1、 g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58coatings of cadmium on iron and steel Specification and test methodsICS 25.220.40Metallic coatings
2、Physical vapour-deposited BRITISH STANDARDBS ISO 22778:2006BS ISO 22778:2006This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 November 2006 BSI 2006ISBN 0 580 49743 7Amendments issued since publicationAmd. No. Date Commentscontract. Users ar
3、e responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations. National forewordThis British Standard was published by BSI. It is the UK implementation of ISO 22778:2006.The UK participation in its preparation was entrusted to Technical Co
4、mmittee STI/33, Electrodeposited and related coatings.A list of organizations represented on STI/33 can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a Reference numberISO 22778:2006(E)INTERNATIONAL STANDARD ISO22778First edition
5、2006-11-15Metallic coatings Physical vapour-deposited coatings of cadmium on iron and steel Specification and test methods Revtements mtalliques Revtements de cadmium appliqus par vide sur fer et acier Spcification et mthodes dessai BS ISO 22778:2006ii iiiContents Page Foreword iv Introduction v 1 S
6、cope . 1 2 Normative references . 1 3 Term(s) and definition(s) 2 4 Information to be supplied by the purchaser to the processor . 2 5 Designation . 3 6 Requirements 5 7 Sampling 9 8 Rejection 9 Annex A (informative) Additional information concerning equipment, substrate preparation, and process par
7、ameters 10 Annex B (normative) Determination of the average thickness of cadmium coatings 12 Annex C (normative) Adhesion test methods . 13 Annex D (normative) Sampling. 14 Bibliography . 15 BS ISO 22778:2006iv Foreword ISO (the International Organization for Standardization) is a worldwide federati
8、on of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee
9、. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance w
10、ith the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires appr
11、oval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 22778 was prepared by Technical Commit
12、tee ISO/TC 107, Metallic and other inorganic coatings, Subcommittee SC 3, Electrodeposited coatings and related finishes. BS ISO 22778:2006vIntroduction Cadmium coatings are applied by physical vapour-deposition techniques to iron, steel and other substrates to enhance appearance and improve resista
13、nce to corrosion. Unlike electroplating, physical vapour deposition does not introduce hydrogen into the basis material. Hence, vapour-deposited cadmium coatings are especially beneficial for protecting high-strength steels that are susceptible to hydrogen embrittlement. Hydrogen, however, can be in
14、troduced into the substrate during fabrication, cleaning, pickling and other treatments, and care must still be exercised to prevent the introduction of hydrogen prior to vapour deposition. Cadmium is toxic and health, safety and environmental concerns are now eliminating its non-essential uses. The
15、re remain, nevertheless, critical applications, often aerospace-related, where the unique properties of cadmium coatings, for example, their corrosion resistance, intrinsic lubricity, ductility, electrical conductivity and low contact resistance, make continued use necessary. One benefit of depositi
16、ng cadmium by physical deposition techniques is that the process is conducted in a sealed vacuum chamber and exposure to cadmium is at an absolute minimum. The corrosion resistance of physical vapour-deposited cadmium coatings may be further enhanced by the use of chromate conversion coatings and ot
17、her supplementary treatments. BS ISO 22778:2006blank1Metallic coatings Physical vapour-deposited coatings of cadmium on iron and steel Specification and test methods WARNING The use of this International Standard may involve hazardous materials, operations and equipment. This standard does not addre
18、ss all the safety problems associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices, and to determine the applicability of regulatory limitations prior to use. 1 Scope This International Standard specifies requirements for hi
19、gh-purity cadmium coatings produced by physical vapour deposition on iron, steel, and other substrates. It provides test methods to determine that the requirements have been met, and a method for designating the cadmium and chromate conversion coatings and other supplementary treatments. Cadmium coa
20、tings are not suitable for production items that will reach a temperature of 225 C or higher in service, or that will come into contact with other parts that will reach that temperature. 2 Normative references The following referenced documents are indispensable for the application of this document.
21、 For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 1463, Metallic and oxide coatings Measurement of coating thickness Microscopical method ISO 2064, Metallic and other inorganic coatings
22、 Definitions and conventions concerning the measurement of thickness ISO 2080, Electroplating and related processes Vocabulary ISO 2177, Metallic coatings Measurement of coating thickness Coulometric method by anodic dissolution ISO 2360, Non-conductive coatings on non-magnetic electrically conducti
23、ve basis materials Measurement of coating thickness Amplitude-sensitive eddy-current method ISO 2819, Metallic coatings on metallic substrates Electrodeposited and chemically deposited coatings Review of methods available for testing adhesion ISO 2859 (all parts), Sampling procedures for inspection
24、by attributes ISO 3497, Metallic coatings Measurement of coating thickness X-ray spectrometric methods ISO 3543, Metallic and non-metallic coatings Measurement of thickness Beta backscatter method ISO 3882, Metallic and other inorganic coatings Review of methods of measurement of thickness ISO 3892,
25、 Conversion coatings on metallic materials Determination of coating mass per unit area Gravimetric methods BS ISO 22778:20062 ISO 4518, Metallic coatings Measurement of coating thickness Profilometric method ISO 4519, Electrodeposited metallic coatings and related finishes Sampling procedures for in
26、spection by attributes ISO 4520, Chromate conversion coatings on electroplated zinc and cadmium coatings ISO 9220, Metallic coatings Measurement of coating thickness Scanning electron microscope method ISO 9227, Corrosion tests in artificial atmospheres Salt spray tests ISO 9587, Metallic and other
27、inorganic coatings Pretreatments of iron or steel to reduce the risk of hydrogen embrittlement ISO 9588, Metallic and other inorganic coatings Post-coating treatments of iron or steel to reduce the risk of hydrogen embrittlement ISO 12686, Metallic and other inorganic coatings Automated controlled s
28、hot-peening of metallic articles prior to nickel, autocatalytic nickel or chromium plating, or as a final finish ISO 16348, Metallic and other inorganic coatings Definitions and conventions concerning appearance EN 12508, Corrosion protection of metal and alloys Surface treatment, metallic, and othe
29、r inorganic coatings Vocabulary IEC 60454, Specifications for pressure-sensitive adhesive tapes for electrical purposes Part 2: Methods of test 3 Terms and definitions For the purposes of this document, the terms and definitions in ISO 2064, ISO 2080, ISO 2859, ISO 4519 and EN 12508 apply. 4 Informa
30、tion to be supplied by the purchaser to the processor When ordering articles for physical vapour deposition of cadmium in accordance with this International Standard, the purchaser shall provide the following information in writing in the contract or purchase order, or in the engineering drawing: a)
31、 the designation (see Clause 5); b) the specification and metallurgical condition of the basis metal, any process-temperature limitations (see 6.1.2) and shot-peening requirements see 6.1.3 c); c) the significant surface, including the coating of holes, recesses and presence of rack marks (see 6.1.1
32、 and 6.3.1); d) details of any sensitive material and whether ultra high-purity argon is required (see 6.1.2); e) the requirement for any consolidation, for example, by glass bead peening (see 6.4.1); f) the requirement for coating thickness (see 5.4 and Table 1) and a chromate conversion coating (s
33、ee 5.5 and 6.4.2); g) the requirement for a supplementary treatment, such as paint, and details of the specification involving the organic finish (see 5.5 and 6.4.3); BS ISO 22778:20063h) the requirement for coating adhesion (see 6.3.3 and Annex C). i) the requirement for special test specimens and
34、for the type of test method, for example, destructive or non-destructive (see 6.6); j) sampling and inspection requirements (see Clause 7 and Annex D). 5 Designation The designation shall appear on engineering drawings, in the purchase order, the contract or in the detailed product specification. Th
35、e designation specifies the basis material, the requirements for stress relief before vapour deposition, the nominal composition and thickness of the vapour-deposited cadmium coating, the type of chromate conversion coating and other supplementary treatment, and the heat treatment to reduce suscepti
36、bility to hydrogen embrittlement. 5.1 General The designation shall comprise the following: a) the term: vapour-deposited coating; b) the number of this International Standard, ISO 22778; c) a hyphen; d) the chemical symbol of the basis metal; e) a stroke (/); symbols for the cadmium coating, as wel
37、l as any coatings that may be applied prior to and after deposition, separated by strokes for each stage in the coating sequence in the order of application. The coating designation shall include the thickness of the coating, in micrometres. 5.2 Basis metal The basis metal shall be designated by its
38、 chemical symbol, or its principal constituent, if it is an alloy. For example: Fe for iron and steel; Zn for zinc alloys; Cu for copper and copper alloys; Al for aluminium and aluminium alloys. The specific alloy may be identified by its standard designation (for example, its UNS number, or its nat
39、ional or regional equivalent) placed between the symbols, , for example, Fe. See Reference 3 in the Bibliography. 5.3 Pre-process stress-relief heat treatment Stress-relief heat treatment prior to coating may be required for some basis materials. Brackets shall be placed around the letters SR, the t
40、emperature in degrees Celsius, and the time in hours. The temperature shall be in parentheses after the letters SR; for example SR(210)1. BS ISO 22778:20064 5.4 Type and thickness of cadmium The cadmium coating shall be designated by its chemical symbol, Cd, followed by a number giving the minimum l
41、ocal thickness of the coating in micrometres. For example, Cd5, designates a cadmium coating that is 5 m thick. The minimum thickness of the vapour-deposited cadmium coatings shall be selected in accordance with Table 1. Allowances for the thickness of the coating should be made by adjusting the dim
42、ensional tolerances during the manufacture of threaded items, and those with close tolerances. Table 1 Minimum thickness requirements for physical vapour-deposited cadmium coatings Application Minimum local thickness m Steels, normal requirements 15 Threaded articles of less than 20 mm nominal diame
43、ter, as follows: 1,5 u 0,5 to u 1,0 aChromium in hexavalent form may or may not be present. BS ISO 22778:20065Table 3 Supplementary treatments other than conversion coatings Code Type of treatment T1 T2 T3 T4 T5 Application of paints, varnishes, powder coatings or similar coating materials Applicati
44、on of organic or inorganic sealants. Dyeing Application of grease or oil, or other lubricants Application of wax NOTE The function of chromate conversion coatings and other supplementary treatments is to retard or prevent the formation of white corrosion products on surfaces exposed to corrosive atm
45、ospheres, and to delay the appearance of red corrosion of cadmium coatings on steel. The iridescent yellow to olive drab chromate films are satisfactory for the application of subsequent paint coatings, but bleached or leached chromate films are not recommended as a supplementary finish with vapour-
46、deposited cadmium coatings. Chemical conversion coatings that do not contain hexavalent chromium are commercially available. Some contain trivalent chromium; others are chromium-free. Substitutes shall meet the corrosion requirements given in Table 4. 5.6 Post-coating heat treatment Heat treatment t
47、o reduce the susceptibility of high-strength steels to hydrogen embrittlement may be required in some circumstances (see Clause 8). Brackets shall be placed around the letters ER, the temperature in degrees Celsius, and the time in hours. The temperature shall be in parentheses after the letters ER;
48、 for example ER(400)12. 5.7 Examples of coating designations Example of a physical vapour-deposited cadmium coating 8 m thick on steel (Fe), with a supplementary chromate conversion coating that is iridescent yellow (C): Physical vapour-deposited coating ISO 22778 Fe/Cd8/C Example of a coating 5 m t
49、hick on steel, with a supplementary chromate conversion coating that is transparent or colourless (A) and that shall receive a subsequent organic sealant (T2): Physical vapour-deposited coating ISO 22778 Fe/Cd5/A/T2 Example of a coating on high-strength steel that is to be stress relieved at 150 C for 2 h before applying a cadmium coating 5 m thick, with a supplementary black chromate conversion (F): Physical vapour-deposited coating ISO 22
