1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA
2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any
3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. ISBN 978-0-626-21537-8 SANS 50657:2009Edition 2EN 657:2005Edition 2SOUTH AFRICAN NATIONAL STANDARD Thermal spraying Terminology, classification This nati
4、onal standard is the identical implementation of EN 657:2005 and is adopted with the permission of CEN, rue de Stassart 36, B-1050 Brussels. Published by SABS Standards Division 1 Dr Lategan Road Groenkloof Private Bag X191 Pretoria 0001Tel: +27 12 428 7911 Fax: +27 12 344 1568 www.sabs.co.za SABS S
5、ANS 50657:2009 Edition 2 EN 657:2005 Edition 2 Table of changes Change No. Date Scope National foreword This South African standard was approved by National Committee SABS TC 107, Metallic and other inorganic coatings, in accordance with procedures of the SABS Standards Division, in compliance with
6、annex 3 of the WTO/TBT agreement. This SANS document was published in January 2009. This SANS document supersedes SABS EN 657:1994 (first edition). EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 657 March 2005 ICS 01.040.25; 25.220.20 Supersedes EN 657:1994 English version Thermal spraying - T
7、erminology, classification Projection thermique - Terminologie, classification Thermische Spritzen - Begriffe, Einteilung This European Standard was approved by CEN on 3 February 2005. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving
8、 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 Central Secretariat or to any CEN member. This European Standard exists in three official version
9、s (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 Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Cyp
10、rus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EURO
11、PEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2005 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 657:2005: EEN 657:2005 (E) 2 Contents Page Foreword3 1 Scope 4 2 Normat
12、ive references 4 3 Terms and definitions .4 4 Process variations.4 5 Process descriptions 6 6 Thermal spraying terms .14 Annex A (informative) Master chart of thermal spraying processes Classification according to the energy carriers.20 Bibliography 21 EN 657:2005 (E) 3 Foreword This document (EN 65
13、7:2005) has been prepared by Technical Committee CEN/TC 240 “Thermal spraying and thermally sprayed coatings”, the secretariat of which is held by DIN. 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
14、 by September 2005, and conflicting national standards shall be withdrawn at the latest by September 2005. This document supersedes EN 657:1994. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Sta
15、ndard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EN 657:2005 (E) 4 1 S
16、cope This document defines processes and general terms for thermal spraying. It classifies thermal spraying processes according to type of spray material, to type of operation and to type of energy carrier. 2 Normative references The following referenced documents are indispensable for the applicati
17、on 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 ISO 14923, Thermal spraying Characterization and testing of thermal sprayed coatings (ISO 14923:2003) EN ISO 17836,
18、Thermal spraying Determination of the deposition efficiency for thermal spraying (ISO 17836:2004) 3 Terms and definitions For the purposes of this document, the following term and definition applies. 3.1 thermal spraying (TS) process in which surfacing materials are heated to the plastic or molten s
19、tate, inside or outside of the spraying gun/torch, and then propelled on to a prepared surface; the substrate remains unmelted NOTE To obtain specific properties of the deposit, a subsequent thermal, mechanical or sealing treatment may be used. 4 Process variations 4.1 Classification according to th
20、e type of spray material Distinction of the following variations: wire spraying; rod spraying; cord spraying; powder spraying; molten-bath spraying. 4.2 Classification according to the operation 4.2.1 Manual spraying All operations typical of the spraying process are manual. EN 657:2005 (E) 5 4.2.2
21、Mechanised spraying All operations typical of the spraying process are mechanised. 4.2.3 Automatic spraying All operations typical of the spraying process are fully mechanised including all handling, e.g. workpiece loading and unloading, and are integrated in a programmed system. 4.3 Classification
22、according to the energy carrier Abbreviations of spray processes listed In classification according to the energy carrier sub-classifications are necessary due to different spray materials. Annex A provides a master chart of the spray processes with sub-classifications. Table 1 Classification and ab
23、breviations of spray processes Spray processes Classification according to energy carrier Process abbreviations Process description in subclause TS by atomising a melt Molten-bath spraying MBS 5.1 Wire flame spraying WFS 5.2.2 High velocity wire flame spraying HVWFS 5.2.3 Powder flame spraying PFS 5
24、.2.4 High velocity flame spraying HVOF 5.3 / 5.3.1 / 5.3.2 TS by means of gaseous or liquid fuels Detonation spraying DGS 5.4 TS by means of expansion of highly pressurised gases without combustion Cold spraying CGS 5.5 Arc spraying AS 5.6.1 Shrouded arc spraying SAS 5.6.2 Plasma spraying in air APS
25、 5.7.1 Shrouded plasma spraying SPS 5.7.2 Plasma spraying in a chamber under vacuum VPS 5.7.3 Plasma spraying in a chamber at pressures exceeding 1 bar HPPS 5.7.3 Liquid stabilised plasma spraying LSPS 5.8.1 TS by means of electric arc or gas discharge Inductively coupled plasma spraying ICPS 5.8.2
26、TS by means of a bundled light stream Laser spraying LS 5.9 EN 657:2005 (E) 6 5 Process descriptions 5.1 Molten-bath spraying A surfacing material is heated to the molten state, in most cases in a reservoir, and propelled on to the prepared substrate by a preheated atomising gas, e.g. compressed air
27、. See Figure 1. Key 1 Atomising gas 2 Gas inlet 3 Molten metal 4 Resistance heating 5 Spray stream 6 Spray deposit 7 Substrate Figure 1 Molten-bath spraying 5.2 Flame spraying 5.2.1 General Flame spraying is a process in which a surfacing material is heated in an oxy-fuel gas flame and then propelle
28、d in atomised form on to a substrate. The material may be initially in the form of powder, rod, cord or wire. The hot material is projected on to the substrate by the oxy-fuel gas jet alone or with the additional aid of an atomising gas, e.g. compressed air. 5.2.2 Wire flame spraying In wire flame s
29、praying, the metal wire to be deposited is supplied to the gun continuously. It is heated to the molten state by the oxy-fuel gas flame and propelled on to the prepared substrate surface by the additional aid of an atomising gas, e.g. compressed air. See Figure 2. Key 1 Compressed air 2 Fuel gas 3 O
30、xygen 4 Wire or rod 5 Wire feed mechanism 6 Spray deposit 7 Substrate 8 Melting wire tip 9 Spray stream Figure 2 Wire flame spraying EN 657:2005 (E) 7 The fuel gases predominantly used are, e.g. acetylene, propane and hydrogen. Variations are rod flame spraying where cut lengths of material rod are
31、used, and cord flame spraying where cords of surfacing material are used. 5.2.3 High velocity wire flame spraying Essential higher gas pressures are used for high velocity wire flame spraying contrary to processes usually applied. Consequently, a finer atomisation of the molten wire tip and higher p
32、article velocities are obtained. In addition, these systems use a stream of compressed air, which serves for cooling as well as for accelerating the flame stream. The coating properties are improved due to less porosity and higher tensile adhesive strength. 5.2.4 Powder flame spraying With this meth
33、od, the material to be sprayed is supplied to the gun in powder form and heated to the plastic or partially or completely molten state in the oxy-fuel gas flame. It is propelled on to the prepared substrate by the expanding fuel gas. In some cases, an additional gas jet may be used to accelerate the
34、 powder particles. See Figure 3. Key 1 Flame 2 Fuel gas 3 Oxygen 4 Powder and carrier gas 5 Spray stream 6 Spray deposit 7 Substrate Figure 3 Powder flame spraying 5.3 High velocity flame spraying 5.3.1 High velocity flame spraying with gaseous fuel In high velocity flame spraying continuous combust
35、ion is obtained in the combustion chamber which, in conjunction with the expanding nozzle, produces an extremely high velocity in the gas jet. The spray material is injected axially into the combustion chamber or radially into the high velocity gas stream. The location to the powder injection will r
36、esult in a different dwell time in the flame, which will affect the particle velocity and temperature. Coatings of high density and adhesion are produced by the high kinetic energy imparted to the spray stream. See Figure 4. Fuel gases like acetylene, propane, propylene, methylacetylene-propadene an
37、d hydrogen can be applied. EN 657:2005 (E) 8 Key 1 Compressed air 2 Fuel gas 3 Oxygen 4 Powder and carrier gas 5 Spray stream 6 Spray deposit 7 Substrate Figure 4 High velocity flame spraying with gaseous fuels 5.3.2 High velocity flame spraying with liquid fuel In high velocity flame spraying with
38、liquid fuel like kerosene, N-paraffin a. o. higher combustion pressure are applied compared to spraying with gaseous fuel. The spray powder is radially injected at a position, where the combustion gases are expanded completely and already somewhat cooled down. This creates coatings of higher density
39、 and higher adhesive strength values. Eventually, residual stresses on pressure may be generated in the coating. See Figure 5. Key 1 Combustion chamber 2 Liquid fuel 3 Oxygen 4 Powder and carrier gas 5 Spray stream 6 Spray deposit 7 Substrate Figure 5 High velocity flame spraying with liquid fuels 5
40、.4 Detonation spraying In detonation spraying, the gun contains a chamber into which certain quantities of a powder are injected. The gas mixture in the chamber is detonated at controlled intervals. This creates a hot, high velocity gas stream that heats the powder to its plastic or partially or com
41、pletely molten state and accelerates the particles as they leave the gun barrel. The detonation gun consists of the barrel and the gun chamber. The injected gas and powder mixture are ignited by an electric spark. The resulting shock wave generated in the barrel accelerates the particles, which are
42、further heated in the flame front and are propelled in a directed jet on to the prepared substrate. Nitrogen is used to flush clean the gun chamber and barrel after every detonation. See Figure 6. EN 657:2005 (E) 9 Key 1 Ignition 2 Fuel gas 3 Oxygen 4 Powder and carrier gas 5 Spray stream 6 Spray de
43、posit 7 Substrate 8 Flush gas nitrogen Figure 6 Detonation spraying 5.5 Cold spraying In the cold spraying process a gas (especially nitrogen) is accelerated to supersonic velocity in a de-Laval-type nozzle. The spray material is injected into the gas jet in powder form upstream of the nozzle and th
44、en propelled with high kinetic and less thermal energy on to the substrate. Above a certain particle velocity which is characteristic of the respective spray material, the particles form a dense and solid adhesive coating upon impact. External heating up the gas jet e.g. in an electric heated contin
45、uous heater increases the flow velocity of the gas and also the particle velocity. The related rise in particle temperature assists the deformation upon impact. However, the gas temperature is clearly below the melting temperature of the spray material, which means the particles cannot be melted in
46、the gas jet. Consequently, drawbacks like oxidation and other phase transformations can be avoided. Figure 7 shows the process schematically. Key 1 Process gas 2 Laval nozzle 3 Powder and carrier gas 4 Spray stream 5 Spray deposit 6 Substrate Figure 7 Cold spraying 5.6 Arc spraying processes 5.6.1 A
47、rc spraying Arc spraying utilises an electric arc between two wires to melt their tips; the wires may be of identical or dissimilar composition. A jet or jets of gas, normally compressed air, atomises the molten metal and projects the particles on to the prepared substrate. See Figure 8. EN 657:2005
48、 (E) 10 Key 1 Compressed air 2 Voltage 3 Contact tubes 4 Wires 5 Wire feed mechanism 6 Spray deposit 7 Substrate 8 Melting wire tips 9 Spray stream Figure 8 Arc spraying 5.6.2 Shrouded arc spraying Improvement of the two wires arc spraying process may be done by reducing the porosity and oxidation i
49、n the coating. Therefore, the atomising gas shall be free of oxygen or of reducing type and a secondary gas stream in a shroud or as a gas sheath around the arc and spray stream may prevent air penetrating into the hot gas and particles stream. See Figure 9. Additionally, in order to increase the density of the coating the velocity of the spray stream should be increased to reduce the contact time of the finer particles with the atomising and sheath gas. Key 1 Main atomising gas 2 Secondary atomising gas 3 Shield gas 4 Melting wire ti
