GB/T 40512-2021 English PDF (GBT40512-2021)

Delivery: 3 seconds. Download true-PDF + Invoice.
Get QUOTATION in 1-minute: Click GB/T 40512-2021
Historical versions: GB/T 40512-2021
Preview True-PDF (Reload/Scroll if blank)

GB/T 40512-2021: Test method of exposure to weathering for motor vehicle
GB/T 40512-2021
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 43.020
CCS T 04
Test method of exposure to weathering for motor
vehicle
ISSUED ON: AUGUST 20, 2021
IMPLEMENTED ON: MARCH 01, 2022
Issued by: State Administration for Market Regulation;
Standardization Administration of the People's Republic of
China.
Table of Contents
Foreword ... 3 
1 Scope ... 4 
2 Normative references ... 4 
3 Terms and definitions ... 5 
4 Principle ... 6 
5 Test conditions ... 6 
6 Instruments and equipment... 8 
7 Test sample ... 9 
8 Exposure period and testing cycle ... 10 
9 Test procedures and requirements ... 11 
10 Data processing ... 16 
11 Result evaluation ... 19 
12 Test report ... 19 
Annex A (normative) Aging phenomenon, appearance inspection items and
principles of aging evaluation ... 21 
Bibliography ... 26 
Test method of exposure to weathering for motor
vehicle
1 Scope
This Standard specifies test principle, test conditions, instruments and
equipment, test samples, exposure period and test cycle, test procedures and
requirements, data processing, result evaluation and test report for exposure to
weathering for motor vehicle.
This Standard is applicable to exposure test to weathering for the parts and
assemblies installed on the entire vehicle.
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 250, Textiles - Tests for colour fastness - Grey scale for assessing
change in colour
GB/T 1766, Paints and Varnishes - Rating Schemes of Degradation of Coats
GB/T 3511, Rubber, vulcanized or thermoplastic - Resistance to weathering
GB/T 3681, Plastics - Test methods of exposure to weathering
GB/T 6739, Determination of film hardness by pencil test
GB/T 8807, Test method for specular gloss of plastics
GB/T 9286, Paints and varnishes - Cross cut test for films
GB/T 9754, Paints and varnishes - Determination of specular gloss of non-
metallic paint films at 20° 60°and 85°
GB/T 9761, Paints and varnishes - Visual comparison of the colour of paints
GB/T 11186.2, Methods for measuring the colour of paint films - Part 2:
Colour measurement
corrosion of metals in the natural environment of the atmosphere
3.7 temperature normalized radiation; TNR
the radiation equivalent related to total solar radiation and black mark
temperature, that is, the total solar radiation after the correction of the total solar
radiation using the black mark temperature measured at the same time
4 Principle
Expose the prototype vehicle under natural atmospheric environmental
conditions that can be representative of a certain climate type area for the
exposure test. Let it withstand the combined effects of sunlight, heat, water
vapor, rain, oxygen, ozone and other environmental factors. According to the
specified exposure test period, regularly inspect the appearance and other
properties of non-metallic material products for prototype vehicles, the
corrosion of metal material products and the operation of functional parts, so as
to evaluate the resistance of the prototype to the natural environment,
atmospheric aging, atmospheric corrosion, and operation and use functions.
5 Test conditions
5.1 Exposure site requirements
5.1.1 Exposure site selection
The exposure site shall be selected within a natural environment that can
represent a certain climate type or an environmental area where the prototype
vehicle is actually used.
NOTE 1: According to climatic conditions, China’s climate can be divided into 14 climatic
zones (see GB/T 17297-1998).
NOTE 2: Industrial exposure sites with special needs are located in concentrated areas of
factories and mines. Salt spray climate exposure sites are located on the seashore or
island where the air is rich in salt.
5.1.2 Standard exposure site requirements
The site shall be flat and open, free of water, and far away from buildings and
trees. The distance between the surrounding obstacles and the edge of the site
shall not be less than 3 times the height of the obstacle. There shall be no
factory chimneys, vents or other facilities that can emit large amounts of
corrosive gases and impurities near the site. The site shall maintain the local
natural vegetation status. The height of the plant shall not exceed 200mm.
NOTE: In order to adapt to special test purposes, cement floors can also be used and
indicated in the report.
5.1.3 Exposure site equipment requirements
Meteorological element observation and atmospheric media analysis
equipment shall be installed in or near the exposure site, so as to carry out the
long-term continuous observation and recording of the main meteorological
elements and regular measurement of the atmospheric composition of the
surrounding environment. In addition to general meteorological equipment in
the exposure field, there shall be different angles (5°, 45°, 90°, local latitude)
under the glass and direct solar radiation energy receiving devices. Flat glass
for automobiles shall be used.
NOTE: Angle refers to the angle between the sensor plane and the ground.
5.2 Test environment
5.2.1 Visual inspection environment
Under normal circumstances, natural daylight shall be used. It is advisable to
use the cloudy daylight of the northern sky in the northern hemisphere or the
cloudy daylight of the southern sky in the southern hemisphere (that is, from 3h
after sunrise to 3h before sunset, avoid the skylight directly exposed to sunlight).
There shall be no reflected light from colored objects, such as red brick walls or
green trees.
For special requirements, the visual evaluation of the appearance of the whole
vehicle shall use strictly controlled artificial light sources. Observers shall wear
neutral-colored clothing. In the field of view, there shall be no other colored
objects except the specimen. The artificial light source lighting conditions and
observer conditions in the laboratory shall meet the requirements of GB/T 9761.
The same light source shall be used throughout the test. Other conditions shall
be as consistent as possible.
5.2.2 Environmental conditions for sampling of harmful substances in the
air in the vehicle
The sampling of harmful substances in the air in the vehicle shall be carried out
in a sunny day during the day.
After the test sample vehicle is cleaned and dried, it shall be parked for more
than 24h under the environmental conditions specified in 7.3. It can also be
parked for more than 24h under normal laboratory conditions and indicated in
the record and report.
8 Exposure period and testing cycle
8.1 Exposure period setting method
8.1.1 The exposure period can be set according to the time (such as month,
year), the total solar radiation received by the surface of the main components
or a specified limit reached by TNR, and a specified limit reached by the change
(such as loss of light, discoloration) in the performance of the sample.
8.1.2 If there are no special requirements, the exposure period is generally not
less than 1 year when setting by time.
8.2 Representation of exposure period
8.2.1 When the time limit is used, the unit is day, month, and year.
8.2.2 When the total solar radiation or TNR is the ...