1、April 2011 Translation by DIN-Sprachendienst.English price group 11No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS
2、25.220.20!$ny b) Clause 3 “Terms and definitions” has been added; c) the former Clause 3 has been restructured and is now Clause 4 “Component and coating design considerations”; d) Clause 5 “Preliminary machining by turning, milling, or grinding” (former Clause 4) now includes a reference to EN 1552
3、0 (Recommendations for constructional design); e) the former Clause 8 has been revised and is now Clause 9 “Inspection after spraying”, including a reference to ISO 14923 (Characterization and testing of thermally sprayed coatings); f) the former Clause 10 is now Clause 11 “Finishing”, including a r
4、eference to ISO 14924 (Post-treatment and finishing of thermally sprayed coatings); g) Annex C “Record for the applied thermal spray procedure” has been revised and supplemented; h) the Bibliography has been added. Previous editions DIN EN ISO 14921: 2001-11 2 DIN EN ISO 14921:2011-04 National Annex
5、 NA (informative) Bibliography DIN EN ISO 2063, Thermal spraying Metallic and other inorganic coatings Zinc, aluminium and their alloys DIN EN ISO 8501-1, Preparation of steel substrates before application of paints and related products Visual assessment of surface cleanliness Part 1: Rust grades an
6、d preparation grades of uncoated steel substrates and of steel substrates after overall removal of previous coatings DIN EN ISO 8503-1, Preparation of steel substrates before application of paints and related products Surface roughness characteristics of blast-cleaned steel substrates Part 1: Specif
7、ications and definitions for ISO surface profile comparators for the assessment of abrasive blast-cleaned surfaces DIN EN ISO 14918, Thermal spraying Approval testing of thermal sprayers DIN EN ISO 14920, Thermal spraying Spraying and fusing of self-fluxing alloys DIN EN ISO 14923, Thermal spraying
8、Characterization and testing of thermally sprayed coatings DIN EN ISO 14924, Thermal spraying Post-treatment and finishing of thermally sprayed coatings 3 DIN EN ISO 14921:2011-04 4 This page is intentionally blank EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 14921 December 2010 ICS 25.2
9、20.20 Supersedes EN ISO 14921:2001English Version Thermal spraying Procedures for the application of thermally sprayed coatings for engineering components (ISO 14921:2010) Projection thermique Mode opratoire dapplication de revtements obtenus par projection thermique pour les pices mcaniques (ISO 14
10、921:2010) Thermisches Spritzen Vorgehen fr das Anwenden thermischer Spritzschichten fr Bauteile im Maschinenbau (ISO 14921:2010) This European Standard was approved by CEN on 10 December 2010. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions fo
11、r giving this EuropeanStandard 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
12、 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 bodi
13、es 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, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United King
14、dom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2010 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 14921:2010: ECo
15、ntents Page Foreword .3 Introduction.4 1 Scope5 2 Normative references5 3 Terms and definitions .5 4 Component and coating design considerations5 4.1 General .5 4.2 Pre-inspection in the case of repair 6 4.3 Component substrate .6 4.4 Coating .6 5 Preliminary machining by turning, milling, or grindi
16、ng 7 6 Masking 7 7 Methods of surface preparation.7 8 Thermal spraying.8 9 Inspection after spraying8 10 Sealing8 11 Finishing.8 12 Final inspection .8 13 Documentation 9 Annex A (informative) Flow chart for assessment of suitability of thermal spraying .10 Annex B (informative) Check list for evalu
17、ation of the most suitable coating system for the intended purpose 11 Annex C (informative) Record for the applied thermal spray procedure 12 Bibliography16 EN ISO 14921:2010 (E) DIN EN ISO 14921:2011-04 2Foreword This document (EN ISO 14921:2010) has been prepared by Technical Committee CEN/TC 240
18、“Thermal spraying and thermally sprayed coatings”, the secretariat of which is held by DIN, in collaboration with Technical Committee ISO/TC 107 “Metallic and other inorganic coatings”. This European Standard shall be given the status of a national standard, either by publication of an identical tex
19、t or by endorsement, at the latest by June 2011, and conflicting national standards shall be withdrawn at the latest by June 2011. 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 fo
20、r identifying any or all such patent rights. This document supersedes EN ISO 14921:2001. 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, Czec
21、h Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. EN ISO 14921:2010 (E) DIN EN ISO 14921:2011-0
22、4 3Introduction Components might fail if the surface does not fulfil the physical, chemical, and/or technological requirements. For several applications, this deficiency can be avoided by a thermally sprayed coating. Where appropriate, a coating may be applied to protect the components surface or to
23、 improve its behaviour by increasing the resistance against wear and/or corrosion, or the electrical or thermal conductivity or insulation or by reducing the friction coefficient. There are limits to the applicable thickness of some thermally sprayed coatings. However, several different coatings may
24、 be built up one upon another. In the case of extensive loss of material through corrosion or wear, an alternative suitable spraying material may be applied prior to the top coat or the bond and top coat. EN ISO 14921:2010 (E) DIN EN ISO 14921:2011-04 41 Scope This International Standard specifies t
25、he general procedure, when a thermally sprayed coating is applied to enhance the surface properties of a component or to reclaim worn and non-conforming parts. This International Standard does not provide definitive methods for specific work due to the variety of the technological, physical and/or c
26、hemical requirements and of the components shape. This International Standard specifies the general conditions for the selection of the spraying procedure and materials for this purpose. It does not apply to thermally sprayed zinc and/or aluminium coatings for protection of steel structures against
27、atmospheric corrosion, for which ISO 2063 applies. This International Standard also does not apply to coatings of self-fluxing alloys which are subsequently fused. That procedure is covered by ISO 14920. 2 Normative references The following referenced documents are indispensable for the application
28、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. ISO 14923, Thermal spraying Characterization and testing of thermally sprayed coatings EN 657:2005, Thermal spraying Termi
29、nology, classification EN 13507, Thermal spraying Pre-treatment of surface of metallic parts and components for thermal spraying EN 15520, Thermal spraying Recommendations for constructional design of components with thermally sprayed coatings 3 Terms and definitions For the purposes of this documen
30、t, the terms and definitions given in EN 657:2005 apply. 4 Component and coating design considerations 4.1 General If any of the considerations in 4.2 to 4.4 cannot be met satisfactorily, thermal spraying is not recommended. Factors which should be considered are illustrated in the flow chart shown
31、in Annex A. EN ISO 14921:2010 (E) DIN EN ISO 14921:2011-04 5Judgements of the possibility for coating new parts may be carried out by assessing the drawing of the component and the area to be sprayed. If a coating specification defines the spraying material, the factors to be considered are reduced.
32、 4.2 Pre-inspection in the case of repair Before carrying out a preparation procedure on the component, it shall be inspected to assess its suitability for spraying. Attention shall be given to the following: The concentricity and straightness of parts which rotate when operating and the shape and g
33、eometry of parts operated with a reciprocating or sliding motion shall be checked and, where necessary, corrected. The surface to be coated shall be inspected to check that it is free from cracks or other damage which can affect the performance of the coating. If any serious defects cannot be remove
34、d or repaired, spraying cannot be carried out satisfactorily. Establish dimensions of the area to be sprayed. The component shall be checked for any evidence of a previous coating, which, if present, shall usually be removed. Check and take into account the surface hardness of the work piece. 4.3 Co
35、mponent substrate To establish whether a thermally sprayed coating is suitable for the intended purpose, consideration should be given to the following. Certain substrate materials are not suitable for thermal spraying or require special consideration in processing. Thermally sprayed coatings do not
36、 increase the strength of the part generally, and therefore the effects of any reduction in the dimensions of the original component shall be considered. The fatigue strength can be affected by the method of surface preparation, the spray material and the spray procedure. Certain processes to improv
37、e the surface condition, such as nitriding, can leave gaseous inclusions which can have a detrimental effect on the surface preparation, bonding, and porosity in the coating. Where hardened surfaces prevent a proper preparation, the limitations of the coating system which can be applied, and the pro
38、perties subsequently derived, shall be considered. The area to be coated shall be accessible for applying the complete coating procedure. Therefore, the requirements for the processes of preparing, spraying and testing, spray gun with its electrical and/or gas connections, required distance and spra
39、y angle shall be considered. 4.4 Coating The spray process and spray material can exert a tremendous influence on the coating properties. To determine the most suitable coating system, consideration of the following is required: bond strength requirement; thickness requirement; surface requirement (
40、roughness); EN ISO 14921:2010 (E) DIN EN ISO 14921:2011-04 6 surface load; thermally sprayed coatings are sensitive to spot or line stress; the coating properties required, e.g. resistance to different types of wear mechanism, corrosion, chemical attack, temperature, thermal cycling, and other envir
41、onmental conditions; where the level of porosity in the coating is unacceptable, it is to be checked, whether a suitable method of sealing, and type of sealant is available; is it possible to keep the oxide content within the accepted tolerance by control of process variables and the spray material?
42、 Annex B gives a check list which details the information required to determine the most suitable coating system for the intended purpose. 5 Preliminary machining by turning, milling or grinding Coatings which have to be renewed shall be removed completely. However, consideration shall be given to t
43、he condition of a surface treatment previously applied, e.g. for increasing fatigue strength. Pre-machining shall be carried out to remove wear profiles, if applicable, and to ensure a uniform coating thickness. Sharp edges shall be avoided and shall be rounded or chamfered. Coatings shall be “inlai
44、d” in the component, where possible, or continued around the rounded or chamfered edge. Recommendations for design are given in EN 15520. The surface to be coated shall be machined concentrically to the relevant axis, to ensure a uniform thickness of the deposit. Wherever possible, pre-machining sha
45、ll be carried out without the use of a lubricant. This is particularly important in the case of porous substrate materials. Where necessary, the component shall be degreased after preliminary machining. 6 Masking Where appropriate, surfaces that shall not be sprayed can be masked with a suitable mat
46、erial. This material should be resistant to abrasive grit blasting and thermal spraying. Otherwise, separate masking for each operation shall be used. Precautions shall be taken to ensure that the surface to be sprayed will not be contaminated by the masking material or otherwise at all times. 7 Met
47、hods of surface preparation Contamination caused by pre-treatments shall be removed and the surface shall be cleaned immediately before the specific surface preparation commences. A suitable surface preparation is required to achieve maximum bond strength to metallic substrates. Grit blasting is the
48、 normal method. The surface preparation shall be in accordance with EN 13507. Deviations from this shall be agreed between the contracting parties. EN ISO 14921:2010 (E) DIN EN ISO 14921:2011-04 78 Thermal spraying The thermally sprayed coating should be applied as soon as possible after preparation
49、, with parameters as given in the thermal spraying procedure specification. Reasonable precautions shall be taken to prevent contamination of the prepared surface during the time period between blasting and spraying. Where appropriate, the surface to be sprayed may be pre-heated immediately prior to spraying. However, no contamination or local overheating (visible by tempering colour) of the prepared surface shall appear. Before and during spraying, the surface shall be warm enough to prevent moistu
