1、Guide forAluminum HullWeldingAWS D3.7:2004An American National StandardReproduced by Global Engineering Documents With the Permission of AWS Under Royalty Agreement 550 N.W. LeJeune Road, Miami, Florida 33126AWS D3.7:2004An American National StandardApproved byAmerican National Standards InstituteDe
2、cember 17, 2003Guide forAluminum Hull WeldingSupersedes ANSI/AWS D3.7-90Prepared byAWS D3 Committee on Welding in Marine ConstructionUnder the Direction ofAWS Technical Activities CommitteeApproved byAWS Board of DirectorsAbstractThis guide provides information on the welding of sea going aluminum h
3、ulls and other structures in marine construction.Included are sections on hull materials, construction preparation, welding equipment and processes, qualificationrequirements, welding techniques, and safety precautions.Key WordsAluminum hull welding, ship welding, hull welding, aluminum hulls, boats
4、, crafts, shipsStatement on Use of AWS American National 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 theAmer
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7、this contractual relationship exists, changes in or deviations from requirements of an AWSstandard must be by agreement between the contracting parties.International Standard Book Number: 0-87171-690-9American Welding Society, 550 N.W. LeJeune Road, Miami, FL 33126 2004 by American Welding Society.
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17、revision at any time by the AWS D3 Committee on Welding in Marine Construction. It mustbe reviewed every five years, and if not revised, it must be either reaffirmed or withdrawn. Comments (recommenda-tions, additions, or deletions) and any pertinent data that may be of use in improving this standar
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19、 the AWS D3 Committee on Welding in Marine Constructionto express their comments verbally. Procedures for appeal of an adverse decision concerning all such comments areprovided in the Rules of Operation of the Technical Activities Committee. A copy of these Rules can be obtained fromthe American Wel
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21、that theappropriate fee is paid to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, Tel: 978-750-8400;online: http:/.iiiDedicationPaul B. Dickerson19262004The AWS D3 Committee on Welding in Marine Construction dedicates this edition ofAWS D3.7, Guide for Aluminum Hull Welding,
22、to the memory of Paul B. Dickerson. Paulwas an AWS Fellow and contributed unselfishly to several technical committees of theAmerican Welding Society. His knowledge of aluminum alloy welding was prodigious,and Paul freely shared this knowledge with anyone that needed his help. Paul will begreatly mis
23、sed by his family, friends, peers, and associates.This page is intentionally blank.vPersonnelAWS D3 Committee on Welding in Marine ConstructionR. D. Holdsworth, Chair Management Systems TechnologyK. Masubuchi, Vice Chair Mass Institute of TechnologyA. Davis, Secretary American Welding SocietyG. M. C
24、ain Oxylance CorporationC. B. Champney Nelson Stud Welding*S. A. Collins Maine Maritime AcademyD. Cottle DC FabricatorsJ. H. Devletian Oregon Graduate Institute*P. D. Dickerson ConsultantC. E. Grubbs Global DiversW. Hanzalek ABS Americas*L. D. Holt The ESAB GroupA. W. Johnson A W. Johnson values for
25、 other alloys can be found inreference books.Since the as-welded strength of heat treatable alloysvaries with time at temperature (heat input) in the heat-affected zone, welding heat input can significantly affectthe as-welded tensile strength of these alloys.2.2.2 Nonheat Treatable Alloys. The prin
26、cipal non-heat treatable marine aluminum alloys are 5052, 5083,5086, 5454, and 5456. Alloy 5052 was one of the firstcommercial aluminum-magnesium marine alloys and isstill in use for small pleasure craft. However, it is notnormally employed for structures in commercial or mili-tary craft because of
27、its lower strength.Where operating temperatures in excess of 150F(65C) are anticipated, 5454 alloy is used to avoid theproblem of stress corrosion cracking found in aluminumalloys with higher magnesium content. It is useful instack enclosures and similar applications.Alloys 5083, 5086, and 5456, in
28、the H116 temper, arethe chief aluminum materials used in hulls and otherAWS D3.7:20043marine structures. These alloys are specifically recom-mended in the Technical and Research Bulletin No. 2-15,Guide for the Selection of Wrought Aluminum Plate andShapes for Ship Structure, published by the Society
29、 ofNaval Architects and Marine Engineers (SNAME).Alloy 50863is recommended for most marine con-struction. The nonheat treatable aluminum alloy in theaforementioned SNAME bulletin, designated as GradeA, is termed “a general purpose material for ship struc-ture requiring a comparatively medium-strengt
30、h, lower-magnesium-content, weldable alloy having good “corro-sion-resistance and fabrication characteristics.” Typicalapplications of this alloy include hull, deck, and bulk-head plate and shapes, towers, masts, bulwarks, tanks,and similar components.Alloys 50833and 5456 are also employed for com-m
31、ercial marine construction. Designated as Grade “B,”non-heat treatable aluminum alloys in the aforemen-tioned SNAME Bulletin, 5083 and 5456 alloys aredescribed as recommended material “for components ofship structure which require a higher-strength, higher-magnesium content, weldable alloy having go
32、odcorrosion resistance and moderately good fabricationcharacteristics.” Typical applications of these alloysinclude structures requiring a high strength-to-weightratio, such as hydrofoil hulls, surface-effect craft,amphibious vehicles, and similar components. Alloy5456 has been widely used in naval
33、and crewboatconstruction.2.3 Temper Designations. Temper designations formarine aluminum alloys indicate the level of strengthachieved by a specific sequence of metallurgical treat-ments. Basic tempers are indicated by a letter, with sub-divisions of basic tempers indicated by one or moredigits foll
34、owing the letter. Heat treatable alloy temperdesignations begin with “T,” and non-heat treatablealloys with “H.” The letter “O” denotes fully annealedmaterial, and the letter “F” denotes “as fabricated” tem-pers, which are common to both groups of alloys.Temper designations of nonheat treatable wrou
35、ghtaluminum alloys consist of the letter “H” in conjunctionwith two or more digits; e.g., H34, H116. The first digitindicates the process as follows:(1) H1 Strain Hardened(2) H2 Strain Hardened and Partially Annealed(3) H3 Strain Hardened followed by StabilizationThe second digit indicates the degre
36、e of work harden-ing as follows:(1) 1 is 1/8 hard3. The International Organization for Standardization (ISO)equivalent for 5083 and 5086 alloys are AlMg4.5Mn0.7 andAlM4, respectively.(2) 2 is 1/4 hard(3) 4 is 1/2 hard(4) 6 is 3/4 hard(5) 8 is fully hardenedSometimes a third digit is used to designat
37、e specialconditions of tempering and hardening. The third digitindicates a variation of the two digit “H” temper. It isused to control the degree of temper or the mechanicalproperties that are different from, but are close to, thecorresponding two digit “H” temper to which it is added.For marine alu
38、minum alloys 5083, 5086, and 5456,mildly cold-worked tempers provide the most desirablecombination of mechanical properties and corrosionresistance for welded ship structures.For general hull construction, and particularly forplate in the bilge areas, these marine alloys are now sup-plied in the H11
39、6 temper. This temper makes them pre-dominately free of continuous grain boundary networks.Such grain boundary networks found in other temperscould, under continuous exposure to stagnant or brackishwater, render the metal susceptible to exfoliation orintergranular corrosion. Federal specification QQ
40、-A-250describes the requirements for the H116 temper for 5083,5086, and 5456 alloys.Heat treatable wrought aluminum alloys respond toheat treatment to give strengths that are higher thanobtained by work hardening only. The heat of weldingthese alloys reduces the mechanical properties, but maybe subs
41、equently heat treated to bring the weldment backto original properties.Heat treated tempers are indicated by the letter Tfollowed by a number. The first number indicates thesequence of operations as follows:(1) T1 cooled from an elevated temperature processand naturally aged to a substantially stabl
42、e condition(2) T2 cooled from an elevated temperature process,cold worked, and naturally aged to a substantially stablecondition(3) T3 solution heat-treated, cold-worked, and natu-rally aged to a substantially stable condition(4) T4 solution heat-treated and naturally aged to asubstantially stable c
43、ondition(5) T5 cooled from an elevated temperature processand then artificially aged(6) T6 solution heat-treated and then artificially aged(7) T7 solution heat-treated and stabilized(8) T8 solution heat-treated, cold worked, and thenartificially aged(9) T9 solution heat-treated, artificially aged, a
44、ndthen cold worked(10) T10 cooled from an elevated temperature process,cold worked, and then artificially agedSometimes second and third digits are used for varia-tions in the same basic sequence of operations that resultAWS D3.7:20044in minor changes in mechanical properties; e.g., T54,T451.Typical
45、 marine application of heat treatable alloys arewrought 6061, 6063, and casting alloy 356.0. These met-als are normally used in the T4 or T6 temper or a varia-tion thereof.2.4 Aluminum Product Forms.4All product forms ofaluminum are used in marine construction, includingplate, extrusions, forgings,
46、and castings. Sheet metalgages, electrical conductors, bar, rod, and wire also areemployed in various ship fittings. The chemical com-position limits of aluminum alloys generally used formarine construction are given in Table 1.2.4.1 Plate and Sheet. Flat-rolled aluminum productof 0.25 in. (6.4 mm)
47、thickness and over is referred toas plate, while that from 0.006 in.0.249 in. (0.15 mm6.4 mm) thick is called sheet. (The term strip is not usedfor aluminum.) Aluminum plate is used in hulls, decks,shell strakes, bulkheads, flat brackets, and other appli-cations. Specific alloy selection depends upo
48、n severalfactors including design and service requirements.The marine alloys are available as plate through 6 in.(150 mm) thickness, and widths through 186 in. (4.72 m).Combined width and maximum length per plate are afunction of thickness, with a limiting weight determinedby the initial ingot size.
49、 Availability of specific platesizes may vary among different suppliers. Extra-wideplate, at a premium price, may provide a significant netsavings if a sufficient number of welded joints are elimi-nated. Minimum mechanical properties of marine alu-minum alloy sheet and plate are given in Table 2.52.4.2 Extrusions. Aluminum also has unique versatil-ity in boat and ship use in the form of extruded sections.Both standard and special extruded shapes may be usedto obtain maximum structural and fabrication economicbenefits. A typical use of extrusions is in longitudinallyf
