ASTM_B_995_-_15a.pdf

Designation:B99515aStandard 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 year 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 chloridecompounds 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 than sodium chloride towardchromium electroplated deposits.The most common of whichis calcium chloride.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 this 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 thesafety 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.Referenced Documents2.1 ASTM Standards:B117 Practice for Operating Salt Spray(Fog)ApparatusB368 Test Method for Copper-Accelerated Acetic Acid-SaltSpray(Fog)Testing(CASS Test)D1193 Specification for Reagent Water3.Significance and Use3.1 This test replicates in the laboratory the corrosiveactions of a film containing hygroscopic chlorides and solidmaterial(mud)on electroplated chromium.The tests reactivemedia,the test slurry,was developed to simulate the film foundon electroplated chromium deposits during a winter in Russia,thus the common name for the test,Russian Mud Test.3.2 This test is used for specification acceptance,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 developingimproved quality of chromium electrodeposited componentsand lead to the development of improved electroplated chro-mium systems.3.3 This test simulates the amount of electrodepositeddecorative and functional chromium deposit lost when exposedto the combination of“mud/solid material”and hygroscopicchlorides,most commonly calcium chloride.The metric is theloss of only the chromium and adjacent nickel layer.Other testsused with nickel/chromium electroplated components,such asCASS(Test Method B368),simulate the resistance of the partto basis metal corrosion involving all of the componentsdeposits and substrate.4.Apparatus4.1 The apparatus required for this test consists of anenvironment chamber capable of controlling both temperatureand humidity within the specified range(see 7.4).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 be themselvescorroded by the test environment.Practice B117 offers a guidefor chamber design.1This test method is under the jurisdiction ofASTM Committee B08 on Metallicand Inorganic Coatings and is the direct responsibility of Subcommittee B08.10 onTest Methods.Current edition approved Nov.1,2015.Published December 2015.Originallyapproved in May 2015.Last previous edition approved in 2015 as B995-15.DOI:10.1520/B99515A.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.Reagents and Materials5.1 Table 1 specifies the laboratory grade consumable ma-terials used in this test.TABLE 1 ACS Reagent-Grade or Equivalent ConsumableMaterialsItem NameCAS#Description/UseWater(Practice D1193 Type IV)7732-18-5Test slurry ElectrolyteKaolin1332-58-7Soil/mud base mediaCalcium Chloride Dihydrate10035-04-8Corrosive mediaSodium HydroxideA1310-73-2Solution pH adjustmentSulfuric AcidA7664-93-9Solution pH adjustmentIsopropyl Alcohol67-63-0Test sample cleaningAFor ease of control,solutions that are approximately 0.25 N are recommended.6.Test Slurry Formulation6.1 Stock SolutionUsing the consumable materials listedin Table 1,prepare a stock solution containing dissolvedcalcium chloride produced by maintaining a ratio of 57.5 gcalcium chloride dihydrate for every 94 mL of water and 8 mLof 0.25 N NaOH.The pH of