1、_ SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical 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 there
2、from, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions. Copyright 2011 SAE International All rights reserved. No part of this publication m
3、ay be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, 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: 724-776-4970 (outside USA)
4、 Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/AMS6940A AEROSPACE MATERIAL SPECIFICATION AMS6940 REV. A Issued 2004-01 Revised 2011-08 Supersed
5、ing AMS6940 Titanium Alloy Bars, Forgings and Forging Stock 3.0Al - 2.5V Annealed (Composition Similar to UNS R56320) RATIONALE AMS6940A is a Five Year Review and update of this specification. 1. SCOPE 1.1 Form This specification covers a titanium alloy in the form of bars, forgings, and stock for f
6、orging. 1.2 Application This material has been used typically for parts requiring strength and oxidation resistance up to 600 F (316 C) and weldability, but usage is not limited to such applications. 2. APPLICABLE DOCUMENTS The issue of the following documents in effect on the date of the purchase o
7、rder forms 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 cancelled and no superseding document has been specified, the last published issue
8、 of that document shall apply. 2.1 SAE Publications Available 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. AMS2241 Tolerances, Corrosion and Heat-Resistant Steel, Iron Alloy, Titanium,
9、 and Titanium Alloy Bars and Wire AMS2249 Chemical Check Analysis Limits, Titanium and Titanium Alloys AMS2368 Sampling and Testing of Wrought Titanium Raw Material Except Forgings and Forging Stock AMS2631 Ultrasonic Inspection, Titanium and Titanium Alloy Bar and Billet AMS2643 Structural Examinat
10、ion of Titanium Alloys, Chemical Etch Inspection SAE AMS6940A Page 2 of 8 AMS2750 Pyrometry AMS2808 Identification, Forgings AMS2809 Identification, Titanium and Titanium Alloy Wrought Products 2.2 ASTM Publications Available from ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Consho
11、hocken, PA 19428-2959, Tel: 610-832-9585, www.astm.org. ASTM E 8 / E 8M Tension Testing of Metallic Materials ASTM E 399 Plane-Strain Fracture Toughness of Metallic Materials ASTM E 1409 Determination of Oxygen and Nitrogen in Titanium and Titanium Alloys by the Inert Gas Fusion Technique ASTM E 144
12、7 Determination of Hydrogen in Titanium and Titanium Alloys by the Inert Gas Fusion Thermal Conductivity/Infrared Detection Method ASTM E 1941 Determination of Carbon in Refractory and Reactive Metals and Their Alloys ASTM E 2371 Analysis of Titanium and Titanium Alloys by Atomic Emission Plasma Spe
13、ctrometry 3. TECHNICAL REQUIREMENTS 3.1 Composition Shall conform to the percentages by weight shown in Table 1; carbon shall be determined in accordance with ASTM E 1941, hydrogen in accordance with ASTM E 1447, oxygen and nitrogen in accordance with ASTM E 1409, and other elements in accordance wi
14、th ASTM E 2371. Other analytical methods may be used if acceptable to the purchaser. TABLE 1 - COMPOSITION Element min max Aluminum 2.50 3.50 Vanadium 2.00 3.00 Iron - 0.30 Oxygen - 0.12 Carbon - 0.050 Nitrogen - 0.020 (200 ppm) Hydrogen - 0.015 (150 ppm) Yttrium (3.1.1) - 0.005 ( 50 ppm) Other Elem
15、ents each (3.1.1) - 0.10 Other Elements, total (3.1.1) - 0.40 Titanium remainder SAE AMS6940A Page 3 of 8 3.1.1 Determination not required for routine acceptance. 3.1.2 Check Analysis Composition variations shall meet the applicable requirements of AMS2249. 3.1.3 When using ASTM E 1447 for hydrogen
16、determination, sample size may be as large as 0.35 gram. 3.1.4 No variation over maximum will be permitted for yttrium. 3.2 Melting Practice 3.2.1 Alloy shall be multiple melted. The first melt shall be made by consumable electrode, nonconsumable electrode, electron beam cold hearth, or plasma arc c
17、old hearth melting practice. The subsequent melt or melts shall be made under vacuum using vacuum arc remelting (VAR) practice. Alloy additions are not permitted in the final melt cycle. 3.2.1.1 The atmosphere for nonconsumable electrode melting shall be vacuum or shall be argon or helium at an abso
18、lute pressure not higher than 1000 mm of mercury. 3.2.1.2 The electrode tip for nonconsumable electrode melting shall be water-cooled copper. 3.3 Condition The product shall be supplied in the following condition: 3.3.1 Bars Hot finished with or without subsequent cold reduction, annealed, and desca
19、led. A machined or ground surface is permitted unless prohibited by the purchaser. The product shall be processed to the final thickness/diameter by metallurgical working operations prior to any straightening, dimensional sizing or surface finishing operations. Bar shall not be cut from plate. 3.3.2
20、 Forgings Annealed and descaled. 3.3.2.1 Stock for Forging As ordered by the forging manufacturer. 3.4 Heat Treatment Bars and forgings shall be annealed at 1200 to 1450 F (649 to 788 C) holding at the selected temperature within 25 F (14 C) for a time commensurate with section thickness and the hea
21、ting equipment and procedure used, and cooling at a rate equivalent to an air cool or slower. Pyrometry shall be in accordance with AMS2750. SAE AMS6940A Page 4 of 8 3.5 Properties The product shall conform to the following requirements: 3.5.1 Bars and Forgings 3.5.1.1 Tensile Properties Shall be as
22、 specified in Table 2, determined in accordance with ASTM E 8 / E 8M with the rate of strain set at 0.005 inch/inch/minute (0.005 mm/mm/minute) and maintained within a tolerance of 0.002 inch/inch/minute (0.002 mm/mm/minute) through the 0.2% offset yield strain 3.5.1.1.1 Tensile property requirement
23、s apply in both the longitudinal and transverse directions. Transverse tensile properties of Table 2 apply only to product that a test specimen not less than 2.50 inches (63.5 mm) in length can be obtained. 3.5.1.1.2 Specimens for the longitudinal requirements in Table 2 shall be taken with the axis
24、 of the specimen within 15 degrees of parallel to the grain flow. 3.5.1.1.3 Yield strength and reduction of area requirements do not apply to product under 0.125 inch (3.18 mm) in nominal diameter. TABLE 2 - MINIMUM TENSILE PROPERTIES (SEE 8.2) Nominal Diameter or Least Distance Between Parallel Sid
25、es Inch (mm) Tensile Strength ksi (MPa) Yield Strength At 0.2% Offset ksi (MPa) Elongation in 2 Inches (50.8 mm) or 4D % Reduction of Area % Up to 1.00 (25.40), incl. 90 (620) 75 (517) 15 30 3.5.1.2 Microstructure Shall be that structure resulting from processing within the alpha-beta phase field. M
26、icrostructure shall conform to 3.5.1.2.1 or 3.5.1.2.2 (See 8.3). 3.5.1.2.1 Equiaxed and/or elongated primary alpha in a transformed beta matrix with no continuous network of alpha at prior beta grain boundaries. 3.5.1.2.2 Essentially complete field of equiaxed and/or elongated alpha with or without
27、intergranular beta and with no continuous network of alpha at prior beta grain boundaries. 3.5.1.3 Surface Contamination Except as specified in 3.5.1.3.1, the product shall be free of any oxygen-rich layer (See 8.4), such as alpha case, or other surface contamination, determined by microscopic exami
28、nation at not lower than 400X magnification or by other method agreed upon by purchaser and vendor. 3.5.1.3.1 When permitted by purchaser, product to be machined all over may have an oxygen-rich layer, provided such layer is removable within the machining allowance on the product. SAE AMS6940A Page
29、5 of 8 3.5.1.4 Fracture-Toughness When specified, the product shall be subjected to fracture toughness testing. ASTM E 399 is a recommended method of test for product over 0.5 inch (12.7 mm) in nominal thickness. Method of test and standards for acceptance shall be as agreed upon by purchaser and ve
30、ndor. 3.5.1.5 Macrostructure Product shall be uniform in quality and condition, homogenous, sound, and free from foreign materials and from internal imperfections detrimental to fabrication or performance of parts. 3.5.2 Forging Stock When a sample of stock is forged to a test coupon and heat treate
31、d as in 3.4, specimens taken from the heat treated coupon shall conform to the requirements of 3.5.1.1. If specimens taken from the stock after heat treatment as in 3.4 conform to the requirements of 3.5.1.1, the tests shall be accepted as equivalent to tests of a forged coupon. 3.6 Quality The prod
32、uct, as received by purchaser, shall be uniform in quality and condition, sound, and free from foreign materials and from imperfections detrimental to usage of the product. 3.6.1 Ultrasonic Inspection Product over 0.500 inch (12.70 mm) in nominal thickness, diameter or least between parallel sides s
33、hall meet Class A1 requirements of AMS2631. 3.7 Tolerances Bars shall conform to all applicable requirements of AMS2241. 4. QUALITY ASSURANCE PROVISIONS 4.1 Responsibility for Inspection The vendor of the product shall supply all samples for vendors tests and shall be responsible for the performance
34、 of all required tests. Purchaser reserves the right to sample and to perform any confirmatory testing deemed necessary to ensure that the product conforms to the specified requirements. 4.2 Classification of Tests 4.2.1 Acceptance Tests The following requirements are acceptance tests and shall be p
35、erformed on each heat or lot as applicable. 4.2.1.1 Composition (3.1) of each heat. 4.2.1.2 Hydrogen content (3.1), tensile properties (3.5.1.1), microstructure (3.5.1.2), surface contamination (3.5.1.3), macrostructure (3.5.1.5), and, when specified, fracture-toughness (3.5.1.4) of each lot of bars
36、 and forgings. 4.2.1.3 Ultrasonic quality (3.6.1) of each bar, forging, or forging stock. 4.2.1.4 Tolerances (3.7) of bars. SAE AMS6940A Page 6 of 8 4.2.2 Periodic Tests Ability of forging stock (3.5.2) to develop specified properties is a periodic test and shall be performed at a frequency selected
37、 by the vendor unless frequency of testing is specified by purchaser. 4.3 Sampling and Testing Shall be in accordance with AMS2368 and as follows: A lot shall be all product of the same nominal size from the same heat processed at the same time. 4.3.1 For Acceptance Tests 4.3.1.1 Composition At leas
38、t one sample from each heat, except that for hydrogen determinations one sample from each lot obtained after all thermal and chemical processing is completed. 4.3.1.2 Tensile Properties At least one sample from bars from each lot. The number, location, and orientation of samples from each lot of for
39、gings shall be as agreed upon by purchaser and vendor. 4.3.1.3 A specimen at least 0.5 inch (12.7 mm) long by full cross-section from each end of the bars selected for sampling shall be macrostructurally examined for conformance to the quality requirements. Unless otherwise specified, macrostructura
40、l examination shall be performed in accordance with AMS2643. The number of bars selected for examination shall not be less than the amounts shown in Table 3. TABLE 3 - NUMBER OF BARS SELECTED FOR MACROSTRUCTURAL EXAMINATION Number of Bars in Lot Number of Bars Selected 1 to 15 1 16 to 50 2 51 to 150
41、 3 151 to 500 5 over 500 4 + amount shown above over 500 4.4 Reports 4.4.1 The vendor shall provide a copy of the original material manufacturers (producers) report (material certification) including: producer name and country where the metal was melted (e.g., final melt in the case of metal process
42、ed by multiple melting operations). This report shall document the results of tests for chemical composition of each heat and for the hydrogen content, tensile properties, surface contamination, and when specified, fracture toughness of each lot, ultrasonic quality, and state that the product confor
43、ms to the other technical requirements. The report shall include the purchase order number, heat and lot numbers, AMS6940A, product form and mill produced size (and/or part number, if applicable), specific annealing treatment used, and quantity. If forgings are supplied, the size and melt source of
44、stock used to make the forgings shall also be included. 4.4.2 Report the nominal metallurgically worked cross sectional size and the cut size, if different (See 3.3.1). 4.5 Resampling and Retesting Shall be in accordance with AMS2368. SAE AMS6940A Page 7 of 8 5. PREPARATION FOR DELIVERY 5.1 Identifi
45、cation 5.1.1 Bars In accordance with AMS2809, as applicable. 5.1.2 Forgings In accordance with AMS2808, except that marking shall be applied using a marking fluid whose residue shall contain not more than traces of halogen containing compounds. 5.1.3 Stock for Forging As agreed upon by purchaser and
46、 vendor. 5.2 Packaging The product shall be prepared for shipment in accordance with commercial practice 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. ACKNOWLEDGMENT
47、A vendor shall include this specification number and its revision letter in all quotations and when acknowledging purchase orders. 7. REJECTIONS Product not conforming to this specification, or to modifications authorized by purchaser, will be subject to rejection. 8. NOTES 8.1 A change bar (l) loca
48、ted in the left margin is for the convenience of the user in locating areas where technical revisions, not editorial changes, 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 revi
49、sions. Change bars and (R) are not used in original publications, nor in documents that contain editorial changes only. 8.2 These mechanical properties for product up through 1.00 inch (25.40 mm) have been taken from MIL-T-9047 and have not been substantiated by AMS statistical procedures. 8.3 Terminology relating to titanium microstructures is presented in AS1814. 8.4 An oxygen-rich layer, such as
