GOST 12119.1-98
GOST 12119.1−98 electrotechnical Steel. Methods for determining magnetic and electrical properties. Methods of measurement of magnetic induction and the coercive force in the office of the Epstein and ring samples in a constant magnetic field
GOST 12119.1−98
Group B39
INTERSTATE STANDARD
Electrotechnical steel
METHODS FOR DETERMINING MAGNETIC AND ELECTRICAL PROPERTIES
Methods of measurement of magnetic induction and coercive force
in the apparatus of Epstein and ring samples
in a constant magnetic field
Electrical steel. Methods of test for magnetic and electrical properties.
Methods for measurement of magnetic induction and coercivity
in Epshtein and apparatus on ring-shaped specimens in magnetostatic field
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 12119.1−98 introduced directly as state standard of the Russian Federation from July 1, 1999
4 REPLACE GOST 12119−80 in section 2
5 REISSUE
1 Scope
This standard specifies methods of measurement of magnetic induction basic curve of magnetization at a magnetic field of 0.2−2500 A/m and the coercive force limit of the saturation hysteresis loop in the apparatus of Epstein and ring samples in a constant magnetic field.
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 20798−75 measures the mutual inductance. General specifications
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 GOST 12119.0.
Terms used in this standard - GOST 12119.0.
4 Preparation of samples for testing
4.1 Samples of the ring-shaped machined from billet, collected from the stamped and machined rings with a thickness of 0.1 to 4.0 mm, or 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. the Ratio of outer diameter to inner must be less than 1.3; the cross-sectional area of the sample not less than 0.1 cm.
4.2 samples for the Epstein apparatus are manufactured from strips with a thickness of 0.1 to 4.0 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 bands must equal 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 — Schema for measurement in a constant magnetic field
Figure 1 — Schema for measurement in a constant magnetic field
5.1.1 Ammeter to measure DC current and subsequent determination of the magnetic field must have a range from 15 mA to 15 A, accuracy class not less than 0.2 according to GOST 8711.
Use a DC voltmeter with a resistor.
5.1.2 Ammeter of any system, in addition to the detector for measuring AC demagnetizing current has to have a limit of measurement from 1 mA to 15 A accuracy class not below 2.5 GOST 8711.
Use a voltmeter to assess the value of the demagnetizing current according to the voltage of measuring winding and the magnetization curve for the relevant steel grade. The device should have a limit of measurement from 1 mV to 30 V, accuracy class not lower than 2.5 churchyard 8711.
5.1.3 Ballistic galvanometer to measure the magnetic flux must have the period of natural oscillations of at least 15; intermittent, close to critical; sensitivity of at least 100 cases/DHS; the category of the constancy of the zero position — no more than one.
Use of ballistic galvanometer with a shunt, magneto or electronic integrating fluxmeter to measure magnetic flux of 0.1 to 10.0 MVB with an accuracy within ±0.5% webartery with voltage dividers to expand the limits of measurement and (or) receiving of the samples is numerically equal to the amplitude of the magnetic induction in the sample.
5.1.4 Resistors and
for modulating the current in interval from 2 mA to 15 A with a resolution of 0.1%.
5.1.5 resistance boxes ,
,
to adjust the sensitivity and the mode of the galvanometer should have a range from 0.1 Ohms to 10 ohms, accuracy class not less than 0.2 churchyard 23737.
5.1.6 auto-transformer for demagnetization of the sample should have a capacity of not less than 0.4 kV·A and provide smooth control of current from 0.2 mA to 15 A.
5.1.7 Coil for calibrating the ballistic galvanometer must have coefficient of mutual inductance from 1 mH to 10, accuracy class not less than 0.2 according to GOST 20798.
5.1.8 Coil for compensating 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 of the coil
and apparatus Epstein without a model should not go beyond ±5%.
Allowed to exclude from the scheme (see figure 1) the coil when the magnetic flux out of the sample, does not exceed 0.2% measured, or the introduction of amendments to this magnetic flux.
5.1.9 Magnetization (I) and the measuring (II) the winding ring of the sample shall conform to the requirements of GOST 8.377.
5.1.10 Apparatus Epstein to be used for testing samples composed of bands must have four coils on the frame of a nonmagnetic insulating material 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
| The magnetic field, Vehicles |
The number of turns in the winding | |
| I — magnetizing |
II — measuring | |
| From 0.2 to 1.0, incl. |
4 | 600−2000 |
| SV. 1,0 «100,0 « |
150−700 | 200−700 |
| «100,0» 2500,0 « |
600−1500 | 20−700 |
Notes
1 Magnetizing winding of the four windings are made of copper liners with a thickness of 0.2−0.3 mm, located along the frames. The liner should have a gap of 2−3 mm, on both sides at the same distance solder the five findings and, combining them together, get the beginning and end of one loop.
2 the Remaining winding 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.
5.1.11 power Source for magnetization of the sample should provide a constant output voltage not less than 20 V, the change of the magnetizing current is not more than 0.2% per minute, the ratio of the amplitude of the variable component of the output voltage to the DC component is not more than 0.05%. In magnetic field of 5 A/m allowed increase the ratio to 0.1%. You may use a DC regulator.
5.1.12 the Source of network alternating voltage for demagnetization of the sample should have power output of not less than 0.5 kVA and smooth regulation of the output voltage.
5.1.13 Switches ,
,
and
should be designed for a maximum current of 15 A.
6 Preparation for measurements
6.1 Winding ring of the sample or apparatus Epstein connected, as shown in figure 1.
Strips of the sample placed in the apparatus Epstein, as shown in figure 2. Permitted to fix the position of the bands, creating a pressure not exceeding 1 kPa perpendicular to the sample surface outside the magnetizing coils.
Figure 2 — Scheme of laying pattern of the sample
Figure 2 — Scheme of laying pattern of the sample
6.2 cross-sectional Area of the samples S, m, calculate the following:
6.2.1 cross-sectional Area , m
, for samples with ring shape of the tape thickness without any coating or tape with a minimum thickness of 0.2 mm coated 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, %.
6.2.2 cross-sectional Area , m
, for samples with ring shape of the tape thickness less than 0.2 mm, the insulation coating 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
.
6.2.3 the cross-sectional Area of samples , m
, is composed of strips for office of Epstein, calculated by the formula
where is the length of the strip M.
6.3 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%.
6.4 Before the measurement should be carried out calibration of ballistic galvanometer to determine the constant , WB/del. The calibration is carried out on the installation (see figure 1) in the absence of the test sample.
6.4.1 resistance in the circuit of the galvanometer in the calibration and subsequent measurement of the magnetic induction in the sample should be constant. The current in the winding I of the coil must be such that the reading of the galvanometer ranged from 20 to 50% of the length scale with the zero mark in the middle. The deviation of the pointer of the galvanometer must be in the same direction as in the definition of magnetic quantities.
6.4.2 In the calibration switches and
put in position 1, the keys
and
close the source
off. In the coil I coil
sets a predetermined value of current
, and upon opening the circuits of the switches
and
determine the indication of the galvanometer
, del. The operation is repeated not less than three
time.
6.4.3 ballistic Constant of the galvanometer , WB/cases., calculated as the arithmetic mean of the constant of the galvanometer
, WB/cases., obtained at at least three predetermined values of current.
6.4.4 Constant of the galvanometer , WB/cases., for a given current value
, And is calculated by the formula
where - coefficient of mutual inductance coil
, RH;
- the arithmetic mean of the readings of the galvanometer
, determined as described in 6.4.2, del.
When using the galvanometer with a shunt constant , WB/del. should be determined for each value of the ratio of the bypass.
6.5 When using the fluxmeter from the unit exclude: switch , coil
and resistors
,
,
(see figure 1).
6.6 When measuring magnetic induction of constant magnetic field of less than 100 A/m conducted demagnetization of the samples. The maximum amplitude of tension of the demagnetizing field should exceed the coercivity of the sample is more than fifty times. The amplitude of the magnetic field at which the demagnetization finish should be less than 0.1 A/m.
6.6.1 When the thickness of the sheet or tape sample at least 1,0 mm demagnetization is carried out in the field frequency of 50 Hz.
The switch is put to position 2, the key is
completing (see figure 1). Set current corresponding to the maximum amplitude of the demagnetizing field intensity, and then gradually reduce it.
6.6.2 When the thickness of the sheet or tape of more than 1.0 mm, the demagnetization is carried out with direct current. The switch is put to position 1
- in position 2 of the locking key
and the voltage applied from the generator
corresponding to the maximum amplitude of the demagnetizing current. Commute current switch
no more than once per second simultaneously and smoothly reduce it.
6.6.3 demagnetization Time should not be less than 40 C.
6.6.4 the measurement of magnetic induction field of strength less than 1.0 a/m samples after demagnetization withstand 24 h, when 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 condensed excerpts within ±2%.
6.6.5 the measurement of the coercive force limit of the hysteresis loop and magnetic induction of more than 100 A/m samples were not demagnetized.
6.7 the Magnetizing current , And that matches a specified value of the field strength
, A/m, is calculated by the formula
where — the average length of the magnetic lines of force m;
the number of turns of the winding I of the sample.
For samples with ring shape average length of the magnetic lines of force , m, is calculated by the formula
In the standard tests for a sample of the bands are equal to 0.94 m. If necessary, increase the accuracy of determining the magnetic value of the values allowed
to select 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 |
7 procedures for measuring
7.1 Magnetic induction determine the pulse-induction method: change the speed of the tension constant magnetic field; forming voltage pulse in winding II of the sample associated with the magnetic flux, and measure the increase of magnetic induction ballistic galvanometer or fluxmeter.
7.1.1 Switches and
put in position 1
- in position 2, close the key
and install a resistor
the value of the magnetizing current
, And calculated by the formula (6) for the smallest values of the magnetic field.
7.1.2 Commute current switch at least ten times, change the direction of the current in this switch, disconnect an key
and determine the indication
, del., galvanometer or the value of the magnetic flux
, WB, according to the fluxmeter. When switching the current in the magnetizing coil must change monotonically.
7.1.3 Smoothly sets a higher current, and repeat the operations specified
7.2 Coercivity in closed magnetic circuit determine the pulse-induction method: changing the magnetizing current from the value corresponding to the coercive force, to a maximum value and measure the magnetic flux, which have a constant polarity to be less than half the maximum magnetic flux of the hysteresis loop.
7.2.1 Switches and
put in position 1
- in position 2 of the locking key
and at the maximum value of the resistor
set resistor
the current
And corresponding magnetic field strength
, A/m, more than fifty R
AZ.
7.2.2 disconnect an key , change the direction of the current switch
and determine the indication
, del., ballistic galvanometer, or
and
return the switch
to position
1.
7.2.3 disconnect an key , change the direction of current switch
, resistor
increase the current up to values close to the coercive force, and simultaneously de-energised-key
.Determine the indication of the galvanometer
, del., or fluxmeter
, WB, with the closure of the key
.
7.2.4 Repeat the operations specified and
the corresponding indications of the galvanometer
, and
for which you must follow the terms:
The indications of the galvanometer , and
should not differ from the value of 0.5
by more than ±0,03
.
8 Rules for processing results of measurements
8.1 Induction , TL corresponding to a given magnetic field strength
, A/m, is calculated by the formula
where is the constant of the galvanometer, as defined, as specified in 6.4, the WB/del.;
— the average value of the readings of the galvanometer, as defined, as specified in 7.1.2, del.;
— number of turns in the winding II of the sample;
- the cross-sectional area of specimen, m
.
In the absence of the coil is introduced a correction for the magnetic flux outside the sample. The actual value of the magnetic induction
, T, is calculated by the formula
where 
the cross — sectional area of the winding II of the sample, m
;
- the cross-sectional area of specimen, m
.
When using the fluxmeter magnetic induction , T, is calculated by the formula
where — reading fluxmeter, WB.
8.2 Coercivity , A/m, is calculated by the formula
where is the number of turns of the winding I of the sample;
— the average length of the magnetic lines of force determined as specified in 6.7, m;
the value of the current corresponding to the values of
and
, And;
the average of maximum readings of the galvanometer, as defined, as specified in 7.2.1 and 7.2.2, del.
Allowed subject to the condition 
b.
8.3 When using a straightforward scale of the galvanometer is introduced the amendment , del., calculated according to the formula
where - the distance between the mirror galvanometer and scale, the scale marks.
Then, in the formula (5), (8) and (11) the values of del., replace the values of
del., calculated according to the formula
8.4 the measurement Error of the magnetic induction must not exceed the limits specified in table 3.
Table 3
| Magnetic induction, T |
The error of measurement, % | |
| for isotropic steel |
for anisotropic steel | |
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 |
8.5 the Error of measurement of the coercive force 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
