GB/T 29459.2-2012 PDF in English
GB/T 29459.2-2012 (GB/T29459.2-2012, GBT 29459.2-2012, GBT29459.2-2012)
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GB/T 29459.2-2012 | English | 130 |
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Small punch test methods of metallic materials for in-service pressure equipment -- Part 2: Method of test for tensile properties at room temperature
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Standards related to (historical): GB/T 29459.2-2012
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GB/T 29459.2-2012: PDF in English (GBT 29459.2-2012) GB/T 29459.2-2012
GB
NATIONAL STANDARD OF
THE PEOPLE’S REPUBLIC OF CHINA
ICS 77.040.10
H 22
Small punch test methods of metallic materials for in-
service pressure equipments - Part 2. Method of test
for tensile properties at room temperature
ISSUED ON. DECEMBER 31, 2012
IMPLEMENTED ON. JULY 1, 2013
Issued by. General Administration of Quality Supervision, Inspection and
Quarantine;
Standardization Administration Committee.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative references ... 4
3 Symbols... 4
4 Test requirements ... 5
5 Data obtained in test and test record ... 6
6 Test data processing ... 8
7 Test report ... 11
Foreword
GB/T 29459 Small punch test methods of metallic materials for in-service
pressure equipments consists of the following two parts.
- Part 1. General requirements;
- Part 2. Method of test for tensile properties at room temperature.
This Part is the second part of GB/T 29459.
This Part was drafted in accordance with the rules given in GB/T 1.1-2009.
This Part mainly referred to relative technical content of CWA 15627 Small
punch test methods of metallic materials and was formulated based on the
combination of the actual situation of China and research results.
This Part was proposed by and shall be shall be under the jurisdiction of
National Technical Committee on Boiler and Pressure Vessel of Standardization
Administration of China (SAC/TC 262).
The drafting organizations of this Part. China Special Equipment Inspection and
Research Institute, East China University of Science and Technology, Nanjing
University of Technology, Nanjing University of Technology, Jiangsu Special
Equipment Safety Supervision and Inspection Institute, Fujian Boiler and
Pressure Vessel Inspection and Research Institute.
Main drafters of this Part. Guan Kaishu, Xu Tong, Yuan Biao, Ling Xiang, Wang
Zhiwen, Jia Guodong, Sun Liang, Gong Lingzhu.
Small punch test methods of metallic materials for in-
service pressure equipments - Part 2. Method of test
for tensile properties at room temperature
1 Scope
This Part of GB/T 29459 specifies the explanation on symbols, test
requirements, test records, test data processing and test reports of small punch
test method which obtains tensile properties of material at room temperature.
This Part is applicable to metallic materials for pressure equipment.
2 Normative references
The following referenced documents are indispensable for the application of
this document. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any
amendments) applies.
GB/T 228.1, Metallic materials - Tensile testing - Part 1 . Method of test at
room temperature
GB/T 29459.1, Small punch test methods of metallic materials for in-service
pressure equipments - Part 1. General requirements
3 Symbols
Symbols specified in GB/T 29459.1 and the following ones apply to this
document.
A - elongation at break after conventional tensile test, %;
E - elastic modulus, in megapascals (MPa);
F(u) - load-displacement function obtained in test, in newtons (N);
F(u) - load-displacement function fitted by curve obtained in test, in newtons
(N);
Fp - yield load of small punch test, in newtons (N);
hf - minimum thickness of fracture, in millimeters (mm);
ReL - conventional tensile test yield strength, in megapascals (MPa);
RP - non-proportional elongation strength of conventional tensile test, in
megapascals (MPa);
Rm - tensile strength of conventional tensile test, in megapascals (MPa);
umax - punch displacement at the maximum load of small test punch, in
millimeters (mm);
Z - reduction rate of cross section of conventional tensile test, %;
ZSP - reduction rate of cross section of small punch test, %.
4 Test requirements
4.1 General requirements
In addition to the requirements of this Part, it shall also comply with GB/T
29459.1.
4.2 Test environment
The test shall be carried out in the laboratory. The test is normally carried out
at temperatures between 10°C and 35°C, unless otherwise specified. If the test
has demanding requirements for temperature, the temperature should be (23 ±
5)°C. Special precautions should be taken when there is a harsh environment.
4.3 Test loading process
Through the punch head, a downward load is applied to the center of the
specimen. The deformation of the specimen increases with increasing load until
it breaks. Figure 1 shows specimen clamping and loading diagram.
a large number of materials. The returned values of R1 and b1 shall be
applicable to the same material contained. As long as the FP value on the
loading-displacement curve of small punch test of material for test can be
obtained, the ReL value of material for test can be obtained after substituting in
equation (2).
6.4 Determination of tensile strength
Similar to the method of determining the yield strength in Clause 6.2, carry out
a large number of pre-tests. Taking Fmax as abscissa, Rm as ordinate, input the
measured data into the coordinates respectively. Then fit a straight line
according to the least squares method. Establish equation (4).
Then establish the relationship between the yield load of the small punch and
the conventional tensile yield strength of the material, so as to estimate the yield
strength of the material based on results of small punch test. Where, R2 and b2
are related to the geometry of the small punch specimen. The values of R2 and
b2 can be determined by standard specimen tensile of a large number of
materials and linear regression of small punch test.
6.5 Association with conventional elongation at break A
Equation (5) can be established by the association between the center
displacement umax of specimen and the elongation A of material.
R3 and b3 are constants related to the geometry of the small punch specimen.
The values of R3 and b3 can be determined by standard specimen tensile of a
large number of materials and linear regression of small punch test.
6.6 Association with conventional section shrinkage Z
The specimen thickness after fracture hf can be obtained by the section
shrinkage measured in small punch test, by use of section shrinkage ZSP, as
shown in equation (6), i.e., the percentage of the maximum reduction in
thickness of the specimen after fracture (h-hf) and the original thickness (h) is
associated with the conventional section shrinkage Z, in equation (7).
...... Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.
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