GOST 24715-81

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  ГОСТ 24715-81

GOST 24715−81 Connections soldered. Quality control methods

GOST 24715−81

Group B09

STATE STANDARD OF THE USSR

CONNECTION BRAZED

Quality control methods

Brazed and Soldered Joints.
Methods for Inspection of Quality

Valid from 01.01.83
prior to 01.01.88*
______________________________
* Expiration removed
by the decree of Gosstandart of the USSR from 29.06.87 N 2304
(IUS N 10, 1987). — Note the «CODE"

Resolution of the USSR State Committee for standards, dated April 29, 1981 N 2182 validity period is set with 01.01.1983 01.01.1988 to G.


This standard applies to the basic types of brazed joints, made according to GOST 19249−73 all soldering methods.

The standard establishes methods of quality control of brazed joints for the detection of surface, internal and through defects listed in table.1.

Table 1

Defects of solder joints

Note. Nespa, soldering, residual stresses, General and local erosion, structural defects of solder joint reveals the methods of destructive testing (tab.5).


The choice of method or combination of methods of control (table.2, 3, 4, 5) for detecting defects of solder joints should be in accordance with the requirements to the quality of brazed joints standards, specifications and drawings, approved in the established procedure, and taking into account the size of actual detected defects and performance control methods.

Table 2

NDT methods for the detection of surface defects in the solder joints

Note. The size of actual detected defects dependent on the technical characteristics of the applied inspection hardware, the design features of products and manufacturing technology.

Table 3

NDT methods to detect internal defects in the solder joints

________________
* Standards 20426−82. — Note the CODE.

Notes:

1. When radiographic and radioscopic control is not provided detection of defects:

any defects, if their length in the direction of the radiation is less than twice the sensitivity of control, as defined by standards of sensitivity, or if the images of the defects coincide with other images, complicating the decryption (images of extraneous details, sharp angles of the product, abrupt changes of thicknesses of brazed items, etc.);

crack with opening less than 0.1 mm;

cracks, the plane of the disclosure which do not coincide with the direction of radiation;

nepraev in the case that the difference between the coefficients of attenuation of radiation solder and brazed material and the thickness of the solder joint do not provide enough radiation contrast.

Radiographic and radioscopic control should be used when bilateral access to the controlled solder connection, providing the ability to install source and radiation detector in accordance with the schemes of control.

2. The size of actual detected defects dependent on the technical characteristics of the applied inspection hardware, design features of the products and manufacturing technology.

Table 4

NDT methods for detection of through defects in the solder joints

Used in formulas:  — volume of the product;  — duration of the test; the volume of the chamber;  — the smallest detectable bubble diameter; the surface tension coefficient; is the density of the indicator liquid; is the acceleration of free fall;  — the height of the layer of indicator fluid;  — atmospheric pressure;  — pressure in the evacuated space above the layer of indicator fluid; the lower limit of the measuring gauge;  — the time from the moment of formation of the bubble before its detachment.

Table 5

Methods of destructive testing

The use of other methods of quality control of brazed joints while ensuring sensitivity to guarantee detection of defects, which are unacceptable according to the requirements of technical documentation for the product, duly approved.

Specific control methods for solder joints must be specified in the technical documentation for the manufacture, acceptance and maintenance products.

To check the mechanical properties of the samples brazed joints subjected to impact tests according to GOST 23046−78, tensile GOST 23047−78 and bending according to GOST 24167−80.

Control technology of brazed joints must be established in the technical documentation developed in accordance with GOST 3.1102−74* and GOST 3.1502−74*".

________________
* Valid GOST 3.1102−81
** A GOST 3.1502−85. — Note the CODE.