1、AWS C7.4/C7.4M:2017An American National StandardProcessSpecificationand OperatorQualificationfor Laser BeamWeldingAWS C7.4/C7.4M:2017An American National StandardApproved by theAmerican National Standards InstituteJune 27, 2017Process Specification andOperator Qualification forLaser Beam Welding2nd
2、EditionSupersedes AWS C7.4/C7.4M:2008Prepared by theAmerican Welding 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 laser beam welding discusses applicabl
3、e specifications, safety, requirements, fabrication, qualityexamination, equipment calibration and maintenance, approval of work, and delivery of work.iiAWS C7.4/C7.4M:2017ISBN: 978-0-87171-912-6 2017 by American Welding SocietyAll rights reservedPrinted in the United States of AmericaPhotocopy Righ
4、ts. No portion of this standard may be reproduced, stored in a retrieval system, or transmitted in anyform, including mechanical, photocopying, recording, or otherwise, without the prior written permission of thecopyright owner.Authorization to photocopy items for internal, personal, or educational
5、classroom use only or the internal, personal, oreducational classroom use only 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: .iiiAWS C7.
6、4/C7.4M:2017Statement on the Use of American Welding Society StandardsAll standards (codes, 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 the
7、American National Standards Institute (ANSI). When AWS American National Standards are either incorporated in, ormade part of, documents that are included in federal or state laws and regulations, or the regulations of other governmentalbodies, their provisions carry the full legal authority of the
8、statute. In such cases, any changes in those AWS standardsmust be approved by the governmental body having statutory jurisdiction before they can become a part of those lawsand regulations. In all cases, these standards carry the full legal authority of the contract or other document that invokesthe
9、 AWS standards. Where this contractual relationship exists, changes in or deviations from requirements of an AWSstandard must be by agreement between the contracting parties.AWS American National Standards are developed through a consensus standards development process that bringstogether volunteers
10、 representing varied viewpoints and interests to achieve consensus. While AWS administers the processand establishes rules to promote fairness in the development of consensus, it does not independently test, evaluate, orverify the accuracy of any information or the soundness of any judgments contain
11、ed in its standards.AWS disclaims liability for any injury to persons or to property, or other damages of any nature whatsoever, whetherspecial, indirect, consequential, or compensatory, directly or indirectly resulting from the publication, use of, or relianceon this standard. AWS also makes no gua
12、rantee or warranty as to the accuracy or completeness of any information publishedherein.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
13、person or entity to someoneelse. Anyone using these documents should rely on his 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 it
14、s provisions is entrusted to appropriately qualified and competent personnel.This standard may be superseded by new editions. This standard may also be corrected through publication of amendmentsor errata, or supplemented by publication of addenda. Information on the latest editions of AWS standards
15、 includingamendments, errata, and addenda is posted on the AWS web page (www.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 acceptany and
16、all liabilities for infringement of any patent or trade name items. AWS disclaims liability for the infringement ofany patent 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.Offi
17、cial interpretations of any of the technical requirements of this standard may 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: Director, Standards Development, 8669 NW 36 St, # 130,
18、 Miami, FL 33166 (see Annex F). With regard totechnical inquiries made concerning AWS standards, oral opinions on AWS standards may be rendered. These opinionsare offered solely as a convenience to users of this standard, and they do not constitute professional advice. Such opinionsrepresent only th
19、e personal opinions of the particular individuals giving them. These individuals do not speak on behalfof AWS, nor do these oral opinions constitute official or unofficial opinions or interpretations of AWS. In addition, oralopinions are informal and should not be used as a substitute for an officia
20、l interpretation.This standard is subject to revision at any time 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 pertinen
21、t data that may be of use in improving this standard are required 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 t
22、he comments. Guests are invited to attend all meetings of the AWS C7 Committee on HighEnergy Beam Welding and Cutting to express their comments verbally. Procedures for appeal of an adverse decisionconcerning all such comments are provided in the Rules of Operation of the Technical Activities Commit
23、tee. A copy ofthese Rules can be obtained from the American Welding Society, 8669 NW 36 St, # 130, Miami, FL 33166.This page is intentionally blank.ivAWS C7.4/C7.4M:2017vAWS C7.4/C7.4M:2017PersonnelAWS C7 Committee on High-Energy Beam Welding and CuttingT. A. Palmer, Chair Applied Research Laborator
24、y, Penn State UniversityK. W. Lachenberg, Vice Chair Sciaky, IncorporatedD. Kautz, 2nd Vice Chair Los Alamos National LaboratoryP. Portela, Secretary American Welding SocietyA. N. Black PTRPrecision Technologies, IncorporatedP. E. Denney The Lincoln Electric CompanyJ. W. Elmer Lawrence Livermore Nat
25、ional LaboratoryP. W. Hochanadel Los Alamos National LaboratoryF. Kong ESAB Welding and Cutting ProductsG. R. LaFlamme PTRPrecision Technologies, IncorporatedE. D. Levert Lockheed Martin Missiles (2) Nonferrous Alloys (e.g., Alloys of Al, Ni, Ti, etc. and Super-alloys);(3) Heat-Resisting and Refract
26、ory Metal Alloys (e.g., Alloys of Mo, Ta, W, etc.);(4) Other Alloys (e.g., Be and Cu alloys, precious metals);(5) Nonmetals (Plastics, polymers, etc.).1.1.2 Qualification Categories. There are three categories to which welds may be qualified: Class A, B, or C. Classi-fication levels are intended to
27、delineate inspection level and process control. Examples of acceptance criteria, which maybe applied to the classification levels, are presented in Annex D.1.1.2.1 Class ACritical Applications. Critical weldments include those where a failure of any portion of aweldment would cause loss of system, l
28、oss of major component, loss of control, unintentional release of critical stores,such as fuel or cargo, or endangerment of personnel.1.1.2.2 Class BSemicritical Applications. Semicritical weldments include those where a failure of any portionof a weldment would reduce the overall efficiency of the
29、system, but loss of the system or endangerment of personnelwould not be experienced.1.1.2.3 Class CNoncritical Applications. Noncritical weldments include those where a failure of any portionof a weldment would not affect the efficiency of the system or endanger personnel.1.2 Units of Measure. This
30、standard makes use of both U.S. Customary Units and the International System of Units(SI). The latter are shown within brackets or in appropriate columns in tables and figures. The measurements may notbe exact equivalents; therefore, each system must be used independently.1.3 Safety. Safety and heal
31、th issues and concerns are beyond the scope of this standard; some safety and health informa-tion is provided, but such issues are not fully addressed herein.Safety and health information is available from the following sources:American Welding Society:(1) ANSI Z49.1, Safety in Welding, Cutting, and
32、 Allied Processes(2) AWS Safety and Health Fact Sheets(3) Other safety and health information on the AWS websiteAWS C7.4/C7.4M:20172Laser Institute of America (LIA):ANSI Z136.1, Safe Use of LasersMaterial or Equipment Manufacturers:(1) Safety Data Sheets supplied by materials manufacturers(2) Operat
33、ing Manuals supplied by equipment manufacturers2. Normative ReferencesThe following standards contain provisions which, through reference in this text, constitute provisions of this AWS stan-dard. For undated references, the latest edition of the referenced standard shall apply. For dated references
34、, subsequentamendments to, or revisions of, any of these publications do not apply.American Welding Society (AWS) standards:AWS A3.0M/A3.0, Standard Welding Terms and Definitions, Including Terms for Adhesive Bonding, Brazing, Sol-dering, Thermal Cutting, and Thermal Spraying;AWS A5.32M/A5.32 (ISO 1
35、4175:2008 MOD), Welding ConsumablesGases and Gas Mixtures for Fusion Weldingand Allied Processes;AWS B2.1/B2.1M, Specification for Welding Procedure and Performance Qualification;AWS B4.0, Standard Methods for Mechanical Testing of Welds; andAWS C7.2M, Recommended Practices for Laser Beam Welding, C
36、utting, and Drilling.American National Standards Institute (ANSI) standards:ANSI Z49.1, Safety in Welding, Cutting, and Allied Processes;ANSI Z87.1, Practices for Occupational and Educational Eye and Face Protection; andANSI Z136.1, Practices for the Safe Use of Lasers.International Organization for
37、 Standardization (ISO) standards:ISO 11146-1, Laser and laser related equipment Test methods for laser beam widths, divergence angles and beampropagation ratios;ISO 22826, Destructive test on welds in metallic materials Hardness testing of narrow joints welded by laser andelectron beams; andISO 2282
38、7-2, Acceptance tests for ND:YAG laser beam welding machines Machines with optical fiber delivery Part 2: Moving mechanism.American Society for Nondestructive Testing (ASNT) standard:ASNT Recommended Practice No. SNT TC-1A, Personnel Qualification and Certification in Nondestructive Testing.3. Terms
39、 and DefinitionsAWS A3.0M/A3.0, Standard Welding Terms and Definitions, provides the basis for terms and definitions used herein.However, the following terms and definitions are included below to accommodate usage specific to this document. A listof acronyms used within the document can be found in
40、Annex E.AWS Accredited Testing Facility (ATF). An organization accredited by the American Welding Society in accordancewith AWS B5.4, Specification for the Qualification of Welder Test Facilities, for the purpose of qualification of weld-ing personnel.AWS C7.4/C7.4M:20173beam cover tubes. Typically
41、cylindrical hardwarehollow tubesarranged to cover the path of the laser beam. Theyprovide safety for personnel working around the laser, and also exclude airborne contamination that would interferewith the laser beam. Beam cover tubes are often interlocked with the laser system so that if there is a
42、n intrusion orinterception of the laser beam, the system will shut down.chiller. A device often attached to the laser power supply and the laser head to provide controlled cooling of both.correlation factor. Electronic laser beam diagnostic equipment often compares the spatial profile of the laser b
43、eam to amathematically defined profile. The difference between the two is typically expressed as a correlation factor. TheFactor of 1.0 (=100%) represents a complete conformance of the computed and the actual spatial profile.craters. A region of underfill, typically at the termination of a weld bead
44、, susceptible to shrinkage stresses and cracking.employer. The contractor or manufacturer that adopts this AWS C7.4/C7.4M:2017 Process Specification and OperatorQualification for Laser Beam Welding standard.fiber. See fiber optic cable.fiber laser. A solid-state laser design in which the active medi
45、um is a specially constructed optical fiber.fiber optic cable. An optical fiber that is designed to transmit the laser beam with minimal loss of power. Sometimescalled the process fiber. An important characteristic of the fiber optic cable is the (core) diameter, since it ultimatelyaffects the diame
46、ter of the focused laser beam.focal distance. The distance between the focusing optics and the focal point of the optics. Focal distance needs to beidentified as free air or working focal distance. Working focal distance is the actual focal distance during the laserwelding operation.focus shift. Uni
47、ntended change in the axial position of the focal point of the final focus optics during laser processing,such as laser welding.free air distance. The focal length of the focusing optics as measured when there are no changes in the optical proper-ties of the air between the optical component and the
48、 focal point of the optic.inclusions. Foreign material in the original metal or in the welded metal.laser spot weld. A fusion weld between two or more pieces of material or upon overlapping members with coalescenceinitiating and occurring at faying surfaces or proceeding from the outer surface of on
49、e member. Depending upon thelaser peak power density, the weld fusion zone may have a semi-circular cross section in the plane of the faying sur-faces due to the limited effects of laser translation on the molten pool geometry. Typically, pulsed laser power is usedfor laser spot welding.lens. A transparent optical element with curved surfaces that will converge or diverge (focus or defocus) light rays (laserbeams) via refraction. Some lenses may be designed to change the spatial profile of the original laser beam.M2(pronounced as m squared). D
