SIST EN 4826:2015

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

This standard specifies the plating of a Zinc-Nickel (12 % to 16 %) alloy on mechanical parts and fasteners in steels (UTS ≤ 1 450 MPa), stainless steels (UTS ≤ 1 450 MPa), copper 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 allowing 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 doesn’t give complete in-house process instructions, these shall be given in the manufacturers detailed process instructions.

Luft- und Raumfahrt - Zink-Nickel (12 % bis 16 % Ni) Stahlbeschichtung mit festgelegter Zugfestigkeit ≤ 1 450 MPa, Kupfer-, Nickel- und Aluminiumlegierungen für Verbindungsteile und Verschlüsse

Série aérospatiale - Dépôt électrolytique Zinc-Nickel (12 %-16 % Ni) sur aciers de résistance ≤ 1 450 MPa, sur alliages de cuivre, alliages de nickel et alliages d'aluminium pour pièces et éléments de fixation

La présente norme spécifie le dépôt électrolytique d’alliage de Zinc-Nickel (12 % à 16 %) sur pièces mécaniques et fixations en acier (Rm ≤ 1 450 MPa), aciers inoxydables (Rm ≤ 1 450 MPa), alliages de cuivre, alliages de nickel et alliages d’aluminium (non applicable pour les composants électriques), ainsi que la passivation et le lubrifiant de finition qui peuvent y être associés. Le procédé Zinc-Nickel est un procédé de dépôt électrolytique sous intensité contrôlée permettant de déposer une couche de Zinc-Nickel à partir, le plus souvent, d’un électrolyte alcalin. Seul, le Zinc-Nickel alcalin est considéré dans la présente norme.
L’objet de la présente norme est de fournir des exigences techniques et qualité pour le dépôt électrolytique Zinc-Nickel. Elle ne fournit pas les instructions de procédé internes complètes ; celles-ci doivent être données par les gammes détaillées de traitement des fabricants.

Aeronavtika - Cink-nikljeva (12 %–16 % Ni) prevleka jekel z določeno natezno trdnostjo ? 1 450 MPa z bakrovimi, nikljevimi in aluminijevimi zlitinami za dele in vezne elemente

Ta standard določa prevleko iz cink-nikljeve (12 % do 16 %) zlitine na mehanskih delih in veznih elementih pri jeklih (UTS ≤ 1450 MPa), nerjavnih jeklih (UTS ≤ 1450 MPa), bakrovih zlitinah in aluminijevih zlitinah (ne velja za električne komponente), ter tudi zaključno obdelavo za pasiviranje in mazivo, ki ju je mogoče povezati z njimi. Cink-nikljev proces je proces elektroliznega nanašanja prevleke pod nadzorovanim tokom, ki omogoča nalaganje cink-nikljevega sloja, najpogosteje iz alkalnega elektrolita. Alkalni cink-nikelj je obravnavan samo v tem standardu.
Namen tega standarda je določiti tehnične zahteve in zahteve glede kakovosti za cink-nikljevo prevleko. Ne podaja popolnih navodil glede internega procesa, ki bodo podana v podrobnih navodilih proizvajalcev glede procesa.

General Information

• Status: Published
• Publication Date: 18-Jan-2015
• ICS: 49.040 - Coatings and related processes used in aerospace industry
• Technical Committee: I13 - Imaginarni 13
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 05-Jan-2015
• Due Date: 12-Mar-2015
• Completion Date: 19-Jan-2015
• Ref Project: EN 4826:2014 - 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

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN 4826:2015
01-februar-2015
$HURQDYWLND&LQNQLNOMHYD±1LSUHYOHNDMHNHO]GRORþHQRQDWH]QR
WUGQRVWMR"03D]EDNURYLPLQLNOMHYLPLLQDOXPLQLMHYLPL]OLWLQDPL]DGHOHLQ
YH]QHHOHPHQWH
$HURVSDFHVHULHV=LQF1LFNHO1LSODWLQJRIVWHHOVZLWKVSHFLILHGWHQVLOH
VWUHQJWK”03DFRSSHUDOOR\VQLFNHODOOR\VDQGDOXPLQLXPDOOR\VIRUSDUWVDQG
IDVWHQHUV
/XIWXQG5DXPIDKUW=LQN1LFNHOELV1L6WDKOEHVFKLFKWXQJPLWIHVWJHOHJWHU
=XJIHVWLJNHLW”03D.XSIHU1LFNHOXQG$OXPLQLXPOHJLHUXQJHQIU
9HUELQGXQJVWHLOHXQG9HUVFKOVVH
6pULHDpURVSDWLDOH'pS{WpOHFWURO\WLTXH=LQF1LFNHO1LVXUDFLHUVGH
UpVLVWDQFH”03DVXUDOOLDJHVGHFXLYUHDOOLDJHVGHQLFNHOHWDOOLDJHVG
DOXPLQLXP
SRXUSLqFHVHWpOpPHQWVGHIL[DWLRQ
Ta slovenski standard je istoveten z: EN 4826:2014
ICS:
49.040 Prevleke in z njimi povezani Coatings and related
postopki, ki se uporabljajo v processes used in aerospace
letalski in vesoljski industriji industry
SIST EN 4826:2015 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

SIST EN 4826:2015

---------------------- Page: 2 ----------------------

SIST EN 4826:2015

EUROPEAN STANDARD
EN 4826

NORME EUROPÉENNE

EUROPÄISCHE NORM
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
Série aérospatiale - Dépôt électrolytique Zinc-Nickel (12 %- Luft- und Raumfahrt - Zink-Nickel (12 % bis 16 % Ni)
16 % Ni) sur aciers de résistance ≤ 1 450 MPa, sur alliages Stahlbeschichtung mit festgelegter Zugfestigkeit ≤ 1 450
de cuivre, alliages de nickel et alliages d'aluminium pour MPa, Kupfer-, Nickel- und Aluminiumlegierungen für
pièces et éléments de fixation Verbindungsteile und Verschlüsse
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 bibliographical 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 responsibility 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 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
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR 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 Ref. No. EN 4826:2014 E
worldwide for CEN national Members.

---------------------- Page: 3 ----------------------

SIST EN 4826:2015
EN 4826:2014 (E)
Contents
Page
Foreword .3
1 Scope .4
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 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

2

---------------------- Page: 4 ----------------------

SIST EN 4826:2015
EN 4826:2014 (E)
Foreword
This document (EN 4826:2014) has been prepared 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 countries 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.
Attention 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 the 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, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.
3

---------------------- Page: 5 ----------------------

SIST EN 4826:2015
EN 4826:2014 (E)
1 Scope
This European Standard specifies the plating of a Zinc-Nickel (12 % to 16 %) alloy on mechanical parts and
fasteners in steels (R ≤ 1 450 MPa), stainless steels (R ≤ 1 450 MPa), copper alloys, nickel alloys and
m m
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
allowing 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 doesn’t give
complete in-house process instructions, these 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,
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 — Requirements 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 chemically 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 and varnishes — Determination of resistance to liquids
1)
NASM 1312-5, Fastener test methods — Method 5: Stress durability
1)
NASM 1312-14, Fastener test methods — Method 14: Stress durability internally threaded fasteners
ASTM F 519, Standard test method for mechanical hydrogen embrittlement evaluation of plating/coating
2)
processes and service environments

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/
4

---------------------- Page: 6 ----------------------

SIST EN 4826:2015
EN 4826:2014 (E)
3 Terms and 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
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 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 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
R
m
Ultimate Tensile Strength
3.9
nodule
rounded projection formed on a cathode during electrode position (2.5) that may be seen without
magnification
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 coating. The Zinc-Nickel plating has also electrical conductivity
properties and may also provide anti-galling properties when associated with an appropriate lubricant
finishing.
5

---------------------- Page: 7 ----------------------

SIST EN 4826:2015
EN 4826:2014 (E)
5 Applicability and limitations of the process
This standard applies whenever referenced.
It is applicable on parts with or without threads, and fasteners, and on:
 low alloys steels and stainless steels R ≤ 1 450 MPa,
m
 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 electrolyte,
 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 trivalent 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 and 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 (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.
6

---------------------- Page: 8 ----------------------

SIST EN 4826:2015
EN 4826:2014 (E)
6.2 Coating thicknesses
Unless otherwise specified in the product standard or definition document, the coating thicknesses are as
follows:
 Class A: 4 µm to 7 µm [typical thickness for screws with diameter < 3,5 mm and tight fits (bushes)].
 Class B: 7 µm to 13 µm (typical thickness for parts with tigh tolerances or threaded, and screws with
diameter > 3,5 mm).
 Class C: 10 µm to 20 µm (typical thickness for other cases for maximum corrosion resistance).
 It is permissible that thicknesses obtained on parts 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 µm (class B) above the minimum shall be allowed 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 considered to be insignificant. For fasteners,
the pos
...