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1、BRITISH STANDARD BS EN ISO 14920:1999 Thermal spraying Spraying and fusing of self-fluxing alloys The European Standard EN ISO 14920:1998 has the status of a British Standard ICS 25.220.20 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 09:05:09 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS E
2、N ISO 14920:1999 This British Standard, having been prepared under the direction of the Sector Committee for Materials and Chemicals, was published under the authority of the Standards Committee and comes into effect on 15 April 1999 BSI 02-2000 ISBN 0 580 32022 7 National foreword This British Stan
3、dard is the English language version of EN ISO 14920:1999. The UK participation in its preparation was entrusted to Technical Committee STI/40, Thermally sprayed inorganic finishes, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/Europe
4、an committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. Cro
5、ss-references Attention is drawn to the fact that CEN and CENELEC standards normally include an annex which lists normative references to international publications with their corresponding European publications. The British Standards which implement these international or European publications may
6、be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British St
7、andards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, the EN ISO title page, pages 2 to 7 and a back cover. Th
8、is standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No.DateComments Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 09:05:09 GMT+00:00 2006
9、, Uncontrolled Copy, (c) BSI BS EN ISO 14920:1999 BSI 02-2000i Contents Page National forewordInside front cover Foreword2 Text of EN ISO 149203 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 09:05:09 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ii blank Licensed Copy: sheffieldun sheffieldun,
10、 na, Sun Nov 19 09:05:09 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 14920 February 1999 ICS 25.220.20 Descriptors: Thermal spraying, metal coatings, melting, alloys, choice, surface treatment, specifications, quality, hardness, hardness tests,
11、 certification English version Thermal spraying Spraying and fusing of self-fluxing alloys (ISO 14920:1999) Projection thermique Projection et fusion des revtements obtenus par projection thermique des alliages auto-fondants (ISO 14920:1999) Thermisches Spritzen Spritzen und Einschmelzen thermisch g
12、espritzter Schichten von selbstflieenden Legierungen (ISO 14920:1999) This European Standard was approved by CEN on 20 November 1998. 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 st
13、andard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other
14、 language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Gre
15、ece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1999 CEN All right
16、s of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 14920:1999 E Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 09:05:09 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 14920:1999 BSI 02-2000 2 Foreword The text of EN ISO 14920:1999 h
17、as 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”. This European Standard shall be given the status of a national
18、standard, either by publication of an identical text or by endorsement, at the latest by August 1999, and conflicting national standards shall be withdrawn at the latest by August 1999. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries
19、 are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Contents Page Foreword2 1Scope3 2Normative references3 3
20、Design considerations3 3.1Substrate (base metal)3 4Self-fluxing alloy selection3 4.1Choice3 4.2Composition3 4.3Final machining3 5Preparation of the component3 5.1Preliminary3 5.2Method of surface preparation4 5.3Cleanliness4 6Processes4 6.1Spraying with simultaneous fusion4 6.2Spray and subsequently
21、 fuse4 6.3Spraying technique5 7Powder supply conditions and quality requirements5 7.1Chemical composition5 7.2Powder particle size range (see 6.2.2)5 7.3Conditions of supply5 7.4Certification5 7.5Hardness5 Annex A (informative) Guide to approximate hardness of the fused deposit7 Annex ZA (informativ
22、e) Normative references to international publications with their relevant European publications7 Table A.1 Self-fluxing alloys and expected hardness7 Table ZA.1 ISO standards conforming to the EN standards quoted in clause 27 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 09:05:09 GMT+00:00
23、2006, Uncontrolled Copy, (c) BSI EN ISO 14920:1999 BSI 02-20003 1 Scope This standard covers thermal spraying of self fluxing alloys that are simultaneously or subsequently fused to create a homogeneous, diffusion bonded coating. 2 Normative references This European Standard incorporates by dated or
24、 undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text, and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only
25、 when incorporated in it by amendment or revision. For undated references, the latest edition of the publication referred to applies. EN 1274:1996, Thermal spraying Powders Composition Technical supply conditions. EN 10109-1, Metallic materials Hardness test Part 1: Rockwell test (scales A, B, C, D,
26、 E, F, G, H, K) and rockwell superficial test (scales 15N, 30N, 45N, 15T, 30T and 45T). 3 Design considerations To ascertain whether sprayed and fused alloy coatings are suitable for the intended engineering application, consideration shall be given to the factors in the following sub-clauses. 3.1 S
27、ubstrate (base metal) 3.1.1 As the process requires the application of heat to fuse the coating to the substrate, consideration shall be given to the possible effects of such heating on the substrate, including: a) distortion; b) scaling; c) the need to stress relieve; d) an irreversible transformat
28、ion of the mechanical and/or metallurgical properties. Martensitic steels are susceptible to stress cracking and alloys containing significant amounts of C, Al, Ti, Mg, S, sulfides, P, and Nitrogen can create porosity in the coating and may render the substrate liable to stress cracking. 3.1.2 The p
29、reparation of the component for a sprayed and fused coating usually includes a reduction of the design dimensions. Consideration shall be given to the effect of such reduction on the required physical properties and the fact that the resultant sprayed and fused coating may have differing physical pr
30、operties. 3.1.3 The fatigue strength, shock resistance and other properties of the component may be affected by the application of the coating. 4 Self-fluxing alloy selection 4.1 Choice The choice of coating alloy will determine the properties of the final deposit, e.g. a) hardness; b) resistance to
31、 wear and corrosion; c) machinability; d) suitibility for the application. 4.2 Composition The composition of the coating will determine the properties of the final deposit. Consideration shall be given to the effects of the stresses anticipated in service. Substrate alloys which are subject to a ma
32、rtensitic change require a coating alloy with a high ductility. Consideration should also be given to the need for post heat treatment. Guide to approximate hardness of the fused deposit see Annex A. 4.3 Final machining 4.3.1 When selecting a suitable self-fluxing alloy, consideration should be give
33、n to the machining properties. 4.3.2 Many of the self-fluxing alloys are not machinable with standard tipped tools and can only be finished by using suitable grinding wheels. Manufacturers advice should be sought on suitable machining tools. 4.3.3 As the process involves heating the component to a h
34、igh temperature, it is recommended that the coating process be completed before final machining of other areas which may be affected by the heat treatment. 5 Preparation of the component 5.1 Preliminary 5.1.1 All components to be treated shall be free from surface contamination such as oil or grease
35、. Particular attention shall be paid to porous components where oil and grease in the pores may exude during the preheating or coating process. 5.1.2 Any prior surface treatments, for example nitriding, electroplating or protective coatings shall be removed before the preparation of the surface to b
36、e coated. Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 09:05:09 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 14920:1999 4 BSI 02-2000 5.1.3 When the surface of the component is machined as part of the surface preparation, the machined surface and the form of the ends and/or edges of t
37、he prepared area shall be suitable for the coating process. Where the coating is required to terminate at a point other than the end or edge of the component, the edge of the recess shall be machined to provide angle of 30 to 40 degrees, blending smoothly with the adjoining surface. Where the coatin
38、g shall finish to a square edge, the relevant edge shall be left longer than the proposed finished overall size and machined to the final dimension when the coating process is completed. 5.2 Method of surface preparation 5.2.1 The surface should be prepared using standard angular grit. 5.2.2 The gri
39、t blasting operation shall be confined to the area to be prepared for coating only, and the adjacent areas shall be masked in a manner best suited to the particular component. Masking materials used shall resist the impact of the grit and shall not contaminate the adjacent prepared surface. 5.2.3 Ma
40、sking materials used to prevent the adherence of sprayed metal shall withstand the temperature of spraying and, where necessary, the fusing process, without contaminating the surface to be sprayed. 5.2.4 Drilled holes and other orifices which are required to be kept free from foreign matter shall be
41、 plugged. Plugs of steel or rubber are recommended for this purpose and should be shaped and positioned in such a manner as not to mask any part of the surface to be prepared. After grit blasting the plugs shall be removed and replaced with pieces of carbon suitably shaped to prevent ingress of the
42、coating material and protruding sufficiently for their top surfaces to be exposed during the subsequent machining operation. 5.3 Cleanliness After preparation, it is essential that the surface to be coated is not contaminated. Care shall be taken to ensure that the prepared surface is not contaminat
43、ed with oil, grease, water or fingermarks. In the event of contamination the surface shall be re-prepared. 6 Processes 6.1 Spraying with simultaneous fusion This is a manual process using an oxy/acetylene torch fitted with a hopper. A suitable self-fluxing powder is fed via the hopper into the gas s
44、tream, through the flame and on to the component where it is simultaneously fused. The continuous process of pre-heating the workpiece with the flame through which the powder is fed and fused produces a coating with properties dependant on the choice of self-fluxing powder. 6.1.1 Powder particle siz
45、e range This is determined by the powder feed parameters selected and designed by the torch manufacturer. To avoid powder feed restrictions and blockages powders shall be purchased to the screen analysis recommended by the torch manufacturer. 6.1.2 Coating thickness The limitation on deposit thickne
46、ss is dependant on the chosen alloy, the required coating quality and due consideration to acceptable residual stresses which will increase with deposit thickness. Thicker coatings are more demanding on operator skill. 6.2 Spray and subsequently fuse A manual or mechanised process using a powder fla
47、me spray gun to apply the required thickness of coating material to the component. This sprayed coating is subsequently fused. A selected self-fluxing alloy powder is fed via a powder hopper into the carrier gas, through the flame, on to the workpiece until the desired thickness is achieved. Fusing
48、of the deposit is a separate operation performed as soon as possible after spraying using the following methods: a) manually, using an oxy/acetylene torch; b) induction coil; c) furnace fusing (vacuum or inert gas); d) laser beam; e) other heating processes. 6.2.1 Powder particle size range This is
49、determined by the powder feed parameters selected and designed by the manufacturer of the flame spray gun. To avoid powder feed restrictions and blockages, powders shall be purchased to the screen analysis recommended by the manufacturer. 6.2.2 Thickness of deposit Generally limited to 1,6 mm with 1 mm being preferred. Deposits in the “as sprayed” state may be 25 % thicker to allow for contraction/shrinkage during fusion. Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 09:05:09 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 14920:1999