1、Designation: B 686/B 686M 08Standard 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 () 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-st
3、rengthcastings 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 Alloy and temper designations are in accordance withANSI H35.1/H35.1 (
4、M). The equivalent Unified NumberingSystem alloy designations are in accordance with PracticeE 527.1.4 Unless the order specifies the “M” specification desig-nation, the material shall be furnished to the inch-pound units.1.5 For acceptance criteria for inclusion of new aluminumand aluminum alloys a
5、nd their properties in this specification,see Annex A1 and Annex A2.1.6 UnitsThe values stated in either SI units or inch-pound units are to be regarded separately as standard. Thevalues stated in each system may not be exact equivalents;therefore, each system shall be used independently of the othe
6、r.Combining values from the two systems may result in non-conformance with the standard.1.7 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices
7、 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 of this specification to the extentreferenced herein:2.2 ASTM Standards:2B 179 Specification for Aluminum Alloys in Ingot
8、 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 Testing Wrought and CastAluminum- and Magnesium-Alloy ProductsB 557M Test Methods for Tension Testing Wrought andCast Alumi
9、num- and Magnesium-Alloy Products (Metric)B 660 Practices for Packaging/Packing of Aluminum andMagnesium ProductsB 881 Terminology Relating to Aluminum- andMagnesium-Alloy ProductsB 917/B 917M Practice for Heat Treatment of Aluminum-Alloy Castings from All ProcessesD 3951 Practice for Commercial Pac
10、kagingE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE34 Test Methods for ChemicalAnalysis ofAluminum andAluminum-Base AlloysE94 Guide for Radiographic ExaminationE 155 Reference Radiographs for Inspection of Aluminumand Magnesium CastingsE 165 Test
11、 Method for Liquid Penetrant ExaminationE 527 Practice for Numbering Metals 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 Aluminu
12、mAlloys for Spectrochemical AnalysisE 1251 Test Method for Analysis of Aluminum 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
13、.4 ANSI Standards:4H35.1 / H35.1 (M) 2006 Alloy and Temper Designation1This 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 May 1, 2008. Publi
14、shed June 2008. Originallyapproved in 1981. Last previous edition approved in 2007 as B 686/B 686M 07.2For 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
15、Document Summary page onthe ASTM website.3Available from 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 Change
16、s section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Systems for AluminumZ1.4 Sampling Procedures and Tables for Inspection byAttributes2.5 Military Standard:5MIL-STD-129 Marking for Shipment a
17、nd Storage2.6 Federal Standard:5Fed. Std. No. 123 Marking for Shipment (Civil Agencies)2.7 Other Standards:6CEN EN 14242 Aluminum and aluminum alloys . Chemicalanalysis. Inductively coupled plasma optical emissionspectral analysis3. Terminology3.1 Definitions: Refer to Terminology B 881 for definiti
18、onsof 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 in the loss of a missile, aircraft, or othervehicle.4.1.1.2 Class 2Class 1 cast
19、ings 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, thisincludes loss of major components, loss of control, uninten-tional release of
20、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 %, or for which no stress analysis is required.All target drone castings and aerosp
21、ace 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.4.1.2 Grades (Radiographic Quality):NOTE 1Caution should be exercised in specifyin
22、g 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 alloywill require the higher grades of radiographic quality. However, sectionsiz
23、e 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 oruneconomical.4.1.2.1 Grade AA grade in which there is no discerniblediscontinuity visible
24、 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 casting or area ofa casting for general applications.4.1.2.4 Grade DA grade includ
25、ed 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 year, and the revision letter, if applicable).NOTE 2For inch-pound application, s
26、pecify Specification B 686 andfor metric application specify Specification B 686M. Do not mix units.5Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http:/dodssp.daps.dla.mil.6Available from European Committee for Standar
27、dization (CEN), 36 rue deStassart, B-1050, Brussels, Belgium, http:/www.cenorm.be.TABLE 1 Chemical Composition LimitsNOTE 1When single units are shown, they indicate the maximum amounts permitted.NOTE 2Analysis shall be made for the elements for which limits are shown in this table.NOTE 3The followi
28、ng 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 rounded to the nearest unit in the last right-hand place of figures used in expressing the specified limitin accordance wi
29、th the rounding-off method of Practice E29.Composition, %ANSIH35.1ASTME 527Former Silicon Iron CopperMan-ganeseMagne-siumZinc TitaniumOthersAluminumEachATotalBA201.0 A12010 0.05 0.10 4.05.0 0.200.40 0.150.35 0.150.35C0.03 0.10 remainder354.0 A03540 SC92A 8.69.4 0.20 1.62.0 0.10 0.400.6 0.10 0.20 0.0
30、5 0.15 remainderC355.0 A33550 SC51B 4.55.5 0.20 1.01.5 0.10 0.400.6 0.10 0.20 0.05 0.15 remainderA356.0 A13560 SG70B 6.57.5 0.20 0.20 0.10 0.250.45 0.10 0.20 0.05 0.15 remainderA357.0 A13570 6.57.5 0.20 0.20 0.10 0.400.7 0.10 0.040.20D0.05 0.15 remainderA“Others” includes listed elements for which n
31、o 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 not required and may not cover all metallic “Others” elements. Should any analysis by the producer or the purchaserestabli
32、sh 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 considerednonconforming.BOther ElementsTotal shall be the sum of unspecified metallic elements 0.010 % or more, rounded to the second decimal
33、 before determining the sum.CSilver 0.40 to 1.0 %.DBeryllium 0.040.07.B 686/B 686M 0825.1.2 Alloy number (Section 7.1, Table 1) radiographicgrade (4.1.2, Table 2) inspection class of castings (4.1.1, Table3 or Table 4) and class of mechanical properties (Table 5 orTable 6),5.1.3 Tensile property req
34、uirements on the drawing orpurchase order (9.1.5, 15.4, 15.5, 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,5.1.6 The quantity in either pieces or kilograms,5.2 Additionally, orders for material to this sp
35、ecificationshall include the following information 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 t
36、est reports (14.2.1 and 14.2.2),5.2.3 Penetrant inspection standards (15.2).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 respon
37、sibility of furnishing castings that can be laidout and machined to the finished dimensions within thepermissible variations specified, as shown on the blueprints ordrawings, shall rest with the producer, except where patternequipment is furnished by the purchaser and any dimensionaldiscrepancies ca
38、n 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 f
39、urnace 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, recycled materials, and master alloysmay be used to make alloys conforming to this specification,provided chemic
40、al analysis can be taken and adjusted toconform to Table 1 prior to pouring any castings.7. Chemical Composition and Sampling7.1 The product shall conform to the chemical compositionlimits prescribed in Table 1. Conformance shall be determinedby the producer by taking samples at the time castings ar
41、epoured in accordance with E 716 and analyzed in accordancewith E 607, E 1251, E34or CEN EN 14242. If the producerhas determined the composition of the material during casting,they shall not be required to sample and analyze the finishedproduct.7.2 If it becomes necessary to analyze castings for con
42、form-ance to chemical composition limits, the method used tosample castings for the determination of chemical compositionTABLE 2 Discontinuity-Level Requirements for High-Strength Aluminum CastingsMaximum Permissible in Accordance with(Reference Radiographs E155)NOTE 1When two or more types of disco
43、ntinuities 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 discontinuities are present within a 2 by 2-in. 50 mm by 50 mm area
44、 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 personnel from the manufacturer and purchaser.NOTE 4Gas holes, san
45、d 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. Banding or striated segregation shall be acceptable to the ext
46、ent 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 by white spheroids, shall be evaluated for size and concent
47、ration by using the standards for gas holes.Grade A Grade B Grade C Grade DDiscontinuity Radiograph Section Thickness, in.146 mm3419 mm146 mm3419 mm146 mm3419 mm146 mm3419 mmGas holes 1.1 none 1 1 2 2 5 5Gas porosity (round) 1.21 none 1 1 3 3 7 7Gas porosity (elongated) 1.22 none 1 1 3 4 5 5Shrinkag
48、e cavity 2.1 none 1A2A3AShrinkage porosity or sponge 2.2 none 1 1 2 2 4 3Foreign material (less densematerial)3.11 none 1 1 2 2 4 4Foreign material (more densematerial)3.12 none 1 1 2 1 4 3Segregation none none none noneCracks none none none noneCold shuts none none none noneLaps none none none none
49、Surface irregularity not to exceed drawing toleranceCore shift not to exceed drawing toleranceANot available. Use14 in.6 mm for all section thicknesses.B 686/B 686M 083shall be by agreement between the producer and the purchaser.Analysis shall be performed in accordance with E 716, E 607,E 1251, E34or CEN EN 14242 (ICP method).7.3 Other methods of analysis or in the case of dispute maybe by agreement between the producer and the purchaser.7.4 A sample for determining of chemical composition shallb
