GOST 26126-84
GOST 26126−84 nondestructive testing. Joints brazed. Ultrasonic methods of quality control (with Change No. 1)
GOST 26126−84
Group B09
STATE STANDARD OF THE USSR
Nondestructive testing
CONNECTION BRAZED
Ultrasonic methods of quality control
Non-destructive Testing Brazed and Soldered Joints Ultrasonic
Methods for Inspection of Quality
AXTU 4276
Valid from 01.07.85
before 01.07.90*
_______________________________
* Expiration removed
Protocol 4−93 N Interstate
Council for standardization, Metrology
and certification (I & C N 4, 1994). -
Note the manufacturer’s database.
DEVELOPED by the Ministry of higher and secondary special education of the USSR
PERFORMERS
N. P. Aleshin, doctor of engineering. Sciences; A. L. Remizov; Maslov B. G., candidate. tech. Sciences; V. A. Medvedev
INTRODUCED by the Ministry of higher and secondary special education of the USSR
Member Of The Board Of D. I. Ryzhonkov
APPROVED AND put INTO EFFECT by Decision of the USSR State Committee for standards of 23 March 1984 924
The Change N 1, approved and put into effect by the Decree of Gosstandart of the USSR from
Change No. 1 made by the manufacturer of the database in the text ICS N 7, 1990
This standard specifies ultrasonic methods of quality control of brazed joints.
1. GENERAL PROVISIONS
1.1. Methods of ultrasonic testing is used to detect internal defects in the churchyard 24715−81.
1.2. The need for ultrasonic inspection, its scope and the limits of the defects set in the standards or technical specifications for products.
1.3. Ultrasonic testing should be carried out after correcting the defects discovered by external examination.
2. EQUIPMENT
2.1. When control should be used:
pulsed ultrasonic flaw detector with the scale of the attenuator less than 2 dB;
straight and angled dual element transducers in the frequency 1,8; 2,5; 5; 10 MHz;
standard samples and (or) samples according to GOST 14782−86.
(Changed edition, Rev. N 1).
2.2. (Deleted, Rev. N 1).
2.3. The duration of the sweep on the indicator of the flaw detector should be installed so that the highest part of the sweep correspond to the path of an ultrasonic pulse in the metal connection.
2.4. When control use flaw with the display of any type.
2.5. The frequency of ultrasonic vibrations emitted by the transducers should not vary from the nominal value by more than 10%.
2.6. The incident angle of longitudinal and shear waves should not differ from the nominal value by more than ±2°±3°.
(Changed edition, Rev. N 1).
2.7. The requirements to the transducer surface, contacted with the input surface of the solder joint of the products of cylindrical or other curved shape, installed in the technical documentation for the control.
2.8. Flaw detector set up in the control:
lap and t-joints — Besobrasova method or the samples according to GOST 14782−86;
butt joints — standard samples and (or) samples according to GOST 14782−86.
Adjustment methodology must be specified in the technical documentation for the control.
(Changed edition, Rev. N 1).
2.9. Standard samples with regard to the shape and surface quality of the monitored connections have to be made of metal, according to the acoustic properties of the corresponding metal controlled solder joints.
2.10. Used equipment must ensure the possibility of determining the coordinates of defects.
3. PREPARATION FOR CONTROL
3.1. The surface of joint, which moves the transducer should not have dents and irregularities, the surface must be removed nodules of solder, loose scale and dirt.
After machining joints, stipulated by the technological process for manufacturing of brazed structures, the parameter of surface roughness of 40 microns churchyard 2789−73.
3.2. In the absence of adaptations to limit the range of motion of the transducer to the surface of the solder joint should be applied to boundary lines.
3.3. The surface prepared for inspection, immediately before the control must be carefully wiped with a rag and coat a layer of contact fluid.
3.4. In front of the control to be tested with the equipment. The list of parameters, method and frequency of their inspections are set in accordance with GOST 14782−86 in the technical documentation for the control.
(Changed edition, Rev. N 1).
4. CONTROL
4.1. Under the control of brazed joints should be used pulse-echo method. In the control of t-and lap-soldered joints apply the direct pitch-catch, and the testing of butt brazed joints — inclined dual element transducers included in the separate scheme.
(Changed edition, Rev. N 1).
4.2. The main stages of carrying out ultrasonic inspection of solder joints are:
sensitivity of detection of the defect;
sensitivity evaluation and processing of testing results.
The values of the sensitivities of search and evaluation and monitoring schemes specific brazed joints installed in the technical documentation for the control.
4.2.1. The movement of the transducer over the surface of the test object should provide for testing the entire surface of the solder joints. The path of the transducer and the scan step is set in the technical documentation for the control.
4.2.2. When defects are detected, set the sensitivity assessments and determine the following characteristics:
the equivalent area of the defect;
the number of defects on the length of the connection established in the technical documentation for control;
the distance between the defects;
the coordinates of the defects for butt joints;
conditional dimensions of defects;
the length and height for butt joints;
length — for lap joints.
Methods of determining characteristics of defects according to GOST 14782−86.
(Changed edition, Rev. N 1).
5. QUALITY ASSESSMENT AND REGISTRATION OF TESTING RESULTS
5.1. The quality of brazed joints by ultrasonic inspection results is evaluated by dwuhvalentnoe system:
the score is 1 — unsatisfactory. In connection revealed unacceptable defects or acceptable number of defects exceeds the norms established in the technical documentation for control;
score 2 — satisfactory quality. The connection is revealed only permissible defects and their number is below the standards set in the technical documentation on the control or detected defects.
5.2. The inspection results must be recorded in the journal or in custody, which must include:
type solder joint, the index assigned to the product and the solder connection, and the size of the controlled area;
the type of flaw;
the frequency of ultrasonic vibrations;
the incident angle of longitudinal and shear waves, or a type Converter;
the sensitivity of the search and evaluation;
date of control;
name and signature of the radiographer.
5.3. The necessity of abbreviating and designations indicated in the technical documentation for the control.
6. SAFETY REQUIREMENTS
6.1. When working with the equipment must be complied with «safety Rules at operation of electrical installations"*, approved by Gosenergonadzor.
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* On the territory of the Russian Federation act «Interbranch Rules on labor protection (safety rules) for electrical installations» (SWEAT P M-016−2001, RD 153−34.0−03.150−00). — Note the manufacturer’s database.
6.2. Ultrasound parameters that affect NDT — according to GOST 12.1.001−83*.
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* Valid GOST 12.1.001−89. — Note the manufacturer’s database.
6.3. Noise levels generated by equipment at the workplace of the operator, shall not exceed the permissible according to GOST 12.1.003−83.
6.4. When carrying out inspection near the plumbing place of radiographer must be enclosed with a protective screen.
The electronic text of the document
prepared by JSC «Code» and checked by:
the official publication of the
M.: Publishing house of standards, 1984
Revision of the document including
changes and additions
prepared by JSC «Code»
