1、BS EN 4474:2016Aerospace series Aluminiumpigmented coatings CoatingmethodsBSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06BS EN 4474:2016 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN 4474:2016.It supersedes BS EN 4474:2009 whi
2、ch is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee ACE/65, Non-metallic materials for aerospace purposes.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the nece
3、ssaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2016.Published by BSI Standards Limited 2016ISBN 978 0 580 92603 7ICS 49.040Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was pub
4、lished under the authority of theStandards Policy and Strategy Committee on 31 August 2016.Amendments/corrigenda issued since publicationDate T e x t a f f e c t e dBS EN 4474:2016EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 4474 July 2016 ICS 49.040 Supersedes EN 4474:2009English Version Ae
5、rospace series - Aluminium pigmented coatings - Coating methods Srie arospatiale - Revtements alumino-organiques -Mthode dapplication Luft- und Raumfahrt - Aluminiumpigmentierte Beschichtungen - Beschichtungsverfahren This European Standard was approved by CEN on 4 March 2016. CEN members are bound
6、to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-
7、CENELEC 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 translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has
8、 the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Lux
9、embourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brus
10、sels 2016 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 4474:2016 EBS EN 4474:2016EN 4474:2016 (E) 2 Contents Page European foreword 3 1 Scope 4 2 Purpose of process . 4 3 Normative references 4 4 Terms and definitions . 4 5 Appa
11、ratus. 5 5.1 For application by dipping . 5 5.2 For application by spraying 6 5.3 For curing . 6 6 Information for the processor 6 7 Surface roughness of parts prior to application 6 8 Surface preparation . 6 8.1 Parts in titanium and titanium alloys 6 8.2 Parts in corrosion resisting steel 6 9 Coat
12、ing 7 9.1 General 7 9.2 Application by dipping 7 9.3 Application by spraying 7 9.4 Other applications 7 10 Post-treatment . 8 11 Removal of the coating 8 12 Characteristics, requirements and test methods 9 13 Quality assurance 10 13.1 Approval of the processor 10 13.2 Process approval . 10 14 Accept
13、ance . 10 14.1 Appearance and thickness . 10 14.2 Adhesion . 10 14.3 Curing verification 10 15 Re-coating 10 Annex A (informative) Standard evolution form . 11 BS EN 4474:2016EN 4474:2016 (E) 3 European foreword This document (EN 4474:2016) has been prepared by the Aerospace and Defence Industries A
14、ssociation of Europe - Standardization (ASD-STAN). After enquiries and votes carried out in accordance with the rules of this Association, this Standard has received the approval of the National Associations and the Official Services of the member countries of ASD, prior to its presentation to CEN.
15、This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by January 2017, and conflicting national standards shall be withdrawn at the latest by January 2017. Attention is drawn to the possibility that some o
16、f the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN 4474:2009. According to the CEN-CENELEC Internal Regulations, the national standards organizations of the f
17、ollowing countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherland
18、s, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 4474:2016EN 4474:2016 (E) 4 1 Scope This European Standard defines the coating methods and characteristics of aluminium pigmented coatings to EN 4473 which may be applied to fas
19、teners in titanium, titanium alloys, heat resisting nickel base or cobalt base alloys and corrosion resisting steels. 2 Purpose of process To reduce galvanic corrosion, friction and risk of seizing. 3 Normative references The following documents, in whole or in part, are normatively referenced in th
20、is document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 2516, Aerospace series Passivation of corrosion resisting steels and decontaminati
21、on of nickel base alloys EN 3032, Aerospace series Test method for dry film lubricants Thickness measurement EN 4473, Aerospace series Aluminium pigmented coatings Technical specification EN 9100, Quality Management Systems Requirements for Aviation, Space and Defence Organizations EN ISO 1463, Meta
22、llic and oxide coatings Measurement of coating thickness Microscopical method EN ISO 2409, Paints and varnishes Cross-cut test EN ISO 2431, Paints and varnishes Determination of flow time by use of flow cups EN ISO 2884-1, Paints and varnishes Determination of viscosity using rotary viscometers Part
23、 1: Cone-and-plate viscometer operated at a high rate of shear ISO 2859-1, Sampling procedures for inspection by attributes Part 1: Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection ISO 8080, Aerospace Anodic treatment of titanium and titanium alloys Sulphuric acid
24、 process 4 Terms and definitions For the purposes of this standard, the following terms and definitions apply. BS EN 4474:2016EN 4474:2016 (E) 5 4.1 batch parts subjected to the same aluminium pigmented coating application at the same time under the same condition 4.2 pre-production parts parts repr
25、esenting future production parts 4.3 definition document document specifying directly or indirectly all the requirements for the parts 4.4 scratch gouged out or scoring of metallic coating 4.5 run localized excess amount of coating to the extent of creating a drip or running of coating 4.6 indentati
26、on indent or uneven surface thickness (orange peel) 4.7 flaking particles of coating falling off due to poor adhesion or excess coating 4.8 crack separation of coating due to improper mix or poor adhesion of material 4.9 sampling plan plan according to which one or more samples are taken in order to
27、 obtain information and to reach a decision, if possibly 4.10 Acceptable Quality Limit (AQL) maximum percent defective (or the maximum number of defects per hundred units) that, for purposes of sampling inspection, can be considered satisfactory as a process average Note 1 to entry: Variant: quality
28、 level which in a sampling plan corresponds to a specified but relatively high probability of acceptance. 5 Apparatus 5.1 For application by dipping Container with a lid, stirring device and temperature control. The apparatus shall be capable of applying the specified thickness, for example by contr
29、olling the speed of immersion and removal and by draining or centrifuging the parts. BS EN 4474:2016EN 4474:2016 (E) 6 5.2 For application by spraying A dry, oil free air fed gun shall be used, with settings adapted to the characteristics of the aluminium pigmented coating used and to the shape of t
30、he parts to be coated. Preferably a mechanical stirring device in the reservoir. NOTE 1 A device allowing for rotation of the parts to be coated and the automatic displacement of the gun will give a more uniform application. NOTE 2 Use of an aerosol spray is not suitable as it does not always ensure
31、 acceptable reproducibility. 5.3 For curing An oven capable of curing temperatures prescribed by the coating manufacturer and controlled by periodical calibration. 6 Information for the processor The following information is to be given: designation of the aluminium pigmented coating to EN 4473; per
32、centage of solvent plus reference of the solvent product; number of the material standard and metallurgical condition of the latter; areas to be processed; thickness of the pigmented coating, if necessary, (see Table 1); duration and temperature of curing. 7 Surface roughness of parts prior to appli
33、cation It shall be specified on the drawing or in the definition documents. NOTE The surface roughness is an important factor affecting adhesion and behaviour of the coating in service. 8 Surface preparation 8.1 Parts in titanium and titanium alloys Unless otherwise specified, degreasing followed by
34、 abrasive blasting. 8.2 Parts in corrosion resisting steel Unless otherwise specified, or degreasing followed by abrasive blasting. BS EN 4474:2016EN 4474:2016 (E) 7 9 Coating 9.1 General It is recommended to apply the coating: if possible within 24 h, after surface preparation ; precautions shall b
35、e taken to prevent contamination or corrosion of the parts awaiting treatment; in a clean and dry environment, avoiding any operations liable to contaminate the surfaces to be treated. 9.2 Application by dipping Dipping can be performed as follows: adjust the viscosity of the solution (see EN ISO 24
36、31 or EN ISO 2884-1) to the value given by the manufacturer of the product to be deposited; if necessary, pre-heat the parts to about 50 C; immerse the parts at a speed determined by tests on pre-production parts; keep the parts immersed for 2 s to 10 s; remove the parts at a speed determined by tes
37、ts on pre-production parts; drain parts; dry parts avoiding handling them; if necessary, cure the coating in an oven. The temperature and duration shall comply with the values given by the manufacturer of the product used. 9.3 Application by spraying Spaying can be performed as follows: adjust the v
38、iscosity of the solution (see ISO 2431 or ISO 2884-1) to the value given by the manufacturer; if necessary, pre-heat the parts to approx. 50 C; produce the coating by applying successive passes, the gun setting and its distance being determined by tests on pre-production parts; dry parts avoiding ha
39、ndling them; if necessary, cure the coating in an oven. The temperature and duration shall comply with the values given by the manufacturer of the product to be used. 9.4 Other applications Other application methods producing the same quality of deposit may be used (for example: barrel deposition).
40、BS EN 4474:2016EN 4474:2016 (E) 8 10 Post-treatment If the tolerances of the parts necessitate mechanical finishing, it shall be performed by honing, burnishing, barrel finishing or manual brushing according to the size of parts or the batch size. 11 Removal of the coating The following processes ar
41、e generally used separately or as a combination: removal by dry or wet abrasive blasting with appropriate media; chemical removal (by pickling or solvents) using products well known for being compatible with the base metal. Following removal of the coating, the parts shall be subjected to a visual a
42、nd dimensional inspection. BS EN 4474:2016EN 4474:2016 (E) 9 12 Characteristics, requirements and test methods See Table 1. Table 1 Subclause Characteristic Requirement aInspection and test method 12.1 Appearance Uniform colour, a variation of this indicates incorrect distribution of the fillers in
43、the coating. Absence of defects such as: scratches, pits, blisters, runs, indentations, foreign bodies, accumulation of particles, lack of uniformity or any other surface imperfection. Visual inspection 12.2 Thickness Unless otherwise specified: 5 m to 13 m on externally threaded fasteners; 5 m to 2
44、0 m on internally threaded fasteners. Suitable method Qualification: EN ISO 1463 Acceptance: EN 3032 or with the purchasers agreement, a method based on measurement of the mass of the dry coating deposited In the case of dispute, EN ISO 1463 shall be applied. 12.3 Adhesion No flaking, blisters, crac
45、ks: EN ISO 2409, class 1 or less EN ISO 2409 12.4 Curing verification The coating shall not be damaged by a brief contact with a solvent. There shall be no evidence of deposit on the pad. Move three times back and forward with a pad of cotton-wool impregnated with a solvent (for example methyl-ethyl
46、-ketone). aOn parts, if not possible, on accompanying test pieces. BS EN 4474:2016EN 4474:2016 (E) 10 13 Quality assurance 13.1 Approval of the processor See EN 9100. 13.2 Process approval Before beginning production, the processor shall apply the coating on pre-production parts and/or test pieces a
47、s agreed between the purchaser and processor. All the tests required by this standard (see Clause 12) shall be carried out on these coated pre-production parts and/or test pieces, unless otherwise agreed between the purchaser and processor. If the test results are satisfactory for the purchaser, he
48、shall give his written approval to commence production. The process schedule shall not be changed thereafter without the prior agreement of the purchaser. 14 Acceptance 14.1 Appearance and thickness See Table 1. Unless otherwise specified, sampling in accordance with ISO 2859-1: sample size code let
49、ter, Table 1, special inspection level S3; simple sampling plan for normal inspection; Acceptance Quality Limit (AQL) 1,5. 14.2 Adhesion See Table 1. The inspection level, the sampling plan and the acceptance quality level according to ISO 2859-1 shall be defined by the purchaser. 14.3 Curing verification See Table 1. The inspection level, the sampling plan and the acceptance quality level according to ISO 2859-1 shall be defined by the purchaser. 15 Re-coating After agreement of
