1、Designation: B995 15Standard Test Method forChloride Resistance Test for Chromium Electroplated Parts(Russian Mud Test)1This standard is issued under the fixed designation B995; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the y
2、ear of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This standard details a laboratory method to acceleratethe effects of exposure to hygroscopic corrosive chlorid
3、ecompounds on electroplated chromium components. It isapplicable to any substrate and coating system that utilizeselectroplated chromium as the final metallic coating.1.2 Field experience has shown that hygroscopic chloridesare significantly more aggressive toward chromium electro-plated deposits th
4、an sodium chloride. The most common ofwhich is calcium chloride. Corrosion caused by these chloridesis commonly known as the Russian Mud effect.1.3 The standard does not specify exposure periods to beused for a specific product nor the interpretation to be given tothe results. The suitability of thi
5、s test and correlation of resultswith service experience should be determined before it isspecified for coating systems.1.4 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.5 This standard does not purport to address all of the
6、safety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Significance and Use2.1 This test is used for specification acceptan
7、ce, simulatedservice evaluation, manufacturing control, and research anddevelopment. It was developed specifically for use on compo-nents with electrodeposited chromium coatings exposed tohygroscopic chlorides. Test and production specimens may beused. Use of a standardized test could help in develo
8、pingimproved quality of chromium electrodeposited componentsand lead to the development of improved electroplated chro-mium systems.3. Apparatus3.1 The apparatus required for this test consists of anenvironment chamber capable of controlling both temperatureand humidity within the specified range (s
9、ee 6.4). The chambermust be large enough to hold the test specimens withouttouching one another or the walls of the chamber. Also, thereaction products formed on one specimen shall not fall onanother specimen. Materials of construction shall not affect thecorrosiveness of the test environment, nor b
10、e themselvescorroded by the test environment.4. Reagents and Materials4.1 Table 1 specifies the laboratory grade consumable ma-terials used in this test.TABLE 1Item Name CAS # Description/UseDeionized Water 7732-18-5Kaolin 1332-58-7 Soil/mud base mediaCalcium Chloride Dihydrate 10035-04-8 Corrosive
11、mediaSodium HydroxideA1310-73-2 Solution pH adjustmentSulfuric AcidA7664-93-9 Solution pH adjustmentIsopropyl Alcohol 67-63-0 Test sample cleaningAFor ease of control, solutions that are approximately 0.25 N are recommended.5. Preparation of Test Slurry5.1 Prepare a solution containing dissolved cal
12、cium chlorideproduced by maintaining a ratio of 57.5 g calcium chloridedihydrate for every 94 mL of deionized water and the equiva-lent of 8 mL of 0.25 N NaOH. This solution should have a pHof approximately 9.6.5.2 Mix the calcium chloride solution with kaolin at a ratioof 3 g kaolin per 5 mL calciu
13、m chloride water.NOTE 1Various sources of kaolin have been shown to perform equallywithin this test.The kaolin only acts as the “mud/solid material” within thetest slurry accounting for the term Russian Mud Test.5.3 Verification of pH of the slurry:5.3.1 Dilute a portion of the slurry (for example,
14、10 mL) by50% with deionized water.NOTE 2The diluted slurry cannot be used on test samples.5.3.2 Check the pH of the diluted slurry using a calibrateddigital pH meter. A self-flushing probe is recommended.1This test method is under the jurisdiction ofASTM Committee B08 on Metallicand Inorganic Coatin
15、gs and is the direct responsibility of Subcommittee B08.10 onTest Methods.Current edition approved April 1, 2015. Published May 2015. DOI: 10.1520/B99515.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15.3.3 The pH of the diluted slur
16、ry shall be in the range of 6.5to 7.5. If necessary, adjust the pH of the calcium chloride slurrywith either approximately 0.25 N sodium hydroxide (to raisethe pH) or 0.25 N sulfuric acid (to lower the pH) until pH iswithin the specified range using the procedure within 5.3.1 and5.3.2.NOTE 3The amou
17、nt of sodium hydroxide and deionized water in 5.1typically yields a final pH of 6.5 to 7.5. However, some batches of kaolinmay be more acidic and always require further pH adjustment in order toachieve the required pH of the slurry. It is permissible to initially adjust theamount of sodium hydroxide
18、 and deionized water in 5.1 in order to createa final slurry with the required pH of 6.5 to 7.5. Regardless of adjustment,maintain a mixture of 102 mL (NaOH + H2O) for every 57.5 g calciumchloride dihydrate.6. Procedure6.1 Clean the test specimen using a clean, non-abrasivecloth soaked with a 50/50
19、mixture of isopropyl alcohol anddeionized water. Ensure that the test piece is fully dried beforeproceeding.6.2 Identify the surfaces on the specimens being tested thatare to be evaluated during the test.At each designated location,apply approximately 0.6 mL of the slurry in a circular spot,using a
20、pipette, eye dropper or similar application method. Thesolution shall be applied at the center of the circle and allowedto spread out naturally. Do not manually spread the slurry afterapplying it to the surface. Each application spot should beseparated from other spots by at least 1 cm in all direct
21、ions. Ifenough room is available at each location, apply up to threeduplicate spots to observe possible variability in test results.6.3 Test pieces shall be placed into the test chamber so thatthe calcium chloride slurry does not run off of the sample ontoanother sample, each test piece is completel
22、y exposed to thetest environment, and the samples do not interfere with eachother.6.4 The test chamber shall be controlled at a temperature of60 6 3C and 23 6 5% relative humidity.7. Evaluation of Results7.1 The test duration, minimum number of test spots andinspection frequency must be specified an
23、d agreed upon beforethe beginning of the test.7.2 At each inspection interval, remove samples from, orturn off, the test chamber. Remove the agreed upon test spotsfrom each sample by wiping with warm water and a non-abrasive cloth. Evaluate the area from which the slurry wasremoved under 10 magnific
24、ation.Assign a rating to each spotaccording to the scale in Appendix X1. The acceptance criteriafor evaluation are to be specified by the requestor. Continuetest in the controlled chamber until the next inspection intervalor until the end of the test.NOTE 4Operations should be scheduled that the cum
25、ulative maximumtime for these interruptions is held to 60 minutes or less per day. It isrecommended to have only one interruption per day if possible. Ifinterruption time is longer than 60 minutes, it should be noted in the testreport.8. Records and Report8.1 The following information will be includ
26、ed in the testreport unless previously agreed upon:8.1.1 Identification of the test specimens, including platingcycle and source.8.1.1.1 Plating cycle, including thickness and type of chro-mium layer.8.1.1.2 Identification of the layer prior to the chromiumdeposit and, if applicable, after the chrom
27、ium layer.8.1.2 The chamber temperature and relative humidity.8.1.3 The frequency of evaluation, including the time inter-vals.8.1.4 The test results using Appendix X1.9. Precision and Bias9.1 Information is being generated to develop the precisionand bias of this test method.9.2 The reliability, re
28、producibility, and accuracy of the testdepend on proper and consistent control of a number of factors,including:9.2.1 Preparation of the test solutions,9.2.2 Cleaning of the test samples,9.2.3 Chamber temperature and relative humidity,9.2.4 Positioning of the specimens in the test chamber, and9.2.5
29、Frequency of evaluation including the time interval.10. Keywords10.1 chloride; chromium; corrosion; decorative; electroplat-ing; finishes; functional; Russian MudB995 152APPENDIX(Nonmandatory Information)X1. CHROMIUM LOSS RATING SCALEFIG. X1.1 Chromium Loss Rating ScaleB995 153ASTM International tak
30、es no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own re
31、sponsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addres
32、sed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at th
33、e address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 154
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