EN 4868:2019
(Main)Aerospace series - Anodic electrodeposition of hexavalent chromium free primer
Aerospace series - Anodic electrodeposition of hexavalent chromium free primer
This document defines the requirements for hexavalent chromium free anodic electrodeposition of organic coatings on aluminium and aluminium alloys for corrosion protection of parts.
The purpose of this standard is to give design, quality and manufacturing requirements. It doesn’t give complete in-house process instructions; these shall be given in the processor detailed process instructions.
Luft- und Raumfahrt - Anodische Elektrotauchlackierung von sechswertiger chromfreier Grundierung
Dieses Dokument definiert die Anforderungen für die anodische Elektrotauchlackierung zum Korrosionsschutz von Teilen aus Aluminium und Aluminiumlegierungen mit organischen Beschichtungen ohne Verwendung von sechswertigem Chrom.
Der Zweck dieser Norm ist die Festlegung von Gestaltungs-, Qualitäts- und Herstellungsanforderungen. Diese Norm gibt keine vollständigen Anweisungen für interne Prozesse; diese müssen in den detaillierten Prozessanweisungen des Verarbeiters festgelegt werden.
Série aérospatiale - Electrodéposition anodique d'un primaire sans chrome hexavalent
Le présent document définit les exigences relatives à l'électrodéposition anodique sans chrome hexavalent de revêtements organiques sur l'aluminium et les alliages d'aluminium pour assurer la protection contre la corrosion de pièces vis-à-vis de la corrosion.
L'objet de la présente norme est d'indiquer les exigences de conception, de qualité et de fabrication. Elle ne donne pas de gamme de production complète ; ces informations doivent être données dans les instructions détaillées de l’applicateur relatives au procédé.
Aeronavtika - Anodno potopno barvanje s temeljno barvo brez šestvalentnega kroma
Ta dokument določa zahteve za anodno potopno barvanje organskih prevlek na aluminiju ali aluminijevih zlitinah s temeljno barvo brez šestvalentnega kroma za korozijsko zaščito vseh delov. Namen tega standarda je določiti zahteve glede zasnove, kakovosti in proizvodnje. Ne podaja popolnih navodil glede internega postopka, ki bodo podana v podrobnih navodilih izvajalcev postopka glede postopka.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-november-2019
Aeronavtika - Anodno potopno barvanje s temeljno barvo brez šestvalentnega
kroma
Aerospace series - Anodic electrodeposition of hexavalent chromium free primer
Luft- und Raumfahrt - Anodische Elektrotauchlackierung von sechswertigem
chromfreiem Grundierung
Série aérospatiale - Electrodéposition anodique d'un primaire sans chrome hexavalent
Ta slovenski standard je istoveten z: EN 4868:2019
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
87.020 Postopki za nanašanje Paint coating processes
barvnih premazov
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN 4868
EUROPEAN STANDARD
NORME EUROPÉENNE
September 2019
EUROPÄISCHE NORM
ICS 49.040
English Version
Aerospace series - Anodic electrodeposition of hexavalent
chromium free primer
Série aérospatiale - Electrodéposition anodique d'un Luft- und Raumfahrt - Anodische
primaire sans chrome hexavalent Elektrotauchlackierung von sechswertigem
chromfreiem Grundierung
This European Standard was approved by CEN on 5 May 2019.
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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, 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: Rue de la Science 23, B-1040 Brussels
© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 4868:2019 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 5
4 Purpose of process . 6
5 Protection system classification . 6
6 Process requirements . 7
7 Required characteristics . 9
8 Quality requirements . 9
Annex A (normative) Engineering requirements . 11
Annex B (normative) Tests methods . 15
Annex C (normative) Parts acceptance inspections . 16
Annex D (normative) Periodic tests requirements . 17
Bibliography . 18
European foreword
This document (EN 4868:2019) 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 March 2020, and conflicting national standards shall be
withdrawn at the latest by March 2020.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN 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, France, Germany, Greece, Hungary, Iceland, Ireland,
Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North
Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United
Kingdom.
1 Scope
This document defines the requirements for hexavalent chromium free anodic electrodeposition of
organic coatings on aluminium and aluminium alloys for corrosion protection of parts.
The purpose of this standard is to give design, quality and manufacturing requirements. It doesn’t give
complete in-house process instructions; these shall be given in the processor detailed process
instructions.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 3840, Aerospace series — Paints and varnishes — Technical specification
EN ISO 1463, Metallic and oxide coatings — Measurement of coating thickness — Microscopical method
EN ISO 1518-1, Paints and varnishes — Determination of scratch resistance — Part 1: Constant-loading
method
EN ISO 1519, Paints and varnishes — Bend test (cylindrical mandrel)
EN ISO 2360, Non-conductive coatings on non-magnetic electrically conductive base metals —
Measurement of coating thickness — Amplitude-sensitive eddy-current method
EN ISO 2409, Paints and varnishes — Cross-cut test
EN ISO 2812-1, Paints and varnishes — Determination of resistance to liquids — Part 1: Immersion in
liquids other than water
EN ISO 2812-2, Paints and varnishes — Determination of resistance to liquids — Part 2: Water immersion
method
EN ISO 4623-2, Paints and varnishes — Determination of resistance to filiform corrosion — Part 2:
Aluminium substrates
EN ISO 4628-8, Paints and varnishes — Evaluation of degradation of coatings — Designation of quantity
and size of defects, and of intensity of uniform changes in appearance — Part 8: Assessment of degree of
delamination and corrosion around a scribe or other artificial defect
EN ISO 4628-10, Paints and varnishes — Evaluation of degradation of coatings — Designation of quantity
and size of defects, and of intensity of uniform changes in appearance — Part 10: Assessment of degree of
filiform corrosion
EN ISO 9220, Metallic coatings — Measurement of coating thickness — Scanning electron microscope
method
EN ISO 9227, Corrosion tests in artificial atmospheres — Salt spray tests
EN ISO 17872, Paints and varnishes — Guidelines for the introduction of scribe marks through coatings on
metallic panels for corrosion testing
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
Mechanically Disturbed Layer
MDL
layer that is present at the surface resulting from the rolling process of the material
3.2
pit
surface corrosion defect at which the anodic coating is penetrated
Note 1 to entry: Typical characteristics of corrosion pits are:
• rounded or irregular or elongated geometry;
• comet tail or line or halo that emerges from the cavity;
• some corrosion by products inside pits (on aluminium the by-product may be granular, powdery or amorphous
and white, grey or black in colour).
To be considered as a corrosion pit, a surface cavity shall exhibit at least 2 (two) of the above characteristics.
3.3
process instruction
document that describes the application scopes, detailed process (key parameters, detailed steps, etc.),
quality management, environmental and safety regulations, etc.
3.4
rework
repetition of the anodic electrodeposition process step after complete stripping of the layer
3.5
batch
unless otherwise specified, it comprises parts of the same type (i.e. shape, size, material), processed at
the same time in the same bath
3.6
anodic electrodeposition
industrial coating method in which negatively charged organic coating particles in aqueous solution
migrate (electrophoresis) toward the anode of a direct-current electrical circuit passing through the
solution, so that electrolysis of water creates a localized pH gradient, precipitating a uniform layer of
coating on the anode
3.7
ultra-filtrate
effluent generated from an electrocoat bath passing across an ultrafilter membrane
Note 1 to entry: The effluent is mainly composed of water and water soluble species.
4 Purpose of process
4.1 General
This specification establishes the requirements for a waterborne, hexavalent chromium free corrosion
inhibiting, chemical and solvent resistant, anodic electrodeposition of organic coating capable of curing
at 110 °C to 120 °C.
The anodic electrodeposition process applies a protective coating with uniform film thickness control,
complete coverage of recessed areas, minimal surface defects and high transfer efficiency. Once the film
is deposited on the substrate, a thermal cure is required to achieve the final properties of the coated parts.
4.2 Applicability
It can be used as a protection against corrosion, as a painting primer before top coating application, for
electrical insulation, and as a masking before anodizing and/or conversion.
4.3 Limitations
4.3.1 All processes that can compromise the anodic electrodeposition film (e.g. forming, blasting, shot
peening, heat-treatment) shall be performed prior to surface preparation of the parts to be coated).
4.3.2 Anodic electrodeposition shall not be applied:
• in areas where electrical conductivity is required;
• for high temperature applications (> 180 °C);
• for components which can permanently entrap treatment solutions, except components that can be
adequately masked;
• for assemblies with overlap areas (e.g. spot-welded and riveted parts) containing tight tolerances that
cannot provide adequate pre-treatment and/or coating penetration between the overlap area.
5 Protection system classification
Coating layer is classified by the three following types:
• Type A: thin layer thicknesses (4 µm to 12 µm);
• Type B: medium layer thicknesses (12 µm to 30 µm);
• Type C: thick layer thicknesses (> 30 µm).
6 Process requirements
6.1 Information for the processor
• system type;
• substrate standard reference and heat treatment;
• areas to be coated;
• coating thickness measurement inspection points;
• electrical contact points or areas where these are inadmissible;
• specification for testing parts and/or samples.
6.2 Condition of parts prior to the treatment
All prior operations such as welding, soldering/brazing, blasting, shot peening, machining and heat
treatments shall have been completed.
• the parts shall be free of oil, grease, marking inks and other surface contaminations;
• if needed/required, mechanically disturbed layer shall be removed either by mechanical or chemical
processes;
• surface treatments prior electrodeposition process are possible. In case of anodic electrodeposition
rework, all organic coatings residues from the previous coating shall be completely removed.
6.3 Process conditions
6.3.1 Tooling
The tools, bars, electrical contact systems, and metal masking tooling shall be free of 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;
• the electrical contacts shall be kept in good condition for the correct flow of the current;
• electrical contact point locations should be defined between purchaser and processor, avoid any
accidental contact between the parts to be treated and the tank equipment or electrodes, and between
the different parts during all the process;
• the contact is preferably achieved at several poi
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