1、AEROSPACE MATERIAL SPECIFICATIONAMS4257Issued 2014-09Aluminum Alloy, Extrusion3.7Cu - 1.15Li - 0.5Zn - 0.45Ag - 0.4Mg - 0.3Mn - 0.1Zr (2055-T84)Solution Heat Treated, Stress Relieved by Stretching 2% to 5% and AgedRATIONALEAMS4257 is a new specification for 2055-T84 aluminum alloy extrusions, soluti
2、on heat treated, stress relieved by stretching 2% to 5% and aged.1. SCOPE1.1 FormThis specification covers an aluminum alloy in the form of extruded bars, rods, and profiles.1.1.1 This specification covers an aluminum alloy in the form of extruded bars, rods, and profiles (shapes) produced with cros
3、s sectional area of 18.5 square inches (11 935 mm2) maximum and a circumscribing circle diameter (circle size) of 14.5 inches (368.3 mm) maximum (See 8.5.1).1.2 ApplicationThese extrusions have been used typically for structural applications requiring a combination of high strength andcompressive pr
4、operties and with good corrosion resistance but usage is not limited to such applications.1.3 Certain processing procedures may cause this product to become susceptible to stress-corrosion cracking; ARP823 recommends practices to minimize such conditions.2. APPLICABLE DOCUMENTSThe issue of the follo
5、wing documents in effect on the date of the purchase order form a part of this specification to the extent specified herein. The supplier may work to a subsequent revision of a document unless a specific document issue is specified. When the referenced document has been canceled and no superseding d
6、ocument has been specified, the last published issue of that document shall apply.2.1 SAE DocumentsAvailable from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org.AMS2355 Quality Assurance, Samp
7、ling and Testing, Aluminum Alloys and Magnesium Alloy, Wrought Products (Except Forging Stock), and Rolled, Forged, or Flash Welded RingsAMS2772 Heat Treatment of Aluminum Alloy Raw Materials_SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of t
8、echnical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefrom, is the sole responsibility of the user.”SAE reviews each technical report at least every five years at w
9、hich time it may be revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions.Copyright 2014 SAE InternationalAll rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electroni
10、c, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE.TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada)Tel: +1 724-776-4970 (outside USA)Fax: 724-776-0790Email: CustomerServicesae.orgSAE WEB ADDRESS: http:/www.sae.orgSAE values your inpu
11、t. To provide feedbackon this Technical Report, please visithttp:/www.sae.org/technical/standards/AMS4257SAE INTERNATIONAL AMS4257 Page 2 of 8ARP823 Minimizing Stress-Corrosion Cracking in Wrought Heat-Treatable Aluminum Alloy ProductsAS1990 Aluminum Alloy Tempers2.2 ASTM PublicationsAvailable from
12、ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959, Tel: 610-832-9585, www.astm.org.ASTM B 594 Ultrasonic Inspection of Aluminum-Alloy Wrought ProductsASTM B 645 Linear-Elastic PlaneStrain Fracture Toughness Testing of Aluminum AlloysASTM B 660 Packaging/Packi
13、ng of Aluminum and Magnesium Products.ASTM B 666/B 666M Identification Marking of Aluminum and Magnesium ProductsASTM E 9 Compression Testing of Metallic Materials at Room TemperatureASTM E 399 Plain-Strain Fracture Toughness KIc of Metallic MaterialsASTM G 34 Exfoliation Corrosion Susceptibility in
14、 2xxx and 7xxx Aluminum Alloys (EXCO Test)ASTM G 47 Determining Susceptibility to Stress-Corrosion Cracking of 2XXX and 7XXX Aluminum Alloy ProductsASTM G 85 Modified Salt Spray (Fog) Testing, Annex A2 (cyclic acidified salt spray test - dry bottom MASTMAASIS)2.3 ANSI PublicationsAvailable from Amer
15、ican National Standards Institute, 25 West 43rd Street, New York, NY 10036-8002, Tel: 212-642-4900, www.ansi.org.ANSI H 35.2 Dimensional Tolerances for Aluminum Mill ProductsANSI H 35.2M Dimensional Tolerances for Aluminum Mill Products (Metric)2.4 Aluminum Association DocumentsAvailable from The Al
16、uminum Association, Inc., 1525 Wilson Boulevard, Suite 600, Arlington, VA 22209 or www.aluminum.orgInternational Alloy Designations and Chemical Composition Limits for Wrought Aluminum and Wrought Aluminum Alloys(known as the “Teal Sheets”)3. TECHNICAL REQUIREMENTS3.1 CompositionShall conform to the
17、 percentages by weight shown in Table 1, determined in accordance with AMS2355.3.1.1 In case there is a discrepancy in the values listed in Table 1 with those listed in the “International Alloy Designations and Chemical Composition Limits for Wrought Aluminum and Wrought Aluminum Alloys”(known as th
18、e “Teal Sheets”), the composition limits registered with the Aluminum Association and published in the “Teal Sheets” shall be the controlling composition.SAE INTERNATIONAL AMS4257 Page 3 of 8TABLE 1 - COMPOSITIONElement min maxSilicon - 0.07Iron - 0.10Copper 3.2 4.2Manganese 0.10 0.50Magnesium 0.20
19、0.6Zinc 0.30 0.7Titanium - 0.10Silver 0.20 0.7Lithium 1.0 1.3Zirconium 0.05 0.15Other impurities - each - 0.05Other impurities - total - 0.15Aluminum Remainder3.2 ConditionExtruded, solution heat-treated and stress-relieved by stretching to produce a nominal permanent set of 2% to 5% (target of 3%)
20、and then artificially aged to the -T84 (See AS1990). Solution and precipitation heat treatment shall be performed in accordance with AMS2772 as applicable to 2XXX alloys. The actual practices are considered proprietary.Product shall be supplied with an as-extruded surface finish; light polishing to
21、remove minor surface conditions is permissible provided such conditions can be removed within specified dimensional tolerances. Product may receive minor straightening, after stretching, of an amount necessary to meet the requirements of 3.5.3.3 PropertiesProduct shall conform to the following requi
22、rements, determined in accordance with AMS2355.3.3.1 Mechanical property requirements for product outside of the range covered by 1.1.1 and Tables 2 shall be agreed upon between purchaser and producer.3.3.2 Longitudinal and, when specified, long transverse tensile properties shall be as shown in Tab
23、le 2A and 2B.SAE INTERNATIONAL AMS4257 Page 4 of 8TABLE 2A - MINIMUM LONGITUDINAL TENSILE PROPERTIES, INCH/POUND UNITSNominal ThicknessInchesTest DirectionTensileStrengthksiYield Strengthat 0.2% OffsetksiElongation in2 inches or 4D%0.04 to 0.125, incl L 82.0 78.0 50.126 to 0.249, inclL 83.0 79.0 6LT
24、 84.0 78.0 50.250 to 0.499, inclL 85.0 80.0 7LT 84.0 78.0 50.500 to 0.749, inclL 87.0 82.0 8LT 84.0 78.0 50.750 to 1.249, inclL 88.0 84.0 8LT 84.0 78.0 51.25 to 1.500, inclL 90.0 86.0 8LT 84.0 78.0 5TABLE 2B - MINIMUM LONGITUDINAL TENSILE PROPERTIES, SI UNITSNominal ThicknessMillimetersTest Directio
25、nTensileStrengthMPaYield Strengthat 0.2% OffsetMPaElongation in50.8 mm or 4D%1.02 to 3.18, incl L 565 538 53.20 to 6.32, inclL 572 545 6LT 579 538 56.35 to 12.67, inclL 586 552 7LT 579 538 512.70 to 19.02, inclL 600 565 8LT 579 538 519.05 to 31.72, inclL 607 579 8LT 579 538 531.75 to 38.10, inclL 62
26、1 593 8LT 579 538 53.3.3 Compression Yield StrengthWhen specified, the longitudinal compressive strength, determined in accordance with ASTM E9, shall be as shown in Table 3A and 3B.SAE INTERNATIONAL AMS4257 Page 5 of 8TABLE 3A - MINIMUM LONGITUDINAL COMPRESSIVE YIELD STRENGTH, INCH/POUND UNITSNomin
27、al ThicknessInches Test DirectionLongitudinal Compressive Yield Strength ksi0.04 to 0.125, incl L 80.00.126 to 0.249, incl L 81.00.250 to 0.499, incl L 81.00.500 to 0.749, incl L 83.00.75 to 1.249, incl L 84.01.250 to 1.500, incl L 87.0TABLE 3B MINIMUM LONGITUDINAL COMPRESSIVE YIELD STRENGTH, SI UNI
28、TSNominal ThicknessMillimeters Test DirectionLongitudinal Compressive Yield Strength MPa1.02 to 3.18, incl L 5523.20 to 6.32, incl L 5586.35 to 12.67, incl L 55812.70 to 19.02, incl L 57219.05 to 31.72, incl L 57931.75 to 38.10, incl L 6003.3.4 Fracture ToughnessWhen specified, plane strain fracture
29、 toughness shall be tested in the L-T and T-L orientations in accordance with ASTM E 399 and ASTM B 645. A valid KIc meeting the requirements of ASTM E 399 or a KQ “usable for lot release” in accordance with ASTM B 645 shall meet or exceed the values shown in Table 4. TABLE 4 - FRACTURE TOUGHNESS PA
30、RAMETERSNominal ThicknessInchesNominal ThicknessMillimetersSpecimenOrientationMinimum KIcand KQ “usable for lot release”Minimum KIcand KQ “usable for lot release”MPam 0.750 to 1.500, incl 19.05 to 38.10, inclL-T 22 240.750 to 1.500, incl 19.05 to 38.10, incl T-L 19 21ksi inchSAE INTERNATIONAL AMS425
31、7 Page 6 of 83.3.5 Exfoliation Corrosion ResistanceSpecimens cut from extrusions shall not exhibit exfoliation corrosion at a T/10 plane greater than that illustrated by Photograph EA, Figure 2, of ASTM G 34 when specimens are exposed for 2 weeks according to the procedures in ASTM G 85 Annex A2, us
32、ing the dry-bottom MASTMAASIS Test Method. (See 8.3)3.3.6 Stress Corrosion CrackingSpecimens from extrusions with section thickness 0.750 inches (19.05 mm) and greater, tested in accordance with ASTM G 47, shall show no evidence of stress corrosion cracking when stressed in the short transverse dire
33、ction (perpendicular to grain flow) to 25 ksi (172 MPa). (See 8.4)3.4 QualityProducts, as received by purchaser, shall be uniform in quality and condition, sound and free from foreign materials and from conditions detrimental to usage of the extrusions.3.4.1 When specified, each extrusion shall be s
34、ubjected to ultrasonic inspection in accordance with ASTM B 594. Extrusions, 0.500 inch (12.7 mm) and over in nominal diameter or least distance between parallel sides, shall meet ultrasonic Class B requirements, as described in ASTM B 594.3.5 TolerancesShall conform to all applicable requirements o
35、f ANSI H35.2 or ANSI H35.2M.4. QUALITY ASSURANCE PROVISIONS4.1.1 ResponsibilityThe vendor of the products shall supply all samples for vendors tests and shall be responsible for the performance of all required tests. Purchaser reserves the right to sample and to perform any confirmatory testing deem
36、ed necessary to ensure that the products conform to specified requirements.4.2 Classification of Tests4.2.1 Acceptance Tests: Composition (3.1), longitudinal tensile properties (3.3.2), long transverse tensile properties (when specified) (3.3.2), compression yield strength (when specified) (3.3.3),
37、fracture toughness (when specified) (3.3.4), ultrasonic inspection (when specified) (3.4.1), and tolerances (3.5), are acceptance tests and, except for composition, shall be performed on each lot.4.2.2 Periodic TestsExfoliation corrosion resistance (3.3.5) and stress corrosion cracking (3.3.6) are p
38、eriodic tests and shall be performed at afrequency selected by the vendor unless frequency of testing is specified by purchaser.4.3 Sampling and TestingShall be in accordance with AMS2355.4.3.1 The fracture toughness test specimens shall meet the following requirements. 4.3.1.1 For extrusions having
39、 a nominal thickness of 0.750 to 1.000 inch (19.05 to 25.40 mm) inclusive, use a test specimen having a width (W) of 2.0 inches (50.8 mm) and a thickness (B) of full extrusion thickness or the maximum thickness obtainable from the extrusion cross-section while meeting the dimensional requirements of
40、 ASTM E 399.SAE INTERNATIONAL AMS4257 Page 7 of 84.3.1.2 For extrusions having a nominal thickness over 1.000 to 1.500 inch (25.42 to 38.10 mm) inclusive, use a test specimen having a width (W) of 2.0 inches (50.8 mm) and a thickness (B) of 1.0 inch (25.4 mm) or the maximum thickness obtainable from
41、 the extrusion cross-section while meeting the dimensional requirements of ASTM E 399.4.3.1.3 When allowed by the profile shape, the test specimen (especially the pre-crack and crack path) shall be located away from junctions and other areas in the extruded shape with mixed grain flow.4.3.1.4 When f
42、racture toughness tests of material less than 0.750 inch (19.05 mm) thick is required by customer, specimen size, test method, and minimum KIc and KQ “usable for lot release” value shall be agreed upon by customer and supplier.4.4 ReportsThe vendor of product shall furnish with each shipment a repor
43、t stating that the product conforms to the chemical composition, tolerances, ultrasonic inspection (when specified), and showing the numerical results of tests on each inspection lot to determine conformance to the other acceptance test requirements and stating that the final product conforms to the
44、 other technical requirements. This report shall include the purchase order number, inspection lot number, AMS4257, size or section identification number, and quantity. The report shall also identify the producer and the size of the mill product.4.4.1 When the product size is outside the range cover
45、ed by 1.1.1 and Table 2, the report shall contain a statement to that effect.4.5 Resampling and RetestingShall be in accordance with AMS2355.5. PREPARATION FOR DELIVERY5.1 IdentificationShall be in accordance with ASTM B 666/B 666M.5.2 PackagingProducts shall be prepared for shipment in accordance w
46、ith ASTM B 660 and in compliance with applicable rules and regulations pertaining to the handling, packaging, and transportation of the product to ensure carrier acceptance and safe delivery.6. ACKNOWLEDGEMENTA vendor shall mention this specification number in all quotations and when acknowledging p
47、urchase orders.7. REJECTIONSProducts not conforming to this specification, or to modifications authorized by purchaser, will be subject to rejection.8. NOTES8.1 A change bar (|) located in the left margin is for the convenience of the user in locating areas where technical revisions, not editorial c
48、hanges, have been made to the previous issue of this document. An (R) symbol to the left of the document title indicates a complete revision of the document, including technical revisions. Change bars and (R) are not used in original publications, nor in documents that contain editorial changes only
49、.8.2 Product should be limited to one re-solution heat treatment. For thinner material, minimize solution heat treat soak times to avoid lithium depletion. SAE INTERNATIONAL AMS4257 Page 8 of 88.3 The solution used for exposure by ASTM G 34, the EXCO Test, has been determined to be inappropriate for Al-Li alloys. For further information on this review ASTM G 112 which describes limitations on this test method for Al-Li alloys. 8.4
