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/AMS6948A AEROSPACE MATERIAL SPECIFICATION AMS6948 REV. A Issued 2011-07 Revised 2
5、015-07 Superseding AMS6948 Titanium Alloy Bars, Wire, Forgings, Rings, and Drawn Shapes 4Al - 2.5V -1.5 Fe Annealed (Composition similar to UNS R54250) RATIONALE AMS6948A results from a Five Year Review and update of this specification that includes the removal of sample size allowance for hydrogen
6、of Table 1 (covered by ASTM E1447), agreement on mechanical property values for material outside specification ranges (3.5.1.1.3 and 8.6), the addition of AS6279 (3.8), adds AMS2368 (4.3 and 4.5) and revises the report paragraph (4.4). 1. SCOPE 1.1 Form This specification covers a titanium alloy in
7、the form of bars, wire, forgings, flash welded rings, drawn shapes 5.000 inches (127.00 mm) and under, and stock for forging or flash welded rings of any size. 1.2 Application These products have been used typically for parts requiring a combination of moderate strength and good ductility with a max
8、imum service temperature up to 750 F (400 C) depending on time at temperature where the product is to be used in the annealed condition, 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 order forms a par
9、t 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 of that documen
10、t 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 Heat-Resistant Steel, Iron Alloy, Titanium, and Titanium
11、 Alloy Bars and Wire AMS2249 Chemical Check Analysis Limits, Titanium and Titanium Alloys SAE INTERNATIONAL AMS6948A Page 2 of 8 AMS2368 Sampling and Testing of Wrought Titanium Raw Material Except Forgings and Forging Stock AMS2750 Pyrometry AMS2808 Identification Forgings AMS2809 Identification, T
12、itanium and Titanium Alloy Wrought Products AMS7498 Rings, Flash Welded, Titanium and Titanium Alloys AS6279 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:
13、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 Alloys by the Inert Gas Fusion Thermal Conduct
14、ivity/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 Emission Spectrometry 3. TECHNICAL REQUIREME
15、NTS 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 accordance with ASTM E2371. Other analytical met
16、hods may be used if acceptable to the purchaser. Table 1 - Composition Element min max Aluminum Vanadium Iron Oxygen Carbon Nitrogen Hydrogen Other Elements, each (3.1.1) Other Elements, total (3.1.1) Titanium 3.5 2.0 1.2 0.20 - - - - - remainder 4.5 3.0 1.8 0.30 0.08 0.03 0.015 0.1 0.3 (800 ppm) (3
17、00 ppm) (150 ppm) 3.1.1 Determination not required for routine acceptance. 3.1.2 Check Analysis Composition variations shall meet the applicable requirements of AMS2249. SAE INTERNATIONAL AMS6948A Page 3 of 8 3.2 Melting Practice Alloy shall be multiple melted. The first melt shall be made by vacuum
18、 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 atmosphere
19、for nonconsumable electrode melting shall be vacuum or shall be argon and/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 con
20、dition: 3.3.1 Bars Hot finished with or without subsequent cold reduction, annealed, and descaled. Unless prohibited by purchaser, bars may be solution heat treated before annealing. The product shall be processed to the final thickness/diameter by metallurgical working operations prior to any dimen
21、sional sizing or surface finishing operations (See 8.6). Bar shall not be cut from plate. 3.3.2 Wire Hot finished with or without subsequent cold reduction, annealed, and descaled. 3.3.3 Forgings and Flash Welded Rings Annealed and descaled. Unless prohibited by purchaser, product may be solution he
22、at treated before annealing. 3.3.3.1 Flash welded rings shall not be supplied unless specified or permitted on purchasers part drawing. When supplied, rings shall be manufactured in accordance with AMS7498. 3.3.4 Drawn Shapes Drawn, annealed, and descaled. Unless prohibited by purchaser, drawn shape
23、s may be solution heat treated before annealing. 3.3.5 Stock for Forging or Flash Welded Rings As ordered by the forging or flash welded ring manufacturer. 3.4 Heat Treatment Bars, wire, forgings, rings, and drawn shapes shall be heat treated as follows; pyrometry shall be in accordance with AMS2750
24、. 3.4.1 Solution Heat Treatment When solution heat treatment is used, heat to a temperature within the range 50 to 200 F (28 to 93 C) degrees below the beta transus, hold at the selected temperature within 25 F (14 C) for a time commensurate with section thickness and the heating equipment and proce
25、dure used, and cool at a rate equivalent to an air cool or faster. 3.4.2 Annealing Heat to a temperature within the range 1250 to 1400 F (677 to 760 C), hold at the selected temperature within 25 F (14 C) for not less than 1 hour, and cool as required. SAE INTERNATIONAL AMS6948A Page 4 of 8 3.5 Prop
26、erties The product shall conform to the following requirements and shall also meet the requirements of 3.5.1.1 and 3.5.1.2 after being heated to any temperature up to 1200 F (649 C), held at heat for 20 minutes 3, cooled in air, and descaled: 3.5.1 Bars, Wire, Forgings, and Flash Welded Rings Produc
27、t, 5.000 inches (127.00 mm) and under in nominal diameter or least distance between parallel sides, shall have the following properties: 3.5.1.1 Tensile Properties Shall be as specified in Table 2, determined in the longitudinal direction in accordance with ASTM E8/E8M on specimens as in 4.3.1.2 wit
28、h 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. Table 2A - Minimum tensile properties, inch/pound units Nominal Diameter or Least Distance Between Parallel S
29、ides Inches Tensile Strength ksi Yield Strength at 0.2% Offset ksi Elongation in 2 Inches or 4D % Reduction of Area % Less than 0.500 145 135 15 30 0.500 to less than 1.000 145 125 15 30 1.000 to less than 2.000 2.000 to 5.000, incl 139 135 125 125 15 15 30 30 Table 2B - Minimum tensile properties,
30、SI units Nominal Diameter or Least Distance Between Parallel Sides Millimeters Tensile Strength MPa Yield Strength at 0.2% Offset MPa Elongation in 50.8 mm or 4D % Long. Reduction of Area % Long. Less than 12.70 1000 931 15 30 12.70 to less than 25.40 1000 862 15 30 25.40 to less than 50.80 50.80 to
31、 127.00, incl 958 931 862 862 15 15 30 30 3.5.1.1.1 Specimens for the longitudinal requirements in Table 2 shall be taken with the axis of the specimen approximately parallel to the grain flow for bars and wire and shall be taken in the circumferential direction from flash welded rings. 3.5.1.1.2 Yi
32、eld strength and reduction of area requirements do not apply to wire and drawn shapes with maximum section thickness under 0.125 inch (3.18 mm) in nominal diameter or least distance between parallel sides. 3.5.1.1.3 Mechanical property requirements for product outside the size range covered by 1.1 s
33、hall 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, or 3.5.1.2.3. 3.5.1.2.1 Equiaxed and/or elongated primary alpha in a transformed bet
34、a 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 no continuous network of alpha at prior beta grain boundaries. SAE INTERNATIONAL AMS6948A Page 5 of 8 3.5.1.2.3 Partially broken and distorted gra
35、in boundary alpha with plate-like alpha. 3.5.1.2.4 A microstructure showing a continuous network of alpha in prior beta grain boundaries is not acceptable. 3.5.1.3 Surface Contamination Except as permitted by 3.5.1.3.1 and 3.5.1.3.2, the product shall be free of any oxygen-rich layer (See 8.2), such
36、 as alpha case, or other surface contamination, determined by microscopic examination at not lower than 100X magnification or other method acceptable to purchaser. 3.5.1.3.1 An oxygen-rich layer not greater than 0.001 inch (0.025 mm) in depth will be permitted on bars other than round, and drawn sha
37、pes. 3.5.1.3.2 When permitted by purchaser, forgings and flash welded rings to be machined all over may have an oxygen-rich layer provided such layer is removable within the machining allowance on the forging or flash welded ring. 3.5.2 Forging Stock When a sample of stock is forged to a test coupon
38、 having a degree of mechanical working not greater than the forging 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 requirements of 3.5.1.1, the test
39、s shall be accepted as equivalent to tests of a forged coupon. 3.5.3 Stock for Flash Welded Rings A sample of stock heat treated as in 3.4 shall conform to the requirements of 3.5.1.1. 3.6 Quality The product, as received by purchaser, shall be uniform in quality and condition, sound, and free from
40、foreign materials and from imperfections detrimental to usage of the product. 3.6.1 Grain flow of die forgings, except in areas that contain flash-line end grain, shall follow the general contour of the forgings showing no evidence of reentrant grain flow. 3.7 Tolerances Bars and wire shall conform
41、to all applicable requirements of AMS2241. 3.8 Production, distribution, 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 sampl
42、es for producers test and shall be responsible for the performance 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 specified requirements. 4.2 Classification of Tests 4.2.1 Acceptance Tests
43、The following requirements are acceptance tests and shall be performed on each heat or lot as applicable: 4.2.1.1 Composition (3.1) of each heat and hydrogen content of each lot. SAE INTERNATIONAL AMS6948A Page 6 of 8 4.2.1.2 Tensile properties (3.5.1.1), microstructure (3.5.1.2), and surface contam
44、ination (3.5.1.3) of each lot of bars, wire, forgings, flash welded rings, and drawn shapes, as received. 4.2.1.3 Tolerances (3.7) of bars and wire. 4.2.2 Periodic Tests The following requirements are periodic tests and shall be performed at a frequency selected by the producer unless frequency of t
45、esting is specified by purchaser: 4.2.2.1 Tensile properties (3.5.1.1) of bars, wire, forgings, flash welded rings, and drawn shapes after reheating as in 3.5. 4.2.2.2 Ability of forging stock (3.5.2) and stock for flash welded rings (3.5.3) to develop required properties. 4.2.2.3 Grain flow of die
46、forgings (3.6.1). 4.3 Sampling and Testing Shall be in accordance with AMS2368 and the following; a lot shall be all product of the same nominal size from the same heat, processed at the same time, and solution heat treated and annealed as a heat treat batch. 4.3.1 For Acceptance Tests 4.3.1.1 Compo
47、sition One sample from each heat, except that for hydrogen determinations one sample from each lot obtained after thermal and chemical processing is completed. 4.3.1.2 Tensile Properties At least one sample from bars, wire, flash welded rings, and drawn shapes from each lot. The number, location, an
48、d orientation of samples from each lot of forgings shall be as agreed upon by purchaser and producer. Specimens from flash welded rings shall be cut from parent metal not including the weld-heat-affected zone. 4.3.1.3 Microstructure and Surface Contamination At least one sample from each lot. 4.4 Re
49、ports 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 tests for composition of each heat and for the hydrogen content and tensile properties of each lot, and state that the product conforms to the other technical requirements. This report shall incl
