FORD FLTM BI 024-01-2018 CORROSION TESTING OF THREADED FASTENER FINISHES.pdf

1、 FORD LABORATORY TEST METHOD BI 024-01 Date Action Revisions Rev. 00 2018 07 27 Released G. Weber / A. Wedepohl, NA Controlled document at www.MATS Copyright 2018, Ford Global Technologies, LLC Page 1 of 6 CORROSION TESTING OF THREADED FASTENER FINISHES Application This test method describes the pre

2、paration and evaluation of threaded fasteners subjected to the Global Laboratory Accelerated Cyclic Corrosion Test, CETP 00.00-L-467. This test may be used to evaluate the relative corrosion performance of fastener finishes. It is a developmental tool for the evaluation of new finishes and for compa

3、ring different finish types. It is not intended to be a routine quality control test. The use of metal test panels with the coatings specified represent actual vehicle interfaces. Apparatus and Materials Required Torque wrench or powered torque controlled device for assembling fasteners to panels So

4、ckets and drive bits for assembling bolts, nuts, or screws to panels Corrosion test chamber capable of running cyclic corrosion testing per CETP 00.00-L-467 Slotted plastic racks with drainage to hold the test panel assemblies Test Panels Dimensions Test panels will be rectangular, 15.2 x 10.1 cm (6

5、 x 4 inches) with holes for fasteners arranged in a pattern so that corrosion from the upper row of fasteners does not run down onto the lower row, see Figure. 1. Holes must be formed prior to coating and test panels can usually be ordered this way from the test panel manufacturers. Test panel clear

6、ance hole size should be specified based on the type and size of fastener being tested, see the Table 1 below for guidance. Figure 1. Test Panel hole spacing 10.1 cm15.2 cm 2.5 cm 2.5 cm 3 cm 5.1 cm 5.0 cm FORD LABORATORY TEST METHOD BI 024-01 Copyright 2018, Ford Global Technologies, LLC Page 2 of

7、6 Table 1. Recommended hole size based on fastener size Bolt Size M4 M5 M6 M8 M10 M12 M14 M16 Clearance Hole Diameter, mm 4.8 5.8 7 10 12 14.5 16.5 18.5 Recommended Torque for bolt and nut assemblies, Nm 1.5 3.1 5.2 12.5 23.5 40.0 66.5 100.0 Test Panel Substrates and Coatings New fastener finishes s

8、hould be tested against panels 1 through 4 to determine the possible range of applications for that finish. Current finishes may be tested to a reduced number of substrates. All requests to run this laboratory test method should specify which panels to use if not all four panels. The basecoat color

9、for panels 2 and 3 should be chosen so that white or red corrosion on the fastener is easily photographed against the basecoat color. Panel 1. Cold Rolled Low Carbon Steel Sheet with E-coat a. Substrate: cold rolled low carbon steel, 0.7- 0.9 mm thick b. Phosphate: Henkel Bonderite 958 + Parcolene 9

10、9X or PPG Chemfos 700 + Chemseal 59, or equivalent c. E-Coat: Axalta Aqua EC6100, BASF Cathoguard 525, or PPG Powercron 590/6100HE/Advantedge, 17-24 m thick Panel 2. Galvanized Steel Sheet with E-coat, Primer, Basecoat and Clear Coat d. Substrate: 50G or 60G EG or HD galvanized cold rolled steel she

11、et, 0.7 0.9 mm thick e. Phosphate: PPG Chemfos 700 or equivalent f. E-Coat: Axalta Aqua EC4027or equivalent, 17-24 m thick g. Primer: BASF U28AU227F Light grey or equivalent 17-24 m thick h. Basecoat: BASF E387AU325F Magnetic Metallic (M-7325), or equivalent, 15-20 m i. Clearcoat: BASF R10CG392D or

12、equivalent, 38-50 m Panel 3. Aluminum Sheet with E-coat, Primer, Basecoat and Clear Coat j. Substrate: 6022-T43 aluminum sheet 0.7 0.9 mm thick k. Zirconium Oxide: PPG Zircobond, or equivalent l. E-Coat: Axalta Aqua EC4027or equivalent, 17-24 m thick m. Primer: BASF U28AU227F Light grey or equivalen

13、t 17-24 m thick n. Basecoat: BASF E387AU325F Magnetic Metallic (M-7325) or equivalent, 15-20 m o. Clearcoat: BASF R10CG392D or equivalent, 38-50 m Panel 4. Cast Aluminum A380 p. Substrate: die cast aluminum (ASTM B85 UNS A13800 or similar), about 3 mm thick q. Coating: none Test panels may be purcha

14、sed to these specifications from a number of sources, for example: ACT Test Panel Technologies 273 Industrial Drive Hillsdale, MI 49242 https:/ FORD LABORATORY TEST METHOD BI 024-01 Copyright 2018, Ford Global Technologies, LLC Page 3 of 6 Test Fasteners, Bolts, Nuts, or Screws 1. Test 15 fasteners.

15、 2. Identify fasteners by the coating suppliers name, the name of the coating, name of the applicator or site location and method of application (dip spin, electroplate) 3. Coating thickness must be measured by the coating applicator and be reported as part of the part identification. 4. Fasteners m

16、ust be from a single certified lot which is representative of production manufacturing processes for both the fastener and coating. 5. If testing bolts or nuts, both the nut and bolt should have a similar corrosion resistant coating. 6. Fasteners must be clean and dry. If residual dirt or oil is pre

17、sent, soak fasteners in soapy water for a few minutes, rinse, then dry. Assemble Fasteners to the Panels 1. The fastener should be snug to the panel to eliminate crevices but not so tight as to damage the panel coating. 2. For bolt and nut assemblies use the torque values in Table 1. The tool should

18、 drive the fastener to be tested. i. When testing nuts, drive the nut with the nut on the front face of the panel. ii. When testing bolts, drive the bolt with the bolt on the front face of the panel 3. For screws, drive them into the panel at a right angle until they are fully driven, seated, and no

19、t stripped. 4. Each panel assembly will have 5 fasteners on test. Each coating requires 3 panels to test 15 fasteners. 5. The default fastener for testing is a bolt and nut assembly, unless otherwise specified. a. M10 x 25 Hex flange bolt PC 10.9. Part Number: W500433 (WA 120) or similar b. M10 Nut

20、PC 10, all metal prevailing torque. Part Number W520113 (WE 111) or similar. 6. Label the panels 1A, 1B, 1C, 2A, 2B, 2C, . . . . and the fastener coating name. Figure 2. Test panel assembly labeled and in the test rack. Recommended fastener position ID also shown. FORD LABORATORY TEST METHOD BI 024-

21、01 Copyright 2018, Ford Global Technologies, LLC Page 4 of 6 Procedure A, Exterior Exposure 1. Photograph all panel assemblies prior to testing. 2. Place the panel assemblies in the slotted plastic racks at an angle of approximately 15 - 20 from vertical. The fastener on test faces upward and the pa

22、nels spaced far enough apart to prevent shielding from the overhead spray. 3. Place the racks with panels into the test chamber. 4. Perform cyclic corrosion testing per CETP 00.00-L-467. 5. Photograph each panel assembly at 2, 4, 6, 9, and 12 weeks. 6. Rate the appearance of each fastener per the ev

23、aluation method below at 2, 4, 6, 9, and 12 weeks. 7. Prior to performing evaluations and taking photographs, the assemblies must be rinsed with warm tap water to remove salt deposits and air dried. Fasteners exhibiting white staining or corrosion products must be wiped with a clean damp cotton clot

24、h to remove adhering deposits. Allow the surface to dry before evaluating. 8. At the completion of testing and after the final visual evaluation is complete, disassemble the test panel assemblies and evaluate the panels for corrosion damage. 9. Photograph one panel of each substrate type to show the

25、 under head condition or gage loss if present. Procedure B, Interior Exposure 1. Photograph all panel assemblies prior to testing. 2. Place the panel assemblies in the slotted plastic racks at an angle of approximately 15 - 20 from vertical. The fastener on test faces upward and the panels spaced fa

26、r enough apart to prevent shielding from the overhead spray. 3. Place the racks with panels into the test chamber. 4. Perform testing per the modified L-467 test for interior body per Table 3. 5. After the first 24 hours, photograph and evaluate the panel assemblies for the showroom requirement. 6.

27、Prior to performing evaluations and taking photographs, the assemblies must be rinsed with warm tap water to remove salt deposits and air dried. Fasteners exhibiting white staining or corrosion products must be wiped with a clean damp cotton cloth to remove adhering deposits. Allow the surface to dr

28、y before evaluating. 7. Since the modified L-467 test does not include daily salt applications and the samples were rinsed for the showroom evaluation, spray the panel assemblies with the salt solution once before returning them to the chamber. 8. Photograph the panel assemblies after test completio

29、n. 9. Rate the appearance of each fastener per the evaluation method below. FORD LABORATORY TEST METHOD BI 024-01 Copyright 2018, Ford Global Technologies, LLC Page 5 of 6 Evaluation 1. Visually examine fasteners at a normal reading distance (approximately 45 cm) for rust, corrosion products, or oth

30、er evidence of coating degradation. For bolts and screws, the evaluation is intended to focus on the fastener head and the side of the panel against which it rests. For nuts, the evaluation is intended to focus on the nut itself and the side of the panel against which it rests. When a washer is also

31、 part of the fastener assembly, evaluate the washer as well. Fastener threads are not part of the evaluation. 2. Rate each fastener for white and red corrosion per the corrosion rating scale and photo guide below. 3. If wiping a fastener with the damp cloth resulted in a dull grey appearance, it sho

32、uld not be considered white corrosion. Reference the photo guide. 4. After the final visual evaluation and the fasteners removed from the test panels, evaluate the test panels for corrosive attack, such as red rust or pitting. Pit depth measurements can be performed by point micrometer, CT scan, opt

33、ical profilometer, ultrasonic analysis, metallographic sectioning or other suitable techniques. When aluminum panels are used with coated steel fasteners, the paint must be removed from the panel to detect and measure galvanic attack and gage loss. Corrosion Ratings White Corrosion: W0: No white cor

34、rosion present. W1: White corrosion is present in one small area, 1 mm2. W1 rating reserved for possible local issue. W2: White corrosion present at a few areas on the fastener, or spanning one larger area 1 to 3 mm2. W3: Obvious corrosion. Extensive white corrosion on the fastener. Red Corrosion: R

35、0: No red corrosion present. R1: Red corrosion is present as hard to see pin points or one small local area on the fastener, 1 mm2. R2: Red corrosion is present at a few areas on the fastener, or spanning one larger area 1 to 3 mm2. R3: Obvious corrosion. Extensive red corrosion on the fastener. Pho

36、to Guide for Corrosion Ratings Report W1 Example W2 Example W3 Example R1 Example R2 Example R3 Example FORD LABORATORY TEST METHOD BI 024-01 Copyright 2018, Ford Global Technologies, LLC Page 6 of 6 The following information must appear in the test report. 1. Coating supplier, coating name, applica

37、tor, and thickness of the coating. 2. Photographs of the panel assemblies at the prescribed intervals 3. Corrosion ratings for white and red rust for each fastener, see Table 2. 4. At least one photographs of each panel substrate after disassembly. 5. Pit depth measurements on panels exhibiting gage

38、 loss. Table 2. Example of corrosion rating report 2 Weeks 4 Weeks 6 Weeks 9 Weeks 12 Weeks Panel 1A White Red White Red White Red White Red White Red 1 2 3 4 5 Panel 1B 1 2 3 4 5 Panel 1C 1 2 3 4 5 Table 3. Modified CETP 00.00-L-467 for Interior Body Normal L-467 humidity temperature cycle Apply th

39、e 0.5% salt solution on Mondays only (If starting on a non-Monday, see * below) Showroom review after first Monday (24 h after first salt application) High visibility review (6, years in service, YIS) after the 2nd Thursday. Monday Weekday Cycle Tuesday Weekday cycle Wed Weekday cycle Thursday Weekd

40、ay Cycle Friday Weekday cycle Sat. Sun. Weekend profile Monday Weekday Cycle Tuesday Weekday cycle Wed Weekday cycle Thursday Weekday Cycle Friday 6 YIS high visibility review Weekday cycle that includes salt application * If test is started on a non-Monday, maintain the schedule: 5 weekday cycles, then 2 weekend profile days, followed by another 4 weekday cycles. Showroom review Tuesday morning