GOST 21547-76

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  ГОСТ 21547-76

GOST 21547−76 Pike. Method of determining temperature desoldering (with Change No. 1)

GOST 21547−76*

Group B09

STATE STANDARD OF THE USSR

SOLDERING

The method of determining the temperature of the desoldering

Brazing and soldering. Method for determination of sealing-off temperature

Date of introduction 1977−01−01

The decision of the State Committee of standards of Ministerial Council of the USSR of February 5, 1976 N 345 the introduction installed from 01.01.1977 g.

Proven in 1981 by the Resolution of Gosstandart from 10.08.81 3745 N validity extended until 01.01.1987 **
______________
** Expiration removed by the resolution of Gosstandart of the USSR from 15.08.91 N 1357 (IUS N 11, 1991). — Note the manufacturer’s database.

* REPRINTED April 1982 Change No. 1 approved in August 1981 (IUS N 10−1981)


This standard applies to solder joints and sets the method for determining the temperature of the desoldering with a uniform heating of the sample under constant static load.

1. SAMPLING

1.1. Testing should be applied to flat samples, soldered lap joint and, in the absence of the sheet material, cylindrical samples, soldered back to back. The shape and dimensions of samples are indicated on the devil.1. The type of the selected samples must be indicated in the test report.

Damn.1

1.2. Before soldering, you should determine the mass of the lower part of the sample. The error in the mass determination not more than 1 year

2. EQUIPMENT AND INSTRUMENTS

2.1. Resistance furnaces or high-frequency setting, which should ensure uniform heating of the sample from a temperature lying at 50−70 °C below the solidus of the solder, at a speed of

10−15 °C / minute for joints made of low-temperature soldering;

20−30 °C per minute for joints made of brazing.

2.2. Thermocouples according to GOST 6616−74 and devices according to GOST 7164−78 to record the temperature of the sample.

3. PREPARATION FOR TESTING

3.1. Samples for determining the temperature of the desoldering should be soldered in a gas atmosphere, vacuum or flux modes used in the respective processes. Clearance at brazing should meet the specifications of the product. In the absence of such data, the clearance should be not more than 0.15 mm.

The clearance should be specified in the test Protocol.

3.2. Before tests on brazed samples should be set at least three thermocouples. Working ends of the thermocouples should be fixed to the specimen by sahakangas, by resistance welding or other method which provides reliable thermal contact at the locations indicated on the devil.2.

Damn.2

3.3 the lower part of the sample hanging an extension rod with a platform for weights or the weights attach by welding.

3.4. The total mass of the lower part of the specimen, extension rod and a platform with weights should be 150±3 g for flat samples and 78±2 g for cylindrical samples.

4. TESTING

4.1 the Sample attached to the extension rod and the platform with the weights should be placed in the heating device, as shown in hell.3.

1 — tested sample; 2 — heating device; 3 — extension rod;
4 — a platform with weights

Damn.3

4.2. Testing should be at least three samples.

4.3. To prevent the formation of scale testing is allowed in an inert or active gas atmosphere, a vacuum or applying a flux on the sample.

4.4. The temperature of desoldering connections must be fixed at the time of separation of the lower part of the specimen, but no later than 2 s.

5. PROCESSING OF THE RESULTS

5.1. For desoldering the temperature of the sample should take the arithmetic average of readings of three thermocouples.

5.2. For temperature desoldering a solder joint should take the arithmetic mean of the results of tests of three samples. The Protocol should indicate the degree of dispersion of the results.

(Changed edition, Rev. N 1).

5.3. The test shall be considered invalid in case of failure during the period of heating at least one of the thermocouple or detection Naropa in the seam after testing more than 5% of a given area of overlap. In such cases the test should be repeated, the number of samples must match the number of invalid test results.

5.4. The test results of each sample should be recorded in the test report, the form of which is specified in the recommended application.

APPLICATION (recommended). Protocol testing of samples to determine the temperature of the desoldering

APP
Recommended

PROTOCOL N __________

testing of samples to determine the temperature of the desoldering