1、 SURFACE VEHICLE RECOMMENDED PRACTICE J2635 MAR2015 Issued 2007-08 Reaffirmed 2015-03 Superseding J2635 AUG2007 Filiform Corrosion Test Procedure for Painted Aluminum Wheels and Painted Aluminum Wheel Trim RATIONALE J2635 has been reaffirmed to comply with the SAE five-year review policy. TABLE OF C
2、ONTENTS 1. SCOPE 2 1.1 Purpose . 2 1.2 Overview . 2 2. REFERENCES 3 2.1 Applicable Publications . 3 2.1.1 SAE Publications . 3 2.1.2 ASTM Publications 3 3. DEFINITIONS . 3 3.1 Filiform Corrosion 3 3.2 Filiform Filament 3 3.3 Density 3 3.4 Equalization Adjustment Factor 3 4. TEST PROCEDURE . 3 4.1 Ca
3、binet Settings 3 4.2 Sample Preperation 4 4.3 Scribing . 4 4.4 Test Part Corrosion Inoculation 4 4.5 Exposure Conditions . 4 4.6 Post Inoculation Rinsing 4 4.7 Part Test 5 4.8 Test Master Samples 5 _ SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the st
4、ate of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefrom, is the sole responsibility of the user.” SAE reviews each technical report at least every five y
5、ears at which time it may be revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions. Copyright 2015 SAE International All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means
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7、 values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/J2635_201503 SAE INTERNATIONAL J2635 Reaffirmed MAR2015 Page 2 of 12 5. FILIFORM EVALUATION 5 5.1 Post Exposure Measurement and Data Reporting . 5 5.2 Filiform Length Measurements . 5
8、 5.3 Filiform Length Data 5 5.4 Filament Distribution Data . 5 5.5 Filament Area Data . 5 5.6 Acceptance Criteria . 6 5.7 Data Recording . 6 6. FILIFORM TEST MASTER SAMPLE . 6 6.1 Master Samples 6 7. PROFICIENCY REQUIREMENTS . 6 APPENDIX A - DEFINITIONS/INSTRUCTION FOR USING THE PROFICIENCY DATA SHE
9、ET 11 TABLE 1 - FILIFORM TESTING BEST PRACTICES . 6 TABLE 2 - FILIFORM PROFICIENCY DATA SHEET; (FILIFORM MASTER SAE J2635 FORM.XLS) 8 FIGURE 1 - FILIFORM CORROSION TEST SAMPLE 9 FIGURE 2 - FILIFORM CORROSION, INDIVIDUAL FILAMENT DETAIL . 9 FIGURE 3 - FILIFORM CORROSION, TEST SAMPLE EXAMPLE . 9 FIGUR
10、E 4 - FILIFORM CORROSION, TEST SAMPLE JPG . 10 FIGURE 5 - FILIFORM TEST MASTER SAMPLE EXAMPLE . 10 1. SCOPE This test procedure defines a laboratory procedure for generating and evaluating filiform corrosion on painted aluminum wheels and painted aluminum wheel trim. While this test was developed sp
11、ecifically for the testing of painted aluminum wheels and wheel trim it may be applicable to other components. The application owner will need to assess if this test generates filiform similar to that found in the relevant usage to ensure it will provide accurate data for the application. 1.1 Purpos
12、e To establish a uniform test method for the wheel and wheel trim industry when assessing the resistance of components to filiform corrosion. An objective is to reduce test procedure proliferation and thereby reduce costs for establishing and maintaining unique test facilities, test methods, measure
13、ment methods, laboratory accreditations, and operator training. The net effect is to reduce cost while improving the quality of the test data by adopting uniform and standardized test methods. The procedure does not establish performance standards for the components. Performance standards are to be
14、established by the users of the test and/or their clients. The method and format for documenting proficiency is defined. 1.2 Overview Filiform corrosion is generated by exposing a coated substrate to a warm, humid environment. This filiform test procedure utilizes SAE J2634 Scribing method to ensure
15、 consistent exposure of the sample substrate to the corrosion products. The test part is inoculated with corrosion products by using ASTM B 368-97 (2003)e1followed by an immersion in de-ionized water to remove excess corrosion products and then placed in a temperature and humidity controlled test ca
16、binet to initiate the formation of filiform corrosion. Post test evaluations of length of filifom filament growth, density of filaments, and area of filiform growth can be assessed to evaluate the corrosion resistance of the component. SAE INTERNATIONAL J2635 Reaffirmed MAR2015 Page 3 of 12 2. REFER
17、ENCES 2.1 Applicable Publications The following publications form a part of this specification to the extent specified herein. Unless otherwise indicated, the latest version of SAE publications shall apply. 2.1.1 SAE Publications Available from SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0001,
18、 Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org. SAE J2634 Scribing of Coatings in Preparation for Testing of Wheels and Wheel Trim SAE J2636 Corrosion Test Master Establishment 2.1.2 ASTM Publications Available from ASTM, 100 Barr Harbor Drive, West Conshohocke
19、n, PA 19428-2959, Tel: 610-832-9585, www.astm.org. ASTM B 368-97 (2003)e1Standard Method for Copper-Accelerated Acetic Acid-Salt Spray (Fog) Testing (CASS Test) ASTM D 1193 Standard Specification for Reagent Water 3. DEFINITIONS 3.1 Filiform Corrosion Filiform corrosion is type of corrosion that mov
20、es across the metal surface underneath a coating. The corrosion is almost always initiated at discontinuities in the coating and propagates in the presence of oxygen and sufficient relative humidity.1Filiform corrosion is characterized by thin “thread-like” corrosion filaments. Each filament has a “
21、head”, (the point of propagation of the corrosion growth) and a “tail”, the corrosion by products2, see Figure 1 and Figure 2. 3.2 Filiform Filament An individual thread like corrosion element that grows in length, see Figure 1. 3.3 Density The number of filiform filaments distributed within a speci
22、fied length such as along a scribe or wheel spoke edge. 3.4 Equalization Adjustment Factor A factor calculated to equalize the data from two or more different test laboratories or test chambers based on a proficiency analysis, (Reference Table 2). 4. TEST PROCEDURE 4.1 Cabinet Settings Set and check
23、 the humidity cabinet for the temperature, humidity, airflow and exhaust vent settings. Correct any discrepancies from predetermined levels. SAE INTERNATIONAL J2635 Reaffirmed MAR2015 Page 4 of 12 The cabinet should be capable of maintaining the following parameters: Temperature 60 Celsius 1 Celsius
24、 Humidity 85% Relative Humidity 3% Air Flow 6 to 24 meters/minute (20 to 80 ft/min) in the test area 4.2 Sample Preparation Visually examine the painted surface and record any adverse conditions, such as sags, paint film porosity, scratches, etc. and record. Photographing the sample anomalies before
25、 testing would document the original sample condition. Do not mark on the candidate test area unless the intent is to disqualify an area from evaluation. If required by client or customer measure the paint film thickness over the area to be scribed, and record on a schematic drawing of the part, (Th
26、e paint film thickness measured at a specific control point should be correlated with cross-sectional analysis for the entire part geometry). Prepare a master test sample in a similar manner. 4.3 Scribing Scribe the test piece to the base metal with a carbide tip-scribing tool per SAE J2634. The scr
27、ibe should be as long as practical (recommended 100 mm) but must be least 40 mm long, (the measuring length shall be at least 30 mm, no data is to be measured for the first 5 mm from the scribe ends.) A Laboratory Scribing Fixture as described in SAE J2634 should be utilized to make a straight scrib
28、e line. Scribes made free-hand will not allow acceptable gage repeatability and reproducibility measurements at end of test. On a wheel the scribe is typically made perpendicular to the machining lines. Check the scribe with a multimeter for electrical continuity from end to end, to assure that the
29、scribe has exposed the base metal. There must be electrical continuity down the full length of the scribe. If continuity is an issue anywhere along the scribe a fresh scribe must be made. This may be done on the same sample if there is at least 15 mm separation from the old scribe and/or from a para
30、llel edge. Electrical continuity is checked to assure that the scribe exposes the base metal. Particular care must be taken to scribe through multiple layers of paint. 4.4 Test Part Corrosion Inoculation Place the scribed parts in CASS per ASTM B 368-97 (2003)e1such that the wheel and scribe, or tes
31、t surface are at an angle of approximately 45 degrees to the horizontal on a suitable non-metallic rack. It is a good policy to photograph the parts at this stage to document which surface(s) are at appropriate test angles. 4.5 Exposure Conditions Expose the parts 6 hours in the CASS cabinet as desc
32、ribed in ASTM B 368-97 (2003)e1. When the CASS exposure is near completion prepare a container at least 5 gallons in size with a constant flow of DI water that meets ASTM D 1193, (Type 4). 4.6 Post Inoculation Rinsing Dip the test samples and the master test sample into deionized water that meets AS
33、TM D 1193, (Type 4). The parts should be dipped in a vertical direction, slowly turned 90 and back to the original position then removed using the same vertical direction. The dip should be for about three seconds. The objective is to remove only the excess CASS solution. The DI water should enter t
34、he bottom of the container to promote flushing of any contamination out of the container with the overflowing water. Flow rate should be dependent on the number of samples being dipped at one time. After approximately 25 samples have been dipped, the water in the container shall be dumped prior to p
35、roceeding with the sample rinsing procedure. SAE INTERNATIONAL J2635 Reaffirmed MAR2015 Page 5 of 12 4.7 Part Test Place the parts directly into the humidity cabinet described in 4.1. Position the samples such that the droplets of moisture will run off of the part, approximately 45 degrees. Expose t
36、he test samples for a duration of 672 hours. Review and assess the growth of the filiform once every 168 hours to evaluate if there are any test anomalies. Check the filiform growth on the master test sample for consistency with that of the master test samples from prior test lots. The test samples
37、must not be kept out of the humidity chamber for more than 15 minutes per measurement. Should the growth not be consistent or if there appear to be test anomalies, the test may be terminated, or the test set up and operating parameters can be assessed and adjusted to conform to the prescribed settin
38、g. Should this occur the action taken must be noted in the comments section of the report. 4.8 Test Master Samples Test master samples, which have been qualified as per SAE J2636 and have a known filiform growth, must be run during the time of part evaluation of test samples. The measurements taken
39、on the test master samples must be consistent within the normal variation of the control limits. Periodically, but no less than twice per year, a master sample shall be run inside a cardboard box, to evaluate the effect of chamber air flow on the master sample results. These results shall be added t
40、o the ongoing filiform control chart. Discrepancies in the results in the chamber and the cardboard box should be addressed in the continuous improvement process for the test procedure. Testing inside a cardboard box could be required in order to obtain acceptable proficiency test data. 5. FILIFORM
41、EVALUATION 5.1 Post Exposure Measurement and Data Reporting Consult the customers requirements for what types of data are required. Measure the corrosion on the master test sample as described in 6.1, at completion of the test duration. Enter the data into the data sheet, reference Table 2 for the t
42、est master samples and determine if the sample performance is within the control limits established. If the sample is within the control limits continue. If the sample is outside the control limits, the test is invalidated and corrective action may be required. Measure the data from the remaining te
43、st samples and record data on the data sheet. 5.2 Filiform Length Measurements Linear measurements. Measurements shall be taken perpendicular to the scribe or the test edge and not at the angle from the scribe edge that the filiform corrosion may have grown. Measurements must be taken from the edge/
44、scribe of the scribe to avoid including the scribe, see Figure 1. Record the data with two significant figures. 5.3 Filiform Length Data Measure the longest filament from either side of the scribe/edge, and record as maximum filiform length. After measuring the maximum filiform length, the data can
45、be equalized with respect to the latest proficiency results. Record the result. All data must be clearly recorded as raw and equalized. 5.4 Filament Distribution Data Measure the length of each filament from either side of the scribe, and record in a table of filament lengths. After measuring the fi
46、lament lengths, equalize the data with the latest proficiency results based upon the maximum filament length measurement, see Figure 1. Record the results. All data must be clearly recorded as raw or equalized. These data can be used to establish the statistical distribution of filament lengths for
47、the part. 5.5 Filament Area Data Area measurements can be done at the request of the customer. The total area in square millimeters of filiform corrosion as measured using an automated image analyzer or equivalent techniques, e.g., manual grid technique, perimeter, etc. If the area of the scribe is
48、included in the measurement, as in the case of the image analyzer, it should be subtracted from the total area measurement, (reference Figure 4). SAE INTERNATIONAL J2635 Reaffirmed MAR2015 Page 6 of 12 5.6 Acceptance Criteria Consult the customers current acceptance specification for part performanc
49、e and or internal specification for part performance. 5.7 Data Recording Photograph the test parts and control samples within 96 hours to document the filiform at the end of test, (Filiform will continue to grow at room temperature). See example photographs Figures 3 and 4. Any sample data not documented by photography or actual area and length meas
