GB/T 229-2020 PDF in English
GB/T 229-2020 (GB/T229-2020, GBT 229-2020, GBT229-2020)
Standard ID | Contents [version] | USD | STEP2 | [PDF] delivered in | Name of Chinese Standard | Status |
GB/T 229-2020 | English | 365 |
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Metallic materials -- Charpy pendulum impact test method
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GB/T 229-2007 | English | 85 |
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Metallic materials -- Charpy pendulum impact test method
| Obsolete |
GB/T 229-1994 | English | 279 |
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Metallic materials--Charpy notch impact test
| Obsolete |
GB 229-1984 | English | 199 |
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Metallic materials--Charpy impact test (U-notch)
| Obsolete |
Standards related to (historical): GB/T 229-2020
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GB/T 229-2020: PDF in English (GBT 229-2020) GB/T 229-2020
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 77.040.10
H 22
Replacing GB/T 229-2007
Metallic materials - Charpy pendulum impact test
method
(ISO 148-1:2016, Metallic materials - Charpy pendulum impact test - Part 1:
Test method, MOD)
ISSUED ON: SEPTEMBER 29, 2020
IMPLEMENTED ON: APRIL 04, 2021
Issued by: State Administration for Market Regulation;
Standardization Administration of PRC.
Table of Contents
Foreword ... 4
1 Scope ... 8
2 Normative references ... 8
3 Terms and definitions ... 8
3.1 Energy-related definitions... 8
3.2 Definitions related to specimens ... 9
4 Symbols and description ... 11
5 Test principle ... 12
6 Specimen ... 13
6.1 General requirements... 13
6.2 Notch geometry ... 14
6.3 Deviation of specimen size ... 14
6.4 Preparation of specimens ... 15
6.5 Marking of specimens ... 15
7 Test equipment ... 15
7.1 General requirements... 15
7.2 Installation and calibration ... 15
7.3 Pendulum blade ... 16
8 Test procedure ... 16
8.1 General requirements... 16
8.2 Determination of friction loss ... 16
8.3 Test temperature ... 18
8.4 Transfer of specimens ... 18
8.5 Capability range of testing machine ... 19
8.6 Incomplete fracture of specimen ... 20
8.7 Pendulum jammed by specimen ... 20
8.8 Post-fracture inspection... 20
8.9 Test results ... 21
9 Test report ... 21
9.1 Necessary content... 21
9.2 Optional content ... 21
Appendix A (Informative) Self-centering clamp ... 23
Appendix B (Informative) Lateral expansion value ... 24
Appendix C (Informative) Shear section rate ... 28
Appendix D (Informative) Absorbed energy-temperature curve and transition
temperature... 31
Appendix E (Informative) Measurement uncertainty of absorbed energy value
K ... 33
References ... 42
Foreword
This standard was drafted in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 229-2007 "Metallic materials - Charpy pendulum
impact test method". Compared with GB/T 229-2007, the main technical
changes are as follows:
- In the scope, ADD the unnotched specimens; MAKE requirements for the
terms and definitions, symbols and descriptions, dimensional deviations,
specimen installation of unnotched specimens (see Chapter 1, 3.2.1, Table
1, Table 2, 8.1, Appendix A);
- MODIFY and ADD some terms and definitions (see 3.1.3, 3.2.1, 3.2.2; 3.2.1,
3.2.2 of the 2007 edition);
- ADD the symbol B of specimen thickness; ADD the symbol α of the angle
when the pendulum is released; ADD the description of the elevation angle
β1 and β2; ADD the symbol KN of the nominal value of the initial potential
energy; ADD the symbol M of the moment; ADD the energy loss symbol p
caused by pointer friction, the energy loss symbol p' caused by bearing
friction and air resistance, the correction symbol pβ for the energy loss
caused by the elevation angle β; MODIFY the symbol of shear section rate,
which is changed to SFA; ADD the transition temperature symbol Tt27
corresponding to the specified absorption energy value of 27J, the
transition temperature symbol Tt50%US corresponding to 50% of the energy
absorbed on the upper platform, the transition temperature symbol Tt50%SFA
corresponding to the shear section rate of 50%, the transition temperature
symbol Tt0.9 corresponding to lateral expansion value 0.9 mm (see Table 1;
Table 1 of the 2007 edition);
- SUPPLEMENT and IMPROVE the principle of impact test (see Chapter 5;
Chapter 5 of the 2007 edition);
- ADD the determination of friction loss (see 8.2);
- MODIFY the test temperature requirements (see 8.3.3; 8.2.3 of the 2007
edition);
- ADD the necessary and optional content of the test report [see 9.1 g), 9.2
j), k)];
- ADD the Informative Appendix E "Measuring uncertainty of absorbed
energy value K" (see Appendix E);
- DELETE the Informative appendix of the high temperature or low
2975" for the convenience of actual operation;
- In Table 2, ADD the size and tolerance of U-notch specimens which have a
ligament width of 8 mm; ADD the notes for unnotched specimens; ADJUST
the angle tolerance between adjacent longitudinal surfaces of the specimen;
DELETE the tolerance grades of the two notches, to meet China's national
conditions;
- For the convenience of application, ADD the symbols KW2 and KW8 used
for the pendulum hammer blade of the unnotched specimen in 7.3;
- In order to facilitate the operation of the application of unnotched specimens,
ADD the requirements for the installation position of unnotched specimens
and the pre-test inspection requirements in 8.1;
- ADD the detailed requirements for bearing friction and windage loss in 8.2.2,
to facilitate the implementation of the standard;
- In 8.5, ADD the lower limit of use of the testing machine and the
requirements for resolution; ADD note 2 to explain it, to improve the
operability of the standard and facilitate the implementation of the standard;
- In order to increase the operability, ADD the description in 8.6 when the
pendulum does not break the specimen due to insufficient impact energy of
the testing machine and the measured absorbed energy exceeds the
energy range of the testing machine;
- In 8.9, ADD the energy-absorption rounding-off requirements to improve
the standard operability;
- In 9.1, ADD the item c) notch type and ligament width (notch depth); in item
d), ADD the requirement for expression method of specimen size, to
improve the standard operability;
- In Appendix A, DELETE the sentence "the size of the centering clamp with
thickness of 5 mm and 3 mm" due to data errors; ADD the requirements for
clamps for unnotched specimens; ADD the requirements for clamps for U-
notches, to improve the standard operability, to facilitate the implementation
of standards.
This standard has made the following editorial changes:
- MODIFY the standard name;
- In the note of 3.1.2, ADD the expression that "use the letter W to represent
unnotched specimens".
This standard was proposed by the China Iron and Steel Association.
Metallic materials - Charpy pendulum impact test
method
1 Scope
This standard specifies the Charpy pendulum impact test method for measuring
the energy absorbed by impact specimens (V-shaped, U-shaped notch,
unnotched specimens) in the impact test of metallic materials.
This standard applies to the Charpy pendulum impact test under room
temperature, high temperature or low temperature conditions, but does not
include the instrumental impact test method, the content of this part is as shown
in GB/T 19748.
2 Normative references
The following documents are essential to the application of this document. For
the dated documents, only the versions with the dates indicated are applicable
to this document; for the undated documents, only the latest version (including
all the amendments) is applicable to this standard.
GB/T 2975 Steel and steel products - Location and preparation of
specimens and test pieces for mechanical testing (GB/T 2975-2018, ISO
377:2017, MOD)
GB/T 3808 Verification of pendulum-type impact testing machines (GB/T
3808-2018, ISO 148-2:2008, MOD)
GB/T 8170 Rules of rounding off for numerical values & expression and
judgement of limiting values
JJG 145 Verification regulation of pendulum impact testing machines
3 Terms and definitions
The following terms and definitions apply to this document.
3.1 Energy-related definitions
3.1.1
7.3 Pendulum blade
The radius of curvature of the edge of the pendulum blade shall be either 2 mm
or 8 mm. Use the subscript number of the symbol to indicate: KV2, KV8, KU2,
KU8, KW2, KW8. The choice of pendulum blade's radius shall be based on the
relevant product standards.
Note: The test results obtained by using 2 mm and 8 mm pendulum blades may be
different.
8 Test procedure
8.1 General requirements
8.1.1 The specimen shall be close to the anvil of the testing machine; the
distance between the symmetry plane of the specimen notch and the middle
plane of the two anvils shall be no more than 0.5 mm. The strike center of the
pendulum blade is located on the symmetry plane of the notch and the opposite
side of the specimen notch (see Figure 1). For unnotched specimens, the strike
center of the pendulum blade shall be located in the middle of the length and
thickness of the specimen.
8.1.2 The anvil span shall be checked before the test; the anvil span shall be
guaranteed to be within mm. Check the anvil's fillet and the pendulum
blade for damage or foreign metal adhesion. If any problems are found, the
faulty parts shall be adjusted, ground or replaced in time, to ensure the accuracy
and reliability of the test results.
8.2 Determination of friction loss
8.2.1 Check the energy loss caused by friction before starting the impact test
every day. The friction loss can be evaluated according to the following methods,
or other methods can be used.
Note: The energy loss of friction includes but is not limited to air resistance, bearing
friction and pointer friction. The increase in friction of the testing machine will affect the
measurement of absorbed energy.
8.2.2 In order to determine the loss of pointer friction, the testing machine can
be operated normally without installing the specimen to obtain the elevation
angle β1 or energy value K1 of the testing machine. Then do another idle swing
without resetting the pointer, to obtain the elevation angle β2 or energy value K2
shall be noted in the test report.
8.9 Test results
Read the impact absorption energy of each specimen; it shall be estimated to
at least 0.5 J or 0.5 division units (whichever is smaller). The test result shall
retain at least two significant digits; the rounding-off method shall be
implemented according to GB/T 8170.
9 Test report
9.1 Necessary content
The test report shall include the following or when the customer allows, the
following information can be traced through the report number provided by the
laboratory:
a) This standard number;
b) Specimen related information (such as steel grade, furnace batch number,
etc.);
c) Notch type and ligament width (notch depth);
d) The size of the specimen when it is different from the standard specimen
[thickness × width × length, in millimeters (mm)];
e) Test temperature;
f) Absorb energy KV2, KV8, KU2, KU8, KW2, KW8;
g) Whether most of the specimens or a group of specimens are broken (not
required for the material acceptance test);
h) Abnormal conditions that may affect the test.
9.2 Optional content
The test report can choose to add the following information based on the
content of 9.1:
a) Orientation of the specimen [5];
b) The nominal initial potential energy of the testing machine, in joules (J);
...... Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.
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