1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN ISO 14921:2010Thermal spraying Proceduresfor the application ofthermally sprayed coatings forengineering components (ISO14921:2010)BS EN ISO 14921:2010 BRITISH STANDARDNati
2、onal forewordThis British Standard is the UK implementation of EN ISO14921:2010. It supersedes BS EN ISO 14921:2001 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee STI/40, Thermally sprayed inorganic finishes.A list of organizations represented on this
3、committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. BSI 2011ISBN 978 0 580 66613 1ICS 25.220.20Compliance with a British Standard cannot confer immunity fromlega
4、l obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 January 2011.Amendments issued since publicationDate Text affectedEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 14921 December 2010 ICS 25.220.20 Supersedes EN ISO 149
5、21:2001English 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 14921:2010) Thermisches Sp
6、ritzen - 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 for giving this European
7、 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 (E
8、nglish, 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, Belgiu
9、m, 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 Kingdom. EUROPEAN COMMIT
10、TEE 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: EBS EN ISO 14921:2010EN
11、 ISO 14921:2010 (E) 3 Foreword This document (EN ISO 14921:2010) has been prepared by Technical Committee CEN/TC 240 “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
12、”. 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 2011, and conflicting national standards shall be withdrawn at the latest by June 2011. Attention is drawn to the possibility that some of t
13、he 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. This document supersedes EN ISO 14921:2001. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the
14、 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, Romania,
15、 Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. BS EN ISO 14921:2010ISO 14921:2010(E) ISO 2010 All rights reserved iiiContents Page Foreword iv Introduction.v 1 Scope1 2 Normative references1 3 Terms and definitions .1 4 Component and coating design considerations1 4.1 Genera
16、l .1 4.2 Pre-inspection in the case of repair 2 4.3 Component substrate .2 4.4 Coating .2 5 Preliminary machining by turning, milling, or grinding 3 6 Masking 3 7 Methods of surface preparation.3 8 Thermal spraying.4 9 Inspection after spraying4 10 Sealing4 11 Finishing.4 12 Final inspection .4 13 D
17、ocumentation 5 Annex A (informative) Flow chart for assessment of suitability of thermal spraying .6 Annex B (informative) Check list for evaluation of the most suitable coating system for the intended purpose 7 Annex C (informative) Record for the applied thermal spray procedure 8 Bibliography12 BS
18、 EN ISO 14921:2010ISO 14921:2010(E) iv ISO 2010 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical
19、 committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with
20、 the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft Intern
21、ational Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may
22、be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 14921 was prepared by Technical Committee CEN/TC 240, Thermal spraying and thermally sprayed coatings of the European Committee for Standardization (CEN) in collaboration with ISO Te
23、chnical Committee ISO/TC 107, Metallic and other inorganic coatings in accordance with the Agreement on technical cooperation between ISO and CEN (Vienna Agreement). This second edition cancels and replaces the first edition (ISO 14921:2001), which has been technically revised. BS EN ISO 14921:2010I
24、SO 14921:2010(E) ISO 2010 All rights reserved vIntroduction 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 app
25、lied to protect the components surface or to 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 coati
26、ngs. However, several different coatings may 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. BS EN ISO 14921:2010BS EN ISO 14921:2010INTERNATION
27、AL STANDARD ISO 14921:2010(E) ISO 2010 All rights reserved 1Thermal spraying Procedures for the application of thermally sprayed coatings for engineering components 1 Scope This International Standard specifies the general procedure, when a thermally sprayed coating is applied to enhance the surface
28、 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 chemical requirements and of the components shape. This International Standard specifies
29、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 atmospheric corrosion, for which ISO 2063 applies. This International Standard also does
30、 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 of this document. For dated references, only the edition cited applies. For undated refe
31、rences, 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 Terminology, classification EN 13507, Thermal spraying Pre-treatment of surface of metallic p
32、arts 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 document, the terms and definitions given in EN 657:2005 apply. 4 Component and coating design
33、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 in Annex A. BS EN ISO 14921:2010ISO 14921:2010(E) 2 ISO 2010 All rights reservedJudgemen
34、ts 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. 4.2 Pre-inspection in the case of repair Before carrying out a prep
35、aration 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 geometry of parts operated with a reciprocating or sliding motion sha
36、ll 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 removed or repaired, spraying cannot be carried out satisfactorily. Establ
37、ish 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 Component substrate To establish whether a thermally sprayed coating i
38、s 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 increase the strength of the part generally, and therefore the effe
39、cts 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 improve the surface condition, such as nitriding, can leave gaseous inclus
40、ions 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 properties subsequently derived, shall be considered. The area to be co
41、ated 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 spray angle shall be considered. 4.4 Coating The spray process and spray
42、 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 (roughness); BS EN ISO 14921:2010ISO 14921:2010(E) ISO 2010 All right
43、s reserved 3 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 environmental conditions; where the level of porosity
44、 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? Annex B gives a check list which details the in
45、formation 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 the condition of a surface treatment previously a
46、pplied, 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 “inlaid” in the component, where possible, or continue
47、d 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 shall be carried out without the use of a lubricant
48、. 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 material. This material should be resistant to abra
49、sive 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 Methods 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
