1、Designation: B 380 97 (Reapproved 2007)Standard Test Method ofCorrosion 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, in
2、 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.1. Scope1.1 This test method describes the Corrodkote2method ofevaluating the corrosion perfor
3、mance 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 reference for information only: Practice B 537, Specification B 456,Test Method B 602,
4、and Specification B 604.1.2 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 prio
5、r to use.2. Referenced Documents2.1 ASTM Standards:3B117 Practice for Operating Salt Spray (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 Exposure
6、B 602 Test Method for Attribute Sampling of Metallic andInorganic CoatingsB 604 Specification 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 containingco
7、rrosive salts to test specimens, allowing the slurry to dry, andexposing the specimens coated 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 andp
8、rotective applications. The Corrodkote test provides a methodof controlling the quality of electroplated 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 th
9、e chamber, andprovisions for air circulation in the chamber.5.2 Drops of moisture that might 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 eli
10、minating fog-spray nozzles, substituting water for the saltsolution in the reservoir, adding 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 Mater
11、ials of construction shall not affect the corrosive-ness of the test.6. Procedure6.1 Corrodkote 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 ferric1This test method is under the jurisdiction ofA
12、STM 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 approved Oct. 1,
13、2007. Published October 2007. Originallyapproved in 1961. Last previous edition approved in 2002 as B 380 85 (2002).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 ASTM website, www.
14、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, United States.chlori
15、de (FeCl36H2O), and 1.0 g of ACS reagent gradeammonium chloride (NH4Cl) in 50 mL of water conforming toSpecification 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 satur
16、ated. Mix the slurry thoroughly just beforeusing.6.1.1 An alternative method of preparing the 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 (FeCl
17、36H2O), and dissolve and dilute withdistilled water in a second volumetric flask to exactly 500 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 sol
18、utions become unstable.) Weigh out 50.0 g ofammonium chloride (NH4Cl) and dissolve and dilute 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;
19、place these in a beaker to which 30.0 g ofkaolin is now added. Stir with a glass stirring rod.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 tes
20、ted, or shall be mutually agreedupon by the manufacturer and the purchaser.6.3 Preparation of 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 wi
21、ll depositprotective films shall not be used.6.4 Slurry ApplicationApply the Corrodkote slurry 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. Al
22、low the specimens to dry at room tempera-ture and at a relative humidity less than 50 % for 1 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 p
23、aint, wax, tape, or other effective media so that thedevelopment of a galvanic effect between 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 a
24、s long as they do not touch each other and the supportsdo not touch the test areas that have 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 chambersh
25、all be maintained between 80 and 90 % shall not producecondensation on any of the parts.NOTE 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.
26、 An Abbeon certified hygrometer Model No. 167, or itsequivalent4is a suitable instrument for 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 c
27、onsidered as one cycle. Continuous operationimplies that the humidity chamber be closed and operatedcontinuously 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 cyc
28、le of 20 h or less is specified, the testspecimen shall be treated as outlined in 6.9 after each 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
29、asthe number of test cycles required, shall be as specified in thespecifications for the material 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
30、test cycleand if the specimen is to be inspected between test cycles, treatthe specimens as outlined 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 sl
31、urry. A mild abrasive such as a water paste of tripoli maybe used to remove any adhering materials.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 for4
32、hinthesalt spray cabinet described inPractice B117, exposure for 24 h in a humidity cabinetoperated 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 o
33、n the test specimen with theslurry in place are not necessarily caused by points of failure in 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 fa
34、ilure, as outlined in6.9.2, make a careful and immediate examination for the extentof corrosion 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 s
35、hall contain the following information,unless otherwise prescribed in the specifications covering thematerial or product being tested:4Model No. 167 hygrometer may be purchased from Sepor Laboratory SupplyCo., P.O. Box 1252, 718 N. Fries, Wilmington, CA 90748.B 380 97 (2007)28.1.1 The title, designa
36、tion, and year of issue of this method,8.1.2 Readings of temperature within the exposure zone 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 cy
37、cle and number of cycles,8.1.6 Results of all inspections, and8.1.7 Method of redeveloping 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
38、 arecarefully controlled. The precision and bias are being deter-mined in interlaboratory test 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
39、determination of the validity of any such patent rights, and the riskof infringement of such 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 reapprove
40、d or withdrawn. Your comments are invited either for revision of this standard or for additional 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
41、 that your comments have not received a fair hearing you shouldmake your views known to the 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 (2007)3
