QC/T 17-1992General rules for weathering exposure tests of automotive parts (English PDF)

1 Subject content and application scope

This Standard specifies contents, methods, conditions and devices of automotive parts' weathering test.

This Standard applies to automobile parts and automotive metal parts that are made up of plastics, rubber, artificial leather fiber.

This Standard does not apply to parts such as electric wire, tire, anti-vibration rubber, air spring.

2 Normative references

GB 250 Gray scale for assessing change in colour

GB 2410 Transparent plastics - Transmissivity and haze test

GB 2918 Standard atmospheres for conditioning and testing of plastic specimens

GB 2941 Rubber - Standard temperatures, humidity and times for the conditioning environmental and testing of test pieces

GB 3511 Rubber vulcanized - The test method of resistance to natural weathering

GB 3681 Methods of exposure to natural weathering of coating

GB 9754 Paints and varnishes - Determination of specular gloss of non-metallic paint films at 20°, 60°and 85°

GB 9277.2 Evaluation of degradation of paint coatings - Part 2: Designation of degree of blistering

GB 9277.3 Evaluation of degradation of paint coatings - Part 3: Designation of degree of rusting

3 Terms

3.1 Weather resistance. refers to anti-weathering ability of specimen under natural climate conditions such as sunlight, ozone, rain and snow, humidity and temperature.

3.2 Light resistance. refers to that surface of specimen resists degradation.

3.3 Degradation. means the phenomenon that when specimen is exposed in natural or artificial environment, its performance becomes worse as time goes by.

3.4 Exposure side. refers to the surface that specimen directly touches with sunlight, ozone, rain and snow.

3.5 Effective side. refers to the surface that has working function. a. Directly visible surface under service conditions. b. Surface of parts that is directly influenced by changes of surface condition.

3.6 Standard specimen. refers to the specimen, used for regular observation and comparison, that is stored in specified conditions.

3.7 Color-fading. refers to changes of specimen test that is caused by changes of color, brightness and other degradations.

3.8 Contact-pollution. refers to changes caused by different materials' interaction.

4 Test type and code name

Test types shall be divided into outdoor and indoor test; it is divided into seven types according to test conditions and types of testing machine (as shown in Table 1).

5 Service conditions and code

Consider comprehensively according to environment and using sites of parts.

6 Importance and classification of parts

Classification shall be conducted according to degree of importance of part design, as shown in Table 3

7 Specimens

7.1 Specimen shall be parts. If there are requirements in test, specimen used for coating, as specified in Table 4, shall be adopted.

7.2 When performance of test material changes, specimen shall be chosen according to different performances tested. P

8 Test methods

9 Evaluation methods

9.1 Evaluation of specimen shall be conducted after and before test, within specified time.

Inspection of specimen after and before shall avoid the top and edge part of specimen.

9.2 Specimen shall be cleaned according to test purpose; if necessary, conduct in accordance with provisions in GB 2918 and GB 2941.WON, WOL and WAN test shall be conducted after stain on effective surface is cleaned.

9.6 Color-fading evaluation. Compare standard piece with specimen; inspect changes of the latter; its color-fading degree shall be decided according to provisions of GB 250.

9.9 Blistering evaluation shall be in accordance with provisions of GB 9277.2.

9.10 Rustiness evaluation shall be in accordance with provisions of GB 9277.3.

9.11 Flaking evaluation shall be in accordance with provisions of GB 9277.5.

9.12 Rubber cracking evaluation. Cracking after rubber test shall be inspected according to method described in b of article 9.3. Rubber cracking shall be evaluated according to level evaluation given in Table 2 of Appendix B Rubber Weathering Test Appearance Inspection Method in GB 3511. Evaluation of coating cracking shall be in accordance with provisions of GB 9277.4.

QC/T 17-92