Rods and blanks of round and rectangular cross-section. Ultrasonic flaw detection methods. Sampling method

GOST 21120-75*

Group B09

STATE STANDARD OF THE USSR UNION

RODS AND BLANKS OF ROUND AND RECTANGULAR SECTION

Ultrasonic flaw detection methods

Round and rectangular bars and tickets. Ultrasonic testing

Date of introduction 1977-01-01

Resolution State Committee standards of the Council of Ministers of the USSR dated August 29, 1975 N 2282, the implementation period was set from 01/01/77

Verified in 1986. By Decree of the State Standard of July 22, 1986 N 2199, the validity period was extended until January 1, 1994**
________________
** The validity period was lifted according to Protocol No. 3-93 of the Interstate Council for Standardization, Metrology and Certification (IUS No. 5/6, 1993). - Database manufacturer's note.

* REISSUE (December 1988) with Amendments No. 1, 2, approved in November 1981, July 1986 (IUS 2-82, 10-86).

This standard applies to rolled rods of round and square cross-section, crimped blanks, blanks for pipes and for rolling with a diameter or square side from 30 to 300 mm from carbon, alloy and high-alloy steels and alloys and establishes echo-pulse, shadow and mirror-shadow methods ultrasonic testing of metal, or a combination of them, in order to identify internal defects that lie within the sensitivity of the method.

General requirements to ultrasonic testing methods - according to GOST 12503-75 and GOST 20415-82.

Terms and definitions - according to GOST 23829-85 and reference appendix.

1. SAMPLING METHOD

1.1. The control sample for adjusting the sensitivity of the flaw detector is a piece of workpiece that does not have defects according to the results of ultrasonic testing. The control sample is made in cross-section equal to or with a deviation of no more than 10% from the dimensions of the controlled product, and in configuration, structure and surface quality - similar to the controlled product.

1.2. To adjust the sensitivity of the flaw detector during ultrasonic testing using direct transducers, control samples are used, the artificial reflectors of which are the side surface (Fig. 1 and 3) or the flat bottom (Fig. 2 and 4) of the hole.

Hole diameter, if not specified in standards or technical conditions, when reflecting ultrasonic waves from the side surface of the hole should be no more than 2.5 mm and from the flat bottom of the hole no more than 3.0 mm. The drilling depth for the case where the artificial reflector is the side surface of the hole must be at least 50 mm.

1.3. The diameters of artificial reflectors must be selected from the following range: 1; 1.5; 2; 2.5; 3; 3.5; 4; 5; 6; 7; 8 mm.

Damn.4

1.4. The depth of artificial reflectors from the input surface of ultrasonic vibrations should be 3/4 of the diameter or thickness of the metal being tested, unless this is specified in the regulatory and technical documentation.

1.5. The accuracy and manufacturing technology of artificial reflectors in control samples for a direct transducer is in accordance with GOST 21397-81, for an inclined transducer - in accordance with GOST 14782-86.

Section 1.

2. PREPARATION FOR TESTS

2.1. The surface of the rolled product should be free of dirt, flaking scale, film and splashes of molten metal. The surface quality must comply with the regulatory and technical documentation for the controlled metal.

2.2. The sensitivity of the ultrasonic flaw detector is adjusted according to the control sample. The sensitivity of an automated ultrasonic installation is adjusted by passing a control sample through the installation 5 times. In this case, there must be 100% registration of artificial reflectors.

The flaw detector sensitivity is adjusted when using inclined transducers in accordance with GOST 14782-86.

Section 2. (Changed edition, Amendment No. 2).

3. TESTING

3.1. Control is carried out using longitudinal and (or) transverse waves. Ultrasonic vibrations are introduced into metal using non-contact, contact, immersion or slot methods.

3.2. When testing the round cross-section of workpieces using contact or slot methods, the working surface of the transducer must be identical in shape to the surface of the workpiece. It is allowed to use nozzles and supports when testing round workpieces with a transducer with a flat working surface.

3.3. The sounding pattern for workpieces is set in such a way that the entire volume of metal is controlled, with the exception of uncontrolled areas inherent in the ultrasonic testing method. In this case, square blanks are sounded from two mutually perpendicular faces, round blanks - along generatrices. When using inclined transducers, scanning is performed in two directions, perpendicular to the generatrix of the round workpiece and the length of the rectangular one.

3.4. The method of relative movement of the finder and the controlled metal surface (type of scanning) must ensure the detection of defects specified in the standards and technical specifications for products, and the scanning speed must ensure the recording of these defects.

3.5. The main measured characteristic of these defects is the amplitude of the signal from the artificial reflector in the control sample.

3.6. When setting the sensitivity of the flaw detector, the amplitude of the signal reflected from the artificial reflector in the control sample must be at least 1/2 the height of the screen of the cathode ray tube of the flaw detector.

3.8. When using manual and mechanized testing methods, the search sensitivity level of the flaw detector and the fixation level are established. The fixation level corresponds to the value of the amplitude of the signal reflected from the artificial reflector in the control sample, the size and location of which is indicated in the regulatory and technical documentation approved in in the prescribed manner. The search sensitivity level is set 6 dB above the clamp level. When using the automatic control method, only the fixation level is set.

3.9. The search for defects is carried out using search sensitivity, and areas of the workpiece in which at least one of the following signs of a defect are observed are subject to fixation:

a reflected signal whose amplitude is equal to or greater than the fixation level;

weakening of a given signal or weakening of a transmitted signal to or below the fixation level.

3.10. Checking the correct settings of the flaw detector is carried out using control samples at least after 4 hours of operation.

3.11. The boundaries of defective areas are determined by the position of the transducer. The conditional length of the defect is determined by the interval of movement of the transducer, within which the signal from the defect is perceived at a given sensitivity of the flaw detector.

3.12. The method, basic parameters, switching circuit of the transducers, method of inputting ultrasonic vibrations, scanning circuit, methods of separating false signals and signals from defects are established in the regulatory and technical documentation for specific metal products.

3.13. It is allowed to combine pulse-echo and mirror-shadow testing methods if the amplitude of the bottom signal in areas that do not contain discontinuities exceeds the amplitude of the echo signal from the reflector of the control sample by at least 6 dB.

Section 3. (Changed edition, Amendment No. 2).

4. PROCESSING RESULTS

4.1. The prevalence of the controlled metal with internal defects at a given control sensitivity is characterized by quality groups in accordance with the table.


Quality group	Conditional length of discontinuity, mm
	No more than 20
	No more than 50
	No more than 100
	From 100 to 300

Note. If the distance between the boundaries of the identified defective areas does not exceed 15 mm, their conditional length is summed up and the defect is assigned to the corresponding quality group.

(Changed edition, Amendment No. 2).

4.1a. The following parameters established in the regulatory and technical documentation are the rejection criteria for all quality groups when controlled by different methods:

with the pulse-echo method - the amplitude of the signal reflected from the discontinuity is equal to or greater than the amplitude of the signal from the control reflector;

with the mirror-shadow method - the amount of attenuation of the amplitude of the bottom signal;

with the shadow method - the amount of attenuation of the amplitude of the transmitted signal.

4.2. The permissible quality group and sensitivity of metal control are established depending on its purpose and are indicated in standards and technical conditions or other regulatory and technical documentation for products.

(Changed edition, Amendment No. 2).

4.3. Registration and execution of control results are carried out in accordance with GOST 12503-75.

APPENDIX (reference). Explanation of terms found in the standard

APPLICATION
Information


Term	Explanation
Control sample	A means for adjusting the sensitivity of a flaw detector, made from a defect-free section of the tested workpiece, having an artificial reflector and certified in the prescribed manner

(Introduced additionally, Amendment No. 2).

Electronic document text
prepared by Kodeks JSC and verified against:

official publication
M.: Standards Publishing House, 1989

Official publication

USSR STATE COMMITTEE ON STANDARDS Moscow

UDC 669.01-422: 620.179.16(083.74) Group B09

STATE STANDARD OF THE USSR UNION

LOTS AND BLANKS OF ROUND AND RECTANGULAR GOST SECTION

Ultrasonic flaw detection methods 21120 75 1

Round and rectangular bars and tickets.

Ultrasonic testing

By Resolution of the State Committee of Standards of the Council of Ministers of the USSR dated August 29, 1975 No. 2282, the introduction date was established

Verified in 19S6 by Decree of the State Standard of July 22, 1986 No. 2199 “validity period extended

Failure to comply with the standard is punishable by law

This standard applies to rolled rods of round and square cross-section, crimped blanks, blanks for pipes and for rolling with a diameter or square side from 30 to 300 mm from carbon, alloy and high-alloy steels and alloys and establishes echo-pulse, shadow and mirror-shadow methods ultrasonic testing of metal, or a combination of them, in order to identify internal defects that lie within the sensitivity of the method.

General requirements for ultrasonic testing methods are in accordance with GOST 12503-75 and GOST 20415-82.

Explanation of terms found in the standard

APPLICATION

Information

Explanation

Control Tool for adjusting sensitivity

flaw detector sample made from defect-free

section of the inspected workpiece, which has an artificial reflector and is certified in the prescribed manner (Introduced additionally, Amendment No. 2).

Editor A. A. Zimovnova Technical editor E. V. Mityai Proofreader G. I. Chuiko

Delivered to embankment 08.12.88 Sub. in the oven 02/15/89 0.5 el. p.l. 0.5 el. cr.-ott. 0.37 academic ed. l"

Circulation 8000 Price 3 kopecks.

Order “Badge of Honor” Publishing house of standards, 123840, Moscow, GSP, NovopresnensknA lane, 3.

Vilnius Printing House Standards Publishing House, st. Dariaus and Gnreno, 39. Zak. 197.

Reissue (December 1988) with Amendments No. 1, 2, approved in November 1981, July 1986 (IUS 2-82, 10-86).

GOST 21120-75*

Group B09

STATE STANDARD OF THE USSR UNION

RODS AND BLANKS OF ROUND AND RECTANGULAR SECTION

Ultrasonic flaw detection methods

Round and rectangular bars and tickets. Ultrasonic testing

Date of introduction 1977-01-01

By Decree of the State Committee of Standards of the Council of Ministers of the USSR of August 29, 1975 N 2282, the introduction date was set from 01/01/77

Verified in 1986. By Decree of the State Standard of July 22, 1986 N 2199, the validity period was extended until January 1, 1994**
________________
** The validity period was lifted according to Protocol No. 3-93 of the Interstate Council for Standardization, Metrology and Certification (IUS No. 5/6, 1993). - Database manufacturer's note.

* REISSUE (December 1988) with Amendments No. 1, 2, approved in November 1981, July 1986 (IUS 2-82, 10-86).

General requirements for ultrasonic testing methods are in accordance with GOST 12503-75 and GOST 20415-82.

Terms and definitions - according to GOST 23829-85 and reference appendix.

1. SAMPLING METHOD

The diameter of the hole, if it is not specified in standards or technical specifications, when ultrasonic waves are reflected from the side surface of the hole, should be no more than 2.5 mm and from the flat bottom of the hole no more than 3.0 mm. The drilling depth for the case where the artificial reflector is the side surface of the hole must be at least 50 mm.

1.3. The diameters of artificial reflectors must be selected from the following range: 1; 1.5; 2; 2.5; 3; 3.5; 4; 5; 6; 7; 8 mm.

Damn.4

1.5. The accuracy and technology of manufacturing artificial reflectors in control samples for a direct transducer is in accordance with GOST 21397-81, for an inclined transducer - in accordance with GOST 14782-86.

Section 1.

2. PREPARATION FOR TESTS

The flaw detector sensitivity is adjusted when using inclined transducers in accordance with GOST 14782-86.

Section 2. (Changed edition, Amendment No. 2).

3. TESTING

3.1. Control is carried out using longitudinal and (or) transverse waves. Ultrasonic vibrations are introduced into metal using non-contact, contact, immersion or slot methods.

3.5. The main measured characteristic of these defects is the amplitude of the signal from the artificial reflector in the control sample.

3.8. When using manual and mechanized testing methods, the search sensitivity level of the flaw detector and the fixation level are established. The fixation level corresponds to the amplitude value of the signal reflected from the artificial reflector in the control sample, the size and location of which is indicated in the regulatory and technical documentation approved in the prescribed manner. The search sensitivity level is set 6 dB above the clamp level. When using the automatic control method, only the fixation level is set.

3.9. The search for defects is carried out using search sensitivity, and areas of the workpiece in which at least one of the following signs of a defect are observed are subject to fixation:

a reflected signal whose amplitude is equal to or greater than the fixation level;

Attenuation of a given signal or attenuation of a transmitted signal to or below the fixation level.

3.10. Checking the correct settings of the flaw detector is carried out using control samples at least after 4 hours of operation.

Section 3. (Changed edition, Amendment No. 2).

4. PROCESSING RESULTS

4.1. The prevalence of the controlled metal with internal defects at a given control sensitivity is characterized by quality groups in accordance with the table.

Quality group	Conditional length of discontinuity, mm
	No more than 20
	No more than 50
	No more than 100
	From 100 to 300

(Changed edition, Amendment No. 2).

4.1a. The following parameters established in the regulatory and technical documentation are the rejection criteria for all quality groups when controlled by different methods:

With the pulse-echo method, the amplitude of the signal reflected from a discontinuity is equal to or greater than the amplitude of the signal from the control reflector;

With the mirror-shadow method - the amount of attenuation of the amplitude of the bottom signal;

With the shadow method, the amount of attenuation of the amplitude of the transmitted signal.

(Changed edition, Amendment No. 2).

4.3. Registration and execution of control results are carried out in accordance with GOST 12503-75.

APPLICATION
Information

Explanation of terms found in the standard

(Introduced additionally, Amendment No. 2).

GOST 21120-75*
Group B09

STATE STANDARD OF THE USSR UNION

RODS AND BLANKS OF ROUND AND RECTANGULAR SECTION

Ultrasonic flaw detection methods

Round and rectangular bars and tickets. Ultrasonic testing

Date of introduction 1977−01−01

By Decree of the State Committee of Standards of the Council of Ministers of the USSR of August 29, 1975 N 2282, the introduction date was set from 01/01/77

Verified in 1986. By Decree of the State Standard of July 22, 1986 N 2199, the validity period was extended until January 1, 1994**
________________
** The validity period was lifted according to Protocol No. 3−93 of the Interstate Council for Standardization, Metrology and Certification (IUS No. 5/6, 1993). — Note from the database manufacturer.

* REISSUE (December 1988) with Amendments No. 1, 2, approved in November 1981, July 1986 (IUS 2−82, 10−86).

General requirements for ultrasonic testing methods are in accordance with GOST 12503-75 and GOST 20415-82.

Terms and definitions - according to GOST 23829-85 and reference appendix.

1. SAMPLING METHOD

1.3. The diameters of artificial reflectors must be selected from the following range: 1; 1.5; 2; 2.5; 3; 3.5; 4; 5; 6; 7; 8 mm.

1.4. The depth of artificial reflectors from the surface where ultrasonic vibrations are introduced should be ¾ of the diameter or thickness of the metal being tested, unless this is specified in the regulatory and technical documentation.

Section 1.

2. PREPARATION FOR TESTS

The flaw detector sensitivity is adjusted when using inclined transducers in accordance with GOST 14782-86.

Section 2. (Changed edition, Amendment No. 2).

3. TESTING

3.1. Control is carried out using longitudinal and (or) transverse waves. Ultrasonic vibrations are introduced into metal using non-contact, contact, immersion or slot methods.

3.5. The main measured characteristic of these defects is the amplitude of the signal from the artificial reflector in the control sample.

3.6. When setting the sensitivity of the flaw detector, the amplitude of the signal reflected from the artificial reflector in the control sample must be at least ½ the height of the screen of the cathode ray tube of the flaw detector.

3.8. When using manual and mechanized testing methods, the search sensitivity level of the flaw detector and the fixation level are established. The fixation level corresponds to the amplitude value of the signal reflected from the artificial reflector in the control sample, the size and location of which is indicated in the regulatory and technical documentation approved in the prescribed manner. The search sensitivity level is set 6 dB above the clamp level. When using the automatic control method, only the fixation level is set.

3.9. The search for defects is carried out using search sensitivity, and areas of the workpiece in which at least one of the following signs of a defect are observed are subject to fixation:

a reflected signal whose amplitude is equal to or greater than the fixation level;

weakening of a given signal or weakening of a transmitted signal to or below the fixation level.

3.10. Checking the correct settings of the flaw detector is carried out using control samples at least after 4 hours of operation.

Section 3. (Changed edition, Amendment No. 2).

4. PROCESSING RESULTS

4.1. The prevalence of the controlled metal with internal defects at a given control sensitivity is characterized by quality groups in accordance with the table.

(Changed edition, Amendment No. 2).

4.1a. The following parameters established in the regulatory and technical documentation are the rejection criteria for all quality groups when controlled by different methods:

with the pulse-echo method, the amplitude of the signal reflected from the discontinuity is equal to or greater than the amplitude of the signal from the control reflector;

with the mirror-shadow method - the amount of attenuation of the amplitude of the bottom signal;

with the shadow method, the amount of attenuation of the amplitude of the transmitted signal.

(Changed edition, Amendment No. 2).

4.3. Registration and execution of control results are carried out in accordance with GOST 12503-75.

APPENDIX (reference). Explanation of terms found in the standard

APPLICATION
Information

(Introduced additionally, Amendment No. 2).

Electronic document text
prepared by Kodeks JSC and verified against:

official publication
M.: Standards Publishing House, 1989

ROUND RODS AND BLANKS
AND RECTANGULAR SECTION

METHODS OF ULTRASONIC DEFECTOSCOPY

GOST 21120-75

USSR STATE COMMITTEE ON STANDARDS

Moscow

STATE STANDARD OF THE USSR UNION

* Reissue (December 1988) with Amendments No. 1, 2, approved in November 1981, July 1986 (IUS 2-82, 10-86).

By Resolution of the State Committee of Standards of the Council of Ministers of the USSR dated August 29, 1975 No. 2282, the introduction date was established

from 01.01.77

Verified in 1986. By Decree of the State Standard of July 22, 1986 No. 2199, the validity period was extended

until 01/01/94

Failure to comply with the standard is punishable by law

This standard applies to rolled rods of round and square cross-section, crimped blanks, blanks for pipes and for rolling with a diameter or square side from 30 to 300 mm from carbon, alloy and high-alloy steels and alloys and establishes echo-pulse, shadow and mirror-shadow methods of ultrasonic testing of metal, or a combination thereof, in order to identify internal defects that lie within the sensitivity of the method.

General requirements for ultrasonic testing methods are in accordance with GOST 12503-75 and GOST 20415-82.

Terms and definitions - according to GOST 23829-85 and reference appendix.

1. SAMPLING METHOD

Hole diameterd, unless specified in standards or specifications, the reflection of ultrasonic waves from the side surface of the hole should be no more than 2.5 mm and from the flat bottom of the hole no more than 3.0 mm. The drilling depth for the case where the artificial reflector is the side surface of the hole must be at least 50 mm.

1.3. The diameters of artificial reflectors must be selected from the following range: 1; 1.5; 2; 2.5; 3; 3.5; 4; 5; 6; 7; 8 mm.

Crap. 4