GB/T 7998-2023_English: PDF (GB/T7998-2023)
Standard ID | Contents [version] | USD | STEP2 | [PDF] delivered in | Standard Title (Description) | Status | PDF |
GB/T 7998-2023 | English | 459 |
Add to Cart
|
4 days [Need to translate]
|
Method for evaluating the susceptibility to intergranular corrosion of aluminum alloys
| Valid |
GB/T 7998-2023
|
GB/T 7998-2005 | English | 90 |
Add to Cart
|
0--9 seconds. Auto-delivery
|
Test method for intergranular corrosion of aluminium alloy
| Obsolete |
GB/T 7998-2005
|
GB/T 7998-1987 | English | 199 |
Add to Cart
|
2 days [Need to translate]
|
The method for determining the intergranular corrosion of aluminium alloy
| Obsolete |
GB/T 7998-1987
|
Standard ID | GB/T 7998-2023 (GB/T7998-2023) | Description (Translated English) | Method for evaluating the susceptibility to intergranular corrosion of aluminum alloys | Sector / Industry | National Standard (Recommended) | Classification of Chinese Standard | H25 | Classification of International Standard | 77.040.30 | Word Count Estimation | 22,290 | Date of Issue | 2023-05-23 | Date of Implementation | 2023-12-01 | Older Standard (superseded by this standard) | GB/T 7998-2005,GB/T 26491-2011 | Drafting Organization | Northeast Light Alloy Co., Ltd., Guangdong Academy of Sciences Industrial Analysis and Testing Center, Southwest Aluminum Industry (Group) Co., Ltd., Nonferrous Metal Technology and Economic Research Institute Co., Ltd., National Standard (Beijing) Inspection and Certification Co., Ltd., Central South University, Youyan Engineering Technology Research Institute Co., Ltd., Guangxi Nannan Aluminum Processing Co., Ltd., Shandong Nanshan Aluminum Co., Ltd., Liaoning Zhongwang Group Co., Ltd., Northwest Aluminum Co., Ltd. | Administrative Organization | National Nonferrous Metals Standardization Technical Committee (SAC/TC 243) | Proposing organization | China Nonferrous Metals Industry Association | Issuing agency(ies) | State Administration for Market Regulation, National Standardization Management Committee | Standard ID | GB/T 7998-2005 (GB/T7998-2005) | Description (Translated English) | Test method for intergranular corrosion of aluminium alloy | Sector / Industry | National Standard (Recommended) | Classification of Chinese Standard | H25 | Classification of International Standard | 77.040.30 | Word Count Estimation | 7,790 | Date of Issue | 2005-07-04 | Date of Implementation | 2005-12-01 | Older Standard (superseded by this standard) | GB/T 7998-1987 | Drafting Organization | Northeast Light Alloy Co., Ltd. | Administrative Organization | National Nonferrous Metals Standardization Technical Committee | Regulation (derived from) | Announcement of Newly Approved National Standards No. 10 of 2005 (No. 84 overall) | Proposing organization | China Nonferrous Metals Industry Association | Issuing agency(ies) | General Administration of Quality Supervision, Inspection and Quarantine of the People Republic of China, China National Standardization Administration Committee | Summary | This standard specifies: intergranular corrosion between aluminum Determination. This standard applies to: 2 �� �� �� series, 7 �� �� �� series alloys and 5 �� �� �� alloys processed products intergranular corrosion inspection and measurement. | Standard ID | GB/T 7998-1987 (GB/T7998-1987) | Description (Translated English) | The method for determining the intergranular corrosion of aluminium alloy | Sector / Industry | National Standard (Recommended) | Classification of Chinese Standard | H25 | Classification of International Standard | 77.040.30 | Word Count Estimation | 3,364 | Date of Issue | 1987/6/26 | Date of Implementation | 1988/3/1 | Regulation (derived from) | Announcement of Newly Approved National Standards 2005 No. 10 (No. 84 overall) | Issuing agency(ies) | National Bureau of Standards |
GB/T 7998-2023: Evaluation method for intergranular corrosion susceptibility of aluminum alloys
ICS 77:040:30
CCSH25
National Standards of People's Republic of China
Replace GB/T 7998-2005, GB/T 26491-2011
Evaluation method of intergranular corrosion susceptibility of aluminum alloy
Released on 2023-05-23
2023-12-01 implementation
State Administration for Market Regulation
Released by the National Standardization Management Committee
foreword
This document is in accordance with the provisions of GB/T 1:1-2020 "Guidelines for Standardization Work Part 1: Structure and Drafting Rules for Standardization Documents"
drafting:
Gold Intergranular Corrosion Test Method Mass Loss Method: Compared with GB/T 7998-2005 and GB/T 26491-2011, this document except
In addition to structural adjustments and editorial changes, the main technical changes are as follows:
a) The scope has been changed (see Chapter 1, Chapter 1 of GB/T 7998-2015 and GB/T 26491-2011);
b) The principle has been changed (see Chapter 4, Chapter 2 of GB/T 7998-2015 and GB/T 26491-2011);
c) Increased test conditions (see Chapter 5);
d) Added warning clauses (see Chapter 6) and added etchant (see 6:7);
e) Added "marking of the main deformation direction of the sample" and "sampling diagram of mass loss method" (see 8:4);
f) Added "Schematic Diagram of Forging Sample" (see 8:5);
h) Change the concentration of nitric acid for pretreatment (see 9:1, 7:1:1 of GB/T 7998-2015);
i) The test temperature of the corrosion depth method has been changed (see 9:3:2, 7:3:1 of GB/T 7998-2015);
j) Added a schematic diagram of sample placement for the mass loss method (see 9:3:3);
k) A schematic diagram of the sample preparation position of the corrosion depth method is added (see 9:4:1:1);
l) Changed the sample cleaning method after mass loss method test (see 9:4:2:2, 6:10 of GB/T 26491-2011);
m) Added pictures of typical characteristics of intergranular corrosion (see 10:1):
Please note that some contents of this document may refer to patents: The issuing agency of this document assumes no responsibility for identifying patents:
This document is proposed by China Nonferrous Metals Industry Association:
This document is under the jurisdiction of the National Nonferrous Metals Standardization Technical Committee (SAC/TC243):
This document is drafted by: Northeast Light Alloy Co:, Ltd:, Industrial Analysis and Testing Center of Guangdong Academy of Sciences, Southwest Aluminum (Group) Co:, Ltd:
Co:, Ltd:, Nonferrous Metal Technology and Economic Research Institute Co:, Ltd:, National Standard (Beijing) Inspection and Certification Co:, Ltd:, Central South University, Youyan
Cheng Technology Research Institute Co:, Ltd:, Guangxi Nannan Aluminum Processing Co:, Ltd:, Shandong Nanshan Aluminum Co:, Ltd:, Liaoning Zhongwang Group Co:, Ltd:
Division, Northwest Aluminum Co:, Ltd:
The main drafters of this document: Hou Yi, Wang Meiqi, Zhou Renliang, Gu Liu, Liu Yingkun, Feng Jing, Li Dan, Zhang Zhen, Yan Lizhen, Hu Tianlong, Song Wencheng,
Bai Xiaoxia, Zheng Xu, Liu Di, He Wenxiu, Ma Xiaoqian:
The release status of previous versions of this document and the documents it replaces are as follows:
---First published as GB/T 7998-1987 in 1987, first revised in:2005;
--- This is the second revision, which incorporates the contents of GB/T 26491-2011:
Evaluation method of intergranular corrosion susceptibility of aluminum alloy
1 Scope
This document describes a method for the evaluation of susceptibility to intergranular corrosion of aluminum alloy products:
2 Normative references
The contents of the following documents constitute the essential provisions of this document through normative references in the text: Among them, dated references
For documents, only the version corresponding to the date is applicable to this document; for undated reference documents, the latest version (including all amendments) is applicable to
this document:
GB/T 3246:1 Deformed Aluminum and Aluminum Alloy Products Microstructure Test Method Part 1: Microstructure Test Method
GB/T 6682 Analytical laboratory water specifications and test methods
GB/T 6684-2002 chemical reagent 30% hydrogen peroxide
GB/T 8170 Numerical rounding off rules and expression and determination of limit values
JJG (Education Committee) 012 Metallographic Microscope Verification Regulations
3 Terms and Definitions
The following terms and definitions apply to this document:
3:1
Corrosion that develops along or adjacent to the grain boundaries of a metal or alloy:
Note: The grain itself corrodes very slightly: This kind of corrosion greatly weakens the bonding force between grains, and in severe cases, the mechanical strength can be completely lost:
4 principles
According to the principle of cathodic depolarization, the aluminum alloy sample is placed in a specific test solution for a certain period of time to accelerate the alloy grain boundary or crystallization:
The intergranular corrosion susceptibility of aluminum alloys can be evaluated by measuring the corrosion depth or mass loss near the intergranular corrosion:
The intergranular corrosion of gold samples was measured, and the depth of intergranular corrosion was measured:
volume loss: When the test results are in doubt, the qualitative evaluation of the intergranular corrosion in its longitudinal section by means of an optical (metallographic) microscope
analyze:
Note 1: Cathode depolarization refers to the elimination or reduction of the corrosion cell retardation effect caused by cathode polarization, and the enhancement of cathode depolarization can accelerate the corrosion rate:
5 Test conditions
The test environment temperature should not be higher than the test temperature, and ventilation facilities should be equipped:
......
GB/T 7998-2005
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 77.040.30
H 25
GB 7998-2005
Replacing GB 7998-1987
Test method for intergranular corrosion of
aluminium alloy
ISSUED ON. JULY 4, 2005
IMPLEMENTED ON. DECEMBER 1, 2005
Jointly Issued by. General Administration of Quality Supervision,
Inspection and Quarantine of the People's Republic of
China;
Standardization Administration of the People's
Republic of China.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Method summary ... 4
4 Reagents ... 4
6 Sample ... 5
7 Corrosion test of sample ... 6
8 Metallographic examination ... 7
9 Result expression ... 8
10 Test report ... 8
Foreword
This Standard is formulated by reference to ASTM G110-1992 “Standard Practice for
Evaluating Intergranular Corrosion Resistance of Heat Treatable Aluminum Alloys by
Immersion in Sodium Chloride + Hydrogen Peroxide Solution”.
This Standard replaces GB/T 7998-1987.
This Standard makes a lot of editorial changes to GB/T 7998-1987.
This Standard was proposed by China Nonferrous Metals Industry Association.
This Standard shall be under the jurisdiction of the National Non-ferrous Metals
Standardization Technical Committee.
This Standard is responsibly drafted by the Northeast Light Alloy Co., Ltd.
Main drafters of this Standard. Gao Zhenzhong, Hou Yi, Zheng Yunlong, Wang Meiqi,
and Sun Yanchang.
This Standard shall be responsibly interpreted by the National Standardization
Technical Committee of Non-ferrous Metals.
The historical version replaced by this Standard is as follows.
- GB/T 7998-1987.
Test method for intergranular corrosion of
aluminium alloy
1 Scope
This Standard specifies the test method for intergranular corrosion of aluminum alloy.
This Standard applies to intergranular corrosion’s inspection and measurement of
intergranular corrosion of series-2XXX alloy, series-7XXX alloy, and series-5XXX
alloy.
2 Method summary
This method uses metalloscope to perform the intergranular corrosion’s inspection to
the surface of samples or products that have not gone through corrosion, or to the
samples that are after corrosion test (in sodium chloride solution, add hydrogen
peroxide or hydrochloric acid; immerse the sample; conduct intergranular corrosion’s
accelerated corrosion test of reinforced cathode depolarization), and measure the
depth of intergranular corrosion.
3 Terms and definitions
3.1
intergranular corrosion
It refers to the corrosion phenomenon that is occurred along the metal grain boundary
or near the grain boundary.
3.2
cathode depolarization
Those, that can eliminate or reduce the polarization caused by the convergence of the
original battery blockade, are known as depolarization. The depolarization effect that
is corrosive to battery cathode polarization is called cathode depolarization.
Enhancing the cathode depolarization can accelerate the corrosion rate.
4 Reagents
the removed thickness is 2 times of the product nominal aluminium-cladded
layer-thickness. If there still remains aluminium-cladded layer, this sample is void, a
new sampling shall be conducted.
7.2 Preparing test solution
7.2.1 For series-2XXX and series-7XXX alloy samples, pipette sodium chloride
solution (4.5) into a container; according to per liter of solution containing 10 mL of
hydrogen peroxide (4.1), add hydrogen peroxide; mix well.
7.2.2 For series-5XXX alloy sample, pipette sodium chloride solution (4.6) into a
container; according to per liter of solution containing 10 mL of hydrochloric acid (4.2),
add hydrochloric acid; mix well.
7.3 Sample corrosion
7.3.1 test shall be conducted at constant temperature of 35°C ± 2°C. Test temperature
is controlled by a thermostat device.
7.3.2 The sample is hung with a plastic wire, and completely immersed in the test
solution that is newly prepared (7.2). The ratio of sample’s surface area to the test
solution’s volume is less than 20 mm2/mL. Different alloy samples can not be placed
in the same container; between the samples or between the sample and the container,
they can not touch each other.
7.3.3 For series-2XXX alloys and series-7XXX alloys, the test time is 6h; for
series-5XXX alloys, the test time is 24 h.
7.3.4 After corrosion, the sample is washed with water and dried.
8 Metallographic examination
8.1 After corrosion, the test sample is cut out (do not use shear-cut method) by 5mm
at one end along vertical main deformation direction. After cutting, the cross-section is
processed according to 8.2. The sample that is not gone through corrosion test shall
be directly processed according to 8.2.
8.2 According to metallographic sample preparation method, grind and polish (prevent
chamfer) the sample; without immersion-corrosion, observe by optical metalloscope
(magnification 100X – 500X). If net-shaped grain boundary appears, then it is deemed
as intergranular corrosion (typical intergranular corrosion photograph is shown in
Figure 2); measure its maximum depth of intergranular corrosion.
c) Alloy designation or chemical composition;
d) Processing status;
e) The sample is with or without aluminium-cladded;
f) If test results have intergranular corrosion, indicate.
1) The distribution of intergranular corrosion;
2) The maximum depth of intergranular corrosion (or grade);
3) When necessary, photo shall be attached for illustration.
g) Other test results that may affect the situation or that are required to be
indicated.
......
|