GOST 12119.6-98
GOST 12119.6−98 electrotechnical Steel. Methods for determining magnetic and electrical properties. A method of measuring the relative magnetic permeability and specific magnetic losses by a bridge AC
GOST 12119.6−98
Group B3
INTERSTATE STANDARD
Electrotechnical steel
METHODS FOR DETERMINING MAGNETIC AND ELECTRICAL PROPERTIES
A method of measuring the relative magnetic permeability
and specific magnetic losses by a bridge AC
Electrical steel. Methods of test for magnetic and electrical properties.
Method for measurement of relative magnetic permeability
and specific magnetic losses by a.c. bridge
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 12119.6−98 introduced directly as state standard of the Russian Federation from July 1, 1999
4 INTRODUCED FOR THE FIRST TIME
5 REISSUE
1 Scope
1.1 this standard specifies a method for determining real and imaginary components of the complex relative magnetic permeability characterizing the magnetic properties of the material, on the basic harmonics of the magnetic field and magnetic induction, and specific magnetic losses in the form of magnetic flux curve similar to a sine wave. The definition of magnetic permeability is carried out at induction to 1.0 Tesla.
1.2 the Method used in the frequency range 0.05−10 kHz at an amplitude of magnetic induction from 0.1 to 1.2 T for the isotropic steel and from 0.1 to 1.6 T for anisotropic and specific magnetic losses are not more than 50 W/kg.
2 Normative references
The present standard features references to the following standards:
GOST 6746−94 Measures electrical capacitance. General technical requirements
GOST 10160−75 Alloys are magnetically soft. Specifications
GOST 12119.0−98 electrotechnical Steel. Methods for determining magnetic and electrical properties. General requirements
GOST 21427.1−83 cold-rolled anisotropic electrotechnical Steel sheet. Specifications
GOST 21427.2−83 cold-rolled isotropic electrotechnical Steel sheet. Specifications
GOST 23737−79 measure of electrical resistance. General specifications
3 General requirements
General requirements for methods of tests according to 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 not less than 0.1 cm.
Samples with ring shape shall conform to the requirements given in table 1.
Table 1
The frequency of magnetization kHz |
The mass of sample, g |
The number of turns in the windings of the sample |
| 0,4−5,0 | From 100 to 300 | 40−100 |
| 2,0−10,0 | «30» 100 |
30−50 |
| 5,0−10,0 | «3» 10 | 20−30 |
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.
5 Used equipment
5.1 Install. Installation diagram is shown in figure 1.
Figure 1 — Circuit for measuring bridge method
Figure 1 — Circuit for measuring bridge method
5.1.1 Voltmeter to measure the amplitude of the magnetic induction has to have a limit of measurement from 1 to 100 V, the input resistance is not less than 1.0 MW, the error of measurement in the frequency range of 0.05−10 kHz within ±0.5%.
5.1.2 distortion Meter for measuring harmonic distortion from 0.1% to 10% with a margin of error of ±10%.
5.1.3 resistance to balance the bridge for the active component of conductivity have an upper limit of 10 or 100 kω; time constant characterizing the residual reactivity, not more than 2 µs; accuracy class not less than 0.1 according toGOST 23737.
5.1.4 Shop capacity to handle bridge for reactance, conductance should have an upper limit of at least 1 UF, tangent of dielectric loss angle is not more than 1·10
, smooth regulation of capacity and accuracy class not less than 0.2 according toGOST 6746.
5.1.5 Generator should have output voltage 10 mV to 5 V, the frequency range of (0.05−10 kHz), the impedance load of 5 ohms, harmonic distortion of output voltage not more than 0.1%.
5.1.6 the Amplifier should have a nominal output voltage less than 25 V, the nominal output power of not less than 100 VA, harmonic distortion into resistive load at rated power is not more than 0.5%.
5.1.7 voltage Indicator to determine the equilibrium of the bridge should have a sensitivity not less than 0.1 cases./µv selectivity relative to the third harmonic at least 50 dB; frequency range 0.05−10 kHz.
5.1.8 Frequency counter to measure frequency with an accuracy of ±0,2%.
5.1.9 Filter to protect voltage indicator overload should provide suppression of higher harmonics at least 30 dB.
5.1.10 Winding of the sample magnetization (I) and the measuring (II) must have the same number of turns.
5.1.11 Magnetic comparator to compare the currents of the shops
and
with the magnetizing current must have a magnetic core of annular shape from the ribbon of alloy of the brand 79NM thickness 0,02−0,05 mm GOST 10160; internal diameter not less than 60 mm, the cross-sectional area of at least 0.5 cm
. The magnetic core is placed in a non-magnetic tape on which is uniformly wound in a single layer flat winding of the fourth wire of brand of PEV-2 in diameter of 0.1−0.15 mm, then placing the screen; he wound up on the winding II, III dual coil wire and I the harness with a number of wires not less than five, with a diameter of 0.7−0.8 mm brand of PEV-2. Each winding should be wound evenly around the perimeter of the magnetic circuit and occupy an integer number of layers.
The ratio of the number of turns of the coil II or III to the number of windings I should be equal to 76 at frequency 50 Hz and 16 at higher frequencies. It is recommended to choose the number of turns of winding I is equal to 4 and 19, when the number of turns of the windings II and III — 304.
6 Preparation for measurements
6.1 Samples from the bands or ring shape is connected, as shown in figure 1.
6.2 Samples from strips placed in the apparatus Epstein, as shown in figure 2.
Figure 2 — Scheme of laying pattern of the sample
Figure 2 — Scheme of laying pattern of the sample
Permitted to fix the position of the bands in the device, creating a pressure not exceeding 1 kPa perpendicular to the sample surface outside the magnetizing coils.
6.3 cross-sectional Area , m
, of samples is calculated as follows:
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 is 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 of samples , m
, is composed of strips, for apparatus Epstein is calculated by the formula
where is the length of the strip M.
6.4 accuracy of measuring the mass of the samples should not go beyond ±0,2%; the outer and inner 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 For the voltmeter , calibrated in sredneotraslevyh values, the voltage
, corresponding to a given amplitude of magnetic induction
, T and the frequency of magnetization reversal
in Hz is calculated by the formula
where is the number of turns of winding II of the sample;
6.7 For the voltmeter , calibrated in current values of the sinusoidal voltage, the magnitude value
, is calculated by the formula
6.8 When the magnetic flux out of the sample exceeding 0.2% measured, calculate the correction , according to the formula
where is the number of turns of the winding I of the sample;
— magnetic constant equal to 4·10
, GN/m;
the cross — sectional area of the winding II of the sample, m;
— the average length of the magnetic lines of force m;
— the amplitude of the current, A.
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 to select a value
from table 2.
Table 2
| 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 |
The amplitude of the current And calculated depending on the amplitude of the voltage drop
, Ohm, included in the magnetizing circuit by the formula
6.9 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, calculated for samples of the bands according to the formula
— the mass of sample, kg;
— band length, m.
7 procedures for measuring
7.1 definition of the complex relative magnetic permeability and specific magnetic losses of the bridge method is based on measuring the conductivity of the active and mutual inductance of the sample.
7.2 Set the frequency of the alternating magnetization , Hz, voltage
, V.
7.3 Increase the sensitivity of the voltage indicator until the appearance on his screen image of an ellipse or inclined straight line. Regulate the capacity of the store , then the resistance of the store
to the minimum value of the input voltage of the indicator, in this case, you must be a straight horizontal line.
7.4 Repeat the operation for the next 7.3 the sensitivity of the indicator.
7.5 the Operation is complete, if the parameters change shops ±(0,2−0,3)% will result in voltage at the input of the indicator. Determine the readings of shops , Th, and
F.
7.6 Set the next higher voltage value , and repeat the operations specified in 7.2 to 7.5.
8 Rules for processing results of measurements
8.1 Active conductivity , Cm and mutual inductance
, H is calculated according to the formulas:
where — angular frequency, rad/s;
the number of turns of the winding I of the comparator;
— the active resistance of the winding II of the sample, Ohm;
— the active resistance of the winding II of the comparator, Ohm;
- see 7.5.
8.2 real and imaginary components of the complex relative magnetic permeability and
is calculated by the formula:
where is the length of the magnetic lines of force determined as specified in 5.7, m;
the cross — sectional area of the sample, determined as described in 6.3, m;
;
— magnetic constant equal to 4
·10
, Ng/m
.
8.3 Magnetic losses , W is calculated by the formula
where active conductivity, Cm;
voltage is calculated according to the formula (6), V.
8.4 Specific magnetic losses in W/kg is calculated by the formula
where is the effective mass of the sample, determined as specified in 6.9 kg.
8.5 measurement Error ,
,
must 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
