1、ProcessSpecification forElectron BeamWeldingAWS C7.3:2016An American National StandardAWS C7.3:2016An American National StandardApproved byAmerican National Standards InstituteJanuary 26, 2016Process Specification for Electron Beam Welding2nd EditionSupersedes AWS C7.3:1999RPrepared by theAmerican W
2、elding Society (AWS) C7 Committee on High-Energy Beam Welding and CuttingUnder the Direction of theAWS Technical Activities CommitteeApproved by theAWS Board of DirectorsAbstractThis specification on electron beam welding discusses applicable specifications, safety, requirements, fabrication, qual-i
3、ty examination, equipment calibration and maintenance, approval of work, and delivery of work.ISBN: 978-0-87171-877-8 2016 by American Welding SocietyAll rights reservedPrinted in the United States of AmericaPhotocopy Rights. No portion of this standard may be reproduced, stored in a retrieval syste
4、m, or transmitted in anyform, including mechanical, photocopying, recording, or otherwise, without the prior written permission of the copyrightowner.Authorization to photocopy items for internal, personal, or educational classroom use only or the internal, personal, oreducational classroom use only
5、 of specific clients is granted by the American Welding Society provided that the appro-priate fee is paid to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, tel: (978) 750-8400;Internet: .AWS C7.3:2016iiStatement on Use of American Welding Society StandardsAll standards (code
6、s, specifications, recommended practices, methods, classifications, and guides) of the AmericanWelding Society (AWS) are voluntary consensus standards that have been developed in accordance with the rules of theAmerican National Standards Institute (ANSI). When AWS American National Standards are ei
7、ther incorporated in, ormade part of, documents that are included in federal or state laws and regulations, or the regulations of other governmen-tal bodies, their provisions carry the full legal authority of the statute. In such cases, any changes in those AWS standardsmust be approved by the gover
8、nmental body having statutory jurisdiction before they can become a part of those laws andregulations. In all cases, these standards carry the full legal authority of the contract or other document that invokes theAWS standards. Where this contractual relationship exists, changes in or deviations fr
9、om requirements of an AWS stan-dard must be by agreement between the contracting parties.AWS American National Standards are developed through a consensus standards development process that bringstogether volunteers representing varied viewpoints and interests to achieve consensus. While AWS adminis
10、ters theprocess and establishes rules to promote fairness in the development of consensus, it does not independently test, evalu-ate, or verify the accuracy of any information or the soundness of any judgments contained in its standards.AWS disclaims liability for any injury to persons or to propert
11、y, or other damages of any nature whatsoever, whether spe-cial, indirect, consequential, or compensatory, directly or indirectly resulting from the publication, use of, or reliance onthis standard. AWS also makes no guarantee or warranty as to the accuracy or completeness of any information publishe
12、dherein.In issuing and making this standard available, AWS is neither undertaking to render professional or other services for oron behalf of any person or entity, nor is AWS undertaking to perform any duty owed by any person or entity to someoneelse. Anyone using these documents should rely on his
13、or her own independent judgment or, as appropriate, seek theadvice of a competent professional in determining the exercise of reasonable care in any given circumstances. It isassumed that the use of this standard and its provisions is entrusted to appropriately qualified and competent personnel.This
14、 standard may be superseded by new editions. This standard may also be corrected through publication of amend-ments or errata, or supplemented by publication of addenda. Information on the latest editions of AWS standards includ-ing amendments, errata, and addenda is posted on the AWS web page (www.
15、aws.org). Users should ensure that they havethe latest edition, amendments, errata, and addenda.Publication of this standard does not authorize infringement of any patent or trade name. Users of this standard accept anyand all liabilities for infringement of any patent or trade name items. AWS discl
16、aims liability for the infringement of anypatent or product trade name resulting from the use of this standard.AWS does not monitor, police, or enforce compliance with this standard, nor does it have the power to do so.Official interpretations of any of the technical requirements of this standard ma
17、y only be obtained by sending a request,in writing, to the appropriate technical committee. Such requests should be addressed to the American Welding Society,Attention: Managing Director, Technical Services Division, 8669 NW 36 St, # 130, Miami, FL 33166 (see Annex G).With regard to technical inquir
18、ies made concerning AWS standards, oral opinions on AWS standards may be rendered.These opinions are offered solely as a convenience to users of this standard, and they do not constitute professionaladvice. Such opinions represent only the personal opinions of the particular individuals giving them.
19、 These individualsdo not speak on behalf of AWS, nor do these oral opinions constitute official or unofficial opinions or interpretations ofAWS. In addition, oral opinions are informal and should not be used as a substitute for an official interpretation.This standard is subject to revision at any t
20、ime by the AWS C7 Committee on High-Energy Beam Welding and Cutting.It must be reviewed every five years, and if not revised, it must be either reaffirmed or withdrawn. Comments (recom-mendations, additions, or deletions) and any pertinent data that may be of use in improving this standard are requi
21、red andshould be addressed to AWS Headquarters. Such comments will receive careful consideration by the AWS C7Committee on High-Energy Beam Welding and Cutting and the author of the comments will be informed of theCommittees response to the comments. Guests are invited to attend all meetings of the
22、AWS C7 Committee on High-Energy Beam Welding and Cutting to express their comments verbally. Procedures for appeal of an adverse decision con-cerning all such comments are provided in the Rules of Operation of the Technical Activities Committee. A copy of theseRules can be obtained from the American
23、 Welding Society, 8669 NW 36 St, # 130, Miami, FL 33166.AWS C7.3:2016iiiAWS C7.3:2016ivThis page is intentionally blank.PersonnelAWS C7 Committee on High-Energy Beam Welding and CuttingT. A. Palmer, Chair Penn State UniversityK.W. Lachenberg, Vice Chair Sciaky CorporationD. D. Kautz, 2nd Vice Chair
24、Los Alamos National LaboratoryP. Portela, Secretary American Welding SocietyA. Black PTR-Precision Technologies, IncorporatedP.E. Denney The Lincoln Electric CompanyP. W. Hochandel Los Alamos National LaboratoryG. R. LaFlamme PTR-Precision Technologies, IncorporatedE. D. Levert Lockheed Martin Missi
25、les AWS A3.0M/A3.0, Welding Terms and Definitions, Including Terms for Adhesive Bonding, Brazing, Soldering,Thermal Cutting and Thermal Spraying;AWS B2.1/B2.1M, Specification for Welding Procedure and Performance Qualification; andAWS C7.1M/C7.1, Recommended Practices for Electron Beam Welding and A
26、llied Processes.American National Standards Institute (ANSI) documents:2ANSI Z49.1, Safety in Welding, Cutting, and Allied Processes; andANSI Z87.1, Occupational and Educational Eye and Face Protection.ANSI/ASNT CP-189 Standard for Qualification and Certification of Nondestructive Testing PersonnelA
27、merican Vacuum Society Vacuum Hazards Manual3Other documents:ASNT Personnel Qualification RP SNT-TC-1ANAS 410 Certification and Qualification of Nondestructive Test PersonnelSDS. Safety Data Sheet, available from producer of chemical or other material.3. Terms and DefinitionsAWS A3.0M/A3.0, Standard
28、 Welding Terms and Definitions Including Terms for Adhesive Bonding, Brazing, Soldering,Thermal Cutting, and Thermal Spraying, provides the basis for terminology used herein.reference document. A type of document that outlines procedures as they relate to a particular activity. A reference document
29、outlines the procedures undertaken during an activity to avoid missing steps the next time that the activity isperformed.4. SafetyThese safe practice recommendations are abstracted from AWS C7.1. That document and the manufacturers manualsshould be consulted for a more complete treatment of the subj
30、ect. Some of the following potential hazards of ElectronBeam Welding are above and beyond those traditionally associated with other welding processes.4.1 Electric Shock. The typical primary voltage to an electron beam welding machine is 440 volts AC. That voltage isstepped up to several thousand vol
31、ts for the electron beam gun and also for the vacuum (ionization) gauge(s). Thesevoltages, and their associated currents, can be lethal.4.1.1 All doors and access panels on electron beam welding equipment shall be properly secured and interlocked toprevent accidental or unauthorized access.1AWS stan
32、dards are published by the American Welding Society, 8669 NW 36 St, # 130, Miami, FL 33166.2This ANSI standard is published by the American Welding Society, 8669 NW 36 St, # 130, Miami, FL 33166.3American Vacuum Society Vacuum Hazards Manual is published by American Vacuum Society, 120 Wall Street,
33、and 32nd FloorNew York, NY. 10005.4.1.2 All conductors shall be fully enclosed by grounded, conductive barriers that are also interlocked.4.1.3 A grounding probe must be used before servicing the electron beam gun and high voltage power supply.4.1.4 Appropriate warning signs shall be affixed to the
34、equipment per ANSI Z49.1.4.1.5 Follow appropriate lock-out and tag-out procedures when servicing electron beam equipment.4.2 Materials, Fumes, and Gases. Harmful gases and vapors may be generated during electron beam welding.4.2.1 Exhaust venting and filtering shall be provided for vacuum processing
35、.4.2.2 Hazardous levels of cleaning solution and solvent vapors shall be avoided/prevented when cleaning the vacuumchamber for high vacuum processing.4.2.3 Safety Data Sheets (SDS) shall be read by Welding Operator Maintenance personnel and all those involved in the maintenance process to determine
36、hazards in working with all materials associated with the welding process. SDS shall be followed. These include the SDS for all cleaning solvents, materials contained in the workpiece, andfixturing.4.3 X-Radiation. X-radiation is produced by electron beam welding equipment during operation. The syst
37、em designincorporates shielding which reduces the radiation to allowable levels.4.3.1 Proper shielding shall be employed to protect personnel from X-ray leakage.4.3.2 Equipment shall be inspected and a radiation survey shall be conducted periodically to ensure that shielding isperforming properly, a
38、s specified by the machine manufacturer.4.3.3 All users of the equipment shall establish and adhere to a radiation safety program.4.4 Visible Radiation. Direct viewing of the weld area during welding can expose personnel to visible, infrared, andultraviolet radiation. Appropriate optical filters sha
39、ll be used per ANSI Z87.1 to shield personnel from visible andultraviolet light exposure.4.5 Vacuum. All electron beam welding machines covered by this document use vacuum pumping to protect the beamduring transmission and to prevent degrading of the workpiece.The American Vacuum Society Vacuum Haza
40、rds Manual can be consulted for appropriate safety precautions whenworking with vacuum systems on electron beam welding equipment.5. RequirementsThis section discusses requirements to be met before welding qualification to this specification is allowed.5.1 Equipment. Equipment falls into two categor
41、ies: (1) the electron beam welding machine and associated hardwareand (2) the fixturing and tooling used to make weldments on specific weldments.5.1.1 Electron Beam Welding Machine. This specification pertains only to welding applications utilizing high andmedium vacuum electron beam welding machine
42、s defined in AWS A3.0 and AWS C7.1.5.1.1.1 Welding equipment shall be capable of producing acceptable weldments when operated by a certifiedoperator pursuant to 5.5.4.5.1.1.2 The vacuum chamber or welding enclosure cleanliness shall be maintained so that no contamination istransferred to the weldmen
43、t during welding.5.1.1.3 All equipment shall meet calibration procedures noted in Clause 8.5.1.1.4 At appropriate intervals, a welding equipment readiness check, as listed in the Welding ProcedureSpecification (WPS), shall be made to verify that equipment is in proper working order as in accordance
44、to AWS C7.1Clause 8.8.5.1.1.5 Beam diagnostics should be used per company policy.5.1.2 Fixturing and Tooling. This clause addresses the fixturing and tooling design for electron beam welding.AWS C7.3:201635.1.2.1 To avoid problems with beam deflection, all fixturing should be non-magnetic where prac
45、tical. At intervalsto be noted in the WPS, the levels of residual magnetism of the tooling shall be monitored. If magnetism exceeds theallowable level noted in the WPS, degaussing operations must be accomplished to restore an acceptable level.5.1.2.2 All fixturing should be made from materials that
46、will not affect weld or base metal quality through contact(either directly or via spatter). All tooling shall be cleaned to ensure no contamination is introduced into the weldment.5.1.2.3 All tooling and fixturing shall meet calibration procedures noted in Clause 8.5.2 Materials. This clause address
47、es the materials used during electron beam welding.5.2.1 Base materials shall be specified in the reference document, these include contract, specification, drawing, etc.5.2.2 Filler materials, when required, shall be specified in the reference document or in the WPS.5.2.3 Cleaning materials, chemic
48、al solvents, and etching solutions shall be specified in the reference document or inthe WPS. Some suggested cleaning materials and methods are noted in Annex A.5.3 Joint Design. This clause addresses typical joints and tolerancing.5.3.1 All joints shall be specified in the reference document using
49、the symbols and terminology of AWS A2.4 andAWS A3.0.5.3.2 The tolerances for squareness and parallelism of the faying surfaces shall be specified in the reference document.Proper tolerances for these parameters are essential for the production of acceptable welds. See Clause 8 of AWS C7.1for more information on acceptable tolerance levels for electron beam welding.5.3.3 The tolerances for root opening and mismatch shall be specified in the reference document. Proper tolerances forthese parameters are essential for the production of acceptable welds. See Clause 8 of AWS C7.1 for more informa
