1、Designation: B 699 86 (Reapproved 2003)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 (e) 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 me
3、tals.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 o
4、fhydrogen 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 responsibi
6、lity 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:B 117 Practice for Operating Salt Spray (Fog) Apparatus2B 183 Practice for Preparation of Low-Carbon
7、Steel forElectroplating3B 201 Practice for Testing Chromate Coatings on Zinc andCadmium Surfaces3B 242 Practice for Preparation of High-Carbon Steel forElectroplating3B 254 Practice for Preparation of and Electroplating onStainless Steel3B 320 Practice for Preparation of Iron Castings for Electro-pl
8、ating3B 322 Practice for Cleaning Metals Prior to Electroplating3B 440 Specification for Cadmium4B 487 Test Method for Measurement of Metal and OxideCoating Thickness by Microscopical Examination of aCross Section3B 499 Test Method for Measurement of Coating Thick-nesses by the Magnetic Method: Nonm
9、agnetic Coatings onMagnetic Basis Metals3B 504 Test Method for Measurement of Thickness of Me-tallic Coatings by the Coulometric Method3B 567 Test Method for Measurement of Coating Thicknessby the Beta Backscatter Method3B 568 Test Method for Measurement of Coating Thicknessby X-Ray Spectrometry3B 5
10、71 Practice for Qualitative Adhesion Testing of MetallicCoatings3B 602 Test Method for Attribute Sampling of Metallic andInorganic Coatings3B 697 Guide for Selection of Sampling Plans for Inspectionof Electrodeposited Metallic and Inorganic Coatings3E 396 Test Methods for Chemical Analysis of Cadmiu
11、m5F 519 Method for Mechanical Hydrogen Embrittlement ofPlating Processes and Service Environments63. 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
12、 beidentified by types on the basis of supplementary treatmentrequired, as follows:3.2.1 Type IAs-vacuum-deposited without supplementarychromate treatment (see Appendix X1).3.2.2 Type IIWith supplementary chromate treatment (seeAppendix X2).NOTE 1It is strongly recommended that Type II should be use
13、d rather1This specification is under the jurisdiction of ASTM Committee B08 onMetallic and Inorganic Coatings and is the direct responsibility of SubcommitteeB08.08.04 on Soft Metals.Current edition approved Feb. 10, 2003. Published May 2003. Originallyapproved in 1981. Last previous edition approve
14、d in 1998 as B 699 86 (1998).2Annual Book of ASTM Standards, Vol 03.02.3Annual Book of ASTM Standards, Vol 02.05.4Annual Book of ASTM Standards, Vol 02.04.5Annual Book of ASTM Standards, Vol 03.05.6Annual Book of ASTM Standards, Vol 15.03.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box
15、C700, West Conshohocken, PA 19428-2959, United States.than 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 other governing document:4.1.1 The d
16、esignation 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),4.1.6 Test of coating compositi
17、on, 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 metal for the produc-tion of th
18、e 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 machined,ground, cold-formed, or col
19、d-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 corrosion resistance perfor-mance of t
20、he 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, intergranular attack, and hydrogenembr
21、ittlement. 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 removed by air blasting the parts
22、thoroughly, 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 to remove oil, grease, and other
23、 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 should notbe rougher than the sp
24、ecified 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 passivated.5.4 Deposition ProcessCadmium
25、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 preliminary undercoating ofnickel is
26、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 compound to produce a continuous,
27、 smooth,protective film.5.6.2 The Type 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 thepurchaser and specified by the pro
28、vision 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 conjunctionwith Type II coatings, in order to ensure the conformance to thesalt spray or abrasion resistance t
29、est requirements. Waxes, etc.,may be used to improve lubricity.6. 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 everywhere on thesignificant surfaces shall be at least
30、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 source of corrosion products that deface visiblesurface
31、s 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-lowable thickness for Class 12 shall be Class 8 (8
32、 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, thecoating shall not show separation from the basis metal
33、. 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 supplementary chromatefilm (Type II) on the cadmium coat
34、ing shall be adherent,non-powdery, and shall resist abrasion when tested as detailedin 9.4.6.5 Corrosion ResistanceCadmium coatings with Type IItreatment shall show neither white corrosion products ofcadmium nor basis metal corrosion products at the end of 96 hB 699 86 (2003)2test period, when teste
35、d 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 not constitute failure.NOTE 3The hours given are th
36、e 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 plating thickness of Type II coatings. Although hour
37、s 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, asemi-satin or a light matte luster shall be acceptable
38、.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 surfaces as stated in 6.2,including thread roots, thread
39、 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 rinsing or drying, andvariations in color or luster shall
40、 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 application techniques shall notbe cause for rejection
41、.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 product provide limits for those defects. Ametal finishe
42、r 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 become the subject of a specialagreement between the pu
43、rchaser 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 time, or at approximately thesame time, under esse
44、ntially 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 for conformanceto the requirements of this specific
45、ation, 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 nondestructive test methods and a fourth to be used withdest
46、ructive. 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 should compare the plans with his needs andstate which
47、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, size, and number, and shall be processed as required
48、in 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, but in a noncritical area; or if it destroys the c
49、oating,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 with the articles represented. The separate speci-me
