GOST 2419-78
GOST 2419−78 Alloy with higt electric resistance for electric heating elements. A method of determining survivability (with Change No. 1)
GOST 2419−78
Group B09
STATE STANDARD OF THE USSR
ALLOY WITH HIGT ELECTRIC RESISTANCE
FOR ELECTRIC HEATING ELEMENTS
A method of determining survivability
Precise alloys with high electric resistance for electric heating cells.
The methods of determination of survivability
AXTU 1509
Date of introduction 1979−01−0
INFORMATION DATA
1. DEVELOPED AND INTRODUCED by the Ministry of ferrous metallurgy of the USSR
DEVELOPERS
I. N. Golikov, S. S. Gratsianova, I. M. Plemyannikov, V. V. Karatayev, N. Gorokhova, N. G. Chebotarev, I. F. Medelyan, R. A. Vorobyov
2. APPROVED AND promulgated by the Decree of the State Committee of standards of Ministerial Council of the USSR from
3. REPLACE GOST 2419−58
4. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS
| The designation of the reference document referenced |
The number of the paragraph, subparagraph |
| GOST 111−90* | Sec. 2 |
| GOST 8335−81* |
Sec. 2 |
| GOST 28243−89* |
Sec. 2 |
________________
* On the territory of the Russian Federation there are GOST GOST 111−2001, GOST and GOST 8335−96 28243−96, respectively. Here and further. — Note the manufacturer’s database.
5. Limitation of actions taken by Protocol No. 3−93 Interstate Council for standardization, Metrology and certification (ICS 5−6-93)
6. The re-release (may, 1998) with amendment No. 1 approved in November 1987 (ICS 2−88)
This standard applies to precision alloys with high electrical resistance for the manufacture of electric heating elements, and specifies a method for determining survivability.
The essence of the method consists in testing wire samples of 0.8 mm diameter under conditions of variable heat to a predetermined temperature and cooling to surface Browning.
The methods are subdivided according to the duration of cycles of heating and cooling:
method — heating time 2 min, cooling time 2 min;
method G — the heating time is 23−24 hours, the cooling time of 0.5 h.
In the absence of instructions in the method of normative-technical documents for products testing carried out by the method of V.
Survivability at test in these conditions is determined by the length of time until it fails characterizes the samples and the heat resistance of the metal in terms of thermal cycles.
(Changed edition, Rev. N 1).
1. SAMPLING METHOD
1.1. Samples taken from cold drawn wire with a diameter of 0.8mm cold-worked condition.
1.2. Length 340 mm. Test samples of length 300 mm.
2. EQUIPMENT
Installation for testing the survivability consists of a test stand with cells for samples, control and measuring devices. Location scheme of equipment, instrumentation, electrical schematic and a list of its elements is given in Appendix 1. Installation can be performed on any number of samples, as the food samples is carried out independently from each other.
Metal shield box test cell, open top, should keep in front of the window for measuring the temperature, is protected with a glass thickness up to 3 mm. the Inner surface of the boxes should be black. Boxes should not be exposed to drafts. Design protective boxes, clamps and the mounting bolts for hanging the box is given in Appendix 2.
Glass of the 1st grade according to GOST 111.
A voltage regulator providing a DC voltage with a permissible deviation ±1,0%. Input voltage stabiliziruemost for each sample separately, thus achieving the independence of the conditions of the test samples.
Interrupter for periodically opening and closing the circuit of the sample, providing a cycle of heating and 2 min cooling 2 min. Permissible error of the interval cycles should be no more than 3 seconds.
Step-down transformer capacity of at least 700 watts and a rated voltage of secondary side not less than 36 in.
Thermometers according to GOST and GOST 8335 28243 to measure the temperature.
(Changed edition, Rev. N 1).
3. PREPARING FOR THE TEST
3.1. The sample should not have surface defects, noticeably affecting the result of the test (cracks, scoring, rabini), as well as clear and straightened kinks, and kinks.
The surface quality of the wire is controlled by a magnifying glass with a magnification of at least 6.
3.2. The sample is fixed in the form of slack loops, and the need to observe the following distances:
between the panel and the sample — 55 mm;
between the sample and the glass — 55 mm;
between the clamps and the top clamping boxes — 200 mm;
between the clips — 90 mm.
3.3. Test temperature is established in the normative-technical documentation for metal products.
4. TESTING
4.1 Test of survivability is carried out:
a) prior to the burnout of the samples;
b) until the specified duration of the test.
Type of test envisaged in the normative-technical documentation for metal products. In the absence of instructions, the test is performed under sub — and.
4.2. Temperature measurement of the specimen by a pyrometer is produced in complete darkness through the glass boxes in the middle part of the vertical branch (option A) or at the bottom of the loop (option B).
In the formation on the surface of weakly coupled to the sample scale it needs to be removed at the site of temperature measurement easy scraping or tapping.
4.3. When measuring temperature, corrected for reflection and absorption of light by a glass box, adding to the observed temperature of 10 °C in the temperature range 1000−1300 °C.
To avoid the increase of light absorption of the glass when measuring the temperature of must be clean.
4.4. Sample testing is carried out in the following order:
a) remove the knob of the voltage regulator to the zero position;
b) fix the specimen;
C) switch on the power;
g) turn the knob of the voltage regulator, to achieve that the sample was heated to the desired temperature.
Notes:
1. The heating temperature for the first 2−4 min of the test must be below set at 200 °C (approximately).
2. During the establishment of the test temperature overheating of the samples by more than 20%. When the temperature of the sample should be removed and replaced with another.
3. The control time should not exceed 10 min for each sample.
d) trigger the circuit breaker under test according To the method; turn off voltage for 0.5 h every 23−24 hours when tested according to method G;
e) after 5 and 24 h since the start of the test and then every 24 h the sample temperature podregulirovan to the initial temperature, as indicated in subparagraph g, When tested according to the method G, the adjustment is carried out for 30 minutes after switching on the voltage.
g) at beginning of test and before each adjustment and after measure and record the temperature, and if necessary, the amperage and voltage.
When you see the sample of local overheating in the form of hot spots the temperature podregulirovan, and the sample is removed for subsequent readjustment of temperature and testing is complete, as for the blown sample.
(Changed edition, Rev. N 1).
5. PROCESSING OF THE RESULTS
5.1. Survivability is determined by the number of hours from the moment of reaching the test temperature to the burnout of the sample or until the specified duration of the test.
5.2. The test is carried out on three samples from the party. The test result should be the arithmetic mean of the results of the three definitions, permissible differences should not exceed ±12 from the arithmetic mean.
ANNEX 1 (recommended). LOCATION SCHEME OF EQUIPMENT, INSTRUMENTATION, ELECTRICAL SCHEMATIC AND A LIST OF ITS ELEMENTS
ANNEX 1
Recommended
Damn.1. Layout of equipment and devices
Layout of equipment and devices
Damn.1
Damn.2. The electrical circuit
The electrical circuit
Chart switches B9-B12
| Contacts |
Position | |
| working |
measurement | |
| 1 |
x |
- |
| 2 |
- |
x |
| 3 |
- |
x |
| 4 |
- |
x |
Damn.2
The list of schema elements
| Marking |
Name |
Note |
| And |
Ammeter type 3514/2 2,5−5,0 And Voltmeter type 3515/2 7,5−15−30−60 In | |
| B1 |
Batch-Cam switch |
Cm. note p. 2 |
| B2, B3 |
Batch-Cam switch ICR-10−2-4−1 | |
| V4-V7 |
Batch-Cam switch ICR-10−3-12−1 | |
| B8 |
Switch type W-1 2A 220V | |
| B9-B12 |
Switch universal type UE-5412-С71 | |
| R1 |
Fuse |
Cm. note p. 2 |
| WP2 |
Fuse |
Cm. note p. 2 |
| R |
Working position of the switch | |
| And |
The switch position for measuring current and voltage | |
| R1-R4 |
Relay type RPU-2−36203 220 V, 50 Hz | |
| R5-R8 |
Contactor type PMP-221 | |
| P9 |
Intermediate relays RPU-2 — 362203, 220 V, 50 Hz | |
| SIP |
The counting impulse circuit breaker | |
| TP1-TP4 |
Variator of the type RIO-250−2 | |
| TP5-Тр8 |
Autotransformer |
Damn.3 |
| TP9 |
Current transformer type TC 40−05−30−5 | |
| E1-Э4 |
Test the electric heating element | |
| B4 |
Secondary clock | |
| SN |
Voltage regulator With solenoid-0,75 |
Notes:
1. When listed equipment is allowed to apply a sample voltage to 36 V, current up to 20 A.
2. The scheme is composed of four elements. The number of elements can be any. Equipment B1. PR depends on the number of test cells.
Damn.3. Autotransformer
Autotransformer
Rated power of 720 watts. 220/36 rated voltage V rated current secondary winding 20 A. the cross section of the magnetic core 20x25 cm Steel brand E42. Windings are placed on both terminals: EXT=2х210 turns. Cord PBBs diameter of 1.45. NN=2х55 turns. The rectangular wire size mm 108х8
Damn.3
APPENDIX 1. (Changed edition, Rev. N 1).
APPENDIX 2 (recommended). DESIGN PROTECTIVE BOXES, CLAMPS AND THE MOUNTING BOLTS FOR HANGING THE BOX
ANNEX 2
Recommended
Damn.1. Design a protective box
Design a protective box
Material — sheet steel, copper or brass thickness of 0.5−1.5 mm.
1 — box housing; 2 — clip for mounting; 3 — crystal; 4 — socket for glass
Damn.1
Damn.2. Clips design (material — copper)
Clips design (material — copper)
1 — dielectric core; 2 — clamping insert; 3 — nut; 4 — tip;
5 — insulating plate; 6 — clamping bolt
Damn.2
Damn.3. Mounting bolts for hanging the box
Mounting bolts for hanging the box
1 — screw; 2 — nut; 3 — spacer
Damn.3
The electronic text of the document
prepared by JSC «Code» and checked by:
the official publication of the
M.: IPK Publishing house of standards, 1998
