1、 WORLDWIDE ENGINEERING STANDARDS Test Procedure GMW16862 Calcium Chloride Corrosion Resistance Test for Chrome Plated Exterior Parts Copyright 2013 General Motors Company All Rights Reserved March 2013 Page 1 of 7 1 Scope Note: Nothing in this standard supercedes applicable laws and regulations. Not
2、e: In the event of conflict between the English and domestic language, the English language shall take precedence. 1.1 Purpose. To provide a laboratory method to accelerate and evaluate exposure to calcium chloride, used as a winter road treatment, on chrome plated exterior components. This type of
3、corrosion is significantly more aggressive than the effects of sodium chloride winter road treatments on these components. Calcium chloride corrosion is commonly referred to as Russian Mud effect. 1.2 Foreword. Not applicable. 1.3 Applicability. This test applies to all chrome plated exterior compon
4、ents to be sold in regions of the world that use calcium chloride for dust and ice control. This test was originally requested due to the corrosion effects observed in some areas of Russia. This test may also be used to evaluate the use of an organic topcoat offered as a method for slowing the progr
5、ession of corrosion to a chrome plated base substrate. Additional factors beyond calcium chloride resistance testing may affect the corrosion resistance of chrome plated or topcoated metallic finish parts. Refer to the specifications specific to those finish technologies for more information. See Ap
6、pendix A for typical corrosion patterns exhibited by calcium chloride exposure. 2 References Note: Only the latest approved standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. ASTM D1193 2.2 GM Standards/Specifications. GMW14668 2.3 Additional References. Sigm
7、a-Aldrich, Inc., http:/ U.S. Plastic Corp., http:/ 3 Resources 3.1 Facilities. 3.1.1 Calibration. The test facilities and equipment shall be in good working order and shall have a valid calibration label. 3.1.2 Alternatives. Alternative test facilities and equipment may also be used. However, all me
8、asuring variables as specified in this standard shall be determined correctly with respect to their physical definition. 3.2 Equipment. 3.2.1 Temperature Chamber. A temperature and humidity chamber capable of the conditions outlined in 4.3.3. Copyright General Motors Company Provided by IHS under li
9、cense with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16862 Copyright 2013 General Motors Company All Rights Reserved March 2013 Page 2 of 7 3.2.2 Soil Base Media. Use reagent grade Kaolin. The Chemic
10、al Abstract Service (CAS) number for kaolin is 1332-58-7. One supplier of this product is Sigma-Aldrich, Inc. The Sigma-Aldrich product number is K7375 and can be ordered on the internet at http:/ or by telephone at (800) 325-3010. Other suppliers are available globally for reagent grade kaolin. 3.2
11、.3 Calcium Chloride. Use reagent grade calcium chloride dihydrate. 3.2.4 Sodium Hydroxide. Use reagent grade sodium hydroxide. 3.2.5 Water. Distilled or deionized water per ASTM D1193, Type IV. 3.2.6 pH Meter. A pH Meter is used to confirm the pH of the calcium chloride mud. 3.2.7 Instrumentation. 3
12、.2.7.1 Electrical Balance. The electrical balance must have ability to measure up to the second decimal place. 3.2.8 Miscellaneous Tools. 3.2.8.1 Beaker 500 mL. A beaker with a minimum size of 500 mL is required to mix the kaolin, calcium chloride, and water. 3.2.8.2 Glass Rod. An 8 mm diameter glas
13、s rod or equivalent tool is required to stir the kaolin, calcium chloride, and water. 3.2.8.3 Thick Plastic Sheet 1.6 mm. A 1.6 mm 0.2 mm thick acrylic or similar plastic sheet is to be used as a template for easy application of the calcium chloride mud. One supplier of this product is U.S. Plastic
14、Corp. The U.S. Plastic Corp. product number is 44200 and can be ordered on the internet at http:/ 3.2.8.4 Drill Bit 18 mm. An 18 mm drill bit is required to drill a hole in the 1.6 mm 0.2 mm thick acrylic sheet. 3.2.8.5 Isopropyl Alcohol. Reagent grade Isopropyl alcohol is required to clean test pie
15、ce prior to start of test. 3.2.8.6 Brush. A brush, spoon, or equivalent tool is required to apply the calcium chloride mud to the part. 3.2.8.7 Measurement Tool. A measurement tool is required to confirm the acrylic sheet thickness and the size of the hole drilled into that sheet. 3.3 Test Vehicle/T
16、est Piece. This test can be performed on plaques or production representative parts based on the evaluation. A minimum of six samples is required representing three low and three high current density rack locations are required for this test. 3.4 Test Time. Calendar time: 43 days Test hours: 1008 ho
17、urs Coordination hours: 8 hours This represents the maximum test time. See 4.3.4 for test intervals. 3.5 Test Required Information. 3.5.1 Test Setup Photographs. Take photographs of the test setup prior to start of test. 3.5.2 Part Photographs. Take photographs of the part to be tested at start of t
18、est and depending on total duration of test at 48 h, 96 h, 168 h, 240 h, 336 h, 504 h, 672 h, 840 h, and 1008 h. 3.5.3 Part Metal Thickness. The areas of high and low metal thickness, normally referred to as high and low current density, need to be understood prior to start of test. 3.6 Personnel/Sk
19、ills. Prior experience in setting up and running similar tests and experience in the use of the referenced test equipment are critical to achieving the estimated times in 3.4. 4 Procedure 4.1 Preparation. 4.1.1 Calcium Chloride Mud Distribution Template. Drill an 18 mm 1 mm diameter hole through a 1
20、.6 mm plastic sheet to create a template for distribution of the mud. See Figure 1 for template example. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERI
21、NG STANDARDS GMW16862 Copyright 2013 General Motors Company All Rights Reserved March 2013 Page 3 of 7 Figure 1: Calcium Chloride Mud Distribution Template 4.1.2 Clean Test Piece. Clean the test piece using a clean, non-abrasive cloth soaked with a 50/50 mixture of isopropyl alcohol and water. Do no
22、t use a cloth that could cause corrosion on the test piece or produce a protective film. 4.1.3 Calcium Chloride Mud. Prepare calcium chloride mud. 4.1.3.1 Calcium Chloride Saturated Water. Prepare a saturated solution of calcium chloride dihydrate in water at 40 C 3 C. Slowly mix the calcium chlorid
23、e into water while rapidly stirring the salt into the solution with a glass rod (see Figure 2). The saturation point is defined by the point when calcium chloride will no longer mix into the solution. Gravimetric methods are also allowable when preparing a saturated solution to the desired amounts o
24、f solution needed. Decant any remaining calcium chloride that did not mix into the solution to be used per the ratio defined in Table 1. Figure 2: Calcium Chloride Saturated Water 4.1.3.2 Mix Calcium Chloride Saturated Water and Soil Base Media. Mix the calcium chloride saturated water and soil base
25、 media in a beaker using a glass rod at the ratios specified in Table 1 until the substance reaches an even consistency. These ratios are approximates. See Figure 3. Table 1: Ratio of Calcium Chloride Saturated Water to Mud Substance Ratio Calcium chloride saturated water 5 mL Soil base media (kaoli
26、n) 3 g Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16862 Copyright 2013 General Motors Company All Rights Reserved March 2013 Page 4
27、of 7 Figure 3: Mix Calcium Chloride Saturated Water and Mud 4.1.3.3 Calcium Chloride Mud pH. Use reagent grade sodium hydroxide to adjust the pH of the calcium chloride mud within the range of 6.5 to 7.5. Confirm the pH is within this range with a pH meter. 4.2 Conditions. 4.2.1 Environmental Condit
28、ions. See test instructions in 4.3. 4.2.2 Test Conditions. Deviations from the requirements of this standard shall have been agreed upon. Such requirements shall be specified on component drawings, test certificates, reports, etc. 4.3 Instructions. 4.3.1 Calcium Chloride Mud Application. Place the t
29、emplate created per 4.1.1 on the test piece. Apply the calcium chloride mud created per 4.1.3 over the cutout circle using a brush until that area is evenly covered with mud. This equates to approximately 0.24 g of calcium chloride mud. Remove the template. See Figure 4. Figure 4: Calcium Chloride M
30、ud Application 4.3.1.1 Repeat 4.3.1 until there are ten separate mud applications on the part which allows the part to be reviewed at each planned time interval. See Figure 5. The spacing of mud applications is determined by the size of the part and the current densities under investigation for the
31、test. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16862 Copyright 2013 General Motors Company All Rights Reserved March 2013 Page 5 o
32、f 7 Figure 5: Calcium Chloride Mud Application 4.3.2 Test Piece Position. The test piece(s) are to be positioned in the chamber in a manner that allows each piece to be completely exposed and one piece does not interfere with another. See Figure 6. Figure 6: Test Piece Position 4.3.3 Temperature Cyc
33、le. Place the test piece into a chamber with a constant temperature and humidity of 60 C 3 C, 23% 5% relative humidity (RH) for the minimum number of hours specified in the applicable material finish specification. The recommended minimum number of test hours is 336. Suspend the test to remove parts
34、 and take photographs at the time periods outlined in 3.5.2. 4.3.4 Evaluation. This test procedure is to be used as a comparison of how different chrome plating technologies will perform in a calcium chloride rich environment. One mud application is to be removed and the part is to be reviewed at 48
35、 h, 96 h, 168 h, 240 h, and 336 h. Parts should not be removed from the chamber for more than 15 minutes for each evaluation. If part has no issues at 336 h, continue to test and review part every 168 h until failure or 1008 h, whichever comes first. Refer to GMW14668 for pass/fail requirements for
36、chrome plated plastic parts. For other materials, refer to the applicable material finish specification for requirements. 5 Data 5.1 Calculations. Not applicable. 5.2 Interpretation of Results. Reference GMW14668. 5.3 Test Documentation. Pictures per section 3.5 and results shall be presented in a t
37、est report. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16862 Copyright 2013 General Motors Company All Rights Reserved March 2013 Pa
38、ge 6 of 7 6 Safety This standard may involve hazardous materials, operations, and equipment. This standard does not propose to address all the safety problems associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and deter
39、mine the applicability of regulatory limitations prior to use. 7 Notes 7.1 Glossary. Not applicable. 7.2 Acronyms, Abbreviations, and Symbols. CAS Chemical Abstract Service RH Relative Humidity 8 Coding System This standard shall be referenced in other documents, drawings, etc., as follows: Test to
40、GMW16862 for the specified time interval. 9 Release and Revisions This standard was originated in September 2012. It was first approved by the Corrosion Global Subsystem Leadership Team in March 2013. It was first published in March 2013. Issue Publication Date Description (Organization) 1 MAR 2013
41、Initial publication. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16862 Copyright 2013 General Motors Company All Rights Reserved March 2013 Page 7 of 7 Appendix A Figure A1: Typical Corrosion Patterns for Calcium Chloride Corrosion in Hexavalent Chrome Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
