Non-Electrolytically Applied Zinc Flake Coatings with Top Coat
Surface Protection Requirements
Previous issues
TL 233: 1982-09, 1983-02, 1991-05, 1992-06, 1993-11, 1998-02, 2003-09, 2003-11
Changes
The following changes have been made compared with TL 233: 2003-11:
–Scope changed: Maximum temperature 180 °C for general components, notes on TL 180 added –Tables 1 and 2 changed
–Base layer and specifications supplemented in Section 3.6.2
–Requirement in Section 3.9.2 changed
–Section 3.10 revised
–Referenced standards updated
–Appendix A, new products DELTA-PROTEKT? KL 101, DELTA-PROTEKT? KH 200, as offered
by D?rken MKS-Systeme and Magni-Flake D21 and B46, as offered by Magni Europe included Scope
This standard defines the requirements for non-electrolytically applied surface protection types made of zinc and aluminum flakes (at least 70%) with an additional organic top coat for ferrous materials.In contrast to the surface protection types specified in Technical Supply Specification TL 180 (cur‐rently being prepared) and TL 245, this standard describes a coating system which ensures the functional characteristics of components, e.g., color and/or corrosion protection, by means of a con‐sistent organic top coating with a greater coating thickness. The layers are applied using the following methods: spray coating, spin coating, or electrostatic spray coating. The dip/spin coating method is
especially suitable for small parts.1 Group Standard TL 233
Issue 2010-11
Class. No.:
50223Descriptors:corrosion protection, surface protection, zinc, aluminum, flake, top coat, DELTA-TONE, DELTA-SEAL,
DELTA-PROTEKT, Magni
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This electronically generated Standard is authentic and valid without signature.
The English translation is believed to be accurate. In case of discrepancies, the German version is alone authoritative and controlling.
Page 1 of 8
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This Standard is available to contracting parties solely via the B2B supplier platform https://www.doczj.com/doc/a312419308.html,.
? Volkswagen Aktiengesellschaft VWNORM-2010-08e
Surface protection according to TL 233 can be used for maximum temperature loads of up to 180 °C (exception: DELTA-TONE? 9000, as offered by D?rken MKS-Systeme, max. 120 °C). The color of the surface protection according to TL 233 is generally black. However, it can also have different colors if required and specified accordingly. If silver color is required (e.g., for metric screws), surface protection according to TL 245 s is to be preferred.
For newly designed parts, surface protection types acc. to TL 180 are to be preferred for fasteners with metric threads.
Since, with proper pretreatment, hydrogen embrittlement is not to be expected as a result of the coating process, this coating can also be used as corrosion protection for hardened and high-strength steel parts with tensile strength values ≥ 1000 MPa or surface hardness values > 320 HV.The coating is not suitable for the components given below:
–
Components serving as electrical conductors (e.g., ground connections).Coatings for the following elements must be released separately depending on the application:
–
Metric threaded parts ≤ M8 with specific requirements regarding the loosening torques of the joint at temperatures > 80 °C,–
External threads ≤ M6 and internal threads < M10,–
Triple square force application acc. to VW 01043, nominal size < 8,–
Hexalobular socket acc. to VW 01048, < T30,–
Hexagon socket < 5–
Cross recessed head acc. to DIN EN ISO 4757, < H3.Description See Volkswagen Standard VW 13750, Section 2.
Requirements Surface protection types The surface protection types listed in Table 1 apply. The released surface protection types are listed in the Appendix, Section A.1.
2 3
3.1 Page 2
TL 233: 2010-11
Table 1
a)
Baking temperature 200 °C to 250 °C (baking temperature 300 °C for DELTA-PROTEKT? KH 200).b)As a standard, a black top coat is applied. However, if the coatings are to be in color, this must be mentioned on the drawing or the master data list (for example, surface protection type 630, blue).
General requirements
Approval of first supply and changes according to VW 01155.
Avoidance of hazardous substances according to VW 91101.
Approximately 10 parts (depending on size) are required for a thorough testing. For first-sample release of small parts, e.g., fasteners, a test production of ≥ 50 kg must be performed.
The coating media used as well as the coatings must not contain any Cr(VI) compounds.
Unless certain sections of a part that are marked in the drawing are excluded from the surface coating,the entire surface of the parts must comply with the required surface protection type and display the prescribed properties.
The protective layers must not exhibit any pores, cracks, damage or other flaws impairing corrosion protection and/or specified appearance. The surface protection types must firmly adhere to the base material; there must be no flaking or cracks on the coating under elastic deformation.
The coating must be free of flaws and excess material impairing the part’s function. Metric internal and external threads are to be designed according to VW 11611. After the coating process, the zero line must not be exceeded in the case of external threads, and it must not be fallen below in the case of internal threads. Fasteners with metric threads must comply with the coefficients of friction ac‐cording to VW 01129 (only applies to Ofl-t330 and Ofl-t630).
The production process must be designed and controlled such that functional characteristics of the finished part are not impaired.
If the coated components are properly mounted, the coating must not be damaged in a way that would result in impairment of function and/or in the reduction of the specified corrosion protection.
Manufacturer, surface protection types as well as the coating process are selected on a part-specific basis and must be agreed upon with the responsible department before use (GQL-LM/2, N/GQ-551,I/GQ-322, I/EG-72).
Base material
See drawing or master data list (MDL).
3.2 3.3 Page 3
TL 233: 2010-11
Pretreatment
Bright metal surface; microcrystalline zinc phosphating (1 to 3 g/m 2) is optionally permissible.
In the case of hardened and high-strength steel parts with tensile strength values > 1000 MPa, alkaline or mechanical cleaning (e.g., by abrasive blasting) must always be carried out prior to coating.
Color
Black or colored acc. to drawing or MDL.
Dry film General
Composition acc. to International Material Data System (IMDS).
Base layer
Inorganic zinc flake coatings, with globular structure if applicable, with a Zn proportion of > 70 percent by weight and an Al flake proportion of up to 10 percent by weight (for Magni-Flake, only Zn with globular structure plus inorganic binder system). The use of zinc dust is not permissible.
Top coating
Organic epoxy resin coating with no more than 5 percent by weight lubricant (PTFE).
Top coating containing lubricant
Organic epoxy phenolic resin coating with 25 to 30% lubricant (PTFE) by weight.
Dry film thickness Testing acc. to DIN EN ISO 1463, DIN EN ISO 2064 and DIN EN ISO 2178; position of measuring points and tolerance zone positions for threaded parts with Metric ISO thread acc. to
DIN EN ISO 10683.
Requirements for Ofl-t330 and Ofl-t350
Minimum layer thickness 6 μm (with at least 3 μm of zinc flake coating);
Maximum layer thickness 25 μm.
Requirements for Ofl-t630 und Ofl-t650
In the case of threaded parts, the specifications only apply to the head and/or to the face and wrench bearing surfaces.
Minimum layer thickness 10 μm (with at least 3 μm of zinc flake coating).
Maximum layer thickness 25 μm. Thicker layers are permissible if there are higher corrosion protec‐tion requirements as compared to the basic requirements, for example, for spring clamps (see Section 3.9.2.4).
3.4 3.5 3.6
3.6.1 3.6.2 3.6.2.1 3.6.2.2 3.7 3.7.1 3.7.2 Page 4
TL 233: 2010-11
Adhesion and ductility Cross-cut test This test is to be carried out in accordance with DIN EN ISO 2409, requirement: ≤ characteristic value 1.
Tape test Test procedure: adhesive tape with an adhesive strength of (7±1) N per 25 mm width is used for the adhesion test acc. to DIN EN ISO 10683. It must be firmly pressed onto the specimen surface by hand and then removed with a jerk-like motion perpendicular to the surface. Coating must not be removed from a large area. Small particles of the coating material that adhere to the tape are per‐missible.
Ductility
The coating must not exhibit any flaking when springs expand or contract acc. to specifications or when spring washers are bent during assembly.
Corrosion behavior Load in condensation atmosphere with constant humidity
This test is to be carried out in the CH test atmosphere acc. to DIN EN ISO 6270-2.Requirement: no blisters or other signs of coating separation and no base metal corrosion after 240 h.After subsequent acclimatization for 24 h at (23 ± 2) °C, the requirements specified in Section 3.8are still to be fulfilled.Resistance to salt spray fog
NSS salt spray test and scribing line acc. to DIN EN ISO 9227.
For nuts and bolts, the test requirements apply only to the head, face and/or wrench bearing surfaces.For threaded and thread-like parts, e.g., tap end studs , they apply to the face surfaces. Reduced requirements apply to the thread area. These are described in the following Sections.Requirements for the top coat layers
Coating corrosion up to a maximum of degree of change S5 acc. to DIN 34804, is permissible after 120 h (for all surface protection types) with and without thermal conditioning (aging at elevated tem‐perature/recirculated air) for 96 h at +180 °C.
A reduced requirement of 72h is applicable to the threaded area.
Requirements for general components with Ofl-t330 or Ofl-t350
No base metal corrosion, no corrosion creepage along scribe line after 240 h with and without thermal conditioning (aging at elevated temperature/recirculated air) for 96 h at +180 °C.
A reduced requirement of 120 h is applicable to the threaded area.
3.8
3.8.1 3.8.2 3.8.3 3.9
3.9.1 3.9.2 3.9.2.1 3.9.2.2 Page 5
TL 233: 2010-11
Requirements for general components with Ofl-t630 oder Ofl-t650
No base metal corrosion, no corrosion creepage along scribe line after 480 h with and without thermal conditioning (aging at elevated temperature/recirculated air) for 96 h at +180 °C.
A reduced requirement of 240 h is applicable to the threaded area.
Requirements for spring clamps (Ofl-t650)
No base metal corrosion, no corrosion creepage along scribe line after 720 h with and without thermal conditioning (aging at elevated temperature/recirculated air) for 96 h at +180 °C.
Resistance to chemicals
Testing in oils and brake fluid only for parts used in the engine compartment.Testing according to VDA 621-412 in the following media:premium unleaded gasoline according to DIN EN 228 and VDA 621-412, test A4.1.3 Y,diesel fuel according to TL 788 and VDA 621-412, test A4.1.2 X,reference engine oil according to TL 52185 (Lubrizol OS 206 304) and VDA 621-412, test A4.1.4 X,hydraulic fluid according to TL 52146 and VDA 621-412, test A4.1.6 X,coolant according to TL 774 and VDA 621-412, test A4.2.2 X.
Surface changes are not permissible in any event.Additional testing in brake fluid according to TL 766 and VDA 621-412, test A4.2.1 X. The following requirement applies to this medium: swellings that have disappeared after 24h are permissible.Other applicable documents
The following documents cited in this Standard are necessary to its application.
Some of the cited documents are translations from the German original. The translations of German terms in such documents may differ from those used in this Standard, resulting in terminological inconsistency.
Standards whose titles are given in German may be available only in German. Editions in other languages may be available from the institution issuing the standard.
TL 245
Non-Electrolytically Applied Zinc Flake Coatings; Surface Protection Re‐quirements TL 52146Central Hydraulic System Fluid; Lubricant Requirements TL 52185
Reference Engine Oil SAE 5W-30 for Testing of Compatibility with Respect to Elastomer Materials; Lubricant Requirements TL 766Brake Fluid; Material Requirements TL 774Ethylene Glycol-Based Coolant Additive; Material Requirements TL 788Diesel Fuel; Fuel Requirements VW 01043Multipoint Socket Profile; Drive Shape for Threaded Parts VW 01048Hexalobular Socket Profile; Drive Shape for Threaded Parts
3.9.2.3 3.9.2.4 3.10 4 Page 6
TL 233: 2010-11
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TL 233: 2010-11 VW 01129Limit Values for Coefficients of Friction; Mechanical Fasteners with Metric
ISO Threads
VW 01155Vehicle Supply Parts; Approval of First Supply and Changes
VW 11611Metric ISO Thread; Limit Dimensions with Protective Coating for Medium
Tolerance Class; External Threads 6gh / Internal Threads 6H
VW 13750Surface Protection of Metal Parts; Surface Protection Types, Codes
VW 91101Environmental Standard for Vehicles; Vehicle Parts, Materials, Operating
Fluids; Avoidance of Hazardous Substances
DIN 34804Fasteners - Change of appearance of black surfaces
DIN EN 228Automotive fuels - Unleaded petrol - Requirements and test methods DIN EN ISO 10683Fasteners - Non-electrolytically applied zinc flake coatings
DIN EN ISO 1463Metallic and oxide coatings - Measurement of coating thickness - Micro‐
scopical method
DIN EN ISO 2064Metallic and other non-organic coatings - Definitions and conventions con‐
cerning the measurement of thickness
DIN EN ISO 2178Non-magnetic coatings on magnetic substrates - Measurement of coating
thickness - Magnetic method
DIN EN ISO 2409Paints and varnishes - Cross-cut test
DIN EN ISO 4757Cross recesses for screws
DIN EN ISO 6270-2Paints and varnishes - Determination of resistance to humidity - Part 2:
Procedure for exposing test specimens in condensation-water atmo‐
spheres
DIN EN ISO 9227Corrosion tests in artificial atmospheres - Salt spray tests
VDA 621-412Chemikalienbest?ndigkeit von Kraftfahrzeug-Lackierungen
Released surface protection systems Only the products DELTA-PROTEKT? KL100, DELTA-TONE? 9000, and DELTA-SEAL? GZ are released for threaded parts with metric ISO threads (see Table A.1).
Table A.1 Ofl-t630
(for threaded parts with Metric
ISO thread)
Ofl-t330 and Ofl-t630(for general components)Ofl-t350 und Ofl-t650(for general components)Base layer DELTA-PROTEKT? KL 100,
as offered by D?rken MKS-Sys‐
teme,
DELTA-TONE? 9000,
as offered by D?rken MKS-Sys‐
teme
DELTA-PROTEKT? KL 100, as offered by D?rken MKS-Systeme,DELTA-PROTEKT? KL101, as offered by D?rken MKS-Systeme,DELTA-PROTEKT? KH 200, as offered by D?rken MKS-Systeme,DELTA-TONE? 9000, as offered by D?rken MKS-Systeme,Magni-Flake D21 or B46, as offered by Magni Europe Top coat (generally black,optionally col‐ored)DELTA-SEAL? GZ,
as offered by D?rken MKS-Sys‐
teme,DELTA-SEAL? GZ,as offered by D?rken MKS-Sys‐teme,
Magni-Top GZ,
as offered by Magni Europe DELTA-SEAL?as offered by D?rken MKS-Sys‐teme,Magni-Top,as offered by Magni Europe Appendix A (informative)
A.1 Page 8
TL 233: 2010-11