1、Designation: B 380 97 (Reapproved 2008)e1Standard Test Method forCorrosion Testing of Decorative Electrodeposited Coatingsby the Corrodkote Procedure1This standard is issued under the fixed designation B 380; the number immediately following the designation indicates the year oforiginal adoption or,
2、 in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.e1NOTEThe units statement in subsection 1.2 was corrected editorially in April 2008.1. Scop
3、e1.1 This test method covers the Corrodkote2method ofevaluating the corrosion performance of copper/nickel/chromium and nickel/chromium coatings electrodeposited onsteel, zinc alloys, aluminum alloys, plastics and other sub-strates.NOTE 1The following ASTM standards are not requirements. Theyare ref
4、erence for information only: Practice B 537, Specification B 456,Test Method B 602, and Specification B 604.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 This standard does not purport to address all of thesafety conce
5、rns, 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:3B117 Practice for Operating Salt Spray (
6、Fog) ApparatusB 456 Specification for Electrodeposited Coatings of Cop-per Plus Nickel Plus Chromium and Nickel Plus Chro-miumB 537 Practice for Rating of Electroplated Panels Subjectedto Atmospheric ExposureB 602 Test Method for Attribute Sampling of Metallic andInorganic CoatingsB 604 Specificatio
7、n for Decorative Electroplated Coatingsof Copper Plus Nickel Plus Chromium on PlasticsD 1193 Specification for Reagent Water3. Summary of Test Method3.1 The test is conducted by applying a slurry containingcorrosive salts to test specimens, allowing the slurry to dry, andexposing the specimens coate
8、d with the slurry to a high relativehumidity for a specified period of time.4. Significance and Use4.1 Nickel/chromium and copper/nickel/chromium elec-trodeposited coatings are widely used for decorative andprotective applications. The Corrodkote test provides a methodof controlling the quality of e
9、lectroplated articles and issuitable for manufacturing control, as well as research anddevelopment.5. Apparatus5.1 The apparatus shall consist of a humidity chamber,specimen supports, provision for heating the chamber, andprovisions for air circulation in the chamber.5.2 Drops of moisture that might
10、 accumulate on the ceilingor cover of the chamber of specimen supports shall not bepermitted to fall on the specimens being tested.NOTE 2Suitable apparatus may be constructed from salt-spray equip-ment by eliminating fog-spray nozzles, substituting water for the saltsolution in the reservoir, adding
11、 a manifold for bubbling air through thewater in the reservoir, and adding a fan for circulating the air in thechamber with the fan discharge directed across the surface of the water inthe reservoir.5.3 Materials of construction shall not affect the corrosive-ness of the test.6. Procedure6.1 Corrodk
12、ote SlurryPrepare the Corrodkote slurry in aglass beaker by dissolving 0.035 g of reagent grade cupricnitrate (Cu(NO3)23H2O), 0.165 g of ACS reagent grade ferricchloride (FeCl36H2O), and 1.0 g of ACS reagent gradeammonium chloride (NH4Cl) in 50 mL of water conforming to1This test method is under the
13、 jurisdiction ofASTM Committee B08 on Metallicand Inorganic Coatings and is the direct responsibility of Subcommittee B08.10 onTest Methods.The original work in developing the Corrodkote procedure was initiated by theAmerican Electroplaters Society Research Committee, Project No. 15.Current edition
14、approved April 1, 2008. Published April 2008. Originallyapproved in 1961. Last previous edition approved in 2007 as B 380 85 (2007).2Bigge, D. M., “Experience with the Use of the Corrodkote Test,” Proceedings,Am. Electroplaters Soc., Vol. 46, 1959, p. 149.3For referenced ASTM standards, visit the AS
15、TM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, Unit
16、ed States.Specification D 1193, Type IV. Stir 30 g of water-washed,ceramic-grade kaolin into the solution. Mix the slurry thor-oughly and allow it to stand for about 2 min so that the kaolinwill become saturated. Mix the slurry thoroughly just beforeusing.6.1.1 An alternative method of preparing the
17、 Corrodkoteslurry is as follows. Weigh out 2.5 g of cupric nitrate(Cu(NO3)23H2O), and dissolve and dilute with distilled waterin a volumetric flask to exactly 500 mL. Weigh out 2.50 g offerric chloride (FeCl36H2O), and dissolve and dilute withdistilled water in a second volumetric flask to exactly 5
18、00 mL.(The ferric chloride solution shall be kept in a dark place andstoppered with a rubber or glass stopper when not in use.) (Theferric chloride solution shall not be more than 2 weeks old,since older solutions become unstable.) Weigh out 50.0 g ofammonium chloride (NH4Cl) and dissolve and dilute
19、 withdistilled water in a volumetric flask to exactly 500 mL. Thenmeasure out exactly 7.0 mL of the cupric nitrate solution, 33.0mL of ferric chloride solution, and 10.0 mL of the ammoniumchloride solution; place these in a beaker to which 30.0 g ofkaolin is now added. Stir with a glass stirring rod
20、.6.2 Test SpecimensThe type and number of test specimensto be used, as well as the criteria for evaluation of the testresults, shall be defined in the specifications covering thematerial or product being tested, or shall be mutually agreedupon by the manufacturer and the purchaser.6.3 Preparation of
21、 Test SpecimensMetallic and metallic-coated specimens may be solvent cleaned before testing, usinga suitable solvent such as alcohol, ethyl ether, acetone orpetroleum ether. Solvents that are corrosive or will depositprotective films shall not be used.6.4 Slurry ApplicationApply the Corrodkote slurr
22、y to thespecimen using a clean paint brush. Dip the brush in theCorrodkote slurry and with a circular motion, completely coverthe specimen. Then smooth out the coating by brushing lightlyin one direction. Allow the specimens to dry at room tempera-ture and at a relative humidity less than 50 % for 1
23、 h beforeplacing them in the humidity chamber. Should it be desirable tocut test specimens from parts or from preplated, or otherwisecoated steel sheet, the cut edges shall be protected by coatingthem with paint, wax, tape, or other effective media so that thedevelopment of a galvanic effect between
24、 such edges and theadjacent plated or otherwise coated-metal surfaces, is pre-vented.6.5 Position of Specimens During TestThe position of thespecimens in the humidity chamber during the test is notcritical as long as they do not touch each other and the supportsdo not touch the test areas that have
25、been coated with theCorrodkote slurry.6.6 Conditions in the Humidity ChamberThe exposurezone of the humidity chamber shall be maintained at 38 6 2C.The relative humidity of the exposure zone of the chambershall be maintained between 80 and 90 % shall not producecondensation on any of the parts.NOTE
26、3A fan or blower may be used in the chamber to maintainuniform temperature and humidity. The amount of air circulation in thechamber necessary to maintain these conditions must be determined foreach chamber. An Abbeon certified hygrometer Model No. 167, or itsequivalent4is a suitable instrument for
27、measuring the relative humidity ofthe exposure zone of the humidity chamber.6.7 Test CycleExposure in the humidity chamber shall becontinuous for periods up to 20 h. A single test period up to 20h shall be considered as one cycle. Continuous operationimplies that the humidity chamber be closed and o
28、peratedcontinuously except for the short interruptions necessary toplace or remove test specimens. Operations shall be so sched-uled that these interruptions are held to a minimum. Whenmore than one test cycle of 20 h or less is specified, the testspecimen shall be treated as outlined in 6.9 after e
29、ach testcycle. Fresh slurry shall be applied for each succeeding cycle.After the last test cycle, the test specimen shall be treated asoutlined in 6.9.6.8 Period of TestThe period of each test cycle as well asthe number of test cycles required, shall be as specified in thespecifications for the mate
30、rial or product being tested, or asmutually agreed upon between the manufacturer and thepurchaser.6.9 Cleaning of Testing SpecimensTreat the specimenafter each test cycle as outlined in 6.9.1.After the last test cycleand if the specimen is to be inspected between test cycles, treatthe specimens as o
31、utlined in 6.9.1 and 6.9.2.6.9.1 Remove the specimen from the humidity chamber.Clean the specimen using fresh running water and a piece ofclean cheesecloth or suitable synthetic sponge to remove all ofthe slurry. A mild abrasive such as a water paste of tripoli maybe used to remove any adhering mate
32、rials.6.9.2 Since the cleaning operation described in 6.9.1 willremove any corrosion products, it will be necessary to rede-velop the points of failure. This may be done in several ways,such as exposure for4hinthesalt spray cabinet described inPractice B117, exposure for 24 h in a humidity cabinetop
33、erated at 38C and 100 % relative humidity with condensa-tion, or some other method that will cause corrosion of thebasis metal without any significant damage to the coating.NOTE 4Corrosion products visible on the test specimen with theslurry in place are not necessarily caused by points of failure i
34、n thecoating. Particles of metal accidentally deposited on the test specimenbefore humidity exposure will also cause visible corrosion products.7. Evaluation of Results7.1 After redevelopment of points of failure, as outlined in6.9.2, make a careful and immediate examination for the extentof corrosi
35、on of the test specimen or for other failures asrequired in the specifications covering the material or productbeing tested or by agreement between the manufacturer and thepurchaser.8. Report8.1 The report shall contain the following information,unless otherwise prescribed in the specifications cove
36、ring thematerial or product being tested:8.1.1 The title, designation, and year of issue of this method,4Model No. 167 hygrometer may be purchased from Sepor Laboratory SupplyCo., P.O. Box 1252, 718 N. Fries, Wilmington, CA 90748.B 380 97 (2008)e128.1.2 Readings of temperature within the exposure zo
37、ne ofthe humidity chamber,8.1.3 Readings of relative humidity within the exposurezone of the chamber,8.1.4 Type of specimen and its dimensions or number, ordescription of part,8.1.5 Exposure period for each cycle and number of cycles,8.1.6 Results of all inspections, and8.1.7 Method of redeveloping
38、corrosion spots.9. Precision and Bias9.1 The Corrodkote test provides reliable results if thecomposition of the slurry, the humidity in the chamber, thetemperature, and other factors discussed in this standard arecarefully controlled. The precision and bias are being deter-mined in interlaboratory t
39、est programs.ASTM International takes 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 suc
40、h rights, are entirely their own responsibility.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 addit
41、ional standardsand should be addressed 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
42、 ASTM Committee on Standards, at the 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).B 380 97 (2008)e13
