method for testing the impact strength at low, room and high temperature. Metals test method for impact bending at low, room and elevated temperatures metals. method for testing the impact strength at low, room and high temperature Temper
STATE STANDARD OF THE UNION OF THE SSR
METALS
TEST METHOD FOR IMPACT BENDING AT LOW, ROOM AND Elevated TEMPERATURES
GOST 9454-78
(ST SEV 472-77, ST SEV 473-771)
USSR STATE COMMITTEE ON STANDARDS
Moscow
STATE STANDARD OF THE UNION OF THE SSR
|
METALS Impact test method Metals. Method for testing the impact strength |
GOST (ST SEV 472-77, Instead |
By the Decree of the State Committee for Standards of the Council of Ministers of the USSR dated April 17, 1978 No. 1021, the validity period is established
from 01.01. 1979
in terms of testing samples with a concentrator of the type T () -
from 01.0.1. 1982
until 01.01. 1989
Change No. 1 GOST 9454-78
Decree of the USSR State Committee for Standards dated 10/14/81 No. 4575 established the deadline for introduction
from 01.01.82
Change No. 2 GOST 9454-78 Metals. Test method for impact bending at low, room and elevated temperatures
Approved and put into effect by the Decree of the USSR State Committee for Standards dated March 11, 1988 No. 521
Introduction date from 01.09.88
This standard applies to ferrous and non-ferrous metals and alloys and establishes a test method for impact bending at temperatures from minus 100 to plus 1200 ° C.
The method is based on the destruction of a sample with a concentrator in the middle with one blow of a pendulum impact tester. The ends of the sample are placed on supports. As a result of the test, full work, expended on impact (impact work), TO or toughness.
Impact strength should be understood as the impact work related to the initial cross-sectional area of the sample at the concentrator site.
The standard fully complies with ST SEV 472-77, ST SEV 473-77, ISO 83-1976 and ISO 148-1983.
(Revised edition, Rev. No. 2).
1. SAMPLING METHOD
Dimensions, mm
|
hub radius R |
sample type |
Length L(prev. off ± 0,6) |
Width IN |
Height H(offset limit ±0.1) |
Notch depthh 1 (offset limit ±0.1) |
Concentrator depth h(offset limit ±0.6) |
Working section heightH 1 |
||
|
U |
1 ± 0,07* |
10 ± 0,10 |
8±0.1 |
||||||
|
7.5±0.10 |
|||||||||
|
5 ± 0,05 |
|||||||||
|
2±0.05 |
6±0.1 |
||||||||
|
10 ± 0,10 |
7 ± 0.1 |
||||||||
|
7.5±0.10 |
|||||||||
|
5 ± 0,05 |
|||||||||
|
10 ± 0,10 |
5±0.1 |
||||||||
|
7.5±0.10 |
|||||||||
|
5 ± 0,05 |
|||||||||
|
V |
0.25 ± 0.025 |
10 ± 0,10 |
|||||||
|
7.5±0.10 |
8 ± 0.05* |
||||||||
|
5 ± 0,05 |
|||||||||
|
2±0.05 |
6±0.05 |
||||||||
|
T |
Crack |
10 ± 0,10 |
|||||||
|
7.5±0.10 |
|||||||||
|
5 ± 0,05 |
|||||||||
|
2±0.05 |
|||||||||
|
25 ± 0,10 |
10,0 |
12,0 |
____________
* During control mass tests, it is allowed to manufacture samples with a maximum deviation of ±0.10 mm.
(Revised edition, Rev. No. 2).
It is allowed to use samples without a notch and with one or two raw surfaces, the dimensions of which differ in width from those indicated in.
The scope of the samples is indicated in the reference.
V
Heck. 2
Specimen with view hub T(fatigue crack)
but - general form; b- shape of the concentrator for samples from to ; in- sample concentrator shape
(Revised edition, Rev. No. 2).
3. PREPARATION FOR THE TEST
3.1. Before starting the tests, it is necessary to check the position of the operation indicator when the pendulum is in free fall.
For pendulum impactors with digital reading devices, the work indicator in the initial position must show “zero” with an allowable deviation within the width of the scale stroke in accordance with GOST 8.264-77.
(Revised edition, Rev. No. 2).
3.2. The test temperature shall be the temperature of the specimen at the moment of impact.
The test temperature is indicated in the regulatory and technical documentation for specific products, approved in the prescribed manner.
3.3. Room temperature should be considered as a temperature of 20 ± 10 °C.
3.4. To ensure the required test temperature, the samples must be supercooled (at a test temperature below room temperature) or overheated (at a test temperature above room temperature) before being placed on the impact tester. The degree of subcooling or superheating shall provide the required test temperature and shall be determined experimentally.
The temperature of supercooling or overheating of samples, provided that they can be tested no later than 3-5 s after removal from the thermostat, is indicated in the reference.
Exposure of samples in a thermostat at a given temperature (taking into account the necessary supercooling or overheating) should be at least 15 minutes.
(Revised edition, Rev. No. 1).
3.5. The part of the device in contact with the sample for removing it from the thermostat should not change the temperature of the sample when it is placed on the copra supports.
4. CONDUCTING THE TEST
4.1. The sample must lie freely on the copra supports (see). The sample should be installed using a template that ensures the symmetrical location of the concentrator relative to the supports with an error of no more than ±0.5 mm. When using end stops, the latter should not prevent the samples from being freely deformed.
4.2. The test shall be carried out with the impact of the pendulum from the side opposite to the concentrator, in the plane of its symmetry.
4.3. The impact work is determined on the scale of a pendulum impactor or analog readout devices.
(Revised edition, Rev. No. 2).
5. PROCESSING THE RESULTS
5.1. The test result is taken as the work of impact or impact strength for specimens with species concentratorsU And Vand impact strength for samples with a concentrator of the form T.
(Revised edition, Rev. No. 2).
It is allowed to denote the impact work by two indices (A i ): the first (A) is a symbol of the impact work, the second ( i ) is the sample type symbol according to .
(Revised edition, Rev. No. 1).
5.3. Impact strength is indicated by a combination of letters and numbers.
The first two letters KS denote the symbol of impact strength, the third letter - the type of concentrator; the first digit is the maximum impact energy of the pendulum, the second is the depth of the concentrator, and the third is the width of the sample. The numbers do not indicate in the case specified in.
It is allowed to designate impact strength with two indices (a i); first ( but) - impact strength symbol; second (i) - pattern type character according to .
(Revised edition, Rev. No. 1).
To designate the impact work and impact strength at low and high temperatures, a digital index is introduced indicating the test temperature. The digital index is placed at the top after the alphabetic components.
For example:
TOV -40 50/2/2 - impact work determined on a sample with a view concentrator V at a temperature of minus 40 °C. The maximum impact energy of the pendulum is 50 J, the concentrator depth is 2 mm, and the sample width is 2 mm.
KST +100150/3/7.5 - impact strength, determined on a sample with a type concentrator T at a temperature of plus 100 °C. The maximum impact energy of the pendulum is 150 J, the concentrator depth is 3 mm, and the sample width is 7.5 mm.
KSU (KCV) - impact strength, determined on a sample with a concentrator of the formU (V) at room temperature. The maximum impact energy of the pendulum is 300 J, the concentrator depth is 2 mm, and the sample width is 10 mm.
Impact strength, determined on a sample of type 11 at a temperature of minus 60° C. The maximum impact energy of the pendulum is 300 J.
(Revised edition, Rev. No. 1).
5.4. impact strength ( KS) J / cm 2 (kgf× m / cm 2) is calculated by the formula
where TO- impact work, J (kgf× m);
So- the initial cross-sectional area of the sample at the site of the concentrator, cm 2, calculated by the formula
Sabout = H 1 B,
where H 1- initial height of the working part of the sample, cm;
IN- the initial width of the sample, m (cm).
H 1And IN measured with an error of no more± 0.05 mm ( ± 0.005 cm). Soround off: with a sample width of 5 mm or less - to the third significant figure, with a sample width of more than 5 mm - to the second significant figure.
(Changed edition, Rev. No. 1, 2).
For Specimens with View Hub T meaningH¢ 1 defined as the difference between the total height H measured before testing with an error of not more than± 0.05 mm ( ± 0.005 cm) and the calculated depth of the concentratorhp, measured using any optical means with a magnification of at least 7 on the surface, the fracture of the sample after its testing according to the scheme shown on , with an error of not more than± 0.05 mm ( ± 0.005 cm).
(Revised edition, Rev. No. 2).
5.5. Meaning KS are recorded in the protocol with rounding: up to 1 (0.1) J / cm 2 (kgf× m / cm 2) - at a value KS more than 10 (1) J / cm 2 (kgf× m / cm 2); up to 0.1 (0.01) J / cm 2 (kgf× m / cm 2) - at a value KS less than 10 (1) J / cm 2 (kgf× m / cm 2).
(Revised edition, Rev. No. 1).
5.6. If, as a result of the test, the sample did not completely collapse, then the quality indicator of the material is considered not established. In this case, the test report indicates that the sample at the maximum impact energy of the pendulum was not destroyed.
The test results are not taken into account when the samples are broken due to defects in metallurgical production.
(Revised edition, Rev. No. 2).
5.7. When replacing the sample, the reason is indicated in the test report.
5.8. The initial data and test results of the sample are recorded in the test report. The form of the protocol is given in the recommended appendix 3
Type of concentrator
sample type
Application area
U
When choosing, acceptance testing of metals and alloys
V
When selecting, acceptance testing of metals and alloys for structures of increased reliability ( aircrafts, vehicles, pipelines, pressure vessels, etc.)
T
In the selection and acceptance control of metals and alloys for especially critical structures, for the operation of which the assessment of resistance to crack development is of paramount importance. In the study of the causes of destruction of critical structures» minus 40 » plus 10
» plus 30 » plus 200
» plus 200 » plus 400
5-10
» plus 400 » plus 500
10-15
» plus 500 » plus 600
15-20
» plus 600 » plus 700
20-25
» plus 700 » plus 800
25-30
» plus 800 » plus 900
30-40
» plus 900 » plus 1000
GOST 9454-78
INTERSTATE STANDARD
METALS
IMPACT TEST METHOD
AT REDUCED, ROOM AND INCREASED
TEMPERATURES
IPK STANDARDS PUBLISHING HOUSE
Moscow
INTERSTATE STANDARD
|
METALS Test method for impact bending at low, Metals. Method for testing the impact strength at |
GOST |
Introduction date from 01.01.79
This standard applies to ferrous and non-ferrous metals and alloys and establishes a test method for impact bending at temperatures from minus 100 to plus 1200 ° C.
The method is based on the destruction of a sample with a concentrator in the middle with one blow of a pendulum impact tester. The ends of the sample are placed on supports. As a result of the test, the total work expended on impact (impact work), or impact strength, is determined.
Impact strength should be understood as the impact work related to the initial cross-sectional area of the sample at the concentrator site.
1. SAMPLING METHOD
Heck. one
Specimen with view hub V
Heck. 2
Specimen with concentrator type T (fatigue crack)
but - general form; b - concentrator shape for samples from 15 to 19 types; in - sample concentrator shape 20 type
Heck. 3
Dimensions, mm
|
Type of concentrator |
hub radius R |
sample type |
Length L(offset limit ±0.6) |
Width IN |
Height H(offset limit ±0.1) |
Notch depth h 1 (offset limit ±0.1) |
Concentrator depth h(offset limit ±0.6) |
Working section height H 1 |
|
1 ± 0.07* |
10±0.10 |
8±0.1 |
||||||
|
7.5±0.10 |
||||||||
|
5±0.05 |
||||||||
|
2±0.05 |
6±0.1 |
|||||||
|
10±0.10 |
7 ± 0.1 |
|||||||
|
7.5±0.10 |
||||||||
|
5±0.05 |
||||||||
|
10±0.10 |
5±0.1 |
|||||||
|
7.5±0.10 |
||||||||
|
5±0.05 |
||||||||
|
0.25 ± 0.025 |
10±0.10 |
8±0.05* |
||||||
|
7.5±0.10 |
||||||||
|
5±0.05 |
||||||||
|
2±0.05 |
6±0.05 |
|||||||
|
10±0.10 |
||||||||
|
7.5±0.10 |
||||||||
|
5±0.05 |
||||||||
|
2±0.05 |
||||||||
|
10±0.10 |
* During control mass tests, it is allowed to manufacture samples with a maximum deviation of ±0.10 mm.
It is allowed to use samples without a notch and with one or two raw surfaces, the dimensions of which differ in width from those indicated in the table.
The scope of the samples is indicated in the appendix.
Testing of samples of types 4, 14, 18 is carried out at the request of the consumer for special-purpose products.
1.3. Risks on the surface of concentrators of types U and V visible without the use of magnifiers are not allowed.
1.4. The concentrator type T is obtained at the top of the initial notch with a flat cyclic bending of the sample. The method of obtaining the initial hub can be any.
The number of cycles required to obtain a crack of a given depth must be at least 3000.
Sample deflection is controlled using dial gauges according to GOST 577 or other means that ensure the deflection measurement error is not more than 0.05 mm based on the sample length.
1.6. The type and number of samples, the procedure for retesting must be specified in the regulatory and technical documentation for specific products, approved in the prescribed manner.
If the type of sample is not indicated in the regulatory and technical documentation for metal products, samples of type 1 should be tested - until 01.01.91.
1.4 - 1.6. (Changed edition, Rev. No. 1, 2).
2. EQUIPMENT AND MATERIALS
Heck. 4
The temperature of subcooling or superheating of samples, provided that they can be tested no later than - s after removal from the thermostat, is indicated in the appendix.
Exposure of samples in a thermostat at a given temperature (taking into account the necessary supercooling or overheating) should be at least 15 minutes.
3.5. The part of the device in contact with the sample for removing it from the thermostat should not change the temperature of the sample when it is placed on the copra supports.
4. CONDUCTING THE TEST
4.1. The sample must lie freely on the copra supports (see Fig.). The sample should be installed using a template that ensures the symmetrical location of the concentrator relative to the supports with an error of no more than ±0.5 mm. When using end stops, the latter should not prevent the samples from being freely deformed.
4.2. The test shall be carried out with the impact of the pendulum from the side opposite to the concentrator, in the plane of its symmetry.
4.3. The impact work is determined on the scale of a pendulum impactor or analog readout devices.
(Revised edition, Rev. No. 2).
5. PROCESSING THE RESULTS
5.1. The test result is taken as the work of impact or impact strength for specimens with species concentrators U and V and impact strength for specimens with T concentrator.
(Revised edition, Rev. No. 2).
It is allowed to designate impact strength with two indices ( but i); first ( but) - impact strength symbol; second (i) - sample type symbol according to the table.
To designate the impact work and impact strength at low and high temperatures, a digital index is introduced indicating the test temperature. The digital index is placed at the top after the alphabetic components.
For example:
KV- 40 50/2/2 - impact work determined on a sample with a concentrator of type Vat a temperature of minus 40 °C. The maximum impact energy of the pendulum is 50 J, the concentrator depth is 2 mm, and the sample width is 2 mm.
KST + 100 150/3/7.5 - impact strength, determined on a sample with a type T concentrator at a temperature of plus 100 ° C. The maximum impact energy of the pendulum is 150 J, the concentrator depth is 3 mm, and the sample width is 7.5 mm.
KCU(KCV) - impact strength, determined on a sample with a concentrator of the form U(V ) at room temperature. The maximum impact energy of the pendulum is 300 J, the concentrator depth is 2 mm, and the sample width is 10 mm.
but 11 -60 - impact strength, determined on a sample of type 11 at a temperature of minus 60 °C. The maximum impact energy of the pendulum is 300 J.
(Revised edition, Rev. No. 1).
5.4. impact strength ( KS) in J / cm 2 (kgf× m / cm 2) is calculated by the formula
where TO - impact work, J (kgf× m);
S 0 - the initial cross-sectional area of the sample at the site of the concentrator, cm 2, calculated by the formula
where - initial height of the working part of the sample, cm;
IN -sample initial width, cm.
And IN measured with an error of not more than ±0.05 mm (±0.005 cm).S0round off: with a sample width of 5 mm or less - to the third significant figure, with a sample width of more than 5 mm - to the second significant figure.
For samples with a T type concentrator, the value defined as the difference between the total height H, measured before testing with an error of not more than ±0.05 mm (±0.005 cm) and the calculated depth of the concentratorh R measured using any optical means with a magnification of at least 7 on the fracture surface of the sample after its testing according to the scheme shown in Fig. , with an error of no more than ±0.05 mm (±0.005 cm).
abs - fatigue crack front; I-I- the position of the sight line of the microscope eyepiece at the initial moment
measurements (coincides with the face of the sample); II-II- the position of the sight line of the microscope at the end
measurements (position II-II is chosen so that the shaded area above the line is
equal to the unshaded area below the hairline)
Heck. five
(Changed edition, Rev. No. 1, 2).
5.5. The value of the COP is recorded in the protocol with rounding: up to 1 (0.1) J / cm 2 (kgf m / cm 2) - when the value of the COP is more than 10 (1) J / cm 2 (kgf m / cm 2); up to 0.1 (0.01) J / cm 2 (kgf / cm 2) - with a COP value of less than 10 (1) J / cm 2 (kgf m / cm 2).
(Revised edition, Rev. No. 1).
5.6. If, as a result of the test, the sample did not completely collapse, then the quality indicator of the material is considered not established. In this case, the test report indicates that the sample at the maximum impact energy of the pendulum was not destroyed.
The test results are not taken into account when the samples are broken due to defects in metallurgical production.
(Revised edition, Rev. No. 2).
5.7. When replacing the sample, the reason is indicated in the test report.
5.8. The initial data and test results of the sample are recorded in the test report. The form of the protocol is given in the appendix.
ATTACHMENT 1
Reference
Scope of samples
|
Type of concentrator |
sample type |
Application area |
|||||||||||
|
When selecting, acceptance testing of metals and alloys |
|||||||||||||
|
When selecting, acceptance testing of metals and alloys for structures of increased reliability (aircraft, vehicles, pipelines, pressure vessels, etc.) |
|||||||||||||
|
In the selection and acceptance control of metals and alloys for especially critical structures, for the operation of which the assessment of resistance to crack development is of paramount importance. In the study of the causes of destruction of critical structures. |
|||||||||||||
|
» plus 30 » plus 200 |
|||||||||||||
|
» plus 200 » plus 400 |
|||||||||||||
|
» plus 400 » plus 500 |
|||||||||||||
|
» plus 500 » plus 600 |
|||||||||||||
|
» plus 600 » plus 700 |
|||||||||||||
|
» plus 700 » plus 800 |
|||||||||||||
|
» plus 800 » plus 900 |
Sample Width IN |
Sample height H |
Concentrator depth h |
Working section height H 1 |
Cross-sectional area S 0 , cm 2 |
Impact work TO, J (kgf×m) |
impact strength KS, J / cm 2 (kgf × m / cm 2) |
Note |
|||||
APPENDIX 3(Changed edition, Change No. 1).
INFORMATION DATA
1. DESIGNED AND INTRODUCED by the Ministry ferrous metallurgy of the USSR
2. APPROVED AND INTRODUCED BY Decree of the State Committee for Standards of the Council of Ministers of the USSR dated April 17, 1978 No. 1021
3. The standard fully complies with ISO 83-76 and ISO 148-83
4. REFERENCE REGULATIONS AND TECHNICAL DOCUMENTS
5. The limitation of the validity period was removed according to protocol No. 3 of the Interstate Council for Standardization, Metrology and Certification (IUS 5-6-93)
6. EDITION (October 2002) with Amendments No. 1, 2, approved in October 1981, March 1988 (IUS 12-81, 6-88)
GOST 9454-78
Group B09
STATE STANDARD OF THE UNION OF THE SSR
Test method for impact bending at low,
room and elevated temperatures
Metals. Method for testing the impact strength at low,
room and high temperature
OKSTU 1909
Introduction date 1979-01-01
INFORMATION DATA
1. DEVELOPED AND INTRODUCED by the Ministry of Ferrous Metallurgy of the USSR
DEVELOPERS
V. N. Danilov, Doctor of Engineering sciences; M. N. Georgiev, Ph.D. tech. sciences; N. Ya. Mezhova; L. N. Kosarev, Ph.D. tech. sciences; E. F. Komolova, Ph.D. sciences; B. A. Drozdovsky, Ph.D. tech. sciences; V. G. Kudryashov, Ph.D. tech. sciences; P. D. Odessky, Ph.D. tech. sciences; V. I. Gelmida, Ph.D. tech. sciences; V. I. Zmievsky, Ph.D. tech. Sciences
2. APPROVED AND PUT INTO EFFECT by the Decree of the State Committee of Standards of the Council of Ministers of the USSR dated April 17, 1978 N 1021
3. The standard fully complies with ISO 83-76 and ISO 148-83
4. REFERENCE REGULATIONS AND TECHNICAL DOCUMENTS
Item number, section |
|
GOST 166-89 | |
GOST 577-68 | |
GOST 7565-81 | |
GOST 9293-74 | |
GOST 10708-82 |
5. The limitation of the validity period was removed by decision of the Interstate Council for Standardization, Metrology and Certification (minutes 3-93 dated 17.02.93)
6. REPUBLICATION (October 1993) with Amendments No. 1, 2, approved in October 1981, March 1988, (IUS 12-81, 6-88)
INSTEAD OF GOST 9454-60, GOST 9455-60 and GOST 9456-60.*
___________________
Information about the cancellation of documents is given from the publication: official publication, M .: Standards Publishing House, 1982. Note "CODE".
This standard applies to ferrous and non-ferrous metals and alloys and establishes a test method for impact bending at temperatures from minus 100 to plus 1200 ° C.
The method is based on the destruction of a sample with a concentrator in the middle with one blow of a pendulum impact tester. The ends of the sample are placed on supports. As a result of the test, the total work expended on impact (impact work), or impact strength, is determined.
Impact strength should be understood as the impact work related to the initial cross-sectional area of the sample at the concentrator site.
1. SAMPLING METHOD
1. SAMPLING METHOD
1.1. The shape and dimensions of the test specimens must correspond to those indicated in the table and in drawing. 1-3.
Dimensions, mm
Concentrator view | concentrator radius | Sample type | Length | Width | Height (offset limit ±0.1) | Notch depth | Concentration depth | Working section height |
_____________
* During control mass tests, it is allowed to manufacture samples with a maximum deviation of ±0.10 mm.
Damn.1. Sample with U type concentrator
Heck. 2. Sample with V-type concentrator
Fig 3. Specimen with type T concentrator (fatigue crack)
a - general view; b - the shape of the concentrator for samples from 15 to 19 types; c - concentrator shape for type 20 samples
Heck. 3
It is allowed to use samples without a notch and with one or two raw surfaces, the dimensions of which differ in width from those indicated in the table.
The scope of the samples is indicated in the reference appendix 1.
Testing of samples of types 4, 14, 18 is carried out at the request of the consumer for special-purpose products.
1.2. The place of cutting the workpiece for making samples, the orientation of the axis of the concentrator, the technology for cutting workpieces and making samples - according to GOST 7565-81 for ferrous metals, unless otherwise provided in the regulatory and technical documentation for the product.
For non-ferrous metals and alloys, all this should be indicated in the regulatory and technical documentation for the products.
When cutting blanks, the metal of the samples must be protected from hardening and heating, which change the properties of the metal, unless otherwise provided in the regulatory and technical documentation for the product.
1.1; 1.2. (Changed edition, Rev. No. 2).
1.3. Risks on the surface of concentrators of types U and V, visible without the use of magnifying agents, are not allowed.
1.4. The concentrator type T is obtained at the top of the initial notch with a flat cyclic bending of the sample. The method of obtaining the initial hub can be any.
The number of cycles required to obtain a crack of a given depth must be at least 3000.
1.5. The maximum residual deflection formed during application on specimens of the type T concentrator should not exceed: 0.25 mm - for specimens 55 mm long.
Sample deflection control is carried out using dial indicators according to GOST 577-68 or other means that ensure the deflection measurement error is not more than 0.05 mm based on the sample length.
1.6. The type and number of samples, the procedure for retesting must be specified in the regulatory and technical documentation for specific products, approved in the prescribed manner.
If the type of sample is not indicated in the regulatory and technical documentation for metal products, samples of type 1 should be tested - until 01.01.91.
1.4-1.6. (Changed edition, Rev. N 1, 2).
2. EQUIPMENT AND MATERIALS
2.1. Pendulum copra - in accordance with GOST 10708-82. The speed of the pendulum at the moment of impact should be:
(5±0.5) m/s - for headframes with nominal potential energy of the pendulum 50 (5.0); 150(15); 300 (30.0) J (kgf m);
(4±0.25) m/s - for headframes with nominal potential energy of the pendulum 25 (2.5); 15 (1.5); 7.5 (0.75) J (kgf m);
(3 ± 0.25) m / s - for impactors with a nominal potential energy of the pendulum of 5.0 (0.5) J (kgf m) or less.
It is allowed to use copra with a different nominal potential energy of the pendulum. In this case, the nominal value potential energy of the pendulum must be such that the value of the impact work is at least 10% of the nominal value of the potential energy of the pendulum. Until 01/01/91, it is allowed to use impactors with such a nominal potential energy of the pendulum that the impact work is at least 5% of the nominal potential energy of the pendulum. Rated value The potential energy of the pendulum must be specified in the regulatory and technical documentation for specific products.
The main dimensions of the supports and the pendulum knife must correspond to those indicated in Fig. 4. For headframes of a different design, other radii of curvature of the support edge and the speed of the pendulum from 4.5 to 7.0 m/s are allowed.
Heck. 4. Supports and pendulum knife
2.2. A thermostat that provides uniform cooling or heating, the absence of aggressive environmental influences on the sample and the ability to control the temperature.
2.3. A mixture of liquid nitrogen (GOST 9293-74) or solid carbon dioxide ("dry ice") with ethyl alcohol. The use of liquid oxygen and liquid air as a cooler is not allowed.
The mass fraction of oxygen in liquid nitrogen during the cooling of samples in a thermostat should not exceed 10%.
(Changed edition, Rev. N 1.2).
2.4. Thermometers with an error of no more than ±1 ° С for measuring the temperature of the cooling medium.
2.5. Thermometers, including thermoelectric converters (thermocouples), for measuring the heating temperature of samples, providing measurement with an error not exceeding:
±5 °С - at heating temperature up to 600 °С;
±8 °С - at heating temperature over 600 °С.
2.4, 2.5. (Changed edition, Rev. N 2).
2.6. A crack on the samples is obtained on vibrators manufactured according to regulatory and technical documentation.
2.7. Calipers must comply with the requirements of GOST 166-89. It is allowed to use other measuring instruments that provide measurement with an error not exceeding that specified in clause 1.1.
2.6, 2.7. (Introduced additionally, Rev. N 2).
3. PREPARATION FOR THE TEST
3.1. Before starting the tests, it is necessary to check the position of the operation indicator when the pendulum is in free fall.
For pendulum impactors with digital readout devices, the work indicator in the initial position must show "zero" with an allowable deviation within the stroke width according to the normative and technical documentation.
(Changed edition, Rev. N 1, 2).
3.4. To ensure the required test temperature, the samples must be supercooled (at a test temperature below room temperature) or overheated (at a test temperature above room temperature) before being placed on the impact tester. The degree of subcooling or superheating shall provide the required test temperature and shall be determined experimentally.
The temperature of subcooling or superheating of samples, provided that they can be tested no later than 3-5 s after removal from the thermostat, is indicated in reference annex 2.
Exposure of samples in a thermostat at a given temperature (taking into account the necessary supercooling or overheating) should be at least 15 minutes.
3.5. The part of the device in contact with the sample for removing it from the thermostat should not change the temperature of the sample when it is placed on the copra supports.
4. CONDUCTING THE TEST
4.1. The sample must lie freely on the supports of the impact tester (see Fig. 4). The sample should be installed using a template that ensures the symmetrical location of the concentrator relative to the supports with an error of no more than ±0.5 mm. When using end stops, the latter should not prevent the samples from being freely deformed.
4.2. The test shall be carried out with the impact of the pendulum from the side opposite to the concentrator, in the plane of its symmetry.
4.3. The impact work is determined on the scale of a pendulum impactor or analog readout devices.
(Changed edition, Rev. N 2).
5. PROCESSING THE RESULTS
5.1. The test result is taken as the work of impact or impact strength for samples with concentrators of types U and V and impact strength for samples with a concentrator of type T.
(Changed edition, Rev. N 2).
5.2. The impact work is indicated by two letters (U, V or T) and numbers. The first letter () is a symbol of the impact, the second letter (U, V or T) is the type of concentrator. The following numbers indicate the maximum impact energy of the pendulum, the depth of the concentrator and the width of the sample. The figures are not indicated when determining the impact work on a headframe with a maximum pendulum impact energy of 300 (30.0) J (kgf m), with a concentrator depth of 2 mm for U and V concentrators and 3 mm for a T concentrator and a sample width of 10 mm (samples 1, 11 and 15 types).
It is allowed to designate the impact work with two indices (A):
the first (A) is the impact work symbol, the second () is the sample type symbol according to the table.
(Changed edition, Rev. N 1).
5.3. Impact strength is indicated by a combination of letters and numbers.
The first two letters KS denote the symbol of impact strength, the third letter - the type of concentrator; the first digit is the maximum impact energy of the pendulum, the second is the depth of the concentrator, and the third is the width of the sample. The numbers are not indicated in the case specified in clause 5.2.
It is allowed to designate impact strength with two indices (); the first () is the symbol for toughness; the second () is the sample type symbol according to the table.
To designate the impact work and impact strength at low and high temperatures, a digital index is introduced indicating the test temperature. The digital index is placed at the top after the alphabetic components.
For example:
V 50/2/2 - impact work, determined on a sample with a concentrator of type V at a temperature of minus 40 ° C. The maximum impact energy of the pendulum is 50 J, the concentrator depth is 2 mm, and the sample width is 2 mm.
ST 150/3/7.5 - impact strength, determined on a sample with a type T concentrator at a temperature of plus 100 °C. The maximum impact energy of the pendulum is 150 J, the concentrator depth is 3 mm, and the sample width is 7.5 mm.
CU (CV) - impact strength, determined on a sample with a concentrator of the form U (V) at room temperature. The maximum impact energy of the pendulum is 300 J, the concentrator depth is 2 mm, and the sample width is 10 mm.
- impact strength, determined on a sample of type 11 at a temperature of minus 60 °C. The maximum impact energy of the pendulum is 300 J.
(Revised edition, Rev. N
5.4. Impact strength (KS) in J / cm (kgf m / cm) is calculated by the formula
where is the impact work, J (kgf m);
- the initial cross-sectional area of the sample at the site of the concentrator, cm, calculated by the formula
where is the initial height of the working part of the sample, cm;
Initial sample width, cm.
and measured with an error of not more than ±0.05 mm (±0.005 cm). round off: with a sample width of 5 mm or less - to the third significant figure, with a sample width of more than 5 mm - to the second significant figure.
For samples with concentrator type T, the value is determined as the difference between the total height measured before testing with an error of not more than ± 0.05 mm (± 0.005 cm) and the calculated depth of the concentrator measured using any optical means with a magnification of at least 7 on the fracture surface sample after its testing according to the scheme shown in Fig. 5, with an error of no more than ±0.05 mm (±0.005 cm).
(Changed edition, Rev. N 1, 2
5.5. The value of the COP is recorded in the protocol with rounding: up to 1 (0.1) J/cm (kgf m/cm) - if the COP value is more than 10 (1) J/cm (kgf m/cm); up to 0.1 (0.01) J/cm (kgf m/cm) - when the CV value is less than 10 (1) J/cm (kgf m/cm).
(Changed edition, Rev. N 1
5.6. If, as a result of the test, the sample did not completely collapse, then the quality indicator of the material is considered not established. In this case, the test report indicates that the sample at the maximum impact energy of the pendulum was not destroyed.
The test results are not taken into account when the samples are broken due to defects in metallurgical production.
(Changed edition, Rev. N 2).
5.7. When replacing the sample, the reason is indicated in the test report.
5.8. The initial data and test results of the sample are recorded in the test report. The form of the protocol is given in the recommended appendix 3.
Heck. five
abc - fatigue crack front; I-I - the position of the sight line of the microscope eyepiece at the initial moment of measurement (coincides with the edge of the sample); II-II - the position of the sight line of the microscope at the end of the measurement (position II-II is chosen so that the shaded area above the line would be equal to the unshaded area below the sight line)
APPENDIX 1 (for reference). Scope of samples
ATTACHMENT 1
Reference
Type of concentrator | sample type | Application area |
When choosing, acceptance testing of metals and alloys |
||
When selecting, acceptance testing of metals and alloys for structures with a high degree of reliability (aircraft, vehicles, pipelines, pressure vessels, etc.) |
||
In the selection and acceptance control of metals and alloys for especially critical structures, for the operation of which the assessment of resistance to crack development is of paramount importance. In the study of the causes of destruction of critical structures. |
(Changed edition, Rev. N 1).
APPENDIX 2 (for reference). Subcooling and superheating temperature depending on the test temperature
APPENDIX 2
Reference
Temperature, °C |
|||||||
Test temperature, °C | hypothermia | overheating |
|||||
Copra brand _______________________________________________________________
The maximum impact energy of the pendulum during the test _________________________
The speed of the pendulum at the moment of impact __________________________________________ m/s
Tested material _________________________________________________
Sample marking | Melt number | Lot no. | Sample type | Test temperature, °С | Width per sample | Sample height | Concentrator depth | Working section height | Cross section area, cm | Impact work, J (kgf m) | Impact strength KS, J/cm (kgf m/cm) | Note |
|
(Changed edition, Rev. N 1).
The text of the document is verified by:
official publication
M.: Publishing house of standards, 1994
GOST 9454-78
INTERSTATE STANDARD
METALS
TEST METHOD FOR IMPACT BENDING AT LOW, ROOM AND HIGH
TEMPERATURES
Official edition
IPK PUBLISHING STANDARDS Moscow
Amendment to GOST 9454-78 Metals. Test method for impact bending at low, room and elevated temperatures [em. Amendment No. 2, IUS No. 6-88; Reissues (June 1990), (October 1993), (October 2002) with Changes #1, 2]
(IUS No. 4 2008)
INTERSTATE STANDARD
METALS
Test method for impact bending at low, room and elevated temperatures
Metals. Method for testing the impact strength at low, room and high temperature
Date of introduction from 01.01.79
This standard applies to ferrous and non-ferrous metals and alloys and establishes a test method for impact bending at temperatures from minus 100 to plus 1200 ° C.
The method is based on the destruction of a sample with a concentrator in the middle with one blow of a pendulum impact tester. The ends of the sample are placed on supports. As a result of the test, the total work expended on impact (impact work), or impact strength, is determined.
Impact strength should be understood as the impact work related to the initial cross-sectional area of the sample at the concentrator site.
1. SAMPLING METHOD
1.1. The shape and dimensions of the test specimens must correspond to those indicated in Fig. 1-3 and in the table.
Sample with U type concentrator Sample with Y type concentrator
Official Edition ★
Reprint prohibited
© Standards Publishing, 1978 © Standards Publishing, 2003
Specimen with concentrator type T (fatigue crack)
"v"M
a - general view; b - the shape of the concentrator for samples from 15 to 19 types; c - concentrator shape for type 20 samples
Dimensions, mm
|
Hub radius R |
Length L (limit deviation ±0.6) |
Height H (limit deviation ±0.1) |
Notch depth h x (limit deviation ±0.1) |
Concentrator depth h (limit deviation ±0.6) |
Working section height I, |
|||
Continuation
|
Notch depth Aj (limit deviation ±0.1) |
concentration- | |||||||
|
hub R |
(prev. off |
(prev. off |
torus h (limit deviation ±0.6) |
working |
||||
*During control mass tests, it is allowed to manufacture samples with a maximum deviation of ±0.10 mm.
It is allowed to use samples without a notch and with one or two raw surfaces, the dimensions of which differ in width from those indicated in the table.
The scope of the samples is indicated in Appendix 1.
Testing of samples of types 4, 14, 18 is carried out at the request of the consumer for special-purpose products.
1.2. The place of cutting the workpiece for making samples, the orientation of the axis of the concentrator, the technology for cutting workpieces and making samples in accordance with GOST 7565 for ferrous metals, unless otherwise provided in the regulatory and technical documentation for the product.
For non-ferrous metals and alloys, all this should be indicated in the regulatory and technical documentation for the products.
When cutting blanks, the metal of the samples must be protected from hardening and heating, which change the properties of the metal, unless otherwise provided in the regulatory and technical documentation for the product.
1.1; 1.2.
1.3. Risks on the surface of concentrators of types U and V, visible without the use of magnifying agents, are not allowed.
1.4. The concentrator type T is obtained at the top of the initial notch with a flat cyclic bending of the sample. The method of obtaining the initial hub can be any.
The number of cycles required to obtain a crack of a given depth must be at least 3000.
1.5. The maximum residual deflection formed during application on specimens of the type T concentrator should not exceed: 0.25 mm - for specimens 55 mm long.
Sample deflection is controlled using dial gauges according to GOST 577 or other means that ensure the deflection measurement error is not more than 0.05 mm based on the sample length.
1.6. The type and number of samples, the procedure for retesting must be specified in the regulatory and technical documentation for specific products, approved in the prescribed manner.
If the type of sample is not indicated in the regulatory and technical documentation for metal products, samples of type 1 should be tested - until 01.01.91.
1.4-1.6. (Changed edition, Rev. No. 1, 2).
2. EQUIPMENT AND MATERIALS
2.1. Pendulum impactors - according to GOST 10708. The speed of the pendulum at the moment of impact should be:
(5±0.5) m/s - for headframes with nominal potential energy of the pendulum 50 (5.0); 150(15); 300 (30.0) J (kgf-m);
(4 + 0.25) m / s - for impactors with a nominal potential energy of the pendulum 25 (2.5); 15 (1.5); 7.5 (0.75) J (kgf-m);
(3 ± 0.25) m / s - for impactors with a nominal potential energy of the pendulum of 5.0 (0.5) J (kgf-m) or less.
It is allowed to use copra with a different nominal potential energy of the pendulum. In this case, the nominal value of the potential energy of the pendulum must be such that the value of the impact work is at least 10% of the nominal value of the potential energy of the pendulum. Until 01/01/91, it is allowed to use impactors with such a nominal potential energy of the pendulum that the impact work is at least 5% of the nominal potential energy of the pendulum. The nominal value of the potential energy of the pendulum must be indicated in the regulatory and technical documentation for specific products.
The main dimensions of the supports and the pendulum knife must correspond to those indicated in Fig. 4. For headframes of a different design, other radii of curvature of the support edge and the speed of the pendulum from 4.5 to 7.0 m/s are allowed.
(Revised edition, Rev. No. 2).
2.2. A thermostat that provides uniform cooling or heating, the absence of aggressive environmental influences on the sample and the ability to control the temperature.
2.3. A mixture of liquid nitrogen (GOST 9293) or solid carbon dioxide ("dry ice") with ethyl alcohol. The use of liquid oxygen and liquid air as a cooler is not allowed.
The mass fraction of oxygen in liquid nitrogen during the cooling of samples in a thermostat should not exceed 10%.
(Changed edition, Rev. No. 1, 2).
2.4. Thermometers with an error of no more than ±1 ° С for measuring the temperature of the cooling medium.
2.5. Thermometers, including thermoelectric converters (thermocouples), for measuring the heating temperature of samples, providing measurement with an error not exceeding:
±5 °С - at heating temperature up to 600 °С;
±8 °С - at heating temperature over 600 °С.
2.4, 2.5. (Revised edition, Rev. No. 2).
2.6. A crack on the samples is obtained on vibrators manufactured according to regulatory and technical documentation.
2.7. Calipers must comply with the requirements of GOST 166. It is allowed to use other measuring instruments that provide measurement with an error not exceeding that specified in pi. 1.1.
2.6, 2.7. (Introduced additionally, Amendment No. 2).
3. PREPARATION FOR THE TEST
3.1. Before starting the tests, it is necessary to check the position of the operation indicator when the pendulum is in free fall.
For pendulum impactors with digital readout devices, the work indicator in the initial position must show “zero” with an allowable deviation within the stroke width according to the normative and technical documentation.
(Changed edition, Rev. No. 1, 2).
The test temperature is indicated in the regulatory and technical documentation for a specific
products approved in the prescribed manner.
3.4. To ensure the required test temperature, the samples must be supercooled (at a test temperature below room temperature) or overheated (at
Supports and pendulum knife
test temperature above room temperature). The degree of subcooling or superheating shall provide the required test temperature and shall be determined experimentally.
The temperature of supercooling or overheating of samples, provided that they can be tested no later than 3-5 s after removal from the thermostat, is indicated in Appendix 2.
Exposure of samples in a thermostat at a given temperature (taking into account the necessary supercooling or overheating) should be at least 15 minutes.
3.5. The part of the device in contact with the sample for removing it from the thermostat should not change the temperature of the sample when it is placed on the copra supports.
4. CONDUCTING THE TEST
4.1. The sample must lie freely on the supports of the impact tester (see Fig. 4). The sample should be installed using a template that ensures the symmetrical location of the concentrator relative to the supports with an error of no more than ±0.5 mm. When using end stops, the latter should not prevent the samples from being freely deformed.
4.2. The test shall be carried out with the impact of the pendulum from the side opposite to the concentrator, in the plane of its symmetry.
4.3. The impact work is determined on the scale of a pendulum impactor or analog readout devices.
(Revised edition, Rev. No. 2).
5. PROCESSING THE RESULTS
5.1. The test result is taken as the work of impact or impact strength for samples with concentrators of types U and V and impact strength for samples with a concentrator of type T.
(Revised edition, Rev. No. 2).
5.2. The impact work is indicated by two letters (AU, KV or AT) and numbers. The first letter (K) is a symbol of the impact, the second letter (U, V or T) is the type of concentrator. The following numbers indicate the maximum impact energy of the pendulum, the depth of the concentrator and the width of the sample. The figures are not indicated when determining the impact work on a headframe with a maximum pendulum impact energy of 300 (30.0) J (kgf-m), with a concentrator depth of 2 mm for concentrators of U and V types and 3 mm for a concentrator of type T and a sample width of 10 mm (samples 1, 11 and 15 types).
It is allowed to designate the impact work with two indices (D): the first (A) is the symbol of the impact work, the second (/) is the symbol of the sample type in accordance with the table.
(Revised edition, Rev. No. 1).
5.3. Impact strength is indicated by a combination of letters and numbers.
The first two letters KS denote the symbol of impact strength, the third letter - the type of concentrator; the first digit is the maximum impact energy of the pendulum, the second is the depth of the concentrator, and the third is the width of the sample. The numbers are not indicated in the case specified in clause 5.2.
It is allowed to designate impact strength with two indices (a,) "the first (a) is the symbol of impact strength; the second (/) is the symbol of the sample type in accordance with the table.
To designate the impact work and impact strength at low and high temperatures, a digital index is introduced indicating the test temperature. The digital index is placed at the top after the alphabetic components.
For example:
AV -40 50/2/2 - impact work, determined on a sample with a type V concentrator at a temperature of minus 40 °C. The maximum impact energy of the pendulum is 50 J, the concentrator depth is 2 mm, and the sample width is 2 mm.
AGST +10 ° 150/3/7.5 - impact strength, determined on a sample with a type T concentrator at a temperature of plus 100 °C. The maximum impact energy of the pendulum is 150 J, the concentrator depth is 3 mm, and the sample width is 7.5 mm.
KS U (KCV) - impact strength, determined on a sample with a concentrator of the form U (V) at room temperature. The maximum impact energy of the pendulum is 300 J, the concentrator depth is 2 mm, and the sample width is 10 mm.
ap -60 - impact strength, determined on a sample of type 11 at a temperature of minus 60 °C. The maximum impact energy of the pendulum is 300 J.
(Revised edition, Rev. No. 1).
5.4. Impact strength (KS) in J / cm 2 (kgf m / cm 2) is calculated by the formula
where K - impact work, J (kgf-m);
S 0 - the initial cross-sectional area of the sample at the site of the concentrator, cm 2, calculated by the formula
where I (- the initial height of the working part of the sample, cm;
B is the initial width of the sample, cm.
H\ and B are measured with an error of not more than ±0.05 mm (±0.005 cm). S 0 is rounded off: with a sample width of 5 mm or less - to the third significant figure, with a sample width of more than 5 mm - to the second significant figure.
For samples with concentrator type T, the value is determined as the difference between the total height H, measured before testing with an error of not more than ± 0.05 mm (± 0.005 cm) and the calculated concentrator depth Ap, measured using any optical means with an increase of at least 7 by fracture surface of the sample after its testing according to the scheme shown in Fig. 5, with an error of no more than ±0.05 mm (±0.005 cm).
abc - fatigue crack front; I- I- position of the sight line of the microscope eyepiece at the initial moment of measurement (coincides with the edge of the sample); //-// - position of the sight line of the microscope at the end of the measurement (position II-II is chosen so that the shaded area above the line would be equal to the unshaded area below the sight line)
(Changed edition, Rev. No. 1, 2).
5.5. The value of the COP is recorded in the protocol with rounding: up to 1 (0.1) J / cm 2 (kgf m / cm 2) - if the value of the COP is more than 10 (1) J / cm 2 (kgf m / cm 2); up to 0.1 (0.01) J / cm 2 (kgf / cm 2) - with a COP value of less than 10 (1) J / cm 2 (kgf m / cm 2).
(Revised edition, Rev. No. 1).
5.6. If, as a result of the test, the sample did not completely collapse, then the quality indicator of the material is considered not established. In this case, the test report indicates that the sample at the maximum impact energy of the pendulum was not destroyed.
The test results are not taken into account when the samples are broken due to defects in metallurgical production.
(Revised edition, Rev. No. 2).
5.7. When replacing the sample, the reason is indicated in the test report.
5.8. The initial data and test results of the sample are recorded in the test report. The form of the protocol is given in Appendix 3.
APPENDIX 1 Reference
Scope of samples
APPENDIX 1. (Changed edition, Rev. No. 1).
APPENDIX 2 Reference
Subcooling and superheating temperature depending on the test temperature
IMPACT TEST REPORT
Copra brand___
The maximum impact energy of the pendulum during the test_
Pendulum speed at the moment of impact_m/s
Test material_
APPENDIX 3. (Changed edition, Rev. No. 1).
INFORMATION DATA
1. DEVELOPED AND INTRODUCED by the Ministry of Ferrous Metallurgy of the USSR
2. APPROVED AND INTRODUCED BY Decree of the State Committee for Standards of the Council of Ministers of the USSR dated April 17, 1978 No. 1021
3. The standard fully complies with ISO 83-76 and ISO 148-83
4. REFERENCE REGULATIONS AND TECHNICAL DOCUMENTS
5. The limitation of the validity period was removed according to protocol No. 3 of the Interstate Council for Standardization, Metrology and Certification (NUS 5-6-93)
6. EDITION (October 2002) with Amendments No. 1, 2, approved in October 1981, March 1988 (IUS 12-81, 6-88)
Editor M.I. Makashova Technical editor L.A. Guseva Proofreader V. S. Chernaya Computer layout E.N. Martemyanova
Ed. persons. No. 02354 dated 07/14/2000. Handed over to the set 12/11/2002. Signed for publication on December 23, 2002. Uel. oven l. 1.40. Uch.-ed. l. 0.85. Circulation 119 copies. From 8864. Law. 1153.
IPK Publishing house of standards, 107076 Moscow, Kolodezny per., 14. e-mail:
Typed at the Publishing House on a PC
Branch of IPK Publishing house of standards - type. "Moscow printer", 105062 Moscow, Lyalin per., 6.
GOST 9454-78
Group B09
STATE STANDARD OF THE UNION OF THE SSR
Test method for impact bending at low,
room and elevated temperatures
Metals. Method for testing the impact strength at low,
room and high temperature
OKSTU 1909
Introduction date 1979-01-01
INFORMATION DATA
1. DEVELOPED AND INTRODUCED by the Ministry of Ferrous Metallurgy of the USSR
DEVELOPERS
V. N. Danilov, Doctor of Engineering sciences; M. N. Georgiev, Ph.D. tech. sciences; N. Ya. Mezhova; L. N. Kosarev, Ph.D. tech. sciences; E. F. Komolova, Ph.D. sciences; B. A. Drozdovsky, Ph.D. tech. sciences; V. G. Kudryashov, Ph.D. tech. sciences; P. D. Odessky, Ph.D. tech. sciences; V. I. Gelmida, Ph.D. tech. sciences; V. I. Zmievsky, Ph.D. tech. Sciences
2. APPROVED AND PUT INTO EFFECT by the Decree of the State Committee of Standards of the Council of Ministers of the USSR dated April 17, 1978 N 1021
3. The standard fully complies with ISO 83-76 and ISO 148-83
4. REFERENCE REGULATIONS AND TECHNICAL DOCUMENTS
Item number, section |
|
GOST 166-89 | |
GOST 577-68 | |
GOST 7565-81 | |
GOST 9293-74 | |
GOST 10708-82 |
5. The limitation of the validity period was removed by decision of the Interstate Council for Standardization, Metrology and Certification (minutes 3-93 dated 17.02.93)
6. REPUBLICATION (October 1993) with Amendments No. 1, 2, approved in October 1981, March 1988, (IUS 12-81, 6-88)
INSTEAD OF GOST 9454-60, GOST 9455-60 and GOST 9456-60.*
___________________
Information about the cancellation of documents is given from the publication: official publication, M .: Standards Publishing House, 1982. Note "CODE".
This standard applies to ferrous and non-ferrous metals and alloys and establishes a test method for impact bending at temperatures from minus 100 to plus 1200 ° C.
The method is based on the destruction of a sample with a concentrator in the middle with one blow of a pendulum impact tester. The ends of the sample are placed on supports. As a result of the test, the total work expended on impact (impact work), or impact strength, is determined.
Impact strength should be understood as the impact work related to the initial cross-sectional area of the sample at the concentrator site.
1. SAMPLING METHOD
1. SAMPLING METHOD
1.1. The shape and dimensions of the test specimens must correspond to those indicated in the table and in drawing. 1-3.
Dimensions, mm
Concentrator view | concentrator radius | Sample type | Length | Width | Height (offset limit ±0.1) | Notch depth | Concentration depth | Working section height |
_____________
* During control mass tests, it is allowed to manufacture samples with a maximum deviation of ±0.10 mm.
Damn.1. Sample with U type concentrator
Heck. 2. Sample with V-type concentrator
Fig 3. Specimen with type T concentrator (fatigue crack)
a - general view; b - the shape of the concentrator for samples from 15 to 19 types; c - concentrator shape for type 20 samples
Heck. 3
It is allowed to use samples without a notch and with one or two raw surfaces, the dimensions of which differ in width from those indicated in the table.
The scope of the samples is indicated in the reference appendix 1.
Testing of samples of types 4, 14, 18 is carried out at the request of the consumer for special-purpose products.
1.2. The place of cutting the workpiece for making samples, the orientation of the axis of the concentrator, the technology for cutting workpieces and making samples - according to GOST 7565-81 for ferrous metals, unless otherwise provided in the regulatory and technical documentation for the product.
For non-ferrous metals and alloys, all this should be indicated in the regulatory and technical documentation for the products.
When cutting blanks, the metal of the samples must be protected from hardening and heating, which change the properties of the metal, unless otherwise provided in the regulatory and technical documentation for the product.
1.1; 1.2. (Changed edition, Rev. No. 2).
1.3. Risks on the surface of concentrators of types U and V, visible without the use of magnifying agents, are not allowed.
1.4. The concentrator type T is obtained at the top of the initial notch with a flat cyclic bending of the sample. The method of obtaining the initial hub can be any.
The number of cycles required to obtain a crack of a given depth must be at least 3000.
1.5. The maximum residual deflection formed during application on specimens of the type T concentrator should not exceed: 0.25 mm - for specimens 55 mm long.
Sample deflection control is carried out using dial indicators according to GOST 577-68 or other means that ensure the deflection measurement error is not more than 0.05 mm based on the sample length.
1.6. The type and number of samples, the procedure for retesting must be specified in the regulatory and technical documentation for specific products, approved in the prescribed manner.
If the type of sample is not indicated in the regulatory and technical documentation for metal products, samples of type 1 should be tested - until 01.01.91.
1.4-1.6. (Changed edition, Rev. N 1, 2).
2. EQUIPMENT AND MATERIALS
2.1. Pendulum copra - in accordance with GOST 10708-82. The speed of the pendulum at the moment of impact should be:
(5±0.5) m/s - for headframes with nominal potential energy of the pendulum 50 (5.0); 150(15); 300 (30.0) J (kgf m);
(4±0.25) m/s - for headframes with nominal potential energy of the pendulum 25 (2.5); 15 (1.5); 7.5 (0.75) J (kgf m);
(3 ± 0.25) m / s - for impactors with a nominal potential energy of the pendulum of 5.0 (0.5) J (kgf m) or less.
It is allowed to use copra with a different nominal potential energy of the pendulum. In this case, the nominal value of the potential energy of the pendulum must be such that the value of the impact work is at least 10% of the nominal value of the potential energy of the pendulum. Until 01/01/91, it is allowed to use impactors with such a nominal potential energy of the pendulum that the impact work is at least 5% of the nominal potential energy of the pendulum. The nominal value of the potential energy of the pendulum must be indicated in the regulatory and technical documentation for specific products.
The main dimensions of the supports and the pendulum knife must correspond to those indicated in Fig. 4. For headframes of a different design, other radii of curvature of the support edge and the speed of the pendulum from 4.5 to 7.0 m/s are allowed.
Heck. 4. Supports and pendulum knife
2.2. A thermostat that provides uniform cooling or heating, the absence of aggressive environmental influences on the sample and the ability to control the temperature.
2.3. A mixture of liquid nitrogen (GOST 9293-74) or solid carbon dioxide ("dry ice") with ethyl alcohol. The use of liquid oxygen and liquid air as a cooler is not allowed.
The mass fraction of oxygen in liquid nitrogen during the cooling of samples in a thermostat should not exceed 10%.
(Changed edition, Rev. N 1.2).
2.4. Thermometers with an error of no more than ±1 ° С for measuring the temperature of the cooling medium.
2.5. Thermometers, including thermoelectric converters (thermocouples), for measuring the heating temperature of samples, providing measurement with an error not exceeding:
±5 °С - at heating temperature up to 600 °С;
±8 °С - at heating temperature over 600 °С.
2.4, 2.5. (Changed edition, Rev. N 2).
2.6. A crack on the samples is obtained on vibrators manufactured according to regulatory and technical documentation.
2.7. Calipers must comply with the requirements of GOST 166-89. It is allowed to use other measuring instruments that provide measurement with an error not exceeding that specified in clause 1.1.
2.6, 2.7. (Introduced additionally, Rev. N 2).
3. PREPARATION FOR THE TEST
3.1. Before starting the tests, it is necessary to check the position of the operation indicator when the pendulum is in free fall.
For pendulum impactors with digital readout devices, the work indicator in the initial position must show "zero" with an allowable deviation within the stroke width according to the normative and technical documentation.
(Changed edition, Rev. N 1, 2).
3.4. To ensure the required test temperature, the samples must be supercooled (at a test temperature below room temperature) or overheated (at a test temperature above room temperature) before being placed on the impact tester. The degree of subcooling or superheating shall provide the required test temperature and shall be determined experimentally.
The temperature of subcooling or superheating of samples, provided that they can be tested no later than 3-5 s after removal from the thermostat, is indicated in reference annex 2.
Exposure of samples in a thermostat at a given temperature (taking into account the necessary supercooling or overheating) should be at least 15 minutes.
3.5. The part of the device in contact with the sample for removing it from the thermostat should not change the temperature of the sample when it is placed on the copra supports.
4. CONDUCTING THE TEST
4.1. The sample must lie freely on the supports of the impact tester (see Fig. 4). The sample should be installed using a template that ensures the symmetrical location of the concentrator relative to the supports with an error of no more than ±0.5 mm. When using end stops, the latter should not prevent the samples from being freely deformed.
4.2. The test shall be carried out with the impact of the pendulum from the side opposite to the concentrator, in the plane of its symmetry.
4.3. The impact work is determined on the scale of a pendulum impactor or analog readout devices.
(Changed edition, Rev. N 2).
5. PROCESSING THE RESULTS
5.1. The test result is taken as the work of impact or impact strength for samples with concentrators of types U and V and impact strength for samples with a concentrator of type T.
(Changed edition, Rev. N 2).
5.2. The impact work is indicated by two letters (U, V or T) and numbers. The first letter () is a symbol of the impact, the second letter (U, V or T) is the type of concentrator. The following numbers indicate the maximum impact energy of the pendulum, the depth of the concentrator and the width of the sample. The figures are not indicated when determining the impact work on a headframe with a maximum pendulum impact energy of 300 (30.0) J (kgf m), with a concentrator depth of 2 mm for U and V concentrators and 3 mm for a T concentrator and a sample width of 10 mm (samples 1, 11 and 15 types).
It is allowed to designate the impact work with two indices (A):
the first (A) is the impact work symbol, the second () is the sample type symbol according to the table.
(Changed edition, Rev. N 1).
5.3. Impact strength is indicated by a combination of letters and numbers.
The first two letters KS denote the symbol of impact strength, the third letter - the type of concentrator; the first digit is the maximum impact energy of the pendulum, the second is the depth of the concentrator, and the third is the width of the sample. The numbers are not indicated in the case specified in clause 5.2.
It is allowed to designate impact strength with two indices (); the first () is the symbol for toughness; the second () is the sample type symbol according to the table.
To designate the impact work and impact strength at low and high temperatures, a digital index is introduced indicating the test temperature. The digital index is placed at the top after the alphabetic components.
For example:
V 50/2/2 - impact work, determined on a sample with a concentrator of type V at a temperature of minus 40 ° C. The maximum impact energy of the pendulum is 50 J, the concentrator depth is 2 mm, and the sample width is 2 mm.
ST 150/3/7.5 - impact strength, determined on a sample with a type T concentrator at a temperature of plus 100 °C. The maximum impact energy of the pendulum is 150 J, the concentrator depth is 3 mm, and the sample width is 7.5 mm.
CU (CV) - impact strength, determined on a sample with a concentrator of the form U (V) at room temperature. The maximum impact energy of the pendulum is 300 J, the concentrator depth is 2 mm, and the sample width is 10 mm.
- impact strength, determined on a sample of type 11 at a temperature of minus 60 °C. The maximum impact energy of the pendulum is 300 J.
(Revised edition, Rev. N
5.4. Impact strength (KS) in J / cm (kgf m / cm) is calculated by the formula
where is the impact work, J (kgf m);
- the initial cross-sectional area of the sample at the site of the concentrator, cm, calculated by the formula
where is the initial height of the working part of the sample, cm;
Initial sample width, cm.
and measured with an error of not more than ±0.05 mm (±0.005 cm). round off: with a sample width of 5 mm or less - to the third significant figure, with a sample width of more than 5 mm - to the second significant figure.
For samples with concentrator type T, the value is determined as the difference between the total height measured before testing with an error of not more than ± 0.05 mm (± 0.005 cm) and the calculated depth of the concentrator measured using any optical means with a magnification of at least 7 on the fracture surface sample after its testing according to the scheme shown in Fig. 5, with an error of no more than ±0.05 mm (±0.005 cm).
(Changed edition, Rev. N 1, 2
5.5. The value of the COP is recorded in the protocol with rounding: up to 1 (0.1) J/cm (kgf m/cm) - if the COP value is more than 10 (1) J/cm (kgf m/cm); up to 0.1 (0.01) J/cm (kgf m/cm) - when the CV value is less than 10 (1) J/cm (kgf m/cm).
(Changed edition, Rev. N 1
5.6. If, as a result of the test, the sample did not completely collapse, then the quality indicator of the material is considered not established. In this case, the test report indicates that the sample at the maximum impact energy of the pendulum was not destroyed.
The test results are not taken into account when the samples are broken due to defects in metallurgical production.
(Changed edition, Rev. N 2).
5.7. When replacing the sample, the reason is indicated in the test report.
5.8. The initial data and test results of the sample are recorded in the test report. The form of the protocol is given in the recommended appendix 3.
Heck. five
abc - fatigue crack front; I-I - the position of the sight line of the microscope eyepiece at the initial moment of measurement (coincides with the edge of the sample); II-II - the position of the sight line of the microscope at the end of the measurement (position II-II is chosen so that the shaded area above the line would be equal to the unshaded area below the sight line)
APPENDIX 1 (for reference). Scope of samples
ATTACHMENT 1
Reference
Type of concentrator | sample type | Application area |
When choosing, acceptance testing of metals and alloys |
||
When selecting, acceptance testing of metals and alloys for structures with a high degree of reliability (aircraft, vehicles, pipelines, pressure vessels, etc.) |
||
In the selection and acceptance control of metals and alloys for especially critical structures, for the operation of which the assessment of resistance to crack development is of paramount importance. In the study of the causes of destruction of critical structures. |
(Changed edition, Rev. N 1).
APPENDIX 2 (for reference). Subcooling and superheating temperature depending on the test temperature
APPENDIX 2
Reference
Temperature, °C |
|||||||
Test temperature, °C | hypothermia | overheating |
|||||
Copra brand _______________________________________________________________
The maximum impact energy of the pendulum during the test _________________________
The speed of the pendulum at the moment of impact __________________________________________ m/s
Tested material _________________________________________________
Sample marking | Melt number | Lot no. | Sample type | Test temperature, °С | Width per sample | Sample height | Concentrator depth | Working section height | Cross section area, cm | Impact work, J (kgf m) | Impact strength KS, J/cm (kgf m/cm) | Note |
|
(Changed edition, Rev. N 1).
The text of the document is verified by:
official publication
M.: Publishing house of standards, 1994