1、Designation: B 699 86 (Reapproved 2008)Standard Specification forCoatings of Cadmium Vacuum-Deposited on Iron and Steel1This standard is issued under the fixed designation B 699; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、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 specification covers the requirements for a cad-mium coating vacuum-deposited on iron and steel basis met
3、als.The coating is especially beneficial to those ferrous metals,heat treated to 46HRC and higher or having an ultimate tensilestrength greater than 1500 MPa, wherein protection againstcorrosion and appearance are important (see Appendix X1).1.2 Vacuum-deposited production items are normally free of
4、hydrogen embrittlement, a danger when using electroplatingprocesses for deposition. Vacuum deposition can handle largehigh-strength parts that cannot be conveniently mechanicallyplated in the rotating barrels.1.3 The coating is provided in various thicknesses up to andincluding 12 m (3.1) either in
5、the as-deposited condition orwith a supplementary finish (3.2).1.4 The following precautionary caveat pertains only to thetest methods portion, Section 9, of this specification: Thisstandard does not purport to address all of the safety problems,if any, associated with its use. It is the responsibil
6、ity of the userof this standard to establish appropriate safety and healthpractices and determine the applicability of regulatory limita-tions prior to use.2. Referenced Documents2.1 ASTM Standards:2B117 Practice for Operating Salt Spray (Fog) ApparatusB 183 Practice for Preparation of Low-Carbon St
7、eel forElectroplatingB 201 Practice for Testing Chromate Coatings on Zinc andCadmium SurfacesB 242 Guide for Preparation of High-Carbon Steel forElectroplatingB 254 Practice for Preparation of and Electroplating onStainless SteelB 320 Practice for Preparation of Iron Castings for Electro-platingB 32
8、2 Guide for Cleaning Metals Prior to ElectroplatingB 440 Specification for CadmiumB 487 Test Method for Measurement of Metal and OxideCoating Thickness by Microscopical Examination of CrossSectionB 499 Test Method for Measurement of Coating Thick-nesses by the Magnetic Method: Nonmagnetic Coatings o
9、nMagnetic Basis MetalsB 504 Test Method for Measurement of Thickness of Me-tallic Coatings by the Coulometric MethodB 567 Test Method for Measurement of Coating Thicknessby the Beta Backscatter MethodB 568 Test Method for Measurement of Coating Thicknessby X-Ray SpectrometryB 571 Practice for Qualit
10、ative Adhesion Testing of MetallicCoatingsB 602 Test Method for Attribute Sampling of Metallic andInorganic CoatingsB 697 Guide for Selection of Sampling Plans for Inspectionof Electrodeposited Metallic and Inorganic CoatingsE 396 Test Methods for Chemical Analysis of CadmiumF 519 Test Method for Me
11、chanical Hydrogen Embrittle-ment Evaluation of Plating/Coating Processes and ServiceEnvironments3. Classification3.1 ClassesVacuum-deposited cadmium coatings shall beclassified on the basis of thickness, as follows:Class Minimum Thickness, m12 1288553.2 TypesVacuum-deposited cadmium coatings shall b
12、eidentified by types on the basis of supplementary treatmentrequired, as follows:3.2.1 Type IAs-vacuum-deposited without supplementarychromate treatment (see Appendix X1).1This specification is under the jurisdiction of ASTM Committee B08 onMetallic and Inorganic Coatings and is the direct responsib
13、ility of SubcommitteeB08.08.04 on Soft Metals.Current edition approved Aug. 1, 2008. Published September 2008. Originallyapproved in 1981. Last previous edition approved in 2003 as B 699 86 (2003).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service a
14、t 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.3.2.2 Type IIWith supplementary chromate treatmen
15、t (seeAppendix X2).NOTE 1It is strongly recommended that Type II should be used ratherthan Type I on production items.4. Ordering Information4.1 To make the application of this specification complete,the purchaser needs to supply the following information to thesupplier in the purchase order or othe
16、r governing document:4.1.1 The designation number and year of issue of thisdocument.4.1.2 Class and type (3.1 and 3.2),4.1.3 Hardness or tensile strength of the steel parts (5.2),4.1.4 Heat treatment for stress relief, whether it has beenperformed or is required,4.1.5 Undercoating, if required (5.5)
17、,4.1.6 Test of coating composition, if required (6.1),4.1.7 Significant surfaces (6.2.2),4.1.8 Luster (6.6),4.1.9 Sampling, if other than specified (Section 7),4.1.10 Certification (11.1), and4.1.11 Supplementary requirements, if applicable.5. Materials and Manufacture5.1 Nature of FinishThe cadmium
18、 metal for the produc-tion of the coating and the resultant coating shall conform tothe composition requirements of Specification B 440 and shallcontain not less than 99.95 mass % cadmium.5.2 Stress ReliefSteel parts that have an ultimate tensilestrength of 1000 MPa and above and that have been mach
19、ined,ground, cold-formed, or cold-straightened shall be heat-treatedat a minimum of 190C for3hormore for stress relief beforecleaning and coating.5.3 Cleaning of Basis MetalProper preparatory proce-dures and thorough cleaning of the basis metal are essential toensure satisfactory adhesion and corros
20、ion resistance perfor-mance of the coating. The basis metal shall not be exposed totreatments such as cathodic cleaning, and acid treatmentsinvolving release of hydrogen on the surface of parts; nor shallmaterials be used for cleaning that will have damaging effectson the metal, such as pits, interg
21、ranular attack, and hydrogenembrittlement. If necessary, cleaning materials for surfacepreparation should be evaluated in accordance with MethodF 519. The basis metal shall be abrasive dry-blasted, using newmaterials or materials that have not been used on other metals.All loose particles shall be r
22、emoved by air blasting the partsthoroughly, using clean dry oil-free compressed air. Followingair blasting, the basis metal may be outgassed by subjecting itto an electron bombardment with high-energy positive ions ina glow discharge unit. The following practices, where appro-priate for precleaning
23、to remove oil, grease, and other foreignmaterials should be used: B 183, B 242, B 254, B 320, andB 322.NOTE 2Parts may be cleaned by blasting with 120-mesh aluminumoxide or 100-mesh garnet grit with a nozzle pressure of 410 to 620 kPa toremove scale, oxides, or other contamination. Blasted surfaces
24、should notbe rougher than the specified finish for the part. When necessary toachieve the proper surface roughness, finer grit may be used, butaluminum oxide coarser than 120-mesh or garnet grit coarser than100-mesh should not be used. Following air blasting, stainless steel partsshould be passivate
25、d.5.4 Deposition ProcessCadmium vacuum depositionshall be conducted in a vacuum of 1.33 3 104to 3.3 Pa withan evaporation rate of 0.8 to 1.7 mg/s.5.5 SubstrateUnless otherwise specified, cadmium shallbe deposited directly on the basis metal without a preliminaryundercoating of another metal. A preli
26、minary undercoating ofnickel is permissible with parts made of stainless steel.5.6 Chromate Treatment (Type II):5.6.1 Chromate treatment for Type II shall be done in orwith special aqueous acid solutions composed of hexavalentchromium along with certain anions that act as a catalyst orfilm forming c
27、ompound to produce a continuous, smooth,protective film.5.6.2 TheType II film shall range in color from an iridescentyellow or a thicker more protective iridescent bronze or brownto the heavier olive drab. It may be dyed to a desired color.When necessary, a desired color shall be indicated by thepur
28、chaser and specified by the provision of a suitable coloredsample or indicated on the drawing for the part.5.6.3 Waxes, lacquers, or other organic coatings shall not bepermitted as a substitute, nor shall they be used in conjunctionwithType II coatings, in order to ensure the conformance to thesalt
29、spray or abrasion resistance test requirements. Waxes, etc.,may be used to improve lubricity.6. Coating Requirements Coating Requirements6.1 Coating CompositionWhen specified, the chemicalcomposition of the coating shall be determined (see X1.3).6.2 Thickness:6.2.1 The thickness of the coating every
30、where on thesignificant surfaces shall be at least that of the specified classas defined in 3.1.6.2.2 Significant surfaces defined as those normally visible(directly or by reflection) are essential to the appearance orserviceability of the article when assembled in normal position;or can be the sour
31、ce of corrosion products that deface visiblesurfaces on the assembled article. When necessary, the signifi-cant surfaces shall be indicated by the purchaser on theapplicable drawing of the article, or by the provision ofsuitably marked samples.6.2.3 On nonsignificant visible surfaces, the minimum al
32、-lowable thickness for Class 12 shall be Class 8 (8 m), forClass 8 it shall be Class 5 (5 m), and for Class 5 it shall be 4m.6.3 AdhesionThe cadmium coating shall be sufficientlyadherent to the basis metal to pass the tests in 9.3. Whenexamined at a magnification of approximately 4 diameters, thecoa
33、ting shall not show separation from the basis metal. Theformation of cracks in the coating caused by rupture of thebasis metal that does not result in flaking, peeling, or blisteringof the cadmium coating shall not be considered as nonconfor-mance to this requirement.6.4 Abrasion ResistanceThe suppl
34、ementary chromatefilm (Type II) on the cadmium coating shall be adherent,non-powdery, and shall resist abrasion when tested as detailedin 9.4.B 699 86 (2008)26.5 Corrosion ResistanceCadmium coatings with Type IItreatment shall show neither white corrosion products ofcadmium nor basis metal corrosion
35、 products at the end of 96 htest period, when tested by continuous exposure to salt spray inaccordance with 9.5. The appearance of corrosion productsvisible to the unaided eye at normal reading distance shall because for rejection, except that white corrosion products at theedges of specimens shall
36、not constitute failure.NOTE 3The hours given are the minimum required to guaranteesatisfactory performance. Longer periods before the appearance of thewhite corrosion products, even on the as-coated Type I, and rust arepossible. Salt spray resistance does not vary in exact proportion withincreased p
37、lating thickness of Type II coatings. Although hours to failure(red rust) for Type I coatings are not specified, the hours given for TypeII reflect the added protection of the chromate treatments withoutrequiring impractical testing periods.6.6 LusterUnless otherwise specified by the purchaser, asem
38、i-satin or a light matte luster shall be acceptable.6.7 Workmanship and Finish:6.7.1 The coating shall be smooth, adherent, uniform inappearance, and substantially free of blisters, pits, nodules,flaking, and other defects that may affect the function of thecoating. The coating shall cover all surfa
39、ces as stated in 6.2,including thread roots, thread peaks, corners, recesses, andedges. The coating shall show no indication of contaminationor improper operation of equipment used to produce thedeposit, such as excessively powdery or darkened coatings.Superficial staining, which results from rinsin
40、g or drying, andvariations in color or luster shall not be cause for rejection.6.7.2 Defects and variations in appearance in the coatingthat arise from surface conditions of the substrate (scratches,pores, roll marks, inclusions, etc.) and that persist in the finishdespite the observance of good app
41、lication techniques shall notbe cause for rejection.NOTE 4Applied finishes generally perform better in service when thesubstrate over which they are applied is smooth and free of torn metal,inclusions, pores, and other defects. It is recommended that the specifi-cations covering the unfinished produ
42、ct provide limits for those defects.Ametal finisher can often remove defects through special treatments, suchas grinding, polishing, electropolishing, and chemical treatments. How-ever, these are not normal in the treatment steps preceding the applicationof the finish. When desired, they shall becom
43、e the subject of a specialagreement between the purchaser and the supplier.7. Sampling7.1 Inspection LotAn inspection lot shall be defined as acollection of coated articles that are of the same kind, that havebeen produced to the same specifications, that have beencoated by a single supplier at one
44、time, or at approximately thesame time, under essentially identical conditions, and that aresubmitted for acceptance or rejection as a group.7.2 SelectionA random sample of the size required byTest Method B 602 shall be selected from the inspection lot.The articles in the sample shall be inspected f
45、or conformanceto the requirements of this specification, and the lot shall beclassified as conforming or nonconforming to each requirementin accordance with the criteria of the sampling plans in TestMethod B 602.NOTE 5Test Method B 602 contains three sampling plans that are tobe used with nondestruc
46、tive test methods and a fourth to be used withdestructive. The three methods for nondestructive tests differ in the qualitylevel they require of the product. Test Method B 602 requires the use ofthe plan with the intermediate quality level unless the purchaser specifiesotherwise. The purchaser shoul
47、d compare the plans with his needs andstate which plan is to be used. If the plans in Method B 602 do not servethe needs, additional ones are given in Guide B 697.7.3 SpecimensIf separate test specimens are to be used torepresent the coated articles in a test, the specimens shall be ofthe nature, si
48、ze, and number, and shall be processed as requiredin 8.1, 8.2, and 8.3.NOTE 6When both destructive and nondestructive tests exist for themeasurement of a characteristic, the purchaser needs to state which is tobe used so that the proper sampling plan is selected. Also a test maydestroy the coating,
49、but in a noncritical area; or if it destroys the coating,it may be the tested article can be reclaimed by stripping and recoating.The purchaser needs to state whether the test is to be considereddestructive or nondestructive.8. Specimen Preparation8.1 Vacuum-Coated Parts or Separate SpecimensWhenthe vacuum-coated parts are of such form, shape, size, andvalue as to prohibit their use, or are not readily adaptable to atest, or when destructive tests of small lot sizes are required,the test shall be made by the use of separate specimens coatedconcurrently
