QC/T 484-1999Automotive paint coatings (English PDF)

1 Provisions on paint coating codes

According to the different use conditions of automobile parts and paint quality requirements, the paint coating is divided into 10 groups and several levels, according to the provisions of Table 1.

2 Technical requirements

2.1 The main quality indicators of paint coatings are specified in Table 2 according to the group and level of paint coating codes.

2.3 For the color of the paint coating of automobile parts, this Standard does not specify.

It shall be determined by each company according to the use of parts and user requirements.

3 Marks

Select the code and level of the paint coating according to the use conditions of the automobile parts and the coating quality requirements.

4 Inspection

4.1 The inspection method of paint coating quality indicator is in accordance with the following provisions.

4.1.1 Paint film appearance. compare with standard version through visual inspection.

4.1.7 Adhesion. determine according to GB 1720-79 "Method of test for adhesion of paint films".

4.1.8 Alkali resistance. use the following two inspection methods to determine.

4.1.9 Acid resistance. drop 0.1 NH2SO4 solution onto the sample plate. Observe the change of paint film after 24 hours at 20°C.

4.1.10 Water resistance. immerse the sample plate in a constant temperature water bath at 50 ± 1°C. Observe the change of paint film. Heat at 50 ± 1°C for 8 hours then stop heating. Naturally cool in a heat-insulated device for 16 hours as a cycle.

4.1.12 Gasoline resistance. determine according to GB 1734-79 "Determination of resistance to petrol of films".

4.1.13 Engine oil resistance. determine according to chemical temporary 2017-57 "Determination of resistance to lubricating oil".

4.1.14 Weather resistance. assess the ability of paint film to resist natural damage.

4.1.15 Temperature change resistance. put the test sample plate from room temperature into a +60°C oven for 1 hour. Then take out the sample plate. Cool to room temperature then put into a -40°C freezer for one hour. Take out the sample plate to cool to room temperature and it shall be one cycle. […]