1、Designation: B 686/B 686M 07Standard Specification forAluminum Alloy Castings, High-Strength1This standard is issued under the fixed designation B 686/B 686M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision, the year of last revisio
2、n. A number in parentheses indicates the year of last reapproval.A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope*1.1 This specification covers aluminum-alloy high-s
3、trengthcastings designated as shown in Table 1.1.2 Castings covered by this specification are intended foruse in airframe, missile, and other critical applications wherehigh strength, ductility, and sound castings are required.1.3 Unless the order specifies the “M” specification desig-nation, the ma
4、terial shall be furnished to the inch-pound units.1.4 For acceptance criteria for inclusion of new aluminumand aluminum alloys and their properties in this specification,see Annex A1 and Annex A2.1.5 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. T
5、he values stated ineach system may not be exact equivalents, therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in nonconformancewith the standard.1.6 This standard does not purport to address all of thesafety concerns, if any, associated
6、with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regular limitations prior to use.2. Referenced Documents2.1 The following documents of the issue in effect on thedate of purchase form a part o
7、f this specification to the extentreferenced herein:2.2 ASTM Standards:2B 179 Specification for Aluminum Alloys in Ingot andMolten Forms for Castings from All Casting ProcessesB 275 Practice for Codification of Certain Nonferrous Met-als and Alloys, Cast and WroughtB 557 Test Methods for Tension Tes
8、ting Wrought and CastAluminum- and Magnesium-Alloy ProductsB 557M Test Methods for Tension Testing Wrought andCast Aluminum- and Magnesium-Alloy Products MetricB 660 Practices for Packaging/Packing of Aluminum andMagnesium ProductsB 881 Terminology Relating to Aluminum- andMagnesium-Alloy ProductsB
9、917/B 917M Practice for Heat Treatment of Aluminum-Alloy Castings from All ProcessesD 3951 Practice for Commercial PackagingE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE34 Test Methods for ChemicalAnalysis ofAluminum andAluminum-Base AlloysE88 Pr
10、actice for Sampling Nonferrous Metals and Alloysin Cast Form for Determination of Chemical CompositionE94 Guide for Radiographic ExaminationE 155 Reference Radiographs for Inspection of Aluminumand Magnesium CastingsE 165 Test Method for Liquid Penetrant ExaminationE 527 Practice for Numbering Metal
11、s and Alloys in theUnified Numbering System (UNS)E 607 Test Method for Atomic Emission SpectrometricAnalysis Aluminum Alloys by the Point to Plane Tech-nique Nitrogen AtmosphereE 716 Practices for Sampling Aluminum and AluminumAlloys for Spectrochemical AnalysisE 1251 Test Method for Analysis of Alu
12、minum and Alumi-num Alloys by Atomic Emission SpectrometryIEEE/ASTM SI 10 Standard for Use of the InternationalSystem of Units (SI): The Modern Metric System2.3 AMS Standard:3AMS 2771 Heat Treatment of Aluminum Alloy Castings2.4 ANSI Standards:4H35.1 / H35.1 (M) 2006 Alloy and Temper DesignationSyst
13、ems for Aluminum1This specification is under the jurisdiction of ASTM Committee B07 on LightMetals and Alloys and is the direct responsibility of Subcommittee B07.01 onAluminum Alloy Ingots and Castings.Current edition approved Oct. 1, 2007. Published October 2007. Originallyapproved in 1981. Last p
14、revious edition approved in 2003 as B 686 03.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from
15、Society of Automotive Engineers (SAE), 400 CommonwealthDr., Warrendale, PA 15096-0001, http:/www.sae.org.4Available from Aluminum Association, Inc., 1525 Wilson Blvd., Suite 600,Arlington, VA 22209, http:/www.aluminum.org.1*A Summary of Changes section appears at the end of this standard.Copyright A
16、STM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Z1.4 Sampling Procedures and Tables for Inspection byAttributes2.5 Military Standard:5MIL-STD-129 Marking for Shipment and Storage2.6 Federal Standard:5Fed. Std. No. 123 Marking for Shipment (Civil
17、 Agencies)3. Terminology3.1 Definitions: Refer to Terminology B 881 for definitionsof product terms used in this specification.4. Classification4.1 Castings shall be classified by inspection classes.4.1.1 Classes (Inspection):4.1.1.1 Class 1A class of casting, the single failure ofwhich would result
18、 in the loss of a missile, aircraft, or othervehicle.4.1.1.2 Class 2Class 1 castings not included in Class 1,the single failure of which would cause significant danger tooperating personnel or would result in a significant operationalpenalty. In the case of missiles, aircraft, and other vehicles, th
19、isincludes loss of major components, loss of control, uninten-tional release of inability to release armament stores, or failureof weapon installation components.4.1.1.3 Class 3Castings having a margin of safety of200 % or less.4.1.1.4 Class 4Castings having a margin of safety ofgreater than 200 %,
20、or for which no stress analysis is required.All target drone castings and aerospace ground support equip-ment fall in this category, except for such critical parts, thefailure of which would make the equipment unsatisfactory andcause the vehicles which they are intended to support to beinoperable.4.
21、1.2 Grades (Radiographic Quality):NOTE 1Caution should be exercised in specifying the grade ofmaximum permissible radiographic discontinuity level to be met in thecasting. Radiographic quality has only a qualitative relationship tomechanical properties. In general, the highest property levels of an
22、alloywill require the higher grades of radiographic quality. However, sectionsize and shape parameters may be able to tolerate certain discontinuitieswithout significant reduction in functional integrity. Too severe soundnessrequirements may cause the part producibility to be impractical oruneconomi
23、cal.4.1.2.1 Grade AA grade in which there is no discerniblediscontinuity visible on the radiograph of the specified area ofthe casting.4.1.2.2 Grade BA premium grade of casting for criticalapplications or specified area of a casting with low margins ofsafety.4.1.2.3 Grade CA high-quality grade of ca
24、sting or area ofa casting for general applications.4.1.2.4 Grade DA grade included for less important areasof a casting.5. Ordering Information5.1 Orders for material under this specification shall includethe following information:5.1.1 This specification designation (which includes thenumber, the y
25、ear, and the revision letter, if applicable).NOTE 2For inch-pound application, specify Specification B 686 andfor metric application specify Specification B 686M. Do not mix units.5.1.2 Alloy number (Section 7.1, Table 1) radiographicgrade (4.1.2, Table 2) inspection class of castings (4.1.1, Table3
26、 or Table 4) and class of mechanical properties (Table 5 orTable 6),5.1.3 Tensile property requirements on the drawing orpurchase order (9.1.5, 15.5, 15.6, Table 3 and Table 5 or Table4 and Table 6),5.1.4 Identification of product information (Section 11),5.1.5 Applicable drawings or part number,5.1
27、.6 The quantity in either pieces or kilograms,5Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http:/www.dodssp.daps.mil.TABLE 1 Chemical Composition LimitsNOTE 1When single units are shown, they indicate the maximum amou
28、nts permitted.NOTE 2Analysis shall be made for the elements for which limits are shown in this table.NOTE 3The following applies to all specified limits in this table: For purposes of determining conformance to these limits, an observed value or acalculated value obtained from analysis shall be roun
29、ded to the nearest unit in the last right-hand place of figures used in expressing the specified limitin accordance with the rounding-off method of Practice E29.Composition, %ANSIH35.1ASTME 527Former Aluminum Silicon Iron CopperMan-ganeseMagne-siumZinc Titanium EachAOthersTotalBA201.0 A12010 remaind
30、er 0.05 0.10 4.05.0 0.200.40 0.150.35 0.150.35C0.03 0.10354.0 A03540 SC92A remainder 8.69.4 0.20 1.62.0 0.10 0.400.6 0.10 0.20 0.05 0.15C355.0 A33550 SC51B remainder 4.55.5 0.20 1.01.5 0.10 0.400.6 0.10 0.20 0.05 0.15A356.0 A13560 SG70B remainder 6.57.5 0.20 0.20 0.10 0.250.45 0.10 0.20 0.05 0.15A35
31、7.0 A13570 remainder 6.57.5 0.20 0.20 0.10 0.400.7 0.10 0.040.20D0.05 0.15A“Others” includes listed elements for which no specific limit is shown as well as unlisted metallic elements. The producer may analyze samples for trace elements notspecified in the specification. However, such analysis is no
32、t required and may not cover all metallic “Others” elements. Should any analysis by the producer or the purchaserestablish that an “Others” element exceeds the limit of “Each” or that the aggregate of several “Others” elements exceeds the limit of “Total”, the material shall be considerednonconformi
33、ng.BOther ElementsTotal shall be the sum of unspecified metallic elements 0.010 % or more, rounded to the second decimal before determining the sum.CSilver 0.40 to 1.0 %.DBeryllium 0.040.07.B 686/B 686M 0725.2 Additionally, orders for material to this specificationshall include the following informa
34、tion when required by thepurchaser:5.2.1 Whether heat treatment is to be performed in accor-dance with AMS 2771 (10.2),5.2.2 Where the preproduction samples shall be sent, andactivity responsible for testing, and instructions concerningsubmittal of the test reports (14.2.1 and 14.2.2),5.2.3 Penetran
35、t inspection standards (15.3).5.2.4 Whether the material shall be packed or marked, orboth, in accordance with MIL-STD-129, Practices B 660,orFed. Std. No. 123 (16.3),5.2.5 Whether certification is required (17).6. Materials and Manufacture6.1 The responsibility of furnishing castings that can be la
36、idout and machined to the finished dimensions within thepermissible variations specified, as shown on the blueprints ordrawings, shall rest with the producer, except where patternTABLE 2 Discontinuity-Level Requirements for High-Strength Aluminum CastingsMaximum Permissible in Accordance with(Refere
37、nce Radiographs E155)NOTE 1When two or more types of discontinuities are present withina2by2-in. 50 mm by 50 mm area to an extent equal to or not significantlybetter than the acceptance standards for respective discontinuities, the castings shall be rejected.NOTE 2When two or more types of discontin
38、uities are present within a 2 by 2-in. 50 mm by 50 mm area and the predominating discontinuity isnot significantly better than the acceptance standard, the casting shall be considered borderline.NOTE 3Borderline castings shall be reviewed for acceptance or rejection by competent engineering personne
39、l from the manufacturer and purchaser.NOTE 4Gas holes, sand spots, and inclusions allowed by this table shall be cause for rejection when closer than twice their maximum dimension toan edge or extremity of a casting.NOTE 5Castings with the following characteristics apply to Alloy A201.1 only:1. Band
40、ing or striated segregation shall be acceptable to the extent that the mechanical properties in the affected section meet the requirements ofTable 3.2. Healed hot tears or discrete segregation cracks, evidenced by linear irregular white lines, shall be rejected.3. Spheroidal segregation, evidenced b
41、y white spheroids, shall be evaluated for size and concentration by using the standards for gas holes.Grade A Grade B Grade C Grade DDiscontinuity Radiograph Section Thickness, in.14 6 mm34 19 mm14 6 mm34 19 mm14 6 mm34 19 mm14 6 mm34 19 mmGas holes 1.1 none 112255Gas porosity (round) 1.21 none 1133
42、77Gas porosity (elongated) 1.22 none 113455Shrinkage cavity 2.1 none 1A2A3AShrinkage porosity or sponge 2.2 none 112243Foreign material (less dense material) 3.11 none 112244Foreign material (more dense material) 3.12 none 112143Segregation none none none noneCracks none none none noneCold shuts non
43、e none none noneLaps none none none noneSurface irregularity not to exceed drawing toleranceCore shift not to exceed drawing toleranceANot available. Use14 in. for all thicknesses.TABLE 3 Mechanical Properties of SpecimensACut from Designated Areas of CastingB(Inch-Pound Units).Alloy NumberClassNumb
44、erTensile Strength,min, ksiYield Strength, 0.2% Offset, min,ksiElongation in2 in. or 4D,min, %ANSI H35.1 ASTM E 527 (UNS) FormerA201.0CA12010 12D60.060.050.050.035354.0 A03540 SC92A 12D47.050.036.042.032C355.0 A33550 SC51 123D41.044.050.031.033.040.0332A356.0 A13560 SC70B 123D38.040.045.028.030.034.
45、0533A357.0 A13570 12D45.050.035.040.035AFor purposes of determining conformance with this specification, each value for tensile strength and yield strength shall be rounded to the nearest 0.1 ksi, and eachvalue for elongation shall be rounded to the nearest 0.5 %, both in accordance with the roundin
46、g method of Practice E29.BFor any casting process utilized, special mold, or sand mold permanent mold with chills may be used. Properties in other areas may vary with mold process and foundrytechniques used but will be inspected under foundry control (0.1.2). Special negotiated properties may be cal
47、led for by the drawing note.CAlloy A201.0 is intended for use in the T7 temper, which provides a high level of resistance to stress-corrosion cracking when properly heat treated. In other tempers,alloy A201.0 may exhibit susceptibility to stress-corrosion cracking. Additionally, its tendency for hot
48、 shortness may make alloy A201.0 unsuitable in some casting designs.DThis class is obtainable in favorable casting configurations and must be negotiated with the foundry for particular configuration desired. See Note 1 and 8.3.B 686/B 686M 073equipment is furnished by the purchaser and any dimension
49、aldiscrepancies can be clearly attributed to the pattern equipmentas furnished.6.1.1 Unless otherwise specified, only aluminum alloy con-forming to the requirements of Specification B 179 or produc-ers foundry scrap (identified as being made from alloyconforming to Specification B 179) shall be used in theremelting furnace from which molten metal is taken forpouring directly into castings. Additions of small amounts ofmodifiers and grain refining elements or alloys are permitted.6.1.2 Pure materials
