1、BRITISH STANDARDBS EN 12487:2007Corrosion protection of metals Rinsed and non-rinsed chromate conversion coatings on aluminium and aluminium alloysICS 25.220.40g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44
2、g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58Incorporating October 2008corrigendum BS EN 12487:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 May 2007 BSI 2009ISBN 978 0 580 59569 1 National forewordThe UK participation
3、 in its preparation was entrusted to Technical Committee STI/38, Chemical conversion coatings.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsib
4、le for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard is the UK implementation of EN 12487:2007, which is withdrawn.Amendments/corrigenda issued since publicationDate Comments incorporating corrigendum October 2008. It s
5、upersedes BS EN 12487:2000 Implementation of CEN corrigendum October 2008. Modification of Figure A.1.30 April 2009 EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 12487April 2007ICS 25.220.40English VersionCorrosion protection of metals - Rinsed and non-rinsedchromate conversion coatings on alumi
6、nium and aluminiumalloysProtection contre la corrosion des mtaux - Couches deconversion au chromate rinces et non rinces surlaluminium et les alliages daluminiumKorrosionsschutz von Metallen - Gesplte und no-rinseChromatierberzge auf Aluminium undAluminiumlegierungenThis European Standard was approv
7、ed by CEN on 24 February 2007.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalst
8、andards may be obtained on application to the CEN Management Centre or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified
9、to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Net
10、herlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2007 CEN All rights of exploitation i
11、n any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 12487:2007: ESupersedes EN 12487:2000Incorporating corrigendum October 2008EN 12487:2007 (E) 2 Contents Page Foreword3 1 Scope 4 2 Normative references 4 Information to be supplied by the purchaser .5 Coating types an
12、d designation 5 Coating types .5 Conversion coating designation6 Sampling.6 Coating requirements7 General7 Electrical insulation.7 Adhesion.7 Coating mass per unit area.7 Coating identification 7 Corrosion resistance.8 Annex A (informative) Process systems.9 Annex B (normative) After-treatments.12 A
13、nnex C (normative) Analytical methods for the determination of the coating mass and for the identification of chromium, phosphorus and zinc .13 Annex D (normative) Testing of the layer composition.14 Bibliography 16 BS EN 12487:2007 .4 3 Terms and definitions455.15.2767.17.27.37.47.57.6EN 12487:2007
14、 (E) 3 Foreword This document (EN 12487:2007) has been prepared by Technical Committee CEN/TC 262 “Metallic and other inorganic coatings”, the secretariat of which is held by BSI. This European Standard shall be given the status of a national standard, either by publication of an identical text or b
15、y endorsement, at the latest by October 2007, and conflicting national standards shall be withdrawn at the latest by October 2007. This document supersedes EN 12487:2000. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to i
16、mplement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerl
17、and and United Kingdom. BS EN 12487:2007 EN 12487:2007 (E) 4 1 Scope This European Standard specifies requirements for rinsed and non-rinsed chromate conversion coatings on aluminium and aluminium alloys intended to protect against corrosion and serve as a base for other coatings. 2 Normative refere
18、nces The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 485-1, Aluminium and aluminium alloys - S
19、heet, strip and plate - Part 1: Technical conditions for inspection and delivery EN 485-2, Aluminium and aluminium alloys - Sheet, strip and plate - Part 2: Mechanical properties EN 485-3, Aluminium and aluminium alloys - Sheet, strip and plate - Part 3: Tolerances on dimensions and form for hot-rol
20、led products EN 485-4, Aluminium and aluminium alloys - Sheet, strip and plate - Part 4: Tolerances on shape and dimensions for cold-rolled products EN 515, Aluminium and aluminium alloys Wrought products Temper designations EN 573-1, Aluminium and aluminium alloys Chemical composition and form of w
21、rought products Part 1: Numerical designation system EN 573-2, Aluminium and aluminium alloys Chemical composition and form of wrought products Part 2: Chemical symbol based designation system EN 573-3, Aluminium and aluminium alloys Chemical composition and form of wrought products Part 3: Chemical
22、 composition EN ISO 3892, Conversion coatings on metallic materials Determination of coating mass per unit area Gravimetric methods (ISO 3892:2000) EN ISO 9227, Corrosion tests in artificial atmospheres Salt spray tests (ISO 9227:2006) ISO 4519, Electrodeposited metallic coatings and related finishe
23、s Sampling procedures for inspection by attributes IEC 60603-1, Connectors for frequencies below 3 MHz for use with printed boards - Part 1: Generic specification - General requirements and guide for the preparation of detail specifications, with assessed quality (IEC 60603-1:1991 + A1:1992) 3 Terms
24、 and definitions For the purposes of this document, the following terms and definitions apply. 3.1 rinsed chromate coating chromate coating that is rinsed in water prior to drying BS EN 12487:2007 EN 12487:2007 (E) 5 NOTE This type of coating is typically applied to extruded and rolled aluminium fab
25、ricated parts, castings and long coils. 3.2 non-rinsed chromate coating coil coating chromate coating that is dried immediately after the chromating step without receiving a water rinse NOTE This type of coating is normally used on long coils of aluminium sheet stock that receive immediate painting
26、or adhesive coating. 4 Information to be supplied by the purchaser The following information shall be supplied by the purchaser: a) coating designation (see clause 5); b) sampling methods, acceptance levels or any other inspection requirements if different from those given in ISO 4519 (see clause 6)
27、; c) surface preparation prior to chromate conversion coating (see Annex A for guidance); d) requirements for adhesion (see 7.3) and corrosion resistance (see 7.6); e) nature, condition and finish of the basis metal, if any of these could affect the serviceability and/or appearance of the coating. W
28、ARNING Use of this standard can involve hazardous materials, operations and equipment. This standard does not purport to address 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 determine t
29、he applicability of regulatory limitations prior to use. Chemicals and materials shall be used and disposed of in a professional and environmentally suitable manner. 5 Coating types and designation 5.1 Coating types A conversion coating shall be referred to as type A, type C1, or type E1 in accordan
30、ce with Table 1. NOTE Annex A provides guidance on coating type, purpose, end use and mass per unit area. BS EN 12487:2007 EN 12487:2007 (E) 6 Table 1 Types of chromate conversion coating Type Appearance Coating mass per unit area(g/m) Other properties A Colourless 0,05 to 0,2 Decorative, low insula
31、tion resistance C1 Yellow (light to iridescent) 0,4 to 1,0 Used as a paint base and for bonding to rubber E1 Light green 0,4 to 1,2 Used as a paint base and for bonding to rubber NOTE For chromated long coils for types C1 and E1, the coating mass 0,5 g/m2to 0,8 g/m2is recommended. 5.2 Conversion coa
32、ting designation The conversion coating designation shall be comprised of the following: a) number of this European Standard; b) hyphen; c) aluminium alloy designation in accordance with EN 573-1, EN 573-2 and EN 573-3 (wrought aluminium alloys), EN 485 parts 1 through 4 (cast aluminium alloys) and
33、the temper designation in accordance with EN 515; d) solidus; e) symbol designating the type of coating (see Table 1 and NOTE 1 below). If the chromate conversion coating has to be after-treated, the designation shall also be comprised of the following: f) solidus; g) symbol indicating any after-tre
34、atment of the conversion coating as specified in Table B.1, Annex B (also see NOTE 2 below). NOTE 1 It is recommended that the chemical symbol is followed by the standard designation of the basis metal. NOTE 2 This can be repeated if more after-treatments are required. EXAMPLE The designation of a c
35、hromate conversion coating with a coating mass of 0,4 g/m2to 1,2 g/m2(E1) on wrought aluminium alloy EN AW-6060 T6, that has been after-treated with the application of inorganic or organic sealant (T2) is: Chromate conversion coating EN 12487-EN AW 6060 T6/E1/T2. 6 Sampling Sampling shall either be
36、carried out in accordance with ISO 4519 or as specified by the purchaser (see clause 4, b). BS EN 12487:2007 EN 12487:2007 (E) 7 7 Coating requirements 7.1 General Any tests (including corrosion resistance tests) shall be deferred until the expiry of a 24 h period after treatment. NOTE Conversion co
37、atings harden with age by gradual dehydration; they should, therefore, be handled carefully for the first 24 h after the last treatment. 7.2 Electrical insulation When measured at an open circuit voltage of 9 V and a current of 2 A in accordance with IEC 60603-1, the resistance between an electrical
38、 contact and the aluminium shall be less than 0,1 for type A, type C1 and type E1 coatings. 7.3 Adhesion 7.3.1 The coatings shall be adherent and non-powdery. The conversion coating shall pass the test described in 7.3.2 or 7.3.3. 7.3.2 Rub the dried surface with white soft tissue paper using normal
39、 hand pressure, making 10 movements. This treatment shall not leave any trace of staining on the paper. 7.3.3 If the test described in 7.3.2 is not sufficient to measure the adhesion of a conversion coating on aluminium, carry out a practical evaluation of the adhesion by measuring the adhesion of a
40、 secondary organic film applied to the chromated aluminium. 7.4 Coating mass per unit area For all but thin (type A) coatings, the coating mass per unit area of chromate and chromate-phosphate coatings on aluminium shall be determined in accordance with EN ISO 3892 or with the methods described in C
41、.2 to C.4. For thin (type A) chromate coatings, the coating mass per unit area shall be determined in accordance with C.3 and C.4. NOTE For thin chromate coatings, the errors associated with the methods described in EN ISO 3892 are unacceptably high. 7.5 Coating identification 7.5.1 General The test
42、 methods specified in Annex D shall be used to determine the presence or absence of relevant chemical elements in the conversion coating. 7.5.2 Chromate conversion coatings (yellow) The presence of chromium and the absence of phosphate in the coating shall identify the layer as a chromate conversion
43、 coating. The layer may contain hexavalent chromium. 7.5.3 Chromate phosphate coatings (green) The presence of phosphate and chromium and the absence of zinc shall identify the layer as a chromate-phosphate conversion coating. The layer consists of trivalent chromium. BS EN 12487:2007 EN 12487:2007
44、(E) 8 7.6 Corrosion resistance The corrosion resistance of a conversion coating shall be determined in accordance with EN ISO 9227. NOTE Requirements for corrosion resistance of conversion coatings vary widely depending on the aluminium alloys to which they are applied. The method is only suitable f
45、or production control to show no changes in the coating process during pre-treatment or between different periods of pre-treatment. BS EN 12487:2007 EN 12487:2007 (E) 9 Annex A (informative) Process systems A.1 Surface preparation The surfaces of the parts to be chromated should be clean and substan
46、tially free from any oxidation, scale or soils such as metal turnings, grinding dust, oil, grease, lubricants, hand-sweat or any other contamination that is detrimental to the final finish. The parts should therefore be cleaned before chromating and if necessary, be pickled. Prior to the non-rinsed
47、chromating process, surfaces should be free from non-reactive soluble salts. Care should be taken when rinsing to avoid splattering of chemicals and corrosion initiation. Figure A.1 shows the processing step options available depending on the preparation and intended end use required. BS EN 12487:20
48、07 EN 12487:2007 (E) 10 Degreasing Aqueous acid solution Aqueous alkaline solution Aqueous organic solution Organic solvents Cold water rinse Pickling (de-oxidizing-matt pickling burnishing) (acid) Pickling (de-oxidizing - matt pickling burnishing) (alkaline) Neutralization Cold water rinse Cold wat
49、er rinse Brightening (nitric acid plus hydrofluoric acid) Cold water rinse Chromating Green Colourless - yellowCold water rinse Hot water rinse (below 60 C) Drain water 30 S/cm 1Drying (metal surface temperature 100 C) Organic coating/corrosion protection 1For coatings a final rinse is necessary; for the conductivity of the drain water, see A.2. Figure A.1 Treatment stages of the chromating of aluminium and aluminium alloys A.2 Method of application Different base metals other than aluminium should not be treated in the same
