1、AECMA STANDARD NORME AECMA AECMA NORM Edition approved for publication 1996-01-31 prEN 3769 Edition 1 January 1996 The equivalent versions in French and German languages can be supplied by B.N.A.E. - Technopolis 54 - 199, rue Jean-Jacques Rousseau 92138 ISSY - LES - MOULINEAUX CEDEX - FRANCE PUBLISH
2、ED BY THE EUROPEAN ASSOCIATION OF AEROSPACE INDUSTRIES (AECMA) Gulledelle 94 - 8-1200 BRUXELLES - Tel. (32) 2 775 81 10 - Fax. (32) 2 775 81 11 ICs : 49.040.40 ENGLISH VERSION Aerospace series Electrolytic polishing of corrosion resistant steels and heat resisting alloys Srie arospatiale Luft- und R
3、aumfahrt Polissage lectrolytique Elektrolytisches Polieren des aciers rsistant la corrosion et des alliages rsistant chaud von korrosionsbestndigen Sthlen und hochwarmfesten Legierungen This Aerospace series“ Standard has been drawn up under the responsibility of AECMA (The European Association of A
4、erospace Industries). It is published on yellow paper in three equivalent versions (English, French, German). It will be submitted as a draft European Standard to CEN (European Committee for Standardization) for formal vote. Copyright Association Europeene des Constructeurs de Materiel Aerospatial P
5、rovided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-STD*AECMA PREN 37b9-ENGL 377b O 3032333 O032777 702 O Page 3 prEN 3769 : 1996 1 Scope This standard specifies the electrolytic polishing of corrosion resistant steels and heat re
6、sisting alloys used in aerospace constructions. It shall be applicable whenever referenced. 2 Purpose of process 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
7、dated or undated reference provisions from other publications. These normative references are cited at the appropriate 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 Standar
8、d only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies. IS0 9227 Corrosion tests in artificial atmospheres - Salt spray tests EN 2000 Aerospace series - Quality assurance - EN aerospace products - Approval of the qual
9、ity system of manufacturers EN 251 6 Aerospace series - Passivation of corrosion resistant steels and decontamination of nickel base alloys 4 Definitions For the purposes of this standard, the following definitions apply. 4.1 material), treated at the same time in the same bath. Batch : Unless other
10、wise specified, it shall comprise parts of the same nature (form, size, 4.2 Pre-production parts : Parts representing future production. 5 Information for the processor - Designation, see 11 ; - number of the material standard and metallurgical conditon of the latter ; - areas to be processed ; - pe
11、rmitted electrical contact points or areas where these are prohibited. 1) Published as AECMA Standard at the date of publication of this standard Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or network
12、ing permitted without license from IHS-,-,-STD-AECMA PREN 37b7-ENGL L77b W LOL23LL 0012778 bq7 Page 4 prEN 3769 : 1996 6 Treatment The parts shall be : - degreased and deoxidized ; - treated in a solution. Examples of appropriate solutions are described in annex A ; - rinsed and dried. To improve co
13、rrosion resistance, a passivation in accordance with EN 2516 may be carried out. 7 Required characteristics 7.1 Appearance The surface shall be smooth and glossy, free from corrosion Pittings. 7.2 Surface cleanness and corrosion resistance The surface of the parts shall have no metallic contaminatio
14、n and no signs of corrosion even after 24 h of exposure to salt spray. 7.3 They shall be in accordance with the indications in the design documents. Dimensions and surface roughness after processing 7.4 Intergranular corrosion The surface of the parts shall have no such corrosion. 8 Inspection and t
15、est methods 8.1 Approval of the process 8.1 .I Appearance Visual inspection 8.1.2 The salt spray test shall be made in accordance with IS0 9227 in a 5 % solution of sodium chloride. Surface cleanness and corrosion resistance 8.1.3 They shall be verified by dimensional measurements carried out before
16、 and after processing. Dimensions and surface roughness after processing 8.1.4 Intergranular corrosion Metallographic examination shall be made on a cross-section at a magnification of min. 300 times. 8.2 Acceptance of parts 8.2.1 Appearance See 8.1 .I. Copyright Association Europeene des Constructe
17、urs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I STD-AECMA PREN 37b7-ENGL L77b LOL23LL 0032799 585 Page 5 prEN 3769 : 1996 8.2.2 See 8.1.2. Surface cleanness and corrosion resistance 8.2.3 Dimensi
18、onal 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 The processor shall carry out : - electrolytic polishing on pre-production parts and/or test pieces, determined by agreement between the purchaser a
19、nd processor ; - tests specified in this standard, unless otherwise agreed between the purchaser and processor. Other specific tests may be carried out at the purchasers request, for example creep, impact strength, etc When the test results have been accepted as satisfactory by the purchaser, he sha
20、ll give his written approval to start production. The procedure shall not be changed without previous agreement from the purchaser. 9.3 Acceptance The frequency and nature of the inspection of parts and test pieces shall be defined in the design documents or determined by agreement between the purch
21、aser and processor. The appearance inspection (see 8.2.1) shall be carried out on the whole batch unless otherwise specified. By no means it shall be less than 10 % of the batch with a minimum of 20 parts. In case of accompanying test pieces, the metallographic examination (see 8.2.4) shall be carri
22、ed out at a rate of one test per batch. The frequency of the other tests (see 8.2.2 and 8.2.3) shall be determined by agreement between the purchaser and processor. 9.4 Re-treatment It is permitted if the parts are not within the specified dimensions or if the surface roughness is not achieved. Copy
23、right Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-io The locally applicable regulations and laws shall be observed. Health, safety and environmental aspects
24、11 Designation EXAMPLE : Number of this standard ” Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,- STD-AECflA PREN 37bq-ENGL 177b = LO12311 O013001 83
25、1 Page 7 prEN 3769 : 1996 V A/dm2 Annex A (informative) Electrolytic polishing 15 to 30 12 to 30 11 to 15 100 to 200 20 to 40 60 to 75 Composition of the solution and use conditions Phosphoric acid (d = 1,701 Chromic acid anhydride I Suiphuric acid (d = 1,841 Operating temperature Voltage Current de
26、nsity I Units I no1 1 200I 100 260 f 30 Solution n02 I n03 130 I20 330 i 25 OC 70 to 90 60 to 75 35 to 40 The solutions shall be controlled to maintain product concentrations in the given range. Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
