BS EN 14324-2004 Brazing - Guidance on the application of brazed joints《铜焊 铜焊接合的应用指南》.pdf

1、BRITISH STANDARD BS EN 14324:2004 Brazing Guidance on the application of brazed joints The European Standard EN 14324:2004 has the status of a British Standard ICS 25.160.50 BS EN 14324:2004 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 27

2、September 2004 BSI 27 September 2004 ISBN 0 580 44516 X National foreword This British Standard is the official English language version of EN 14324:2004. It supersedes BS 1723-1:1986 and BS 1723-2:1986 which are withdrawn. The UK participation in its preparation was entrusted to Technical Committee

3、 WEE/19, Brazing and bronze welding, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be f

4、ound in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are re

5、sponsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and kee

6、p the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 48, an inside back cover and a back cover. The BSI copyright notice display

7、ed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEANSTANDARD NORMEEUROPENNE EUROPISCHENORM EN14324 September2004 ICS25.160.50 Englishversion BrazingGuidanceontheapplicationofbrazedjoints BrasagefortGuidedapplicationpourle

8、sassemblages ralissparbrasagefort HartltenAnleitungzurAnwendunghartgelteter Verbindungen ThisEuropeanStandardwasapprovedbyCENon9July2004. CENmembersareboundtocomplywiththeCEN/CENELECInternalRegulationswhichstipulatetheconditionsforgivingthisEurope an Standardthestatusofanationalstandardwithoutanyalt

9、eration.Uptodatelistsandbibliographicalreferencesconcernings uchnational standardsmaybeobtainedonapplicationtotheCentralSecretariatortoanyCENmember. ThisEuropeanStandardexistsinthreeofficialversions(English,French,German).Aversioninanyotherlanguagemadebytra nslation undertheresponsibilityofaCENmembe

10、rintoitsownlanguageandnotifiedtotheCentralSecretariathasthesamestatusast heofficial versions. CENmembersarethenationalstandardsbodiesofAustria,Belgium,Cyprus,CzechRepublic,Denmark,Estonia,Finland,France, Germany,Greece,Hungary,Iceland,Ireland,Italy,Latvia,Lithuania,Luxembourg,Malta,Netherlands,Norwa

11、y,Poland,Portugal, Slovakia, Slovenia,Spain,Sweden,SwitzerlandandUnitedKingdom. EUROPEANCOMMITTEEFORSTANDARDIZATION COMITEUROPENDENORMALISATION EUROPISCHESKOMITEEFRNORMUNG ManagementCentre:ruedeStassart,36B1050Brussels 2004CEN Allrightsofexploitationinanyformandbyanymeansreserved worldwideforCENnati

12、onalMembers. Ref.No.EN14324:2004:EEN 14324:2004 (E) 2 Contents page Foreword4 Introduction .5 1 Scope 6 2 Normative references 6 3 Terms and definitions .6 4 Joint design8 4.1 Principle8 4.2 Types of joint8 4.3 Assembly gap and brazing gap9 4.3.1 General9 4.3.2 Influence of brazing filler materials

13、.11 4.3.3 Influence of parent material11 4.3.4 Influence of dissimilar parent materials11 4.3.5 Influence of surface finish 12 4.3.6 Influence of atmospheres or fluxes .13 4.4 Surface preparation.13 4.5 Stress distribution in service .13 4.6 Application of filler material .13 4.7 Assembly 13 4.8 Goo

14、d brazing design .13 5 Materials .14 5.1 Parent materials.14 5.1.1 Basic considerations.14 5.1.2 Special considerations14 5.2 Filler materials17 5.2.1 General17 5.2.2 Forms available18 5.2.3 Applications .18 5.3 Fluxes19 5.3.1 General19 5.3.2 Flux removal.19 5.4 Atmospheres20 5.4.1 Protective20 5.4.

15、2 Vacuum atmospheres for brazing20 5.5 Safety 20 6 Methods of brazing22 7 Heat treatment22 8 Inspection .22 Annex A (informative) Examples of brazed assemblies.23 Annex B (informative) Typical examples of joint design26 Annex C (informative) Filler materials most commonly used for combinations of pa

16、rent materials .32 EN 14324:2004 (E) 3 Annex D (informative) Suitability of brazing filler material classes for the commoner brazing methods33 Annex E (informative) Methods of brazing 34 E.1 Flame brazing 34 E.1.1 General .34 E.1.2 Hand torch brazing34 E.1.3 Mechanized flame brazing36 E.2 Induction

17、brazing.37 E.2.1 Process.37 E.2.2 Application .38 E.2.3 Advantages/limitations .38 E.2.4 Size limitations 38 E.2.5 Safety38 E.3 Resistance brazing39 E.3.1 Process.39 E.3.2 Application .39 E.3.3 Advantages/limitations .39 E.3.4 Size limitations 39 E.3.5 Safety40 E.4 Furnace brazing.40 E.4.1 Process v

18、ariants40 E.4.2 Protective atmosphere brazing40 E.4.3 Vacuum brazing.42 E.5 Immersion brazing.43 E.5.1 General .43 E.5.2 Flux bath brazing.43 E.5.3 Dip bath brazing 44 E.5.4 Salt bath brazing45 E.6 Special methods 46 E.6.1 Laser beam brazing.46 E.6.2 Brazing/braze welding with an arc.47 E.6.3 Other

19、methods .47 Bibliography48 EN 14324:2004 (E) 4 Foreword This document (EN 14324:2004) has been prepared by Technical Committee CEN/TC 121 “Welding”, 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

20、 text or by endorsement, at the latest by March 2005, and conflicting national standards shall be withdrawn at the latest by March 2005. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: A

21、ustria, 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 14324:2004 (E) 5 Introduct

22、ion The purpose of this document is to provide information and guidance to users whose knowledge of brazing is limited, either as regards the whole process or in some specific areas. It is not intended to replace textbooks but to make readily available certain important information and hopefully pre

23、vent some common errors. Brazing techniques offer a wide field for joining, cladding, building up and comparable applications where brazing filler materials can be used. Structures similar to brazed joints can be achieved by arc brazing processes (MIG, TIG, plasma), infra-red brazing and electron be

24、am brazing, which are better described as braze welding. Where the word material is used for components, they can be metallic or non-metallic, except when the component can only be metallic, when it is so described. The same usage applies to filler materials, although the use of non-metallic filler

25、materials is very limited. EN 14324:2004 (E) 6 1 Scope This document gives guidance on the application of brazing and the manufacture of brazed joints. This standard gives an introduction to brazing and a basis for the understanding and use of brazing in different applications. Because of the wide r

26、ange of applications of brazing this standard does not give detailed guidance that might be product specific. For such information reference should be made to the appropriate product standard or, for applications where this does not exist, the relevant criteria should be clearly established before a

27、ny brazing is undertaken. This standard covers joint design and assembly, material aspects for both parent material and filler materials, brazing process and process variables, pre- and post-braze treatment and inspection. 2 Normative references The following referenced documents are indispensable f

28、or the application 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 1044:1999, Brazing Filler metals. EN 1045, Brazing Fluxes for brazing Classification and technical d

29、elivery conditions. EN 12797, Brazing Destructive tests of brazed joints. EN 12799, Brazing Non-destructive examination of brazed joints. EN 13133, Brazing Brazer approval. EN 13134, Brazing Procedure approval. EN ISO 18279, Brazing Imperfections in brazed joints (ISO 18279:2003). 3 Terms and defini

30、tions For the purposes of this document, the following terms and definitions apply. 3.1 brazing joining process in which a filler material is used which has a liquidus temperatur above 450 C, but below the solidus of the parent material, and which is mainly distributed in the brazing gap by capillar

31、y attraction NOTE Other joining methods exist (see E.6.3). 3.2 brazed joint result of a joining process where the parent materials are not melted and the filling material and braze material have different chemical compositions compared to the parent materials 3.3 brazing gap narrow, mainly parallel

32、gap at the brazing temperature between the components to be brazed (see Figure 1 and 4.3.4) EN 14324:2004 (E) 7 3.4 assembly gap fit up narrow, mainly parallel gap at room temperature between the components to be brazed (see Figure 1 and 4.3.4) A B g 1 g 2g 2 g 1 Shaded component has higher coeffici

33、ent of expansion. b) Tube joint (dissimilar materials) Key A Assembly at ambient temperature B Assembly at brazing temperature g 1Assembly gap g 2 Brazing gap Figure 1 Assembly gap and brazing gap EN 14324:2004 (E) 8 4 Joint design 4.1 Principle The brazing process depends upon capillary flow of a m

34、olten brazing filler material between parts separated by a narrow gap. The filler material has a different composition from the components to be brazed. This compositional difference may affect the properties of the assembly in service, e.g. at elevated temperature, in corrosive media or under fatig

35、ue loading. In addition the properties of the parent material of the components to be brazed can be affected by the brazing cycle. 4.2 Types of joint There are basically two types of joint as shown in Figure 2. In practice very few assemblies are as simple as the basic types shown in Figure 2 (see a

36、nnex A). a) Lap b) Butt Figure 2 Basic joint types Lap joints are generally used because they are easier to fabricate and offer increased strength. Butt joints are used where adequate strength is readily obtained, e.g. where the mechanical properties of the parent materials are lower than those of t

37、he brazed joint, or where the thickness and/or length of a lap joint is undesirable. It should be noted that the useful overlap for a lap joint in shear is related to the thickness of the thinner component; beyond the optimum overlap there is little to be gained in joint strength by increasing the o

38、verlap length. EN 14324:2004 (E) 9 4.3 Assembly gap and brazing gap 4.3.1 General The areas of a brazed assembly are defined as shown schematically in Figure 3. Perhaps the most critical feature in brazing is the control of the brazing gap, i.e. the gap at the brazing temperature, between the compon

39、ents to be brazed and through which the filler material has to flow by capillary action. There are several factors that influence the choice of the brazing gap and which have to be taken into consideration. It is essential to recognise that where joints are to be made between different parent materi

40、als, the assembly gap (fit up) will usually have to be different from the brazing gap (see 4.3.4). NOTE The assembly gap may need to be larger or smaller than the brazing gap, depending on the thermal expansion coefficients of the materials, the configuration and the brazing process. Different fille

41、r materials require different gaps even within the same group, as can be seen from the typical ranges given in Table 1, but the optimum gap may also be affected by a number of other joint parameters (see example in Figure 4), e.g.: parent material(s); geometry of the joint; surface finish of the fay

42、ing surfaces; use of a flux or protective atmosphere; careful control of brazing temperature and heating rate; brazing process. Table 1 Typical brazing gaps Filler material class according to EN 1044 Brazing gap amm AL 0,05 to 0,25 AG 0,05 to 0,30 CP 0,05 to 0,30 CU1XX CU2XX as the brazing temperature becomes higher; as the thermal expansion differential widens.