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/AMS6921B AEROSPACE MATERIAL SPECIFICATION AMS6921 REV. B Issued 2004-01 Revised 2
5、015-07 Superseding AMS6921A Titanium Alloy Bars, Forgings and Forging Stock 3Al - 8V - 6Cr - 4Mo - 4Zr Solution Heat Treated and Aged (Composition similar to UNS R58640) RATIONALE AMS6921B results from a Five Year Review and update of this specification that includes the removal of sample size allow
6、ance for hydrogen of Table 1 (covered by ASTM E1447), requires agreement on mechanical property values for material outside specification ranges (3.5.1.1.5 and 8.6), 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 t
7、he form of bars up through 4.000 inches (101.60 mm) in nominal diameter or least distance between parallel sides, inclusive, forgings of thickness up through 4.000 inches (101.60 mm), inclusive, and stock for forging of any size (See 8.6). 1.2 Application This material has been used typically for pa
8、rts requiring higher tensile strength than is available in the alpha beta alloys, and corrosion resistance, 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 recomm
9、ends practices to minimize such conditions. 2. APPLICABLE DOCUMENTS The issue of the following documents 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 docum
10、ent issue is specified. When the referenced document has been cancelled and no superseding document has been specified, the last published issue of that document shall apply. SAE INTERNATIONAL AMS6921B Page 2 of 8 2.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrend
11、ale, 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 Heat-Resistant Steel, Iron Alloy, Titanium, and Titanium Alloy Bars and Wire AMS2249 Chemical Check Analysis Limits, Titanium and Titanium Alloys AMS2368 Sam
12、pling and Testing of Wrought Titanium Raw Material Except Forgings and Forging Stock AMS2631 Ultrasonic Inspection, Titanium and Titanium Alloy Bar and Billet AMS2643 Structural Examination of Titanium Alloys, Chemical Etch Inspection AMS2750 Pyrometry AMS2808 Identification Forgings AMS2809 Identif
13、ication, Titanium and Titanium Alloy Wrought Products ARP982 Minimizing Stress-Corrosion Cracking in Wrought Titanium Alloy Products AS6279 Practices for Production, Distribution, and Procurement of Metal Stock 2.2 ASTM Publications Available from ASTM International, 100 Barr Harbor Drive, P.O. Box
14、C700, West Conshohocken, PA 19428-2959, Tel: 610-832-9585, www.astm.org. ASTM 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 A
15、lloys by the Inert Gas Fusion Thermal Conductivity/Infrared Detection Method 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
16、 Emission Spectrometry 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 E1941, hydrogen in accordance with ASTM E1447, oxygen and nitrogen in accordance with ASTM E1409, and other elements in acc
17、ordance with ASTM E2371. Other analytical methods may be used if acceptable to the purchaser. SAE INTERNATIONAL AMS6921B Page 3 of 8 Table 1 - Composition Element min max Vanadium 7.50 8.50 Chromium 5.50 6.50 Molybdenum 3.50 4.50 Zirconium 3.50 4.50 Aluminum 3.00 4.00 Iron - 0.30 Oxygen - 0.12 Carbo
18、n - 0.05 Nitrogen - 0.03 (300 ppm) Hydrogen - 0.020 (200 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 Titanium remainder 3.1.1 Determination not required for routine acceptance. 3.1.2 Check Analysis Composition variations shall meet t
19、he applicable requirements of AMS2249. 3.2 Melting Practice Alloy shall be multiple melted. The first melt shall be made by vacuum consumable electrode, nonconsumable electrode, electron beam cold hearth, or plasma arc cold hearth melting practice. The subsequent melt or melts shall be made under va
20、cuum using vacuum arc remelting (VAR) practice. Alloy additions are not permitted in the final melt cycle. 3.2.1 The atmosphere for nonconsumable electrode melting shall be vacuum or shall be argon or helium at an absolute pressure not higher than 1000 mm of mercury. 3.2.2 The electrode tip for nonc
21、onsumable 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, solution heat treated, aged, and descaled. A machined or ground surface is permitted unless prohibited
22、by 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 Forgings Solution Heat treated, aged, and descaled. 3.3.3 Stock for
23、Forging As ordered by the forging manufacturer. SAE INTERNATIONAL AMS6921B Page 4 of 8 3.4 Heat Treatment Bars and forgings shall be solution heat treated and aged. Solution heat treat by heating to a temperature within the range 1450 to 1700 F (788 to 927 C), holding at the selected temperature wit
24、hin 25 F (14 C) for a time commensurate with section thickness and the heating equipment and procedure used, and water quenched, air or fan cooled, and aged at 875 to 1150 F (468 to 621 C), holding at the selected temperature within 15 F (8 C) for 2 to 30 hours. Pyrometry shall be in accordance with
25、 AMS2750. 3.5 Properties The product shall conform to the following requirements: 3.5.1 Bars and Forgings as Solution Heat Treated and Aged 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.
26、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 requirements apply in both the longitudinal and transverse directions. Transverse tensile properties of Table 2 apply only to product th
27、at 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 of the specimen within 15 degrees of parallel to the grain flow. 3.5.1.1.3 Yield strength and reduction of area requirements
28、 do not apply to product under 0.125 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 (76.2 mm) or greater. Table 2 - Minimum tensile properties (see 8.2) N
29、ominal Diameter or Least Distance Between Parallel Sides Inch (mm) 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) Reduction of Area % (3.5.1.1.4) Up to 1.50 ( 38.10), incl. 190 (1310) 180 (1241) 8 15 Over 1.50 ( 38.10) to 3.00
30、 ( 76.20), incl. 180 (1241) 170 (1172) 8 6 15 5 Over 3.00 ( 76.20) to 4.00 (101.60), incl. 170 (1172) 160 (1103) 6 3 10 5 3.5.1.1.5 Mechanical property requirements for product outside the size range covered by Table 2 shall be agreed upon between purchaser and producer. 3.5.1.2 Microstructure Shall
31、 be uniform and essentially that structure resulting from beta processing. Microstructure shall not be cause for rejection unless standards have been agreed upon by purchaser and producer. 3.5.1.3 Surface Contamination Except as specified in 3.5.1.3.1, the product shall be free of any oxygen-rich la
32、yer (See 8.3), 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 producer. SAE INTERNATIONAL AMS6921B Page 5 of 8 3.5.1.3.1 When permitted by purchaser, product to be machined
33、 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 foreign materials and from internal imperfections detrimental to fabrica
34、tion or performance of parts. 3.5.2 Forging Stock 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 specimens taken from the stock after heat treatment as in 3.4 conform to the r
35、equirements of 3.5.1.1, the tests shall be accepted as equivalent to tests of a forged coupon. 3.6 Quality The product, 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 Ultras
36、onic Inspection When specified, the product shall be ultrasonically inspected in accordance with AMS2631 and shall meet the quality standards agreed upon between the purchaser and producer (See 8.6). 3.7 Tolerances Bars shall conform to all applicable requirements of AMS2241. 3.8 Production, distrib
37、ution, and procurement of metal stock 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 performanc
38、e 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
39、performed 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), and macrostructure (3.5.1.4) of each lot of bars and forgings. 4.2.1.3 When specified (See 8.6
40、), ultrasonic quality of each bar, forging or forging stock as required by 3.6.1. 4.2.1.4 Tolerances (3.7) of bars. 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 by the producer unless frequency
41、 of testing is specified by purchaser. SAE INTERNATIONAL AMS6921B Page 6 of 8 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
42、 At least 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 lo
43、t of forgings shall be as agreed upon by purchaser and producer. 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, macr
44、ostructural 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
45、 51 to 150 3 151 to 500 5 over 500 4 + 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) the results of te
46、sts for composition of each heat and for the hydrogen content, tensile properties, and surface contamination of each lot, ultrasonic quality of all product when specified and state that the product conforms to the other technical requirements. The report shall include the purchase order number, heat
47、 and lot numbers, AMS6921B, product form and mill produced size (and part number, if applicable) specific solution and aging treatment used to develop precipitation hardened properties, and quantity. If forgings are supplied, the size and melt source of stock used to make the forgings shall also be
48、included. 4.4.2 Report the nominal metallurgically worked cross sectional size and the cut size, if different (See 3.3.1). 4.4.3 When the product size is outside the range covered by 1.1, the report shall contain a statement to that effect. 4.4.4 The producer of stock for forging shall furnish with
49、each shipment a report showing producer identity, country of origin (e.g., final melt in the case of metal processed by multiple melting operations) and the results of tests for composition of each heat, hydrogen content of each lot and ultrasonic quality of all product, when specified. This report shall include the purchase order number, heat number, AMS6921B, size, and quantity. 4.5 Resampling and Ret
