1、BSI Standards PublicationBS EN 4826:2014Aerospace series Zinc-Nickel (12-16 % Ni) plating of steels with specified tensile strength 1 450 MPa, copper alloys, nickel alloys andaluminium alloys for parts and fastenersBS EN 4826:2014 BRITISH STANDARDNational forewordThis British Standard is the UK impl
2、ementation of EN 4826:2014.The UK participation in its preparation was entrusted to Technical Committee ACE/65/-/3, Paints, Surface Finish and Protective T r e a t m e n t s f o r A e r o s p a c e P u r p o s e s .A list of organizations represented on this committee can be obtained on request to i
3、ts secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2014.Published by BSI Standards Limited 2014ISBN 978 0 580 86330 1 ICS 49.040 Compliance with a British Standard
4、cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 December 2014.Amendments/corrigenda issued since publicationDate T e x t a f f e c t e dEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 4826
5、 December 2014 ICS 49.040 English Version Aerospace series - Zinc-Nickel (12 %-16 % Ni) plating of steels with specified tensile strength 1 450 MPa, copper alloys, nickel alloys and aluminium alloys for parts and fasteners Srie arospatiale - Dpt lectrolytique Zinc-Nickel (12 %-16 % Ni) sur aciers de
6、 rsistance 1 450 MPa, sur alliages de cuivre, alliages de nickel et alliages daluminium pour pices et lments de fixation Luft- und Raumfahrt - Zink-Nickel (12 % bis 16 % Ni) Stahlbeschichtung mit festgelegter Zugfestigkeit 1 450 MPa, Kupfer-, Nickel- und Aluminiumlegierungen fr Verbindungsteile und
7、Verschlsse This European Standard was approved by CEN on 28 June 2014. 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 lists and bibliograph
8、ical references concerning such national standards may be obtained on application to the CEN-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 responsibilit
9、y of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has 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
10、 Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATIO
11、N EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2014 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 4826:2014 EBS EN 4826:2014EN 4826:2014 (E) 2 Contents Page Foreword 3 1 Scope 4
12、2 Normative references 4 3 Terms and definitions .5 4 Purpose of process .5 5 Applicability and limitations of the process .6 6 Coating system classification 6 6.1 System types 6 6.2 Coating thicknesses 7 7 Requirements .7 7.1 Process requirements .7 7.2 Main technical engineering requirements .9 8
13、Quality requirements 11 8.1 Approval of the processor . 11 8.2 Process approval 11 8.3 General points . 12 8.4 Periodic tests 13 8.5 Periodic chemical analysis 13 8.6 Parts acceptance controls . 13 9 Designation . 14 BS EN 4826:2014EN 4826:2014 (E) 3 Foreword This document (EN 4826:2014) has been pr
14、epared by the Aerospace and Defence Industries Association 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 coun
15、tries of ASD, 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 June 2015, and conflicting national standards shall be withdrawn at the latest by June 2015. Attenti
16、on is drawn to the possibility that some of 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. According to the CEN-CENELEC Internal Regulations, the national standards organizations of th
17、e following 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, Netherl
18、ands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 4826:2014EN 4826:2014 (E) 4 1 Scope This European Standard specifies the plating of a Zinc-Nickel (12 % to 16 %) alloy on mechanical parts and fasteners in steels (Rm 1 450 M
19、Pa), stainless steels (Rm 1 450 MPa), copper alloys, nickel alloys and aluminium alloys (not applicable for electrical components), as well as the passivation and lubricant finishing that can be associated to them. The Zinc-Nickel process is an electrolytic plating process under controlled current a
20、llowing to deposit a Zinc-Nickel layer from, most often, an alkaline electrolyte. Alkaline Zinc-Nickel is only considered in this standard. The purpose of this standard is to give technical and quality requirements of Zinc-Nickel plating. It doesnt give complete in-house process instructions, these
21、shall be given in the manufacturers detailed process instructions. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references,
22、 the latest edition of the referenced document (including any amendments) applies. EN 2832, Aerospace series Hydrogen embrittlement of steels Notched specimen test EN 4473, Aerospace series Aluminium pigmented coatings for fasteners Technical specification EN 9100, Quality Management Systems Require
23、ments for Aviation, Space and Defence Organizations EN ISO 1463, Metallic and oxide coatings Measurement of coating thickness Microscopical method (ISO 1463) EN ISO 2409, Paints and varnishes Cross-cut test (ISO 2409) EN ISO 2819, Metallic coatings on metallic substrates Electrodeposited and chemica
24、lly deposited coatings Review of methods available for testing adhesion (ISO 2819) EN ISO 3497, Metallic coatings Measurement of coating thickness X-ray spectrometric methods (ISO 3497) EN ISO 9227, Corrosion tests in artificial atmospheres Salt spray tests (ISO 9227) ISO 2812 (all parts), Paints an
25、d varnishes Determination of resistance to liquids NASM 1312-5, Fastener test methods Method 5: Stress durability 1)NASM 1312-14, Fastener test methods Method 14: Stress durability internally threaded fasteners 1)ASTM F 519, Standard test method for mechanical hydrogen embrittlement evaluation of pl
26、ating/coating processes and service environments 2)1) Published by: AIA National (US) Aerospace Industries Association of America http:/www.aia-aerospace.org/2) Published by: ASTM National (US) American Society for Testing and Materials http:/www.astm.org/BS EN 4826:2014EN 4826:2014 (E) 5 3 Terms an
27、d definitions For the purposes of this document, the following terms and definitions apply. 3.1 batch unless otherwise specified, it comprises parts of the same type (shape, size, material), processed at the same time in the same bath with the same de-embrittlement conditions 3.2 pre-production part
28、 part representative of future production 3.3 electro-plating electrolytical metal deposition 3.4 passivation conversion performed on metal electro-deposition in order to improve corrosion resistance 3.5 lubricant top coat /finishing additional thin organic or inorganic resin based layer in order to
29、 improve functional properties: friction 3.6 Zinc-Nickel coating system Zinc-Nickel coating including: possible undercoat as strike, supplementary treatments as passivation and/or lubricant top coat. See 6.1: type 1 to type 4. 3.7 substrate material upon which a coating is directly deposited, in the
30、 case of a single or first coating, the substrate is identical with the basis metal and for a subsequent coating, the intermediate coating is the substrate 3.8 UTS RmUltimate Tensile Strength 3.9 nodule rounded projection formed on a cathode during electrode position (2.5) that may be seen without m
31、agnification 4 Purpose of process The aim of the Zinc-Nickel plating is to ensure a protection against corrosion for steels or to reduce the effects of galvanic coupling of less noble materials in contact with the plated substrates. For improving corrosion, a passivation is performed on Zinc-Nickel
32、coating. The Zinc-Nickel plating has also electrical conductivity properties and may also provide anti-galling properties when associated with an appropriate lubricant finishing. BS EN 4826:2014EN 4826:2014 (E) 6 5 Applicability and limitations of the process This standard applies whenever reference
33、d. It is applicable on parts with or without threads, and fasteners, and on: low alloys steels and stainless steels Rm 1 450 MPa, copper alloys, nickel alloys, aluminium alloys. The electrolytic Zinc-Nickel plating process must not be used in the following cases: welded parts likely to entrap electr
34、olyte, cavities, holes, recesses for which processing limitations may result in uncontrolled or incomplete, coverage, springs with diameter 1 mm. Zinc-Nickel plating can withstand the following service temperatures: 120 C for parts coated with lubricant top coat, 250 C for parts coated with trivalen
35、t chromium passivation. 6 Coating system classification 6.1 System types Zinc-Nickel coating system is classified by the four following types, depending on the supplementary finishing: Type 1 (T1): Zinc-Nickel (12 % to 16 %) alloy as plated. Type 2 (T2): Zinc-Nickel (12 % to 16 %) alloy as plated an
36、d trivalent chromium passivation in order to improve corrosion resistance. Type 3 (T3): Zinc-Nickel (12 % to 16 %) alloy as plated, trivalent chromium passivation and friction control lubricant for improving corrosion resistance and reaching consistent coefficient of friction of 0.08 to 0.14. Type 4
37、 (T4): Zinc-Nickel (12 % to 16 %) alloy as plated, trivalent chromium passivation and friction control lubricant for improving corrosion resistance and reaching consistent coefficient of friction of 0.12 to 0.18. BS EN 4826:2014EN 4826:2014 (E) 7 6.2 Coating thicknesses Unless otherwise specified in
38、 the product standard or definition document, the coating thicknesses are as follows: Class A: 4 m to 7 m typical thickness for screws with diameter 3,5 mm). Class C: 10 m to 20 m (typical thickness for other cases for maximum corrosion resistance). It is permissible that thicknesses obtained on par
39、ts exceed the maximum thickness values given above provided that the final sizes required by the plan and drawings are satisfied and that the thickness is not exceeding 20 % of the maximum thickness. For internally threaded parts, a maximum limit of 13 m (class B) above the minimum shall be allowed
40、on the external surfaces. The thickness tolerances are those of the Zinc-Nickel electrolytic plating (type 1) and/or Zinc-Nickel coating system (type 2, 3 and 4): Possible undercoat (e.g. strike in order to improve adhesion on stainless steels), Passivation and lubricant finishing thicknesses are co
41、nsidered to be insignificant. For fasteners, the possible undercoat, the passivation or lubricant finishing thicknesses shall not alter mountability, see dimensional test, subclause 8.3. 7 Requirements 7.1 Process requirements 7.1.1 Information for the processor process designation, see Clause 9; ba
42、re substrate standard reference and heat treatment; areas to be plated; plated thickness measuring points; duration and temperature of stress relief and de-embrittlement treatments; electrical contact points or areas where these are not permitted; specification for testing on parts and/or samples. 7
43、.1.2 Condition of parts prior to the treatment Welding, soldering/brazing, mechanical operations and heat treatments shall have been completed. Stress relief may be required for parts which have been cold worked or machined after the heat treatment operation. When shot peening is specified, it shall
44、 be performed after the stress relief operations. BS EN 4826:2014EN 4826:2014 (E) 8 Unless otherwise specified, the stress relief heat treatment conditions for parts in steel shall conform to Table 1. Table 1 Stress relief heat treatment of parts in steel RmStress relief heat treatment MPa 1 100 Not
45、 necessary 1 100 and 1 450 (190 to 230) 10 C, 1 h min. A slight discoloration of the surface by oxidation is admissible after stress relief. 7.1.3 Process conditions a) Tooling The tools, bars, electrical contact systems, and metal masking tooling must be protected against corrosion, and/or free of
46、corrosion or any other damage which may be detrimental to the treatment during use. The part racks and tools must be designed and set up in such a manner as to: avoid any retention of air or treatment solution in the parts, facilitate neutralization and removal of solutions during rinsing operations
47、, assure electrical contact for the electrolytic baths, avoid the treatment any accidental contact between the parts to be treated and the tank equipments or electrodes, and between the different parts. Avoid any galvanic damage between tools and parts. b) Masking The parts shall be previously degre
48、ased prior to masking. Component areas which must not be coated shall be masked with suitable material. c) Surface pre-treatment Surface preparation means any method able to completely eliminate all surface contaminations. Methods which may result in hydrogen embrittlement of the material shall be a
49、voided. The surface preparation prior to Zinc-Nickel plating that guides the plating adhesion depends on the metallic substrate; for aluminium alloys, copper alloys and stainless steels a strike undercoat may be performed. d) Zinc-Nickel plating The Zinc-Nickel shall be deposited in accordance with an approved electrolyte and processor to produce coatings containing 12 % to 16 % nickel. The composition of the bath as well as the process parameters sh
