SIST EN 1011-7:2004

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Schweißen - Empfehlungen zum Schweißen metallischer Werkstoffe - Teil 7: ElektronenstrahlschweißenSoudage
- Recommandations pour le soudage des matériaux métalliques - Partie 7 : Soudage par faisceau d'électronsWelding - Recommendations for welding of metallic materials - Part 7: Electron beam welding25.160.10Varilni postopki in varjenjeWelding processesICS:Ta slovenski standard je istoveten z:EN 1011-7:2004SIST EN 1011-7:2004en01-november-2004SIST EN 1011-7:2004SLOVENSKI
STANDARD



SIST EN 1011-7:2004



EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 1011-7July 2004ICS 25.160.10English versionWelding - Recommendations for welding of metallic materials -Part 7: Electron beam weldingSoudage
- Recommandations pour le soudage desmatériaux métalliques - Partie 7 : Soudage par faisceaud'électronsSchweißen - Empfehlungen zum Schweißen metallischerWerkstoffe - Teil 7: ElektronenstrahlschweißenThis European Standard was approved by CEN on 30 April 2004.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards 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 language made by translationunder the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the officialversions.CEN members are the national standards bodies of 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.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2004 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 1011-7:2004: ESIST EN 1011-7:2004



EN 1011-7:2004 (E) 2 Contents page Foreword.5 Introduction.6 1 Scope.7 2 Normative references.7 3 Terms and definitions.7 4 Quality requirements.12 5 Storage and handling of parent metals and consumables.12 6 Welding facilities.12 7 Qualification of the welding personnel.13 8 Welding procedure specification.13 9 Welding procedure test.14 10 Joint preparation.14 10.1 Machining.14 10.2 Demagnetisation.14 10.3 Cleaning.14 10.4 Assembly.15 11 Joint design.15 11.1 Longitudinal seams.15 11.2 Circular seams.16 12 Evacuation holes.17 13 Tack welds, cosmetic passes.17 14 Thermal pre- and post heat treatment.18 15 Documentation.18 Annex A (informative)
Information about weldability of metallic materials.19 A.1 General.19 A.2 Steels and iron alloys.19 A.3 Nickel and nickel alloys.20 A.4 Aluminium and magnesium alloys.20 A.5 Copper and copper alloys.20 A.6 Refractory and reactive metals.21 A.7 Dissimilar metals.21 A.8 Non-metals.21 Annex B (informative)
Information about causes of weld imperfections and prevention.23 Annex C (informative)
Summary of electron beam weldability of metals with reference to CR ISO 15608:2000 groups.26 C.1 Grouping system for steels.26 C.2 Grouping system for aluminium and aluminium alloys.30 C.3 Grouping system for copper and copper alloys.31 C.4 Grouping system for nickel and nickel alloys.31 C.5 Grouping system for titanium and titanium alloys.32 C.6 Grouping system for zirconium and zirconium alloys.32 C.7 Grouping system for cast iron.33 SIST EN 1011-7:2004



EN 1011-7:2004 (E) 3 Annex D (informative)
Examples of preparation of circular joints.34 Bibliography.41
Figures Figure 1 — Terms of electron beam oscillation.8 Figure 2 — Definition of working distance and focusing distance.9 Figure 3 — Definition for termination of circular seams.10 Figure 4 — Welding with interlayer material.11 Figure 5 — Welding of dissimilar metals with transition material.12 Figure 6 — Example of preparation of surface treated work pieces.14 Figure 7 — Normal square butt weld.15 Figure 8 — Square butt weld with spigot or integral backing.16 Figure 9 — Square butt weld with detached backing.16 Figure 10 — Work piece with run-on and run-off plate for separating the weld start and weld end.16 Figure 11 — Machining-related cavities.17 Figure 12 — Weldment with additional hole for evacuating the cavity.17 Figure A.1 — Sensitivity of hot cracks depending of alloy contents in aluminium.22 Figure D.1 — Various types of radial joints with centring.34 Figure D.2 — Work piece with radial joint, centred using a welding jig.35 Figure D.3 — Work pieces with unsuitable and better positions for radial weld.35 Figure D.4 — Various types of axial joints.36 Figure D.5 — Example of an axial weld with a depth of fusion zone adapted to suit the strength requirement (not welded through the full thickness of the joint).36 Figure D.6 — Improved joint detail for axial welds with reduced stress concentration.37 Figure D.7 — Deterioration of joint fit-up that occurs when welding axial joints assembled with a clearance fit.37 Figure D.8 — Effect of the method of manufacture on the dimensions of gear wheels.38 Figure D.9 — Example of a gear wheel with an unsuitable located axial joint. The joint is too close to the central bore.38 Figure D.10 — Better positioned axial joint compared with figure D.9. The joint is further from the central bore and the wall thickness has been adapted to suit the required weld strength.39 Figure D.11 — Better positioned axial joint compared with figure D.9. The slot has been included to accommodate radial shrinkage.39 Figure D.12 — Example of a difficult to access electron beam weld.39 SIST EN 1011-7:2004



EN 1011-7:2004 (E) 4 Figure D.13 — Relative tendency of axial and radial welds to cause deformation.40 Tables Table B.1 — Causes of weld imperfections and prevention.23 Table C.1 — Grouping system for steels.27 Table C.2 — Grouping system for aluminium and aluminium alloys.30 Table C.3 — Grouping system for copper and copper alloys.31 Table C.4 — Grouping system for nickel and nickel alloys.31 Table C.5 — Grouping system for titanium and titanium alloys.32 Table C.6 — Grouping system for zirconium and zirconium alloys.32 Table C.7 — Grouping system for cast irons.33
SIST EN 1011-7:2004



EN 1011-7:2004 (E) 5 Foreword This document (EN 1011-7:2004) 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 text or by endorsement, at the latest by January 2005, and conflicting national standards shall be withdrawn at the latest by January 2005. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association, and supports essential requirements of EU Directive(s). This European Standard is composed of the following parts: Part 1: General guidance for arc welding Part 2: Arc welding of ferritic steels Part 3: Arc welding of stainless steels Part 4: Arc welding of aluminium and aluminium alloys Part 5: Welding of clad steel Part 7: Electron beam welding Part 8: Welding of cast irons According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: 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. SIST EN 1011-7:2004



EN 1011-7:2004 (E) 6 Introduction This document contains special recommendations for the electron beam welding of metallic materials and should be observed in connection with the general recommendations for welding according to EN 1011-1. It includes details on quality requirements, production welding facilities as well as the weldability of some materials and informs about welding procedures. The special properties of electron beam welding derive from the high power and power density possible in the beam spot, the resulting "deep welding effect" and the unique controllability of the process. Electron beam welding is recommended for welding metallic materials which require low heat input, low shrinkage, low distortion, and for welding dissimilar or reactive metals. It allows high welding speeds and flexibility of design by joining simple components. The electron beam is able to join very thin and very thick sections and the combination of both. It is also suited to automation and quality control. SIST EN 1011-7:2004



EN 1011-7:2004 (E) 7
1 Scope This document may be used for the electron beam welding (process no. 51 according to EN ISO 4063) of weldable metallic materials according to CR ISO 15608. It does not contain data on permissible stresses on weld seams or on the testing and evaluation of weld seams. Such data can either be seen from the relevant application standards or should be separately agreed between the contracting parties. A requirement for the application of this document is that the recommendations should be used by appropriately trained and experienced personnel. 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 references, the latest edition of the referenced document (including any amendments) applies.
EN 1011-1, Welding — Recommendations for welding of metallic materials — Part 1: General guidance for arc welding EN ISO 13919-1:1996, Welding — Electron and laser beam welded joints — Guidance on quality levels for imperfections — Part 1: Steel (ISO 13919-1:1996) EN ISO 13919-2:2001, Welding — Electron and laser beam welded joints — Guidance on quality levels for imperfections — Part 2: Aluminium and its weldable alloys (ISO 13919-2:2001) EN ISO 14744-1:2000, Welding — Acceptance inspection of electron beam welding machines — Part 1: Principles and acceptance conditions (ISO 14744-1:2000) EN ISO 14744-2, Welding — Acceptance inspection of electron beam welding machines — Part 2: Measurement of accelerating voltage characteristics (ISO 14744-2:2000) EN ISO 14744-3, Welding — Acceptance inspection of electron beam welding machines — Part 3: Measurement of beam current characteristics (ISO 14744-3:2000) EN ISO 14744-4, Welding — Acceptance inspection of electron beam welding machines — Part 4: Measurement of welding speed (ISO 14744-4:2000) EN ISO 14744-5, Welding — Acceptance inspection of electron beam welding machines — Part 5: Measurement of run-out accuracy (ISO 14744-5:2000) EN ISO 14744-6, Welding — Acceptance inspection of electron beam welding machines — Part 6: Measurement of stability of spot position (ISO 14744-6:2000) EN ISO 15614-11:2002, Specification and qualification of welding procedures for metallic materials — Welding procedure test — Part 11: Electron and laser beam welding (ISO 15614-11:2002) EN ISO 15609-3:2004, Specification and qualification of welding procedures for metallic materials — Welding procedure specification — Part 3: Electron beam welding (ISO 15609-3:2004) 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN ISO 15609-3:2004,
EN ISO 13919-1:1996, EN ISO 13919-2:2003, EN ISO 14744-1:2000, and EN ISO 15614-11:2002 and the following apply. SIST EN 1011-7:2004



EN 1011-7:2004 (E) 8 3.1 accelerating voltage electric potential difference UA between cathode and anode 3.2 beam current value of the electric current in the beam IB 3.3 beam oscillation periodic deflection of the electron beam from the initial position defined in terms of pattern, dimensions and frequency NOTE See Figure 1.
Key 1 Oscillation width 2 Initial position of the beam 3 Oscillation length Figure 1 — Terms of electron beam oscillation 3.4 cosmetic pass superficial remelting of the weld in order to enhance its appearance NOTE This pass is usually made with a defocused or oscillating beam. 3.5 defocusing deviation from the normal focus position (e. g. focus on work piece surface) 3.6 focusing distance distance between the focusing lens plane and beam focus position SIST EN 1011-7:2004



EN 1011-7:2004 (E) 9 NOTE See Figure 2.
Key 1 Work piece 2 Working distance 3 Heat protection 4 Focusing lens 5 Focusing distance6 Beam focus 7 Beam spot Figure 2 — Definition of working distance and focusing distance 3.7 working distance distance between the surface of the work piece and a standard reference point on the equipment which is traceable to the true focusing lens plane NOTE See Figure 2. 3.8 lens current current IL which flows through the electromagnetic focusing lens 3.9 slope down controlled decrease of the beam power at the end of welding. The slope down region is the region on the work piece in which the effects of slope down occur NOTE See Figure 3. The slope down region can consist of one or two areas, depending on the selected welding mode: a) in partial penetration welding:  a region where penetration decreases continuously. b) in full penetration welding:  a region where beam penetration is still complete;  a region where penetration is partial or decreasing. SIST EN 1011-7:2004



EN 1011-7:2004 (E) 10
a) Partial penetration welding (with overlap)
b) Full penetration welding (without overlap)
c) Typical beam current IB profile for a circular weld with overlap Key 1 Work piece (welded zone) 2 Delay between control starting and weld beginning 3 Slope-up region 4 Overlapping region 5 Electron beam 6 Remelted zone 7 Slope-down region 8 Direction of work piece motion 9 Work piece (unwelded zone) IB
Beam current l
Weld length t
Weld time Figure 3 — Definition for termination of circular seams SIST EN 1011-7:2004



EN 1011-7:2004 (E) 11 3.10 slope-up controlled increase of the beam power at the beginning of welding NOTE See Figure 3. 3.11 spiking locally variation of fusion zone depths as a consequence of instabilities in the beam penetration mechanism 3.12 evacuation hole hole for evacuating cavities in work pieces NOTE See Figure 12. 3.13 working pressure pressure measured in the welding enclosure in the vicinity of the work piece 3.14 interlayer material alloy addition introduced by means of pre-placed foil at the joint interface to modify the weld fusion zone composition to improve weldability or weld performance NOTE See Figure 4.
Joint prepared
Joint welded Key 1 Parent material A 2 Interlayer material 3 Parent material A or B 4 Fusion zone Figure 4 — Welding with interlayer material 3.15 transition material buffer material insert employed to allow welding of metallurgically incompatible materials NOTE See Figure 5. SIST EN 1011-7:2004



EN 1011-7:2004 (E) 12
Joint prepared
Joint welded Key 1 Parent material A 2 Transition material 3 Parent material B 4 Fusion zone Figure 5 — Welding of dissimilar metals with transition material 4 Quality requirements The quality requirements should be given in the design specification prior to the beginning of welding work. They should be based on EN 729-1 and EN 729-2 or EN 729-3 or EN 729-4 and EN ISO 13919-1 or EN ISO 13919-2, unless relevant application standards are available. 5 Storage and handling of parent metals and consumables In order to avoid contact corrosion, foreign metal inclusions etc., parent metals and consumables of dissimilar classes of materials (according to CR ISO 15608) should not be stored and processed jointly. 6 Welding facilities Welding facilities include the electron beam-welding machine, workshop, tools, clamping devices, demagnetisation devices, and cleaning facilities. In the following, only those facilities, which are of particular significance for electron beam welding, will be described in more detail. The electron beam welding machine should be installed so that environmental conditions, such as mechanical vibrations, noise and dirt from neighbouring machines, electric and magnetic fields do not influence the quality of welds. Moreover, noise control regulations pursuant to the equipment safety act should be observed for the vacuum pumps. In larger workshops, the machine operators' and machine setters' workplace should be shielded against disturbances from manufacturing operations (e.g. by means of partition walls). The exhaust gases generated during evacuation of the working chamber shall only be released into the environment in accordance with the relevant emission regulations. Where particularly high demands are placed, on weld quality it is recommended that filtered air or inert gas be used to vent the working chamber. The supply voltage for the electron beam welding machine shall not vary by more than ± 10 % and care should be taken to ensure that the welding machine has a satisfactory earth connection. The electron beam welding machine shall be subjected to an acceptance inspection according to EN ISO 14744-1 to EN ISO 14744-6 as part of an internal quality management upon commissioning or in the case of displacement, modifications and repairs of major welding machine components. In this acceptance inspection the short and long-term consistency as well as the reproducibility of the most important welding parameters and compliance with particular characteristic data deviations will be measured and verified according to given deviation limits. SIST EN 1011-7:2004



EN 1011-7:2004 (E) 13 It is possible using special equipment that electron beam welding can be carried out at atmospheric pressure. In this case, attention is drawn to the need for providing appropriate fume extraction. Electron beam welding machines are operated at different accelerating voltages: up to 150 kV for vacuum equipment and up to 200 kV for non-vacuum equipment. The accelerating voltage dictates the design of the X-ray shielding. All measures to fulfil the applicable radiation protection rules are to be implemented, complied with and supervised by a radiological inspection officer. Normally, the electron beam generator is fixed to the working chamber. Alternatively the electron beam generator can be arranged to move with respect to the work piece mounted either external to the work chamber or internally. Consequently, the relative motion between electron beam and work piece can be performed by work piece or generator motion, by beam deflection or by simultaneous motion of both. 7 Qualification of the welding personnel The requirements for the qualification of personnel for fully mechanised and automatic welding equipment are laid down in EN 1418. Among the different procedures specified in this document, the functional test is particularly suitable as a basis for the recognition of personnel responsible for the operation and set-up of electron beam welding machines as part of an internal quality management system. In a functional test, the operator or setter demonstrates his knowledge of working with a welding procedure specification and of setting, supervising and checking the electron beam-welding machine. 8 Welding procedure specification All details for the electron beam welding of components are to be recorded in a welding procedure specification (WPS) according to EN ISO 15609-3. This includes, for example:  work piece specification;  material specification;  work piece demagnetisation;  joint design;  joint preparation;  thermal pre-treatment;  weld sequence (tacking, welding, cosmetic pass);  clamping device;  work chamber pressure;  working distance;  welding data;  mechanical and thermal post-treatment.
SIST EN 1011-7:2004



EN 1011-7:2004 (E) 14 9 Welding procedure test The successful completion of a procedure test according to EN ISO 15614-11 records that the manufacturer has performed electron beam welding including the preceding and subsequent machining with his operating facilities and personnel according to a recognised welding instruction. EN ISO 15614-11 contains data on the dimensions of test pieces for longitudinal and circular butt welds, for fillet and stake welds and describes the type and scope of weld tests required as a function of the quality levels of imperfections according to EN ISO 13919-1 or
EN ISO 13919-21). 10 Joint preparation 10.1 Machining It is recommended that all joint preparations be produced by machining or high precision cutting. The objective is to prepare clean metal surfaces with a minimum gap when assembled. Where components have surface layers produced by carburising, anodising, cadmium plating, nitriding, phosphating, galvanising etc. these are to be removed preferentially by machining in and adjacent to the weld joint region as shown in Figure 6.
Key 1 Boundary-layer-treated work piece 2 Boundary-layer removed for welding 3 Electron beam 4 3 x upper bead width Figure 6 — Example of preparation of surface treated work pieces 10.2 Demagnetisation Components containing ferromagnetic materials should be checked for residual magnetism and demagnetised if necessary. 10.3 Cleaning The quality of electron beam welding relies on accuracy and cleanliness of the joint preparation.
1) EN ISO 13919-1 and EN ISO 13919-2 are covered steel and aluminium. For other materials these standards can be used, if possible. SIST EN 1011-7:2004



EN 1011-7:2004 (E) 15 Attention should be paid to the resulting surface condition and compatibility of any coolant used. Cleaning of weld joint surfaces should be carried out to remove all contaminants such as oxides, oil, grease, coolant and paint. The specific cleaning method used will be dependent on the material type, component size and the quality requirements as well as the operational circumstances. The following treatments can be used: a) manual
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