GB/T 30789.1-2015 English PDF (GB/T30789.1-2015)

GB/T 30789.1-2015: Paints and varnishes -- Evaluation of degradation of coatings -- Designation of quantity and size of defects, and of intensity of uniform changes in appearance -- Part 1: General introduction and designation system
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GB/T 30789.1-2015
GB
NATIONAL STANDARD OF
THE PEOPLE’S REPUBLIC OF CHINA
ICS 87.040
G 50
GB/T 30789.1-2015 / ISO 4628-1.2003
Paints and varnishes - Evaluation of degradation of
coatings - Designation of quantity and size of defects,
and of intensity of uniform changes in appearance -
Part 1. General introduction and designation system
(ISO 4628-1.2003, IDT)
ISSUED ON. JUNE 2, 2015
IMPLEMENTED ON. JANUARY 1, 2016
Issued by. General Administration of Quality Supervision, Inspection and
Quarantine;
Standardization Administration Committee.
Table of Contents
Foreword ... 3 
1 Scope ... 5 
2 General principles of the designation system ... 5 
3 Assessment of defects and of intensity of changes ... 6 
4 Expression of results ... 7 
5 Test report ... 8 
Foreword
GB/T 30789 Paints and varnishes - Evaluation of degradation of coatings -
Designation of quantity and size of defects, and of intensity of uniform changes
in appearance consists of the following parts.
- Part 1. General introduction and designation system;
- Part 2. Assessment of degree of blistering;
- Part 3. Assessment of degree of rusting;
- Part 4. Assessment of degree of cracking;
- Part 5. Assessment of degree of flaking;
- Part 6. Assessment of degree of chalking by tape method;
- Part 7. Assessment of degree of chalking by velvet method;
- Part 8. Assessment of degree of delamination and corrosion around a
scribe or other artificial defects;
- Part 9. Assessment of degree of filiform corrosion.
This Part is the first part of GB/T 30789.
This Part was drafted in accordance with the rules given in GB/T 1.1-2009.
This Part uses translation method and identically adopts ISO 4628-1.2003
Paints and varnishes - Evaluation of degradation of coatings - Designation of
quantity and size of defects, and of intensity of uniform changes in appearance
- Part 1. General introduction and designation system.
This Part was proposed by China Petroleum and Chemical Industry Federation.
This Part shall be under the jurisdiction of National Technical Committee on
Paints and Pigments of Standardization Administration of China (SAC/TC 5).
The drafting organizations of this Part. CNOOC Changzhou Paint and
Chemicals Research Institute Co., Ltd., China Zhiqi (Shenzhen) Co., Ltd.,
Guangzhou Synthetic Material Research Institute Co., Ltd., AVIC Bermuda New
Material Technology Engineering Co., Ltd., Zhejiang Zhiqiang Paint Co., Ltd.,
Zhejiang Tianyu Group Paint Co., Ltd., Shanghai Jinlitai Chemical Industry Co.,
Ltd., Dongguan Yian Technology Co., Ltd., Shenzhen Hao Feng Technology
Co., Ltd..
Paints and varnishes - Evaluation of degradation of
coatings - Designation of quantity and size of defects,
and of intensity of uniform changes in appearance -
Part 1. General introduction and designation system
1 Scope
This Part of GB/T 30789 defines a system for designating the quantity and size
of defects and the intensity of changes in appearance of coatings and outlines
the general principles of the system used throughout GB/T 30789. This system
is intended to be used, in particular, for defects caused by ageing and
weathering, and for uniform changes such as colour changes, for example
yellowing.
The other parts of GB/T 30789 provide pictorial standards or other means of
evaluating particular types of defect. As far as possible, already existing
evaluation schemes have been used as the basis.
This Part of GB/T 30789 can also be used for assessing defects not covered
by the other parts of GB/T 30789.
2 General principles of the designation system
A uniform convention has been adopted for designating the quantity and size of
defects and the intensity of changes by means of ratings on a numerical scale
ranging from 0 to 5.0 denoting no defects or changes, and 5 denoting defects
or changes so severe that further discrimination is not reasonable. The other
ratings, corresponding to the numbers 1, 2, 3 and 4, are so defined that they
give optimum discrimination over the whole range of the scale.
The use of intermediate half-steps is permissible, if specified, to give a more
detailed report on the defects or changes observed.
NOTE 1 The quantity of small defects scattered over the test area may be assessed by
means of a grid method. Details of such a method are described in ISO 4540, Metallic
coatings - Coatings cathodic to the substrate - Rating of electroplated test specimens
subjected to corrosion tests.
NOTE 2 The GB/T 30789 ranking may be different from the ranking schemes used in
GB/T 30789.1-2015
GB
NATIONAL STANDARD OF
THE PEOPLE’S REPUBLIC OF CHINA
ICS 87.040
G 50
GB/T 30789.1-2015 / ISO 4628-1.2003
Paints and varnishes - Evaluation of degradation of
coatings - Designation of quantity and size of defects,
and of intensity of uniform changes in appearance -
Part 1. General introduction and designation system
(ISO 4628-1.2003, IDT)
ISSUED ON. JUNE 2, 2015
IMPLEMENTED ON. JANUARY 1, 2016
Issued by. General Administration of Quality Supervision, Inspection and
Quarantine;
Standardization Administration Committee.
Table of Contents
Foreword ... 3 
1 Scope ... 5 
2 General principles of the designation system ... 5 
3 Assessment of defects and of intensity of changes ... 6 
4 Expression of results ... 7 
5 Test report ... 8 
Foreword
GB/T 30789 Paints and varnishes - Evaluation of degradation of coatings -
Designation of quantity and size of defects, and of intensity of uniform changes
in appearance consists of the following parts.
- Part 1. General introduction and designation system;
- Part 2. Assessment of degree of blistering;
- Part 3. Assessment of degree of rusting;
- Part 4. Assessment of degree of cracking;
- Part 5. Assessment of degree of flaking;
- Part 6. Assessment of degree of chalking by tape method;
- Part 7. Assessment of degree of chalking by velvet method;
- Part 8. Assessment of degree of delamination and corrosion around a
scribe or other artificial defects;
- Part 9. Assessment of degree of filiform corrosion.
This Part is the first part of GB/T 30789.
This Part was drafted in accordance with the rules given in GB/T 1.1-2009.
This Part uses translation method and identically adopts ISO 4628-1.2003
Paints and varnishes - Evaluation of degradation of coatings - Designation of
quantity and size of defects, and of intensity of uniform changes in appearance
- Part 1. General introduction and designation system.
This Part was proposed by China Petroleum and Chemical Industry Federation.
This Part shall be under the jurisdiction of National Technical Committee on
Paints and Pigments of Standardization Administration of China (SAC/TC 5).
The drafting organizations of this Part. CNOOC Changzhou Paint and
Chemicals Research Institute Co., Ltd., China Zhiqi (Shenzhen) Co., Ltd.,
Guangzhou Synthetic Material Research Institute Co., Ltd., AVIC Bermuda New
Material Technology Engineering Co., Ltd., Zhejiang Zhiqiang Paint Co., Ltd.,
Zhejiang Tianyu Group Paint Co., Ltd., Shanghai Jinlitai Chemical Industry Co.,
Ltd., Dongguan Yian Technology Co., Ltd., Shenzhen Hao Feng Technology
Co., Ltd..
Paints and varnishes - Evaluation of degradation of
coatings - Designation of quantity and size of defects,
and of intensity of uniform changes in appearance -
Part 1. General introduction and designation system
1 Scope
This Part of GB/T 30789 defines a system for designating the quantity and size
of defects and the intensity of changes in appearance of coatings and outlines
the general principles of the system used throughout GB/T 30789. This system
is intended to be used, in particular, for defects caused by ageing and
weathering, and for uniform changes such as colour changes, for example
yellowing.
The other parts of GB/T 30789 provide pictorial standards or other means of
evaluating particular types of defect. As far as possible, already existing
evaluation schemes have been used as the basis.
This Part of GB/T 30789 can also be used for assessing defects not covered
by the other parts of GB/T 30789.
2 General principles of the designation system
A uniform convention has been adopted for designating the quantity and size of
defects and the intensity of changes by means of ratings on a numerical scale
ranging from 0 to 5.0 denoting no defects or changes, and 5 denoting defects
or changes so severe that further discrimination is not reasonable. The other
ratings, corresponding to the numbers 1, 2, 3 and 4, are so defined that they
give optimum discrimination over the whole range of the scale.
The use of intermediate half-steps is permissible, if specified, to give a more
detailed report on the defects or changes observed.
NOTE 1 The quantity of small defects scattered over the test area may be assessed by
means of a grid method. Details of such a method are described in ISO 4540, Metallic
coatings - Coatings cathodic to the substrate - Rating of electroplated test specimens
subjected to corrosion tests.
NOTE 2 The GB/T 30789 ranking may be different from the ranking schemes used in