1、GM DAEWOO Auto Curtin Mathheson Scientific, or its equivalent 2.6. Furnace Re-circulating furnace capable of keeping temperature of 260280 2.7. Carbon analyzer Leco CS 244 or its equivalent (For improved accuracy, equipment using an infrared detector is recommended.) (Note 2) To avoid damage of the
2、instrument panel, a proper acid collecting device shall be provided inside the equipment. For information on each equipment, refer to the supplier of the equipment. 2.8. Vapor degreaser (for method B) Philips manufacturing co., DETROIT, MI T48E or its equivalent 3. TEST CONDITIONS Unless specified o
3、therwise, all test values described here shall be based on materials controlled to temperature of 232 and relative humidity of 505% for min. 24 hours before test. 4. TEST PROCEDURES 4.1. Method A - power washer method EDS-T-7176DETERMINATION OF THE QUANTITY OF CARBON CONTAMINATION ON COLD ROLLED STE
4、EL SURFACES PAGE: 2/3 ISSUED DATE: 1998. 03. 31 REVISED DATE: 2006. 06. 19 VERSION: 2 GM DAEWOO Auto & Technology 4.1.1. At annealing, 300mm wide coil can be taken from the coil portion which corresponds to the coil eye (with minimal quantity of inside wrap removed). Evaluate surface carbon by takin
5、g a test piece from the sample as shown in the figure below. The sample shall be free from any pollutants that may contain rust, adhesive, crayon, pelt pen marker or carbon. (Normal protective oil may be contained.) Sample Discard Sample Fig 1. Sampling portions (unit : mm) (Note 3) The test piece f
6、or carbon contamination measurement is taken from from either end of the coil width. 4.1.2. According to the following washing conditions, power-wash the 300300 mm sample using Parco. Cleaner 348 of Oxy Metal Industries Corporation. (1) Spray time : 58 62 sec (2) Concentration : 7 8 g/l (3) Temperat
7、ure : 60 70 (4) Pressure : 62 76 KPa (5) Distance from nozzle : 15 20 Cm 4.1.3. Rinse with water of 6070 for 2832 seconds. The sample shall not be handled with bare hands but with clean rubber gloves worn. 4.1.4. Prepare solution by mixing HCl (for reagent) and deionized water with volume ratio 50%.
8、 4.1.5. Using clean rubber gloves, take a sheet of filtering paper made by glass fiber. (934 AH class, 5.5Cm - Whatman, Inc. or its equivalent) 4.1.6. With clean rubber gloves worn, completely dip glass fiber filtering paper into 50% HCl solution and proceed as follows: (1) By applying uniform and p
9、roper pressure on the filtering paper, completely clean one end of the sample. Using only this end, fold the filtering paper with caron inside. Slowly press the filtering paper to remove excessive HCl and then put it into the porcelain crucible. (2) Take another filtering paper and completely dip it
10、 into 50% HCl solution. While applying uniform and proper pressure on both ends of the filtering paper, completely clean the same steel surface. Put it into the same crucible. (3) Using clean rubber gloves, prepare a new steel sheet sample. Take same number of new filtering paper (2 sheets) to compl
11、etely dip them into 50% HCl solution. After cleaning the steel sheet surface with this filtering Discard Discard Coil width80 300 300 80 300EDS-T-7176DETERMINATION OF THE QUANTITY OF CARBON CONTAMINATION ON COLD ROLLED STEEL SURFACES PAGE: 3/3 ISSUED DATE: 1998. 03. 31 REVISED DATE: 2006. 06. 19 VER
12、SION: 2 GM DAEWOO Auto & Technology paper, put the paper into another porcelain crucible. Be sure to check if the porcelain is empty. (4) Cover the two crucibles to prevent contamination and place them into a furnace to dry at 1803 for an hour. 4.1.7. Upon completion of drying, take the sample and f
13、iltering paper out of the crucible using the clear pinset. According to the operating procedure of carbon analyzer, put the sample and filtering paper into separate crucibles to conduct analysis by burning carbon. 4.1.8. Subtracting total carbon quantity analyzed from the filtering paper from total
14、carbon quantity in the sample makes final carbon quantity in the sample steel sheet. (Note 4) 1. The filtering paper shall never be treated with bare hands. 2. Before treating the filtering paper, wash gloves with warm water. Dip the filtering paper into 50% HCl solution and clean glove surfaces. Co
15、mpletely rinse them with cold deionized water. 3. Conduct ventilation during drying if necessary considering evaporation of HCl solution. 4. The filtering paper shall never be dried inside the crucible that is used for carbon analyzer. 4.2. Method B - vapor degreasing & power washing 4.2.1. Sampling
16、 is the same as in method A. 4.2.2. Using perichlorethylene as solvent, put the sample inside the vapor degreaser for 210 seconds. 4.2.3. Using clean rubber gloves, take the sample from the vapor degreaser and then proceed as in step 28 of method A. 5. REFERENCE Ford laboratory test method BZ 002-03: Determination of the quantity carbon contamination on cold rolled steel surface
