1、BRITISH STANDARD AEROSPACE SERIES BS EN 3769:1997 Electrolytic polishing of corrosion resisting steels and heat resisting alloys The European Standard EN 3769:1997 has the status of a British Standard ICS 49.040BSEN3769:1997 This British Standard, having been prepared under the directionof the Engin
2、eering SectorBoard, was published underthe authority of the Standards Board and comes intoeffect on 15 August 1997 BSI 09-1999 The following BSI references relate to the work on this standard: Committee reference ACE/44 Draft for comment 90/80759 DC ISBN 0 580 26699 0 Committees responsible for this
3、 British Standard The preparation of this British Standard was entrusted to Technical CommitteeACE/44, Protective treatments and finishes for aerospace purposes, upon which the following bodies were represented: Aluminium Finishing Association British Coatings Federation Ltd. Metal Finishing Associa
4、tion Ministry of Defence National Centre of Tribology Oil and Colour Chemists Association Society of British Aerospace Companies Amendments issued since publication Amd. No. Date CommentsBSEN3769:1997 BSI 09-1999 i Contents Page Committees responsible Inside front cover National foreword ii Foreword
5、 2 1 Scope 3 2 Purpose of process 3 3 Normative references 3 4 Definitions 3 5 Information for the processor 3 6 Treatment 3 7 Required characteristics 3 8 Inspection and test methods 3 9 Quality assurance 4 10 Health, safety and environmental aspects 4 11 Designation 4 Annex A (informative) Electro
6、lytic polishing 5 List of references Inside back coverBSEN3769:1997 ii BSI 09-1999 National foreword This British Standard has been prepared by Technical Committee ACE/44 and is the English language version of EN 3769:1997 Aerospace series Electrolytic polishing of corrosion resistant steels and hea
7、t resisting alloys, published by the European Committee for Standardization (CEN). EN 3769:1997 was produced as a result of international discussions in which the UnitedKingdom took an active part. Cross-references The British Standard corresponding to the European Standard referred to in the text i
8、s identical in number and title with that given inclause 3. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from
9、legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, theEN title page, pages 2 to 6, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicate
10、d in the amendment table on the inside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 3769 March 1997 ICS 49.040.40 Descriptors: Aircraft industry, corrosion resisting steels, heat resistant steels, alloys, electropolishing, characteristics, inspection, tests, quality assurance, de
11、signation English version Aerospace series Electrolytic polishing of corrosionresisting steels and heat resisting alloys Srie arospatiale Polissage lectrolytique des aciers rsistant la corrosion et des alliagesrsistant chaud Luft und Raumfahrt Elektrolytisches Polieren von korrosionsbestndigen Sthle
12、n und hochwarmfesten Legierungen This European Standard was approved by CEN on 1996-10-27. CEN members are bound 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 l
13、ists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. The European Standards exist in three official versions (English, French, German). A version in any other language made by translation under the resp
14、onsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norwa
15、y, Portugal, Spain, Sweden, Switzerland and UnitedKingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1997 Copyright reserved to CEN members Ref. No. EN 3769:1997 EEN3769:1997 BSI 0
16、9-1999 2 Foreword This European Standard has been prepared bytheEuropean Association of Aerospace Manufacturers (AECMA). After inquiries 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 Servi
17、ces of the member countries ofAECMA, prior to its presentation to CEN. 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 September1997, and conflicting national standards shall be withdrawn at the l
18、atest by September1997. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Nor
19、way, Portugal, Spain, Sweden, Switzerland and the UnitedKingdom.EN3769:1997 BSI 09-1999 3 1 Scope This standard specifies the electrolytic polishing of corrosion resisting steels and heat resisting alloys used in aerospace constructions. It shall be applicable whenever referenced. 2 Purpose of proce
20、ss To improve the surface condition and/or increase the corrosion resistance by eliminating any metallic surface contamination 3 Normative references This European Standard incorporates by dated or undated reference provisions from other publications. These normative references are cited at the appr
21、opriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publi
22、cation referred to applies. ISO 9227, Corrosion tests in artificial atmospheres Salt spray tests. EN 2000, Aerospace series Quality assurance EN aerospace products Approval of the quality system of manufacturers. EN 2516, Aerospace series Passivation of corrosion resisting steels and decontamination
23、 of nickel base alloys. 4 Definitions For the purposes of this standard, the following definitions apply: 4.1 batch unless otherwise specified, it shall comprise parts of the same nature (form, size, material), treated at the same time in the same bath 4.2 pro-production parts parts representing fut
24、ure production 5 Information for the processor Designation, see11; number of the material standard and metallurgical conditon of the latter; areas to be processed; permitted electrical contact points or areas where these are prohibited. 6 Treatment The parts shall be: degreased and deoxidized; treat
25、ed in a solution. Examples of appropriate solutions are described inAnnex A; rinsed and dried. To improve corrosion resistance, a passivation in accordance with EN2516 may be carried out. 7 Required characteristics 7.1 Appearance The surface shall be smooth and glossy, free from corrosion pittings.
26、7.2 Surface cleanness and corrosion resistance The surface of the parts shall have no metallic contamination and no signs of corrosion even after24h of exposure to salt spray. 7.3 Dimensions and surface roughness after processing They shall be in accordance with the indications in the design documen
27、ts. 7.4 Intergranular corrosion The surface of the parts shall have no such corrosion. 8 Inspection and test methods 8.1 Approval of the process 8.1.1 Appearance Visual inspection 8.1.2 Surface cleanness and corrosion resistance The salt spray test shall be made in accordance withISO9227 in a5% solu
28、tion of sodium chloride. 8.1.3 Dimensions and surface roughness after processing They shall be verified by dimensional measurements carried out before and after processing. 8.1.4 Intergranular corrosion Metallographic examination shall be made on a cross-section at a magnification of min. 300times.
29、8.2 Acceptance of parts 8.2.1 Appearance See8.1.1. 8.2.2 Surface cleanness and corrosion resistance See 8.1.2.EN3769:1997 4 BSI 09-1999 8.2.3 Dimensional inspection See 8.1.3. 8.2.4 Intergranular corrosion See 8.1.4. 9 Quality assurance 9.1 Approval of the processor See EN 2000. 9.2 Process approval
30、 The processor shall carry out: electrolytic polishing on pre-production parts and/or test pieces, determined by agreement between the purchaser and processor; tests specified in this standard, unless otherwise agreed between the purchaser and processor. Other specific tests may be carried out at th
31、e purchasers request, for example creep, impact strength, etc,. When the test results have been accepted as satisfactory by the purchaser, he shall give his written approval to start production. The procedure shall not be changed without previous agreement from the purchaser. 9.3 Acceptance The freq
32、uency and nature of the inspection of parts and test pieces shall be defined in the design documents or determined by agreement between the purchaser and processor. The appearance inspection (see8.2.1) shall be carried out on the whole batch unless otherwise specified. By no means it shall be less t
33、han10% of the batch with a minimum of20 parts. In case of accompanying test pieces, the metallographic examination (see8.2.4) shall be carried out at a rate of one test per batch. The frequency of the other tests (see8.2.2 and8.2.3) shall be determined by agreement between the purchaser and processo
34、r. 9.4 Re-treatment It is permitted if the parts are not within the specified dimensions or if the surface roughness is not achieved. 10 Health, safety and environmental aspects The locally applicable regulations and laws shall be observed. 11 DesignationEN3769:1997 BSI 09-1999 5 Annex A (informativ
35、e) Electrolytic polishing Composition of the solution anduseconditions Units Solution n 1 n 2 n 3 Phosphoric acid (d = 1,70) g/l 1200 100 1200 100 900 100 Chromic acid anhydride g/l 260 30 130 20 Sulphuric acid (d = 1,84) g/l 330 25 Operating temperature C 70 to 90 60 to 75 35 to 40 Voltage V 15 to
36、30 12 to 30 11 to 15 Current density A/dm 2 100 to 200 20 to 40 60 to 75 The solutions shall be controlled to maintain product concentrations in the given range.6 blankBSEN3769:1997 BSI 09-1999 List of references See national foreword.BS EN 3769:1997 BSI 389 Chiswick High Road London W4 4AL BSIBriti
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