1.0 mm length from 280 to 500 mm, width — (30,0±0,2) mm. Strip of the sample should not differ from each other in length by more than ±0,2%. The cross-sectional area of the sample should be from 0.5 to 1.5 cm. The number of bands in the sample must be a multiple of four, the minimum number of lanes is twelve.
Samples of grain-oriented steel is cut along the direction of rolling. The angle between the directions of rolling and cutting of strips should not exceed 1°.
For samples of isotropic steel half strips cut along the rolling direction and the other across. The angle between the directions of rolling and cutting must not exceed 5°. Stripes are grouped in four packages, two from the strips, cut along the direction of rolling, two — across. Packages with similarly cut strips are placed in parallel spaced coils of the device.
Allowed the band to cut the same angle to the direction of rolling. The direction of rolling for all the strips laid in one coil must be the same.
4.4 Sheet samples manufactured in length from 400 to 750 mm Length of sheet should not be less than the outer length of the yoke; the width of the sheet — not less than 60% of the width of the window of the solenoid. The tolerance along the length should not go beyond ±0,5%, width ±2 mm.
The surface and shape of leaves should correspond to GOST 21427.1 and GOST 21427.2.
5 Used equipment
5.1 Install. Installation diagram is shown in figure 1.
Figure 1 — Scheme for measurements in the dynamic mode of magnetization reversal
Figure 1 — Scheme for measurements in the dynamic mode of magnetization reversal
5.1.1 Voltmeter PV to measure srednetemperaturnogo voltage must have a range of 10 mV to 100 V; the ratio of the peak value to the measured at least three; accuracy class not less than 0.5 according to GOST 8711. Allowed the use of the voltmeter of accuracy class not less than 1.0 in the measurement in fields equal to or more than 1000 A/m.
5.1.2 Frequency PF to measure the frequency with an error not exceeding ±0,2%.
5.1.3 Coil T1 for measuring magnetic quantities must have the resistance winding I is not greater than 5 Ohms, the winding II is not more than 10 Ohms, mutual inductance of at least 1 mH, the error is within ±0,2%. I winding should be designed for long flow of current, the maximum current value which is equal to 5 And for apparatus Epstein, 1−5 A — ring sample and A 10 — sheet apparatus.
5.1.4 Coil T2 to compensate for the magnetic flux outside the sample must have the number of turns of winding I of not more than fifty, and resistance is not more than 0.05 Ω, the resistance of the winding II — no more than 3 Ohms. Windings are placed on a cylindrical structure of nonmagnetic insulating material of length 25 to 35 mm in diameter and from 40 to 60 mm. the axis of the coil must be perpendicular to the plane of the lines of force of the sample when fixing it on the device Epstein. The relative difference between the coefficients of mutual inductance coil T2 and apparatus Epstein without a model should not go beyond ±5%.
Allowed to exclude from the scheme (see figure 1) the coil T2 when the magnetic flux out of the sample, does not exceed 0.2% measured, or the introduction of amendments , In this magnetic flux.
Allowed to use the coil T2 instead of the coil T1.
5.1.5 Magnetizing I and II of the measuring winding of the annular sample T3 should meet the requirements of GOST 8.377.
5.1.6 Epstein Apparatus for testing samples T3, made up of bands must have four coils on the frame of a nonmagnetic insulating material with the following dimensions:
the width of the inner window (32,0±0,5) mm;
height — from 10 to 15 mm;
the wall thickness of frame is 1.5 to 2.0 mm;
the length of the coil with a coil not less than 190 mm;
the length of the coil (220±1) mm.
The number of turns in the windings of the apparatus is selected in accordance with table 1.
Table 1
Frequency magnetization in Hz |
The number of turns in the winding | |
| I — magnetizing | II — measuring | |
| 50 to 60 incl. SV. 60 «400" «400» 2000 « |
300−1500 100−300 100−200 |
200−1000 100−300 100−200 |
Note — Windings is wound evenly along the length of the frames of the coil. The number of layers of each winding to the frame must be odd. | ||
5.1.7 the Leaf apparatus to be used for testing samples T3, must have a solenoid and two yokes. The design of the yokes must provide the parallel contact surfaces and mechanical rigidity, eliminating the influence on the magnetic properties of the sample. The width of the poles of the yokes of the electrical steel must be not less than 25 mm, precision alloy — 20 mm. Magnetic losses in the yokes shall not exceed 5% of the measured; the relative difference between the amplitudes of the magnetic flux in the yokes should not go beyond ±15%.
Allowed the use of the apparatus with open yokes to measure the relative change of specific magnetic losses, for example in the evaluation of residual stresses according to GOST 21427.1.
The solenoid should have a frame made of a nonmagnetic insulating material, on which a first measuring winding of II, then one or more wires — magnetizing I. Each wire is laid evenly in a single layer.
The relative maximum difference of the amplitudes of the magnetic induction in the area of the sample inside the solenoid should not go beyond ±5%.
5.1.8 power Source for magnetization of the samples should have a low frequency oscillator with power amplifier or voltage regulator with a stabilizer, 50 Hz. The coefficient of non-sinusoidal voltages of a loaded power supply should not exceed 5% of the GOST 13109. Nominal power of the source at frequency of 50 Hz magnetization reversal should be not less than 0.45 kV·A 1.0 kg mass of the sample not less than 0.3 kV·A to the values specified in table 2.
Table 2
The frequency of magnetization kHz |
The mass of sample, kg |
| From 0.05 to 1.00 incl. SV. Of 1.00 «10,0 « |
From 0.5 to 1.1 incl. 0.03 «0,30" |
When measuring at 1.1 distortion of the voltage waveform on the winding II of the sample are not standardized. Half-wave of the voltage waveform must be symmetric and not to contain additional peaks.
Allowed to use a feedback amplifier to obtain the waveform of the magnetic flux of the sample is similar to a sine wave. The coefficient of non-sinusoidal waveform of the EMF in the winding shall not exceed 3%; the power consumed by the feedback circuit, voltage should not exceed 5% of the measured magnetic losses.
6 Preparation for measurements
6.1 Samples from strips, sheets or annular shape is connected, as shown in figure 1.
6.2 Samples from strips or sheets are placed in the apparatus. Samples of strips are placed in the Epstein apparatus, as shown in figure 2.
Figure 2 — Scheme of laying pattern of the sample
Figure 2 — Scheme of laying pattern of the sample
Allowed fixing the position of strips and sheets in the apparatus, creating a pressure not exceeding 1 kPa perpendicular to the sample surface outside the magnetizing coils.
6.3 Calculate the cross-sectional area , m
, of samples:
6.3.1 cross-sectional Area , m
, for samples with ring shape from a material with a minimum thickness of 0.2 mm is calculated by the formula
where - the mass of sample, kg;
— external and internal diameters of the ring, m;
— density of material, kg/m
.
Material density , kg/m
, choose according to the Annex 1 GOST 21427.2 or calculated by the formula
where and
- mass fraction of silicon and aluminum, %.
6.3.2 cross-sectional Area , m
, for samples with ring shape from a material with a thickness less than 0.2 mm is calculated by the formula
where 
where is the density of the insulation, adopted equal to 1.6·10
kg/m
for inorganic coatings and 1.1·10
kg/m
for organic;
— the fill factor, defined as specified in GOST 21427.1
.
6.3.3 cross-sectional Area S, m, patterns composed of bands for apparatus Epstein, calculated by the formula
where is the length of the strip M.
6.3.4 cross-sectional Area , m
, of sheet sample is calculated by the formula
where is the length of the sheet M.
6.4 accuracy of measuring the mass of the samples should not go beyond ±0.2%, the external and internal diameters of the ring — ±0,5%, the length of the bands is ±0,2%.
6.5 Measurements in the amplitude of the magnetic induction of less than 1.0 T is carried out after demagnetization of the samples with a field frequency of 50 Hz.
Set the voltage corresponding to the amplitude of the magnetic induction is not less than 1.6 T for anisotropic steel and 1.3 T for the isotropic steel, and then gradually reduce it.
Demagnetization time should not be less than 40 C.
When measuring the magnetic induction in the field of strength less than 1.0 a/m samples after demagnetization withstand 24 hours; measuring the induction field intensity of 1.0 A/m exposure time can be shortened to 10 min.
Allowed to reduce the exposure time and the relative difference of the values of induction obtained after normal and abbreviated extracts, in the range of ±2%.
6.6 Voltage , V, for specified values of the amplitude of magnetic field intensity
, Hz, is calculated by the formula
where is the mutual inductance of the coil T1, GN;
the number of turns of the winding I of the sample;
— active resistance of winding II of the coil T1 and voltmeter PV, Ohm;
— the average length of the magnetic lines of force M.
For samples with ring shape average length of the magnetic lines of force , m, is calculated by the formula
where -the external and internal diameters of the ring M.
In standard tests for sample of stripes average length , in m, taken equal to 0.94 m. If necessary, increase the accuracy of determining the magnetic value of the values allowed
to select from table 3.
Table 3
| The magnetic field strength, A/m | The average length of the magnetic lines of force | |
| for isotropic steel | for anisotropic steel | |
| From 0 to 10 incl. |
0,95 | 0,99 |
| SV. 10 «70 « |
0,97 | 0,99 |
| «70» 200 « |
0,97 | 0,98 |
| «200» 500 « |
0,93 | 0,96 |
| «500» 1000 « |
0,91 | 0,95 |
| «1000» 2500 « |
0,88 | 0,91 |
Sheet sample the average length of the magnetic lines of force , m, is determined by the results of metrological certification of the installation.
6.7 in the absence of coil T2 calculate the amendment , due to the magnetic flux out of the sample by the formula
where — frequency magnetization in Hz;
the cross — sectional area of specimen, m
;
the cross — sectional area of the winding II of the sample, m
;
— the amplitude of the current, A.
The amplitude of the current , And is calculated by srednevyrazhennymi the value of the EMF
, V, induced in coil II coil T1 when the magnetizing winding I in the circuit by the formula
where — frequency magnetization in Hz;
— the mutual inductance of the coil, H; no more than 1·10
GN.
7 procedures for measuring
7.1 the amplitude of the magnetic induction at a given value of the amplitude of the magnetic field is determined by induction.
7.2 the Switch S1 is put to position 1, set the voltage , or (
+
) in the winding II of the coil T1, the frequency of the alternating magnetization
in Hz.
7.3 transfer switch S1 to position 2 and determine the voltage , V, across the coil II of the sample.
7.4 Return of switch S1 to position 1 and repeat the operation for the following values of voltage , V.
8 Rules for processing results of measurements
8.1 the amplitude of the magnetic induction , T, is calculated by the formula
where ;
see 6.7;
the number of turns of the winding II of the sample;
— the total resistance of windings II coil T2 and model T3, Om;
— the active resistance of the voltmeter PV, Om.
8.2. The error of measurement of amplitude of magnetic induction of the samples from the bands and the ring-shaped must not exceed the values given in table 4.
Table 4
| Magnetic induction, T | ||
| for isotropic steel | for anisotropic steel | The error of measurement, % |
1.0·10 |
1.0·10 |
±5 |
SV. 1,0·10 |
SV. 1,0·10 |
±3 |
| «To 1.2» to 2.0 « |
«To 1.4» to 2.0 « | ±1,5 |
On the installation with foliage measurement error of the magnetic induction should not go beyond ±3%.
The text of the document is verified by:
the official publication of the
Electrotechnical steel.
Specifications. Methods of analysis:
SB. Standards. -
M.: IPK Publishing house of standards, 2003
