1、_ SAE Technical Standards Board RuleVSURYLGHWKDW7KLVUHSRUWLVSXEOLVKHGE6$(WRDGYDQFHWKH VWDWHRIWHFKQLFDODQGHQJLQHHULQJVFLHQFHV7KHXVHRIWKLV report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arisiQJWKHUHIURPLVWKHVROHUHVSRQVLELOL
2、WRIWKHXVHU 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 2016 SAE International All rights reserved. No part of this publication may be reproduced, stored
3、 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: +1 724-776-4970 (outside USA) Fax: 724-776-0790 Em
4、ail: 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/AMS4970K AEROSPACE MATERIAL SPECIFICATION AMS4970 REV. K Issued 1965-09 Revised 2016-09 Superseding AMS4970J Titanium
5、 Alloy Bars, Wire, and Forgings 7Al - 4Mo Solution and Precipitation Heat Treated (Composition similar to UNS R56740) RATIONALE AMS4970K results from a Five Year Review and update of this specification that includes the use of ASTM E2994 for anaylysis (3.1), the removal of sample size allowance for
6、hydrogen (covered by ASTM E1447), requires agreement on mechanical property values for material outside specification ranges (3.5.1.1.5), adds AS6279 (3.8), and revises reporting (4.4). 1. SCOPE 1.1 Form This specification covers a titanium alloy in the form of bars, wire, forgings up to 4.000 inche
7、s (101.60 mm) inclusive and forging stock. 1.2 Application This alloy has been used typically for parts requiring strength up to 900 F (482 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 stre
8、ss-corrosion cracking; ARP982 recommends 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 o
9、f 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 document shall apply. SAE INTERNATIONAL AMS4970K Page 2 of 8 2.1 SAE Publications Available from SAE Internatio
10、nal, 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 Alloy Bars and Wire AMS2249 Chemical Check Analysis Limits Titan
11、ium and Titanium Alloys AMS2368 Sampling and Testing of Wrought Titanium Raw Material, Except Forgings and Forging Stock AMS2750 Pyrometry AMS2808 Identification Forgings AMS2809 Identification Titanium and Titanium Alloy Wrought Products ARP982 Minimizing Stress-Corrosion Cracking in Wrought Titani
12、um Alloy Products ARP1917 Clarification of Terms Used in Aerospace Metals Specifications AS1814 Terminology for Titanium Microstructures 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. A
13、STM E8/E8M Tension Testing of Metallic Materials ASTM E139 Conducting Creep, Creep-Rupture, and Stress-Rupture Tests of Metallic Materials ASTM E292 Conducting Time-for-Rupture Notch Tension Tests of Materials ASTM E1409 Determination of Oxygen and Nitrogen in Titanium and Titanium Alloys by Inert G
14、as Fusion ASTM E1447 Determination of Hydrogen in Titanium and Titanium Alloys 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 Titan
15、ium Alloys by Direct Current Plasma and Inductively Coupled Plasma Atomic Emission Spectrometry ASTM E2994 Analysis of Titanium and Titanium Alloys by Spark Atomic Emission Spectrometry and Glow Discharge Atomic Emission Spectrometry 3. TECHNICAL REQUIREMENTS 3.1 Composition Shall conform to the per
16、centages 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 or ASTM E2994. Other analytical methods may be used if acceptable
17、 to the purchaser. SAE INTERNATIONAL AMS4970K Page 3 of 8 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 O
18、ther 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 the applicable requirements of AMS2249; no variation over maximum will be permitted for yttrium. 3.2 Melting Practice Alloy shall be
19、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 vacuum using vacuum arc remelting (VAR) practice. Alloy additions are not per
20、mitted in the final VAR melt. 3.2.1 The atmosphere for nonconsumable electrode melting shall be vacuum or shall be inert gas at a pressure not higher than 1000 mm of mercury. 3.2.2 The electrode tip for nonconsumable electrode melting shall be water-cooled copper. 3.3 Condition The product shall be
21、supplied in the following condition: 3.3.1 Bars Hot finished with or without subsequent cold reduction, solution and precipitation heat treated, and descaled. The product shall be produced using standard industry practices designed strictly for the production of bar stock to the procured size. Cut p
22、late shall not be supplied in lieu of bar. 3.3.1.1 Round bars shall be solution and precipitation heat treated and ground, turned, or machined. 3.3.2 Wire Cold drawn, solution and precipitation heat treated, and descaled. 3.3.3 Forgings Solution and precipitation heat treated and descaled. 3.3.4 For
23、ging Stock As ordered by the forging manufacturer. SAE INTERNATIONAL AMS4970K Page 4 of 8 3.4 Heat Treatment Bars, wire, and forgings shall be solution heat treated by heating to a temperature within the range 1650 to 1775 F (899 to 968 C), holding at the selected temperature within 25 F (14 C) for
24、time commensurate with size and with the heating equipment and procedure used, and quenching in water and precipitation heat treated by heating to a temperature within the range 950 to 1200 F (510 to 649 C), holding at the selected temperature within 15 F (8 C) for a time commensurate with the thick
25、ness and with the heating equipment and procedure used, and cooling at a rate equivalent to air cooling. Pyrometry shall be in accordance with AMS2750. 3.4.1 Stress-Relief When permitted by purchaser, producer may, after coining, cold-sizing, or straightening product heat treated as in 3.4, stress r
26、elieve the product at a temperature not higher than 1125 F (607 C) provided that the requirements of 3.5 are met. 3.5 Properties The product shall conform to the following requirements: 3.5.1 Bars, Wire, and Forgings Product 4.000 inches (101.60 mm) and under in nominal diameter or least distance be
27、tween parallel sides shall have the following properties: 3.5.1.1 Tensile Properties Shall be as specified in Table 2, except as specified in 3.5.1.1.2 and 3.5.1.1.3, 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 w
28、ithin 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 Sides Inches Tensile Strength ksi Yield Strength at 0.2% Offset ksi Elongation in 4D % Re
29、duction of Area % L T L T Up to 1.000, incl 170 160 8 - 20 - Over 1.000 to 2.000, incl 160 150 8 6 15 12 Over 2.000 to 4.000, incl 150 140 8 4 15 12 Table 2B - Minimum tensile properties, SI units Nominal Diameter or Least Distance Between Parallel Sides Millimeters Tensile Strength MPa Yield Streng
30、th at 0.2% Offset MPa Elongation in 4D % Reduction of Area % L T L T Up to 25.40, incl 1172 1103 8 - 20 - Over 25.40 to 50.80, incl 1103 1034 8 6 15 12 Over 50.80 to 101.60, incl 1034 965 8 4 15 12 Note: L = Longitudinal T = Transverse SAE INTERNATIONAL AMS4970K Page 5 of 8 3.5.1.1.1 Tensile and yie
31、ld strength properties apply in both the longitudinal and transverse direction, but tests in the transverse direction, need be made only on product that a specimen not less than 2.50 inches (63.5 mm) in length can be obtained. Tests in the longitudinal direction are not required on product tested in
32、 the transverse direction. 3.5.1.1.2 Yield strength and reduction of area requirements do not apply to wire under 0.125 inch (3.18 mm) in nominal diameter. 3.5.1.1.3 Elongation and reduction of area for die forgings over 2.00 to 4.00 inches (50.8 to 101.6 mm), inclusive, in nominal cross-section sha
33、ll be not less than 6% and 15% respectively. 3.5.1.1.4 Properties of forgings having shapes and dimensions not readily classified by nominal diameter or distance between parallel sides as in Table 2 shall be as agreed upon by purchaser and producer. 3.5.1.1.5 Mechanical property requirements for pro
34、duct outside the size range covered by 1.1 shall be agreed upon between purchaser and producer. 3.5.1.2 Stress-Rupture Properties at 800 F (427 C) When specified, shall be as follows; testing of notched specimens and of combination smooth and notched specimens shall be performed in accordance with A
35、STM E292 and of smooth specimens in accordance with ASTM E139: 3.5.1.2.1 A standard cylindrical combination smooth-and-notched specimen conforming to ASTM E292, maintained at 800 F 3 F (427 C 2 C) while a load sufficient to produce an initial axial stress of 100 ksi (689 MPa) is applied continuously
36、, shall not rupture in less than 100 hours. The test shall be continued to rupture without change of load. Rupture shall occur in the smooth section and, after rupture, elongation and reduction of area of the smooth section, measured at room temperature, shall be not less than 5% and 8%, respectivel
37、y. 3.5.1.2.2 As an alternate procedure, separate smooth and notched specimens, machined from adjacent sections of the same piece, with gage sections conforming to the respective dimensions of ASTM E292 may be tested individually under the conditions of 3.5.1.2.1. The smooth specimen shall not ruptur
38、e in less than 100 hours and elongation and reduction of area after rupture, measured at room temperature, shall be as specified in 3.5.1.2.1. The notched specimen shall not rupture in less time than the companion smooth specimen, but need not be tested to rupture. 3.5.1.2.3 The tests of 3.5.1.2.1 a
39、nd 3.5.1.2.2 may be conducted using a load higher than required to produce an initial axial stress of 100 ksi (689 MPa), but load shall not be changed while test is in progress. Time to rupture, rupture location, elongation, and reduction of area requirements shall be as specified in 3.5.1.2.1. 3.5.
40、1.2.4 When permitted by purchaser, the tests of 3.5.1.2.1 and 3.5.1.2.2 may be conducted using incremental loading. In such case, the load required to produce an initial axial stress of 100 ksi (689 MPa) shall be used to rupture or for 100 hours, whichever occurs first. After the 100 hours and at in
41、tervals of 8 to 16 hours, preferably 8 to 10 hours, thereafter, the stress shall be increased in increments of 10 ksi (68.9 MPa). Time-to-rupture, rupture location, elongation, and reduction of area requirements shall be as specified in 3.5.1.2.1. 3.5.1.3 Creep Properties at 800 F (427 C) 3.5.1.3.1
42、When specified, a combination smooth-and-notched specimen as in 3.5.1.2.1, maintained at 800 F 3 F (427 C 2 C) while a load sufficient to produce an initial axial stress of 35 ksi (241 MPa) is applied continuously for 150 hours, shall not exceed 0.2% creep elongation. Tests shall be conducted in acc
43、ordance with ASTM E292. 3.5.1.3.1.1 Tensile properties of the specimen from the test of 3.5.1.3.1, determined in accordance with 3.5.1.1, shall meet the requirements of 3.5.1.1 except that elongation may be as low as 4% and reduction of area may be as low as 10%; rupture shall occur in the smooth se
44、ction. 3.5.1.3.2 As an alternate procedure, separate smooth and notched specimens, prepared as in 3.5.1.2.2, may be tested individually under the conditions of 3.5.1.3.1. Neither specimen shall show creep elongation greater than 0.2% and tensile properties of the smooth specimen, after exposure, sha
45、ll meet the requirements of 3.5.1.3.1.1. SAE INTERNATIONAL AMS4970K Page 6 of 8 3.5.1.4 Microstructure Shall be that structure resulting from processing within the alpha-beta phase field. Microstructure shall conform to 3.5.1.4.1 (see 8.4). 3.5.1.4.1 Equiaxed and/or elongated primary alpha in a tran
46、sformed beta matrix with no continuous network of alpha at prior beta grain boundaries. 3.5.1.5 Surface Contamination Except as specified in 3.5.1.5.1 and 3.5.1.5.2, the product shall be free of any oxygen-rich layer, such as alpha case, or other surface contamination, determined by microscopic exam
47、ination at not lower than 400X minimum magnification or other method agreed upon by purchaser and producer. 3.5.1.5.1 An oxygen-rich layer (see 8.2) not greater than 0.001 inch (0.025 mm) in depth will be permitted on bars other than rounds. 3.5.1.5.2 When permitted by purchaser, forgings to be mach
48、ined all over may have an oxygen-rich layer provided such layer is removable within the machining allowance on the forging. 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 and, when specified, to 3.5.1.2 and/or 3.5.1.3. If specimens taken from the stock after heat treatment as in 3.4 conform to the requirements of 3.5.1.1 an
