GOST 12766.1-90

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  ГОСТ 12766.1-90

GOST 12766.1−90 Wire of precision alloys with high electrical resistance. Specifications (with Change No. 1)

GOST 12766.1−90

Group В73

INTERSTATE STANDARD

WIRE OF PRECISION ALLOYS WITH HIGH ELECTRICAL RESISTANCE

Specifications

Wire of high electric resistance precision alloys. Specifications

ISS 77.140.65
OKP 12 2600, 2500 12

Date of introduction 1991−01−01

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the Ministry of metallurgy of the USSR

2. APPROVED AND put INTO EFFECT by Decision of the USSR State Committee on management of quality and standards from 07.02.90 N 172

The change in N 1 taken by the Interstate Council for standardization, Metrology and certification (Protocol № 7 from 26.04.95)

The adoption voted:

3. INSTEAD, GOST 12766.1−77

4. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

5. Limitation of actions taken by Protocol No. 5−94 of the Interstate Council for standardization, Metrology and certification (ICS 11−12−94)

6. EDITION with Change No. 1 adopted in February 1996 (IMS 5−96)


This standard applies to cold drawn precision alloy wire with high electrical resistance for the manufacture of heating elements and resistance elements.

1. TECHNICAL REQUIREMENTS

1.1. Wire shall be manufactured in accordance with the requirements of this standard.

1.1.1. Wire classification:

for the purpose:

from grades H15YU5, KH23JU5, KH23JU5T, KH27JU5T, KHN20JUS;

for heating elements — N;

for tubular electric heaters — heater;

resistance elements,

from alloys of H15N60-H; CR20NI80-H; KHN70JU-N:

for heating elements;

for tubular electric heaters — heater;

of grade H15N60 — resistance elements;

by the color of the surface of alloy grade H15N60:

with light surface — SV;

an oxidized surface On

1.2. Basic parameters and dimensions

1.2.1. Wire depending on the brand of alloy manufactured the limiting diameters shown in table.1.

Table 1

1.2.2. Wire diameters should correspond to GOST 2771 for a range of diameters R40.

Limit deviations must comply with qualiteam:

Notes:

1. Allowed rounding limit deviations to hundredths of a millimeter.

2. By agreement between the consumer and the manufacturer produce wire of other diameters.

1.2.3. The mass of one piece of wire must conform to the standards given in table.2.

Table 2

Notes:

1. The segments of wire of low mass allowed in an amount of not more than 15% by weight of the party.

2. By agreement between manufacturer and user wire produced different mass.

3. Allowed welding of several segments of wire, one melting, provided that the weld must meet all of the requirements of this standard.


Examples of symbols

Wire diameter 1.5 mm alloy brand KH23JU5T for heating elements:

Wire 1,5-KH23JU5T-N GOST 12766.1−90

The same diameter of 0.4 mm and oxidized surface of the alloy grade H15N60 resistance elements:

Wire 0,40-H15N60 GOST 12766.1−90

The same, with a diameter of 0.1 mm from the alloy grade CR20NI80-H for tubular heating elements:

Wire 0,1-CR20NI80-H-Teng GOST 12766.1−90

(Changed edition, Rev. N 1).

1.3. Features

1.3.1. Wire produced from the alloys of H15YU5, KH23JU5, H15N60, H15N60-H, CR20NI80-H, KH27JU5T, KH23JU5T, KHN70JU-N, KHN20JUS with the chemical composition according to GOST 10994.

1.3.2. Wire produced in soft annealed condition. By agreement between manufacturer and consumer wire produced with an etched surface.

1.3.3. Specific electric resistance wire soft annealed condition and must conform to the standards given in table.3.

Table 3

1.3.4. Tolerance electrical resistance of 1 m wire from the nominal shall not exceed ±5%.

The nominal electrical resistance of 1 m is given in Appendix 2.

1.3.5. The variation of electrical resistance up to 1 meter of wire within the same winding (coil mandrels) must not exceed 4% at the customer’s request for ten — 3%.

1.3.6. The persistence of the alloys intended for the manufacture of heating elements and the heating element, tested according to the method G, must conform to the standards given in table.4.

Table 4

_______________
* For grade KHN20JUS survivability is not a rejection sign up to 01.01.98. Definition of necessary.


(Changed edition, Rev. N 1).

1.3.7. (Deleted, Rev. N 1).

1.3.8. The surface of the wire must be free of cracks, flaws and rabini. Allowed scratches, fingerprints, risks, sunsets, slivers depth of less than 0.012 mm — for wire diameter from 0.10 to 0.60 mm, inclusive; not more than 0.02 mm diameter wire SV 0.6 to 6.0 mm, inclusive; not more than 0.04 mm — for wire diameter of 6.0 mm. St

The surface must be grey or silver-frosted or covered with a thin oxide film tint, without distinct dark spots. For a wire diameter of 3.0 mm or more of alloys of Nickel-chrome based allowed the dark color of the surface.

The alloy wire H15N60 produce an oxidized surface of a dark color, covered with oxides after annealing or bright surface. In the absence of instructions in the order the color of the surface of the wire sets manufacturer.

By agreement with the consumer it is allowed manufacture of wire samples, agreed in the prescribed manner, if the surface condition does not preclude the use of wire for the intended purpose of the user.

1.3.9. Rupture strength and relative elongation of wire in soft annealed condition shall conform to the requirements given in table.6.

Table 6*

___________________
* Table.5. (Deleted, Rev. N 1).

(Changed edition, Rev. N 1).

1.3.10. Wire diameter from 0.1 mm to 6.0 mm inclusive when the winding of five turns on a rod of appropriate diameter must not break and flake.

1.3.11. Wire diameter of 0.3 mm or more from grades KH23JU5T and KH27JU5T designed to operate the heater, check the tendency to high-temperature pitting corrosion. On the surface of the wire after the test should not be ulcers. If necessary, the evaluation of the surface condition is performed by comparison with reference samples agreed in the prescribed manner.

(Changed edition, Rev. N 1).

1.3.12. Customer’s request wire diameter of 0.1−1.0 mm are made with a normalized uniformity of the pitch of the helix. Norms and methods of control determined by agreement between manufacturer and consumer.

1.3.13. Physical and electrical properties of alloys, the maximum operating temperature, the estimated service life are given in appendices 3−8.

1.4. Marking

1.4.1. Labeling — according GOST 7566 with additions.

1.4.1.1. To each coils (the mandrel, the coil) must be attached a label showing:

trademark or name or name and trademark of manufacturer;

a symbol (without the words «wire»);

the wire diameter;

stamp of technical control;

electrical resistance of 1 m of wire for the heater in agreement with the consumer.

(Changed edition, Rev. N 1).

1.4.1.2. For each coil (a coil mandrel) wire diameter is 3.0 mm or less, attach one label.

1.4.1.3.Transport marking under GOST 14192.

1.4.1.4. Marking wire with a diameter of less than 1.1 mm, intended for submission to the far North and remote areas — according to GOST 15846.

1.5. Packaging

1.5.1. Packaging — according to GOST 7566 with additions.

1.5.1.1. Wire with a diameter of less than 0.6 mm should be wound on a reel or mandrel.

1.5.1.2. Wire diameter from 0.6 mm to 1.0 inclusive, must be in Hanks or on reels (mandrels), more than 1.0 mm, in coils. The wire should be wound on the spool (mandrel) separatornyi dense rows, providing free spooling.

Each skein must consist of a single segment wire. Allowed winding on the coil or mandrel is not more than three pieces of wire, while the total mass of the wire diameter of 0.36 mm or less, intended for heating elements and heater, the coil (the mandrel) should not exceed 5 kg. of wire Segments must be separated by spacers, thus preventing wire entanglement.

1.5.1.3. Coils, coil and mandrel wire with a diameter of less than 1.1 mm should be wrapped in one or more layers of paper according to GOST 8828, GOST 9569*, GOST 10396 or other regulatory-technical documentation and dense rows stacked in boxes type I or type II churchyard 2991 or other regulatory-technical documentation. Between the rows of coils are laid cardboard according to GOST 7376** or other regulatory-technical documentation.
________________
* On the territory of the Russian Federation the document is not valid. Valid GOST 9569−2006, here and hereafter;
** In the territory of the Russian Federation the document is not valid. Valid GOST R 52901−2007. — Note the manufacturer’s database.

Packaging in barrels, containers or other metal container according to normative-technical documentation, developed in accordance with the requirements of GOST 6247, GOST 15102, GOST 26155.

Coils of wire with a diameter of 1.1 mm and more should be wrapped with one layer or several layers of paper according to GOST 8828, 9569 or GOST GOST 10396, film according to GOST 10354, GOST 16272 container or bonded fabrics according to GOST of 14,253, non-woven cloth, stitched flap from the waste of the textile industry, or other types of packaging materials according to normative-technical documentation, with the exception of cotton and linen fabrics. Packed skeins must be tied with wire according to GOST 3282 or other normative and technical documentation or some other way to protect the packs from unwinding.

The outer diameter of the coil wire should be no more than 1200 mm, internal — not less than 150 mm.

1.5.1.4. By agreement with the consumer for protection against corrosion of wire alloy on Fe-basis is allowed to apply both an industrial oil according to GOST 20799 inhibitors.

1.5.1.5. Weight of cargo must not exceed:

80 kg — with manual loading and unloading;

1250 kg — with mechanized loading and unloading.

1.5.1.6. Allowed one packing place to put the wire in several parties.

1.5.1.7. Packaging of wire with a diameter of less than 1.1 mm, intended for submission to the far North regions and equated areas according to GOST 15846.

2. ACCEPTANCE

2.1. Wire take parties. The party must consist of one of the metal melt and of the same diameter and must be issued a document about quality that contains:

the trademark or name and a trademark or the name of the manufacturer;

symbol wire;

the weight of the party;

the results of the tests;

the chemical composition of the alloy.

2.2. To check the quality of wire taken from the party:

to control the diameter, surface quality — 100% skeins (coils, bars);

to control chemical composition — one sample from the melt;

to control the electrical resistivity, the variation of the electrical resistance of one winding (coil mandrels), elongation, temporary tear resistance, nabivanija, electric resistance of 1 m, the uniformity of the pitch of the spiral — three coils (coil mandrel);

to control vitality — one sample from melting ground, enough to make at least 5 m of wire diameter 0,8 mm.

2.3. Control of the variation of the electrical resistance of the wire alloy in the range of a coil (coil mandrels) and test on winding wire alloys CR20NI80-H, H15N60-H, H15N60 the manufacturer conducts periodic, but not less than once per year.

2.4. Monitoring of the survivability of the manufacturer conducts periodically at the direction of the enterprise, smelting metal, but at least five times a year for each brand.

The test results reported by the company, smelting the metal.

2.5. The chemical composition of the alloys is certified by a document of quality issued by the company, smelting the metal.

2.6. Control on the propensity to pitting corrosion of wire carried on a single reel (reel mandrel) from the party. Manufacturer the lack of pitting on the wire is not defined. The lack of pitting corrosion checks, if necessary, business-to-consumer.

2.7. Control of elongation and the temporary tear resistance of a wire with a diameter of 0.1 to 6.0 mm inclusive to the manufacturer may be performed periodically, but not less than one batch per year of each grade alloy.

2.8. If unsatisfactory test results of at least one indicator of a re-test is carried out according to GOST 7566.

3. CONTROL METHODS

3.1. Chemical composition of alloys determined according to GOST 12344−12348 GOST, GOST 12350,12352 GOST, GOST 12356, 12357 GOST, GOST 12364, 12365 GOST, GOST 28473 or other methods providing the required accuracy of the analysis. Sampling — according to GOST 7565.

3.2. The wire diameter is determined in two mutually perpendicular directions of the same cross-section in at least three places using a micrometer according to GOST 6507 or by other measurement means appropriate accuracy at a distance of not less than one turn from the end of a coil (coil mandrels).

3.3. The surface quality of the wire is checked visually. Control of surface quality of wire, wound on a reel or mandrel, carried on the outside of the coils or in the process of technological operations. If there is disagreement in assessing the quality of the surface is inspected at magnification 8. The depth of the defect is determined by the sweep. The location of the defect cleaned with sandpaper or a file with further comparative dimension to the stripped and unstripped areas. If you cannot determine the depth of the defect Stripping determination of the depth and nature of the defect can be carried out by metallographic methods.

3.4. Determination of electrical resistance wire is carried out according to GOST 7229 with the use of instruments of accuracy class not worse than 0,05.

3.5. Electrical resistivity (), μω·m, is calculated by the formula

,

where  — electrical resistance of sample, Ohms;

 — the area of cross section, m;

 — length of sample, m

3.6. To determine the variation of electrical resistance wire within the winding (coil mandrels) measure the electrical resistance of the wire at the beginning and end of a coil (coil mandrels). The difference between the electric resistance refers to the average of the resulting values and multiplied by 100%.

3.7. The definition of survivability is carried out according to GOST 2419 according to the method G to burnout.

(Changed edition, Rev. N 1).

3.8. The test winding is carried out according to GOST 10447. The diameter of the rod to nabivanija sample of wire with a diameter of 0.1−4.5 mm should be equal to four times the diameter of the wire of alloys Nickel-chromium-based and five-time — for alloys Fe based.

The diameter of the rod to nabivanija sample of all grades of alloys with a diameter of over 4.5 mm should be equal to six times the diameter of the wire. The winding of samples of alloy grade KH27JU5T carried out at a temperature of 300−400 °C.

3.9. The definition of elongation and strength of the gap is carried out according to GOST 10446 on samples with an estimated length of 200 mm For wire diameter 1 mm and less is allowed to carry out the determination of mechanical properties on samples with an estimated length of 100 mm.

(Changed edition, Rev. N 1).

3.10. The tendency to pitting corrosion of wire of diameter 3.0 mm and over is determined on specimens tested at a temperature (1300±20) °C for 1000 h according to the method of application 7.

The tendency to pitting corrosion of wire of diameter less than 3.0 mm is determined on samples tested at a temperature of (1150±10) °C for 20 h according to the method of application 7.

3.11. Determination of the mass of the wire is carried in the balance, providing the required weighing accuracy.

3.12. For each test, except the test on the propensity to pitting corrosion, must be taken one sample from each selected coil (coil mandrels); for the test of the tendency to pitting corrosion, with at least four samples from each selected coil (coil mandrels).

4. TRANSPORTATION AND STORAGE

4.1. Transportation and storage — by GOST 7566 with additions.

4.1.1. Storage condition of wire for up to 1 month — 3ЖЗ according to GOST 15150, for a period of more than 1 months — 1L according to GOST 15150.

4.1.2. Transportation and storage of wire with a diameter of less than 1.1 mm, intended for submission to the far North regions and equated areas according to GOST 15846.

4.1.3. When you ship two or more packages to one of the consumer spend consolidation packages in accordance with GOST 21650, GOST 24597.

5. MANUFACTURER’S WARRANTY

5.1. The manufacturer guarantees compliance wire requirements of this standard while complying with the storage conditions.

A storage warranty period — three years from the date of manufacture of alloys for Nickel-chromium-based, and two years for alloys on a Fe-basis.

6. OPERATING INSTRUCTIONS

Wire the consumer has to be unwound from the spool at a speed of 200 m/min if tensile force is not more than 0.6 breaking strength. While unwinding, it shall be ensured concentricity of the coil is more than 0.20 mm. the Location of the axis of the coil is horizontal.

ANNEX 1 (reference). The nominal value of resistivity

ANNEX 1
Reference

Table 7

ANNEX 2 (mandatory). The nominal electrical resistance of 1 m wire

ANNEX 2
Mandatory

THE NOMINAL ELECTRICAL RESISTANCE OF 1 M OF WIRE, Ω/M

Table 8

APPENDIX 3 (reference). Correction factors for calculating changes in electrical resistance depending on temperature

APPENDIX 3
Reference

Table 9

Table 10

The difference in electrical resistance from regulated by this standard

ANNEX 4 (reference). MAXIMUM RECOMMENDED OPERATING TEMPERATURE OF HEATING ELEMENTS OPERATING IN AIR

ANNEX 4
Reference

Table 11

Notes:

1. Given the temperature values are indicative and can be updated calculation depending on the required service life of the heating elements by the techniques available in the literature.

2. In the newly created and upgraded technology instead of alloy KH27JU5T it is recommended to use alloy KH23JU5T.

ANNEX 5 (reference). TEMPERATURE COEFFICIENTS OF ELECTRICAL RESISTANCE

ANNEX 5
Reference

Table 12

APPENDIX 6 (reference). PHYSICAL PROPERTIES OF ALLOYS

APPENDIX 6
Reference

Table 13

_______________
* With a mass fraction up to 3% of ferrite.

** In the presence of ferrite slavogermanica.

ANNEX 7 (obligatory). METHODS OF TEST WIRE TO THE PENCHANT FOR HIGH-TEMPERATURE PITTING CORROSION

ANNEX 7
Mandatory

The essence of the methods is to test samples of wire coiled at a predetermined temperature within the regulated period.

1. Test method wire diameter of 3 mm or more

Heating of the sample is carried out by passing an electric current through the sample heater.

1.1. The selection of wire and prototyping-heaters

1.1.1. For the manufacture of the spiral sample using a length of wire with a diameter of 4.0−6.3 mm length 5−7 m.

1.1.2. The sample manufactured in the form of a spiral with a diameter of 45−50 mm with a helical pitch (2−2,5), where the diameter of the test wire. When coiling spiral heating wire is allowed.

1.1.3. The test at least four samples from each roll of sample.

1.2. Equipment

Lined muffle tube an inner diameter of 80−100 mm.

The ceramic tube or rod is to accommodate a spiral pattern. Allowed coating of the tube or rod refractory mass to prevent electrochemical interactions with the sample.

The pyrometer according to GOST 8335 or GOST 6923, or other regulatory-technical documentation.

Thermocouple platinoidy-platinum.

Potentiometer DC GOST 9245 or other regulatory-technical documentation.

The automatic device according to the GOST 7164 or other regulatory-technical documentation.

1.3. Testing

1.3.1. Spiral pattern on the tube or rod placed horizontally in the Central part of the muffle. The minimum distance between the spiral and the walls of the muffle during the test shall not be less than 10 mm.

1.3.2. Heating of the sample to a predetermined temperature is carried out by passing alternating current of industrial frequency. Surface electrical power must not exceed 1.8 W/cm.

1.3.3. The time of heating to a predetermined temperature should not exceed 10 hours.

1.3.4. Maintenance of the set temperature is bistable with platinoidy-platinum thermocouples installed in the area of Central part of sample, and automatic tracking device.

1.3.5. Measurement control of temperature performed by the thermometer every 12 hours in the middle of the sample. Allowed to carry out test measurements with platinoidy-platinum thermocouple, the junction of which is fixed in the middle part of the sample.

1.3.6. Allowed sample cooling with muffle with the objective of visual inspection at intervals of (250±50) h

1.3.7. The control wire for the heaters on the propensity to pitting corrosion is the umbrella organization of the consumer — the all-Union scientific-research Institute of electrothermal equipment.

1.3.8. Assessment of the propensity to pitting corrosion is carried out by comparing the surface conditions of a sample-heater test and control samples of heaters, as agreed between the all-Union scientific research Institute electrothermal equipment and the Central research Institute of ferrous metallurgy.

2. Test method wire diameter less than 3 mm

Heating of the sample is carried out in electric furnaces.

2.1. The selection of wire and samples

2.1.1. For the manufacture of the spiral sample using a cut wire with a diameter of 0.3−2.8 mm length less than 3 m.

2.1.2. The sample manufactured in the form of a spiral with a diameter of (6−7) increments not less than 2 , where the diameter of the test wire.

2.1.3. The test at least four samples from each selected coil (coil mandrels).

2.2. Equipment

An electric furnace with a maximum temperature of the working space not less than 1150 °C.

Ceramic stand to place the samples of corundum according to GOST 24704 or other high-alumina refractory material, excluding the interaction with the test sample.

Thermocouple platinoidy-platinum according to GOST 9245.

The automatic device according to the GOST 7164 or other regulatory-technical documentation.

2.3. Testing

2.3.1. Spiral patterns on a ceramic stand was placed in the Central part of the heating zone.

2.3.2. Heating the samples to a predetermined temperature is performed according to the mode: heating up to 600 °C, the heating rate is arbitrary, heating from 600 °C to 800 °C at a heating rate of not more than 100 °C/h exposure 2 h, heating from 800 °C to a predetermined temperature with a heating rate of not more than 100 °C/h exposure with 20 h

2.3.3. The rate of cooling the spiral samples after testing is not regulated.

2.3.4. Evaluation of the tendency for high-temperature pitting corrosion is performed visually with the use of increasing 7.

On the surface of the spiral samples should not be ulcers. In cases of dispute, assessment of the surface condition of test specimens is carried out by comparison with the surface of control samples, as agreed between the manufacturer, the all-Union scientific research Institute electrothermal equipment, Central research Institute of ferrous metallurgy.

ANNEX 8 (informative). THE ESTIMATED SERVICE LIFE OF THE WIRE ALLOY WITH HIGH ELECTRICAL RESISTANCE WHEN WORKING AS A HEATER

ANNEX 8
Reference

Table 14

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Steel quality and high quality.
Bars and shapes,
calibrated steel. Part 3: Sat. Standards. -
M.: IPK Publishing house of standards, 2004