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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 07.02.78 N 379

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 0.8ГОСТ 2419-78 Сплавы прецизионные с высоким электрическим сопротивлением для электронагревательных элементов. Метод определения живучести (с Изменением N 1)mm 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 6ГОСТ 2419-78 Сплавы прецизионные с высоким электрическим сопротивлением для электронагревательных элементов. Метод определения живучести (с Изменением N 1).

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

ГОСТ 2419-78 Сплавы прецизионные с высоким электрическим сопротивлением для электронагревательных элементов. Метод определения живучести (с Изменением N 1)


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

ГОСТ 2419-78 Сплавы прецизионные с высоким электрическим сопротивлением для электронагревательных элементов. Метод определения живучести (с Изменением N 1)


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.

ГОСТ 2419-78 Сплавы прецизионные с высоким электрическим сопротивлением для электронагревательных элементов. Метод определения живучести (с Изменением N 1)

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)

ГОСТ 2419-78 Сплавы прецизионные с высоким электрическим сопротивлением для электронагревательных элементов. Метод определения живучести (с Изменением N 1)


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

ГОСТ 2419-78 Сплавы прецизионные с высоким электрическим сопротивлением для электронагревательных элементов. Метод определения живучести (с Изменением N 1)


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