GOST 12119.4-98
GOST 12119.4−98 electrotechnical Steel. Methods for determining magnetic and electrical properties. Method of measurement of specific magnetic losses and actual value of magnetic field intensity
GOST 12119.4−98
Group B39
INTERSTATE STANDARD
Electrotechnical steel
METHODS FOR DETERMINING MAGNETIC AND ELECTRICAL PROPERTIES
Method of measurement of specific magnetic losses and actual value
magnetic field
Electrical steel.
Methods of test for magnetic and electrical properties.
Method for measurement of specific magnetic losses
and actual value of 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 12119.4−98 introduced directly as state standard of the Russian Federation from July 1, 1999
4 REPLACE GOST 12119−80 in section 4
5 REISSUE
1 Scope
This standard specifies method of determination of specific magnetic losses from 0.3 to 50.0 W/kg and the effective value of magnetic field strength from 100 to 2500 A/m at frequencies of 50−400 Hz magnetization reversal by the method of wattmeter and ammeter.
Allowed values of the magnetic parameters for the magnetization reversal frequencies up to 10 kHz on the ring-shaped samples and samples of the bands.
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 8476−93 Devices showing analog electrical measuring direct action and auxiliary parts to them. Part 3. Special requirements for wattmeters and varmeters
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: sheet width — 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 — Schema for measurement wattmeters method
Figure 1 — Schema for measurement wattmeters method
5.1.1 Voltmeters PV1 — srednetemperaturnogo to measure voltages and subsequent determination of the amplitude of the magnetic induction and РV2 — to measure the RMS voltage and the subsequent definition of the shape factor of the curve it must have a limit of measurement from 30 mV to 100 V, the maximum input current of 5 mA, accuracy class not less than 0.5 according to GOST 8711.
Use a voltage divider to the voltmeter PV1 to obtain samples is numerically equal to the amplitudes of magnetic induction.
5.1.2 Wattmeter PW for the measurement of active power and the subsequent definition of specific magnetic losses must have a measurement range from 0.75 to 30 W, rated power factor is not more than 0.1 at a frequency of 50 Hz and 0.2 at higher frequency; accuracy class not less than 0.5 at the frequency of the alternating magnetization of from 50 to 400 Hz or below a 2.5 at a frequency of over 400 Hz according to GOST 8476.
Use a voltage divider to the power meter to obtain readings, is numerically equal to the values of the specific magnetic losses. The output of the voltage divider must be connected to the parallel circuit of the wattmeter, the input winding II of the sample T2.
5.1.3 Ammeter RA for measuring the effective value of the magnetizing current and the subsequent definition of the effective value of the magnetic field should have a limit of measurement of 0.1 to 5.0 A, accuracy class not less than 0.5 according to GOST 8711. May increase the lowest limit of measurement up to 1.0 A for control of a load current circuit of the wattmeter. The maximum power consumed by the ammeter when measuring samples from sheets of a width exceeding 250 mm shall be not more than 1.0·A; for other samples — less than 0.2 V·A.
5.1.4 Frequency PF to measure the frequency with an error not exceeding ±0,2%.
5.1.5 the 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 1.
Table 1
The frequency of magnetization kHz |
The mass of sample, kg |
| From 0.05 to 1.0, incl. |
From 0.5 to 1.1 incl. |
| SV. 1,0 «10,0" |
0.03 «0,30 « |
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.
5.1.6 Voltmeters PV1 and PV2, the voltage circuit of the wattmeter PW, and the feedback amplifier needs to consume power of no more than 25% of the measured value.
5.1.7 Coil T1 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, a diameter of 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 coils T1 and apparatus Epstein without a model should not go beyond ±5%.
Allowed to exclude from the scheme (see figure 1) the coil T1 when the magnetic flux out of the sample, less than 0.2% of the measured.
5.1.8 Magnetizing I and II of the measuring winding of the annular sample T2 should correspond to requirements of GOST 8.377.
5.1.9 office of Epstein to be used for testing samples composed of strips,T2 should 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 2.
Table 2
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. | ||
5.1.10 the Leaf apparatus to be used for testing samples of T2should 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 to use devices with open yokes to measure the relative change of specific magnetic losses, for example, in the evaluation of residual stresses churchyard 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, the magnetizing coil 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%.
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 the Area of cross section of leaf sample , m
, 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, 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 Upper limits of the measured values of magnetic parameters for samples with ring shape composed of strips should correspond to the amplitude of the magnetic field is not more than 5·10A/m at a frequency of reversal of polarity from 50 to 60 Hz and not more than 1·10
A/m at higher frequencies; lower limit — the minimum values of the amplitudes of the magnetic induction are shown in table 3.
Table 3
The frequency of magnetization kHz |
The minimum value of the amplitude of the magnetic induction, T, in the measurement | |
| specific magnetic loss W/kg | magnetic field strength, A/m | |
| From 0.05 to 0.06 incl. |
0,50 | 1·10 |
| SV. 0,06 «1,0 « |
0,20 | 2·10 |
| «To 1.00» 10,0 « |
0,05 | 2·10 |
The smallest amplitude value of magnetic induction for leaf samples should be equal to 1.0 Tesla.
6.7 For the voltmeter PV1, sredneotraslevyh is calibrated in values of voltage, corresponding to a given amplitude of magnetic induction
, T, and the frequency of the alternating magnetization
, Hz, is calculated by the formula
where is the cross-sectional area of specimen, m
;
the number of turns of the winding II of the sample;
— the total resistance of winding II of sample T2 and coil T1, Ω;
— the equivalent resistance of the devices connected to the coil II sample T2, Ω, is calculated according to the formula
where 
Value 
6.8 For the voltmeter PV1, calibrated in current values of the voltage sine wave, the value of U, is calculated by the formula
6.9 in the absence of coil T1 is counting on the amendment , due to the magnetic flux out of the sample by the formula
where 
the cross — sectional area of the measuring coil of the sample, m
;
the cross — sectional area of the sample, determined as described in 6.3, m
;
— 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
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 values allowed values
to select from the table 4.
Table 4
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. SV. 10 «70" «70» 200" «200» 500" «500» 1000" «1000» 2500 « |
0,95 0,97 0,97 0,93 0,91 0,88 |
0,99 0,99 0,98 0,96 0,95 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;
— the amplitude of the current, As; expect, depending on the amplitude of the voltage drop
, Ohm, is included in the magnetizing circuit by the formula
or srednevyrazhennymi the value of the EMF , V, induced in coil II coil T1when the magnetizing winding I in the circuit by the formula
where is the mutual inductance of the coil, H; no more than 1·10
GN;
— frequency magnetization in Hz.
6.10 in determining the specific magnetic losses in the apparatus Epstein should take into account the heterogeneity of magnetization of the corner parts of the magnetic circuit by introducing an effective mass of specimen , kg, which for samples of the bands calculated by the formula
where - the mass of sample, kg;
— band length, m.
For the ring samples the effective mass is taken equal to the mass of the sample.
Effective mass of the leaf sample is determined by the results of metrological certification of the installation.
7 the Procedure of measurement
7.1 determination of the specific magnetic losses is based on the measurement of active power consumed for the magnetization reversal of the sample and consumed by devices PV1, PV2, PW and the feedback circuit of the amplifier. When tested sheet sample take into account the losses in the yokes. The active power is determined using the indirect method, the voltage on the winding II of the sample T2.
7.1.1 On the installation (see figure 1) make the keys S2, S3, S4 are simultaneously de-energised and the key S1.
7.1.2 Set voltage ,
or (
, Hz; check of the ammeter is RA, the power meter PW is not overloaded; at the bottom of the key S1 are simultaneously de-energised and the key S2.
7.1.3 If necessary, regulate the power supply the indication of the voltmeter PV1 to install the specified voltage and measure the RMS voltage In a voltmeter PV2 and power
, watt, wattmeter PW.
7.1.4 Set the voltage corresponding to the larger value of the amplitude of the magnetic induction, and repeat the operations specified in 7.1.2,
7.2 Definition of effective value of magnetic field intensity based on the measurement of the magnetizing current.
7.2.1 upon the installation (see figure 1) closes the key S2, S4 are simultaneously de-energised and the keys S1, S3.
7.2.2 Set the voltage or U, V, the frequency of magnetization reversal
in Hz, and is determined by the ammeter RA values of the magnetizing current
, A.
7.2.3 Sets a higher voltage and repeat the operations specified in 7.2.1 and
8 Rules for processing results of measurements
8.1 Factor voltage waveform on the winding II of the sample is calculated by the formula
where - RMS voltage, In;
- the voltage calculated according to the formula (6), V.
8.2 Specific magnetic losses in W/kg, a pattern of streaks or ring mould is calculated by the formula
where is the effective mass of sample, kg;
— the average value of power, W;
— the effective value of the voltage;
— see 6.7.
Values 
The error in determining the resistance should not go beyond ±1%.
Voltage is allowed to substitute a value equal to 1.11
when
=1,
11±0,02.
8.3 To eliminate the influence of distortion of the waveform of the magnetic flux on the result of measurement of the magnetic losses adjustments, based on the fact that magnetic losses are equal to the sum of the losses on hysteresis and eddy currents, and the first value does not depend on distortion of the waveform of the magnetic flux, and the second is proportional to the squared voltage waveform on the winding II of the sample.
8.3.1 If different values of the coefficient of the stress curve from to 1.11 by more than ±1% of the specific magnetic losses for a sinusoidal waveform of magnetic flux
, watts/kg, is calculated by the formula
where is the specific magnetic loss W/kg;
— the ratio of specific magnetic losses by hysteresis to a specific magnetic losses.
8.3.2 Coefficient of voltage waveform should be in the range of 1,08−1,16 in the measurement of specific magnetic losses and 1,09−1,13 — when measuring the effective value of the magnetic field.
8.3.3 Value selected from table 5.
Table 5
Material |
Mass fraction of silicon, % |
The thickness of rolling, mm |
Frequency, Hz |
|
| Isotropic steel; anisotropic steel | From 0.0 to 1.8 incl. |
0,50 | 50 | 0,8 |
| SV. 1.8 to 3.8 incl. |
0,50 0,35 |
50 50 |
0,7 0,8 | |
| From 2.8 to 3.5 incl. | 0,28−0,50 | 50 | 0,3 |
Allowed amount to calculate the magnetic losses measured at two different values of the coefficient of the stress curve
and constant values of the amplitude of magnetic induction and frequency, according to the formula
where and
— magnetic losses, corresponding to
and
defined as specified in 8.1, W;
= 1,11±0,05.
Magnetic loss , W, is measured as specified in 7.1.1−7.1.4, for inclusion in the magnetizing circuit of the resistor for which the difference (
-
) should be more than 2
%.
8.3.4 When the frequency deviation of the magnetization reversal in Hz, from nominal
in Hz, calculate the correction for the magnetic loss
, W, by the formula
The amendment is introduced at frequency
= 50 Hz, and the ratio
8.4 Specific magnetic losses in W/kg, in leaf sample is calculated by the formula
where 
— see formula (15);
— magnetic losses in the yoke, W, with the amplitude of the magnetic flux
, WB is calculated according to the formula
where - the amplitude of the magnetic induction, T;
the cross — sectional area of specimen, m
.
For the sinusoidal curve of the magnetic flux of the specific magnetic losses in W/kg, is calculated by the formula (16).
8.5 effective value of magnetic field intensity , A/m, is calculated by the formula
where is the length of the magnetic lines of force determined as specified in 5.9, m;
— the magnetizing current, A;
the number of turns of the winding I of the sample.
8.6 the Error of measurement of specific magnetic losses of the samples of the bands and the ring shape should not go beyond ±2,5% at the frequency of the alternating magnetization of from 50 to 400 Hz and ±5% for frequency higher than 400 Hz; sheet samples is ±3%.
8.7 measurement Error of the effective value of the magnetic field should not go beyond ±5%.
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
