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 revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions. Copyright 2015 SAE International All rights reserved. No part of this p
3、ublication may 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: +1 724-776-497
4、0 (outside USA) 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/AMS6915B AEROSPACE MATERIAL SPECIFICATION AMS6915 REV. B Issued 2004-01 Revised 2
5、015-06 Superseding AMS6915A Titanium Alloy Bars, Forgings and Forging Stock 7.0Al - 4.0Mo Annealed (Composition similar to UNS R56740) RATIONALE AMS6915B results from a Five Year Review and update of this specification that includes the removal of sample size allowance for hydrogen of Table 1 (cover
6、ed by ASTM E1447), requires agreement on mechanical property values for material outside specification ranges (3.5.1.1.5 and 8.7), the addition of AS6279 (3.8) and revises the report paragraph (4.4). 1. SCOPE 1.1 Form This specification covers a titanium alloy in the form of bars up through 6.000 in
7、ches (152.40 mm) inclusive, in nominal diameter or least distance between parallel sides, forgings of thickness up through 6.000 inches (152.40 mm), inclusive and stock for forging of any size. 1.2 Application These products have been used typically for parts requiring high strength up to 900 F (482
8、 C), but usage is not limited to such applications. 1.2.1 Certain processing procedures and service conditions may cause these products to become subject to stress-corrosion cracking; ARP982 recommends practices to minimize such conditions. 2. APPLICABLE DOCUMENTS The issue of the following document
9、s in effect on the date of the purchase order 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
10、 been specified, the last published issue 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 +1 724-776-4970 (outside USA), www.sae.org. AMS2241 Tolerances, Corrosion and
11、 Heat-Resistant Steel, Iron Alloy, Titanium, and Titanium Alloy Bars and Wire SAE INTERNATIONAL AMS6915B Page 2 of 7 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
12、 Inspection, Titanium and Titanium Alloy Bar and Billet AMS2643 Structural Examination of Titanium Alloys, Chemical Etch Inspection Procedure AMS2750 Pyrometry AMS2808 Identification Forgings AMS2809 Identification, Titanium and Titanium Alloy Wrought Products ARP982 Minimizing Stress-Corrosion Crac
13、king in Wrought Titanium Alloy Products AS6279 Industry Standard Practices for Production, Distribution, and Procurement of Metal Stock 2.2 ASTM Publications Available from ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959, Tel: 610-832-9585, www.astm.org. AS
14、TM E8/E8M Tension Testing of Metallic Materials ASTM E1409 Determination of Oxygen and Nitrogen in Titanium and Titanium Alloys by the Inert Gas Fusion Technique ASTM E1447 Determination of Hydrogen in Titanium and Titanium Alloys by the Inert Gas Fusion Thermal Conductivity/Infrared Detection Metho
15、d ASTM E1941 Determination of Carbon in Refractory and Reactive Metals and Their Alloys by Combustion Analysis ASTM E2371 Analysis of Titanium and Titanium Alloys by Direct Current Plasma and Inductively Coupled Plasma Atomic Emission Spectrometry 3. TECHNICAL REQUIREMENTS 3.1 Composition Shall conf
16、orm to the percentages by weight shown in Table 1; carbon shall be determined in accordance with ASTM E1941, hydrogen in accordance with ASTM E1447, oxygen and nitrogen in accordance with ASTM E1409, and other elements in accordance with ASTM E2371. Other analytical methods may be used if acceptable
17、 to the purchaser. Table 1 - Composition Element min max Aluminum 6.50 7.30 Molybdenum 3.50 4.50 Iron - 0.30 Oxygen - 0.20 Carbon - 0.10 Nitrogen - 0.05 (500 ppm) Hydrogen - 0.013 (130 ppm) Yttrium (3.1.1) - 0.005 ( 50 ppm) Other Elements each (3.1.1) - 0.10 Other Elements, total (3.1.1) - 0.40 Tita
18、nium remainder SAE INTERNATIONAL AMS6915B Page 3 of 7 3.1.1 Determination not required for routine acceptance. 3.1.2 Check Analysis Composition variations shall meet the applicable requirements of AMS2249. 3.2 Melting Practice 3.2.1 Alloy shall be multiple melted. The first melt shall be made by vac
19、uum consumable electrode, nonconsumable electrode, electron beam cold hearth, or plasma arc cold 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 atmosphe
20、re for nonconsumable electrode melting shall be vacuum or shall be argon or helium at an absolute 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 cond
21、ition: 3.3.1 Bars Hot finished with or without subsequent cold reduction, annealed, and descaled. A machined or ground surface is permitted unless prohibited by purchaser. The product shall be processed to the final thickness/diameter by metallurgical working operations prior to any straightening, d
22、imensional sizing or surface finishing operations. Bar shall not cut from plate. 3.3.2 Forgings Annealed and descaled. 3.3.3 Stock for Forging As ordered by the forging manufacturer. 3.4 Heat Treatment Bars and forgings shall be annealed as follows; Heat to a temperature within the range 1300 to 145
23、0 F (704 to 788 C), hold at the selected temperature within 25 F (14 C) for a time commensurate with section thickness and the heating equipment and procedure used, and cool at a rate equivalent to an air cool or faster. Pyrometry shall be in accordance with AMS2750. 3.5 Properties The product shall
24、 conform to the following requirements: 3.5.1 Bars and Forgings 3.5.1.1 Tensile Properties Shall be as specified in Table 2, determined in accordance with ASTM E8/E8M 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/minut
25、e (0.002 mm/mm/minute) through the 0.2% offset yield strain. 3.5.1.1.1 Tensile property requirements 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 obta
26、ined. SAE INTERNATIONAL AMS6915B Page 4 of 7 3.5.1.1.2 Specimens for the longitudinal requirements in Table 2 shall be taken with the axis 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
27、inch (3.18 mm) in nominal diameter or least distance between parallel sides. 3.5.1.1.4 Values in brackets apply to the short transverse direction for short transverse dimensions of 3.00 inches or greater. When short transverse properties are determined, long transverse properties do not need to be d
28、etermined. Table 2 - Minimum tensile properties (see 8.2) Nominal Diameter or Least Distance Between Parallel Sides Inch (mm) Maximum Cross Sectional Area Square Inches (Square cm) Tensile Strength ksi (MPa) Yield Strength At 0.2% Offset ksi (MPa) Elongation in 2 Inches (50.8 mm) or 4D, % (3.5.1.1.4
29、) Reduction of Area % (3.5.1.1.4) Up to 1.00 (25.40), incl. 48 (309.70) 145 (999) 135 (930) 10 20 Over 1.00 (25.40) to 2.00 ( 50.80), incl. 140 (965) 130 (896) 10 20 Over 2.00 (50.80) to 6.00 (152.40), incl. 140 (965) 130 (896) 10 8 20 15 3.5.1.1.5 Mechanical property requirements for bars and forgi
30、ngs outside the size range covered by Table 2 shall be agreed upon between purchaser and producer. 3.5.1.2 Microstructure Shall be that structure resulting from processing within the alpha-beta phase field. Microstructure 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 e
31、longated 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 intergranular beta and with no continuous network of alpha at prior beta grain boundaries. 3
32、.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 examination at not lower than 400X magnification or by other method agreed upon by purchaser and
33、producer. 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. 3.5.1.4 Macrostructure Product shall be uniform in quality and condition, homogenous, sound, and free from f
34、oreign materials and from internal imperfections detrimental to fabrication or performance of parts. 3.5.2 Stock for Forging When a sample of stock is forged to a test coupon and heat treated as in 3.4, specimens taken from the heat treated coupon shall conform to the requirements of 3.5.1.1. If spe
35、cimens 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. SAE INTERNATIONAL AMS6915B Page 5 of 7 3.6 Quality The product, as received by purchaser, shall be uniform in quality and conditio
36、n, sound, and free from foreign materials and from imperfections detrimental to usage of the product. 3.6.1 Ultrasonic Inspection Product 0.500 inch (12.70 mm) to 1.500 inches (38.10 mm) inclusive in nominal thickness, diameter or least distance between parallel sides shall meet Class A1 requirement
37、s of AMS2631. Product over 1.500 inches (38.10 mm) in nominal thickness, diameter or least distance between parallel sides shall meet Class A requirements of AMS2631. 3.7 Tolerances Bars shall conform to all applicable requirements of AMS2241. 3.8 Production, distribution, and procurement of metal s
38、tock shall comply with AS6279. This requirement becomes effective September 1, 2016. 4. QUALITY ASSURANCE PROVISIONS 4.1 Responsibility for Inspection The producer of the product shall supply all samples for producers tests and shall be responsible for the performance of all required tests. Purchase
39、r 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 performed on each heat or lot as
40、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), and macrostructure (3.5.1.4), of each lot of bars and forgings. 4.2.1.3 Ultrasonic quality of each bar, forging, or forging sto
41、ck as required by 3.6.1. 4.2.1.4 Tolerances (3.7) of bars. 4.2.2 Periodic Tests Ability of stock for forging (3.5.2) to develop specified properties is a periodic test and shall be performed at a frequency selected by the producer unless frequency of testing is specified by purchaser. 4.3 Sampling a
42、nd 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 least one sample from each heat, except that for hydrogen determinations, one sample fro
43、m each lot obtained after all thermal and chemical processing is completed. SAE INTERNATIONAL AMS6915B Page 6 of 7 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 forgings shall be as agreed upon by purchaser a
44、nd producer. 4.3.1.3 Macrostructure 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, macrostructural examination shall be perf
45、ormed 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 3 151 to 500 5 over 500 4
46、+ amount shown above over 500 4.4 Reports 4.4.1 The producer shall furnish with each shipment a report showing producer identity, country where the metal was melted (e.g., final melt in the case of metal processed by multiple melting operations) and the results of tests for chemical composition of e
47、ach heat and for the hydrogen content, tensile properties, microstructure and surface contamination of each lot, ultrasonic quality, when required, of each piece and state that the product conforms to the other technical requirements. The report shall include the purchase order number, heat and lot
48、numbers, AMS6915B, 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 stock used to make the forgings shall also be included. 4.4.2 Report the nominal metallurgically worked c
49、ross sectional size and the cut size, if different (See 3.3.1). 4.4.3 When the bar and forging sizes are outside the range covered by Table 2, the report shall contain a statement to that effect. 4.5 Resampling and Retesting Shall be in accordance with AMS2368. 5. PREPARATION FOR DELIVERY 5.1 Identification 5.1.1 Bars In accordance with AMS2809, as applicable. 5.1.2 Forgings In accordance with AMS2808, except that m
