QC/T Translated English of Chinese Standard: QC/T AUTOMOTIVE INDUSTRY STANDARD

Transcription

1 Translated English of Chinese Standard: QC/T AUTOMOTIVE INDUSTRY STANDARD QC OF THE PEOPLE S REPUBLIC OF CHINA QC/T General rules for automotive part weathering test 汽车零部件耐候性试验一般规则 Issued on: May 21, 1992 Implemented on: June 1, 1993 Issued by: China Automotive Industry Corporation Page 1 of 31

2 Table of Contents 1 Subject content and application scope Normative references Terms Test type and code name Service conditions and code Importance and classification of parts Specimens Test methods Evaluation methods Evaluation of test result Recording items Additional explanation Page 2 of 31

3 General rules for automotive part weathering test 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 Evaluation of degradation of paint coatings - Part 2: Designation of degree of blistering GB Evaluation of degradation of paint coatings - Part 3: Designation of degree of rusting GB Evaluation of degradation of paint coatings - Part 4: Designation of degree of cracking GB Evaluation of degradation of paint coatings - Part 5: Designation of degree of flaking Page 3 of 31

4 GB 1767 Method for exterior exposure tests of paint films 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. 3.9 Dirt: refers to such as harmful gas, organic matter adhering to or permeating to exposed surface, which can not be cleaned Flaking: means falling off, or expansion of protective film, or adhesive part on the surface of specimen Applicable reference: refers to test regulation that is determined by use condition and degree of importance of parts. For example: ES2 and IG3 (as shown in Table 2 and Table 3) Quantity of illumination: refers to amounts of sunlight received by exposed surface, unit is kcal/cm Glossiness: based on glossiness of 60 mirror surface, divided as follows: No-light Below 20% Semi-gloss Between 20% and 80% Page 4 of 31

5 Bright Above 80% 3.14 Specimen: refers to parts or test block prepared according to purpose for test Direct exposure test: is a test that put specimen in natural environment such as sunlight, wind and rain; degradation degree of its surface coating is changed as time goes by Exposure test across glass: is a test that specimen in test box is covered by glass pane for exposure; inspect its degradation degree as time goes by Masking exposure test: a test that specimen is placed under shielding structure, under the condition that it is avoided from direct influence by sunlight and rain-snow, the degradation degree of its surface coating is changed as time goes by Immersion exposure test: is a test that partial part of specimen or the whole specimen is immersed in test solution, placed outdoor; and be put outside, the degradation degree of its surface coating is changed as time goes by Exposure device: refers to devices such as exposure rack and specimen storage box that are used for putting specimen Test box: is a container that is used for environmental conditioning, having ventilation facility; its top part is covered by glass pane Storage box: is a container that is used to place-store specimen Environmental factor: is a generic term of meteorological factors such as air temperature, insolation, rainfall capacity of exposure environment AND environmental pollution factors such as amount of coal ash fallen and sulfur dioxide concentration Exposure duration: refers to that time spent by exposure test of specimen. 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). Page 5 of 31

6 Carbon electrode The upper part (mm) Sunlight carbon rod covered by copper Solid or non-filled carbon electrode The bottom part (mm) Sunlight carbon rod covered by copper Solid or non-filled carbon electrode Average discharge voltage (V) 50±2% 135±2% Average discharge current (A) 60±2% 16±2% Light filter Plate-shape transmittance: below 255nm, 0%; Spherical transmittance: below 279nm, 0%; 400nm, above 90% 400nm, above 90% Adjusting temperature C 63±3 Size Referring to (1) of Figure 1 Referring to (2) of Figure 1 Temperature sensing section of the bi-metal dial thermometer (1 scale as 1 C and the diameter of temperature Black panel sensing section as 3. 5mm) shall be close to stainless steel plate lmmx150mmx70mm for installation. thermometer Description Distance from center of arc lamp to Specimen rotary drum or frame specimen surface (mm) Temperature sensing section shall be painted light resistance black enamel. Black panel thermometer as a trail is used for measuring temperature and correct thermometer. In the process of correction, black panel thermometer shall be placed facing light source. When each indicated temperature is read, error of measured temperature and corrected temperature shall be within ±2 C. 476~ ~384 Diameter (mm) Specimen rotary support 960 Rotation speed min -1 About 1 Relationship among arc lamp, specimen rotating liquid canister, frame and sprayer Referring to (1) of Figure 5 Referring to (2) of Figure 5 Size of nozzle Referring to Figure 6 Pressure kpa 78~127 Jetting condition Amount of water ml/min 2100±100 of water Time of jetting Jet of 12 min, in exposure of 60min Water quality Raw ionized water, PH value is 60-80, conductivity is 10S/cm Condition in test-machine In the form of air-blow of closed loop, auxiliary devices shall be installed to avoid waste heat and harmful gas such as ozone produced during discharge. Page 16 of 31

7 Item Table 14 Test condition Concentration of ozone pphm 50±5 Test temperature C 40±2 Internal capacity of test equipment is 0.11~0.14 m 3,; the length and Test equipment Installation of specimen Determination of concentration of ozone Times of determination of concentration of ozone Conditioning of specimen Number of specimen width are almost equal. Air heater is installed at a place that does not have bad influence on concentration of ozone; its inner air is a device of cyclic type, indicating ventilation flow. Hang vertically, without touching each other Constant current electrolytic method After specimen is placed inside, measure once per 15 min; measure daily after 3 hours. Test shall be conducted after it is placed in closed chamber for 24 hours Surface area of specimen shall not be greater than 60% of the horizontal sectional area of test equipment s inner chamber Note: Determination parts of ozone concentration shall be decided by supplier and buyer. 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 WON, WOL and WAN test shall be conducted after stain on effective surface is cleaned. 9.3 Appearance of specimen after test a. Compare with standard specimen according to requirements. When specimen is finished, its appearance evaluation shall be conducted on effective surface. b. Take opal lamp of w as the light source; ensure that illumination of effective surface is 1000lx. Ray of light shall project with 45 to specimen. At 25cm from the specimen, visually inspected with naked eyes; the same light source shall be adopted in the whole process of test. 9.4 Storage condition of standard specimen shall be in accordance with provisions of article 3.1 of GB Shape and size evaluation of specimen after test a. Changes of shape shall be visually inspected; Page 19 of 31

8 b. Changes of size shall be measured according to relevant measurement equipment. Change rate shall be calculated according to the following formula. Size change rate (%) = Size before test - size after test Size before test X 100% If the size change rate is positive value, then it indicates the specimen expansion. If the size change rate is negative value, then it indicates the specimen shrinkage. 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 Evaluation of light transmittance: Changes of light transmittance shall be inspected according to GB Change rate shall be calculated according to the following formula. % x 100% 9.8 Glossiness evaluation a. Visual evaluation: when there is difficulties in evaluating, compare standard piece with specimen to inspect changes of the latter. b. Evaluation through equipment shall be in accordance with provisions of GB Blistering evaluation shall be in accordance with provisions of GB Rustiness evaluation shall be in accordance with provisions of GB Flaking evaluation shall be in accordance with provisions of GB 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 Evaluation of coating cracking shall be in accordance with provisions of GB Local crack produced by special parts shall be recorded in details Physical and chemical performance evaluation shall be determined by supplier and buyer together Finished products evaluation shall be determined, based on service conditions of parts, by supplier and buyer together. Page 20 of 31

9 10 Evaluation of test result Test result evaluation shall be in accordance with Table 15. Types of materials Plastic Rubber Artificial leather Table 15 Evaluation Evaluation level items Level A Level B Level C Color-fading Level 3 Level 1 Level 1 There is almost no change or Light There is no significant change change of light transmittance is transmittance or change rate is below 15% below 15% There is almost no change, or There is almost no significant glossiness residual rate is change, or glossiness residual Glossiness above 80% in glossiness rate is above 50% in place, and is above 50% in glossiness place, and is above semi-glossiness place. 20% in semi-glossiness. pollution Dirt Not easily identifiable Non-significant Pulverization Non-significant Erosion Flaking Nothing Nothing Cracking Not easily identifiable Hardening Non-significant Rubber Level 2 Level 1 Contactpollution Nothing Not easily identifiable Non-significant Pulverization Blooming Not easily identifiable Non-significant Flaking Nothing Nothing Cracking Above level 1 Above level 2 Above level 3 Hardening Softening Nothing Non-significant Color-fading Above level 3 Level 2 Level 1 There is almost no change or There is almost no visual glossiness residual rate is change, or glossiness residual Glossiness above 80% in glossiness rate is above 50% in place, and is above 50% in glossiness place, and is above semi-glossiness place. 20% in semi-glossiness place. Pollution Contact pollution Dirt Not easily identifiable Not obvious Non-significant Non-significant Flaking Nothing Non-significant Page 21 of 31

10 Lowest humidity % Highest / lowest average humidity % Total rainfall during test mm Ozone concentration at 2 pm. pphm Quantity of illumination Time and reason of why test is stopped or interrupted in the middle Matters discussed by supplier and buyer In accordance with applicable references and level Name of test personnel Other matters Note: 1 Weather observation items shall be recorded every day during test; ozone concentration shall be recorded once every week. Daily quantity of illumination that is automatic recording shall record total number during test. 2 Weather observation item can be decided after negotiation of supplier and buyer Intensified test shall be in accordance with Table 17. Table 17 Item Name and model of test-machine Test name, material quality of test piece, shape, size and quantity Temperature ( C) and humidity (%) of laboratory Average discharge voltage (V) and current (A) Indicating temperature of black panel thermometer ( C) Types of test WON WOL WOS Spray pressure kpa Test conditions Spray water period PH value of water Ozone concentration at 2 pm. pphm Test temperature ( C) Test time (h) Installation status of specimen Observation test item Interruption times of test Matters discussed by supplier and buyer In accordance with applicable references and level Date of test Name of test personnel Other matters Page 23 of 31

11 Additional explanation This Standard was proposed by China Automobile Industry. This Standard shall be under the jurisdiction of Chinese Automotive Standardization Committee. This Standard was drafted by No.2 Automotive Manufacturing Plant. Main drafters of this Standard: Li Yuqing and Guan Xiuqing. END Page 31 of 31