1、BRITISH STANDARD AEROSPACE SERIES BS EN 2516:1997 Passivation of corrosion resisting steels and decontamination of nickel base alloys The European Standard EN2516:1997 has the status of a British Standard ICS49.040BSEN2516:1997 This British Standard, having been prepared under the directionof the En
2、gineering SectorBoard, was published underthe authority of the Standards Board and comes intoeffect on 15 July1997 BSI 09-1999 The following BSI references relate to the work on this standard: Committee reference ACE/44 Draft for comment90/75748DC ISBN 0 580 26696 6 Committees responsible for this B
3、ritish Standard The preparation of this British Standard was entrusted to Technical Committee ACE/44, Protective treatments and finishes for aerospace purposes, upon which the following bodies were represented: Aluminium Finishing Association British Coatings Federation Ltd. Metal Finishing Associat
4、ion Ministry of Defence National Centre of Tribology Oil and Colour Chemists Association Society of British Aerospace Companies Amendments issued since publication Amd. No. Date CommentsBSEN2516:1997 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 Classification 3 5 Information for the processor 4 6 Condition of the parts prior to processing 4 7 Pre-treatments 4 8 Treatment 5 9 Required characteristics and inspection 5 10 Quality assurance 5 11 Health, safety and environmental aspe
6、cts 6 12 Designation 6 Table 1 3 Table 2 5 List of references Inside back coverBSEN2516:1997 ii BSI 09-1999 National foreword This British Standard has been prepared by Technical Committee ACE/44 and is the English language version of EN2516:1997 Aerospace series Passivation of corrosion resisting s
7、teels and decontamination of nickel base alloys, published by the European Committee for Standardization (CEN). EN2516:1997 was produced as a result of international discussions in which the United Kingdom took an active part. Cross-references The British Standards corresponding to the European Stan
8、dards referred to in the text are identical in number and title with those given in clause3. 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 no
9、t of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, theEN title page, pages2 to6, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorp
10、orated. This will be indicated in the amendment table on the inside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN2516 March1997 ICS49.040.40 Descriptors: Aircraft industry, steels, corrosion resisting steels, contamination, nickel alloys, classifications, degreasing, characteristi
11、cs, inspection, quality assurance, designation English version Aerospace series Passivation of corrosion resisting steels and decontamination of nickel base alloys Srie arospatiale Passivation des aciers rsistant la corrosion et dcontamination des alliages base nickel Luft- und Raumfahrt Passivieren
12、 von korrosionbestndigen Sthlen und Dekontaminierung von Nickellegierungen This European Standard was approved by CEN on1996-10-27. 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 stan
13、dard without any alteration. Up-to-date lists 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 la
14、nguage made by translation under the responsibility 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, Irela
15、nd, Italy, Luxembourg, Netherlands, Norway, 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
16、 Ref. No. EN2516:1997EEN2516:1997 BSI 09-1999 2 Foreword This European Standard has been prepared by the European 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 Nat
17、ional Associations and the Official Services of the member countries of AECMA, 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 nati
18、onal standards shall be withdrawn at the latest 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, Ir
19、eland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and theUnitedKingdom.EN2516:1997 BSI 09-1999 3 1 Scope This standard specifies several chemical methods of passivation 1)for corrosion resisting steels (austenitic, ferritic, martensitic and precipitation hardenable)
20、 and of decontamination for nickel base alloys. 2 Purpose of process To improve the corrosion resistant characteristics of a part after such treatments as machining, forming, tumbling and shot peening by removing foreign metal contamination due to these operations Passivation shall not be used on ca
21、stings, welded or brazed parts, carburized or nitrided surfaces nor on parts with mating surfaces when entrapment of acids may occur. 3 Normative references This European Standard incorporates by dated or undated reference provisions from other publications.These normative references are cited at th
22、e 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 Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the
23、 publication referred to applies. ISO9227, Corrosion tests in artificial atmospheres Salt spray tests. EN2000, Aerospace series Quality assurance EN aerospace products Approval of the quality system of manufacturers. EN2032-1, Aerospace series Metallic materials Part1: Designation 2) . 4 Classificat
24、ion The process class to be used depending on the material type is given in Table 1, unless otherwise specified between the manufacturer and the purchaser. The designation of the material type is defined in EN2032-1. Table 1 1) Other processes (e.g.electrolytic polishing) can also produce passivated
25、 surfaces. 2) Published as AECMA Prestandard at the date of publication of this standard Material type and designation Process class Austenitic chromium-nickel steels and austenitic-ferritic steels FE-PA36XX, FE-PA39XX, FE-PA45XX, FE-PA47XX, FE-PA48XX, FE-PA49XX, FE-PA15XX C1 or C2 Ferritic and mart
26、ensitic chromium steels FE-PM15XX, FE-PM17XX, FE-PM19XX C4 Austenitic precipitation hardenable steels FE-PA26XX, FE-PA29XX, FE-PA25XX C1 Martensitic precipitation hardenable steels FE-PM27XX, FE-PM38XX, FE-PM35XX C4 High chromium martensitic steels FE-PM39XX C3 Heat resisting nickel base alloys NI-P
27、H13XX, NI-PH18XX, NI-PH23XX, NI-PH29XX, NI-PD73XX, NI-PH26XX C1 or C2EN2516:1997 4 BSI 09-1999 5 Information for the processor Designation, see12; reference of the material standard and metallurgical condition of the latter; sequence of operations, if necessary; areas to be processed. 6 Condition of
28、 the parts prior to processing Fabrication of the parts shall have been completed. 7 Pre-treatments The parts shall be submitted to one or more of the processes(7.1 to7.4) appropriate to their degree of contamination. These processes are given for guidance. Other methods giving at least equivalent r
29、esults may be applied. Unless otherwise specified, parts shall be processed from one step to the next without delay. 7.1 Degreasing 7.1.1 Organic solvents Approved products shall be used either cold in liquid state or hot in vapour state. 7.1.2 Alkaline solutions a) Degreasing in strong alkaline sol
30、utions The composition may be as follows: b) Degreasing in mild alkaline solutions The composition may be as follows: Addition of a wetting agent is possible. These solutions shall be used for immersion degreasing either anodically or not. 7.2 Abrasive cleaning a) Blasting Use a fine-grain alumina o
31、r glass beads with or without water. b) Tumbling The abrasives shall not have been used on any other type of material (see Table 1) except titanium base alloys. 7.3 Descaling The method shall be chosen according to the type of parts, heat treatment or hot forming. 7.4 Acid-pickling It shall only be
32、used on steels not susceptible to pitting or sensitive to intergranular corrosion by the pickling solution which is most frequently an aqueous solution of nitric and hydrofluoric acids. The concentration can be adjusted within very wide limits by varying the proportions of the ingredients and by adj
33、usting operating temperatures. Parts in steel of R m(max.) 1100MPa 3)shall be de-embrittled by heat treatment at190 C to230 C for at least1h. sodium hydroxide (NaOH) : 15g/l sodium metasilicate pentahydrate (Na 2 SiO 3 ,5H 2 O) : 40g/l sodium metasilicate pentahydrate : 25g/l sodium carbonate (Na 2
34、CO 3 ) : 25g/l 3) R m(max.) = maximum specified R mEN2516:1997 BSI 09-1999 5 8 Treatment The aqueous solutions shall be chosen from Table 2 in accordance with the process class defined in Table 1for the material used to manufacture the parts. The parts shall be completely immersed in the chosen solu
35、tion, then rinsed in clean water and dried. Table 2 9 Required characteristics and inspection 9.1 Parts 9.1.1 Appearance When subjected to visual inspection, the surfaces shall be clean and free from corrosion, pitting or other form of surface attack due to the treatment. A slight discolouration is
36、allowed. 9.1.2 Absence of iron contamination Surfaces of type parts or test specimens shall not show any iron contamination indicated by rust after a salt spray test according to ISO9227 for2h. 9.2 Process 9.2.1 Air used for drying or any other operation shall be dry and free from oil. 9.2.2 The iro
37、n content in the solutions indicated in Table 2 shall be less than5 g/l and the chloride content less than0,1g/l. The nitric acid and sodium dichromate concentration shall be within the limits indicated in Table 2. Chemical analyses of the solutions indicated in Table 2 shall be carried out at regul
38、ar intervals to determine the contents of nitric acid, sodium dichromate, chloride and iron. 10 Quality assurance 10.1 Approval of the processor See EN2000. 10.2 Process qualification Before beginning production, the processor shall submit a series of type parts and test pieces from the first batch
39、treated under series conditions, which shall be tested according to9.1. If the process is different from that described in this standard, it shall be qualified as follows: at least one specimen of each material type to which the process is applicable (see Table 1), with a surface roughness of R ak 1
40、,64m, shall be treated according to the process to be qualified; after visual inspection to9.1.1 each specimen shall be subjected to a salt spray test in accordance with ISO9227 for24h. The exposed surface shall then show not more than a few isolated spots of rust. Process class Solution components
41、g/l Temperature C Time min Anodic voltage V HNO 3 b Na 2 Cr 2 O 7 ,2H 2 O c C1 200 to250 20 to30 50 to55 20 to40 Without 20 to30 30 to60 C2 200 to500 20 to30 30 to60 Without C3 a a) b) 200 to250 20 to30 50 to55 2 to3 3 to5 40 to60 60 to70 30 to40 Without C4 a a) b) 200 to250 20 to30 50 to55 20 to40
42、Without 40 to60 60 to70 30 to40 Without a Step a) shall be followed by step b) with a clean water rinse in between. b HNO 3 : Nitric acide c Na 2 Cr 2 O 7 ,2H 2 O: Hydrated sodium dichromateEN2516:1997 6 BSI 09-1999 10.3 Acceptance The parts shall have the required characteristics (see9.1). Frequenc
43、y of inspection shall be agreed between the purchaser and processor. 10.4 Fault sanction The parts not meeting the requirements shall be rejected. After agreement of the purchaser, these parts may be reprocessed (see7 and8). 11 Health, safety and environmental aspects The locally applicable regulati
44、ons and laws shall be observed. 12 Designation EXAMPLE: NOTEIf the classes of this standard are not used (see4), the designation shall be limited to EN2516.BSEN2516:1997 BSI 09-1999 List of references See national foreword.BS EN 2516:1997 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsI
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