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 theref
2、rom, 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 InternationalAll rights reserved. No part of this publi
3、cation 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: +1 724-776-4970 (out
4、side USA)Fax: 724-776-0790Email: CustomerServicesae.orgSAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedbackon this Technical Report, please visithttp:/www.sae.org/technical/standards/AMS4944LAEROSPACEMATERIAL SPECIFICATIONAMS4944 REV. LIssued 1974-06Revised 2015-06Superseding
5、 AMS4944KTitanium Alloy Tubing, Seamless, Hydraulic3.0Al - 2.5VCold Worked, Stress Relieved(Composition similar to UNS R56320)RATIONALEAMS4944L deletes AS6279 that does not apply to hydraulic tubing. AMS4944K resulted from an update of this specification and included a reduction in hydrogen content
6、and removal of an increased sample weight allowance (Table 1), use of vacuum in the first consumable melting (3.2), use of vacuum/inert gas furnaces (3.3.2), revision of tubing size in tolerance Table 4, included the addition of AS6279 (3.7) (now deleted), reduced flarability sampling (4.3.3) and re
7、vised reporting (4.5). 1. SCOPE1.1 FormThis specification covers a titanium alloy in the form of seamless tubing.1.2 Application This tubing has been used typically for parts, such as hydraulic lines, requiring strength and oxidation resistance up to 600 F (316 C) and weldability, but usage is not l
8、imited to such applications.2. APPLICABLE DOCUMENTSThe 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 document issue is spec
9、ified. When the referenced document has been cancelled and no superseding document has been specified, the last published issue of that document shall apply.2.1 SAE PublicationsAvailable from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Cana
10、da) or +1 724-776-4970 (outside USA), www.sae.org.AMS2244 Tolerances, Titanium and Titanium Alloy TubingAMS2249 Chemical Check Analysis Limits, Titanium and Titanium AlloysAMS2634 Ultrasonic Inspection, Thin Wall Metal TubingSAE INTERNATIONAL AMS4944L Page 2 of 9AMS2750 PyrometryAMS2809 Identificati
11、on, Titanium and Titanium Alloy Wrought ProductsAS33611 Tube Bend Radii2.2 ASTM PublicationsAvailable from ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959, Tel: 610-832-9585, www.astm.org.ASTM E8/E8M Tension Testing of Metallic MaterialsASTM E1409 Determina
12、tion of Oxygen and Nitrogen in Titanium and Titanium Alloys by the Inert Gas Fusion TechniqueASTM E1447 Determination of Hydrogen in Titanium and Titanium Alloys by the Inert Gas Fusion Thermal Conductivity/Infrared Detection MethodASTM E1941 Determination of Carbon in Refractory and Reactive Metals
13、 and Their Alloys by Combustion AnalysisASTM E2371 Analysis of Titanium and Titanium Alloys by Direct Current Plasma and Inductively Coupled Atomic Emission Spectrometry2.3 ASME Publications Available from ASME, P.O. Box 2900, 22 Law Drive, Fairfield, NJ 07007-2900, Tel: 800-843-2763 (U.S./Canada),
14、001-800-843-2763 (Mexico), 973-882-1170 (outside North America), www.asme.org.ASME B46.1 Surface Texture (Roughness, Waviness and Lay)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, hydro
15、gen 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 to the purchaser.Table 1 - CompositionElement min maxAluminumVanadiumIronOxygenCarbonNitrogenHydrogen Yttrium (3.
16、1.1)Other Elements, each (3.1.1)Other Elements, total (3.1.1)Titanium2.502.00-remainder3.503.000.300.120.050.020 (200 ppm)0.005 (50 ppm)0.005 (50 ppm)0.100.40SAE INTERNATIONAL AMS4944L Page 3 of 93.1.1 Determination not required for routine acceptance.3.1.2 Check AnalysisComposition variations shall
17、 meet the 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 un
18、der vacuum 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 and/or helium at an absolute pressure not higher than 1000 mm of mercury.3.2.2 The electrode tip
19、for nonconsumable electrode melting shall be water-cooled copper.3.3 ConditionCold worked and stress relieved by heating to a temperature not lower than 700 F (371 C) and holding at heat for not less than 30 minutes. Tubing that is rotary straightened after final reduction shall be stress relieved a
20、t a minimum temperature of 700 F (371 C) for not less than 2 hours after straightening. Pyrometry shall be in accordance with AMS2750.3.3.1 Furnaces shall meet the requirements of AMS2750. Furnaces shall be a minimum Class 5 (25 F/14 C), with a minimum of Type D instrumentation.3.3.2 Heat treatment
21、operations shall be performed under vacuum or inert gas.3.4 PropertiesTubing shall conform to the following requirements:3.4.1 Tensile PropertiesShall be as shown 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 mai
22、ntained within a tolerance of 0.002 inch/inch/minute (0.002 mm/mm/minute) through the 0.2% offset yield strain.Table 2 - Minimum tensile propertiesProperty ValueTensile StrengthYield Strength at 0.2% OffsetElongation in 2 Inches (50.8 mm)Nominal Wall ThicknessUp to 0.016 inch (0.41 mm), inclOver 0.0
23、16 inch (0.41 mm)125 ksi (862 MPa)105 ksi (724 MPa)8%10%3.4.2 FlarabilitySpecimens as in 4.3.3 shall withstand flaring at room temperature, without formation of cracks or other visible defects, by being forced axially, with steady pressure, over a hardened and polished tapered steel pin having a 74-
24、degree included angle to produce a flare having a permanent expanded OD not less than 1.20 times the original nominal OD.SAE INTERNATIONAL AMS4944L Page 4 of 93.4.3 Pressure TestingTubing shall show no bulges, leaks, pin holes, cracks, or other defects when subjected to an internal hydrostatic press
25、ure (P) sufficient to cause a tensile stress of 105 ksi (724 MPa) in the tubing wall, except that a diametric permanent set of 0.002 inch per inch (0.002 mm/mm) of diameter is acceptable. The hydrostatic pressure (P) shall be determined using Equation 1:(Eq. 1)where:P = Test pressure in ksi (MPa)S =
26、 105 ksi (724 MPa)D = Nominal ODd = Nominal ID3.4.4 BendingTubing shall not develop cracks, tears, breaks, or other flaws when bent 180 degrees around a suitable bend die having a centerline radius equal to three times the nominal OD of the tubing. A solid rod or ball-type retractable mandrel insert
27、ed to the tangent of the bend shall be used to support the inside of the tube during bending to restrict flattening to a value that does not exceed 3% of the nominal OD of the tube. Flattening shall be measured in accordance with AS33611.3.4.5 FlatteningThe inside and outside surfaces of tubing shal
28、l show no cracks, tears, breaks, opened die marks, or opened polishing marks when a full section of the tube is flattened between parallel plates under a load applied gradually and perpendicularly to thelongitudinal axis until the distance between the plates is not greater than shown in Table 3. Aft
29、er examination of the outside surfaces, the samples shall be split longitudinally and the inside surfaces examined. Examination of tube surfaces shall be at 5 to 10X magnification.Table 3 - Flattening parametersOutside Diameter ToWall Thickness RatioOD/tDistance Between Plates(t = Wall Thickness)Up
30、to 12, inclOver 12 to 16, inclOver 16 to 30, inclOver 30 to 50, inclNot Required12t15t17t3.4.5.1 As an alternate flattening test, a half-tube sample shall be pressed to produce a flat surface approximately 3/8 inch (9.5 mm) wide on the tubing ID.3.4.6 MicrostructureShall be predominantly an elongate
31、d wrought structure with some areas of partially transformed beta structure permissible. Standards shall be acceptable to purchaser. Tubing shall be free of any oxygen-rich layer, such as alpha case (See 8.2), or other surface contamination, determined by microscopic examination at not lower than 40
32、0X magnification or by other method agreed upon by purchaser and producer.PSD2d2D2d2+-=SAE INTERNATIONAL AMS4944L Page 5 of 93.5 Quality Tubing, as received by purchaser, shall be uniform in quality and condition and shall have a finish conforming to the best practice for high quality aircraft tubin
33、g. It shall be smooth and free from scale or oxide, burrs, seams, tears, grooves, laminations, slivers, pits, and other imperfections detrimental to usage of the tubing. Surface imperfections, such as handling marks or straightening marks, will not be considered injurious if the imperfections are re
34、movable within the tolerances specified for wall thickness but removal of such imperfections is not required.3.5.1 Each tube shall be ultrasonically inspected in accordance with AMS2634, Class AA, for ID, OD, and subsurface imperfections of all types and orientation (longitudinal and transverse).3.5
35、2 Surface Condition 3.5.2.1 OD SurfaceShall show a uniformly acid-pickled surface finish; not less than 0.001 inch (0.025 mm) shall have been chemically removed from the wall thickness as a finishing operation. Soft, belt polishing prior to the pickling operation is permissible; traces of the polis
36、hing marks may remain after the pickling operation. Centerless grinding or other mechanical operations are not permitted.3.5.2.2 ID SurfaceShall show a uniform matte finish, produced by abrasive blasting with grit not larger than 100 mesh (150 m), followed by forced-flow acid pickling to remove not
37、less than 0.0005 inch (0.013 mm) from the wall thickness.3.5.2.3 Surface RoughnessShall be not greater than 63 microinches (1.6 m) on the ID and 32 microinches (0.8 m) on the OD, determined in accordance with ASME B46.1.3.5.2.4 The ID and OD surfaces of the tubing shall be free from grease and other
38、 foreign matter. Metallic flakes or particles shall not be collected by a clean, white cloth drawn through the length of the bore of a test sample. Discoloration of the cloth, without the presence of flakes or particles, is acceptable.3.6 Tolerances 3.6.1 Outer DiameterShall be as shown in Table 4;
39、tolerances shown include ovality.Table 4A - Tolerances, outer diameter, inch/pound unitsNominal ODInchesToleranceInchPlusToleranceInchMinusOver 0.093 to 0.187, incl 0.002 0.000Over 0.187 to 0.499, incl 0.003 0.000Over 0.499 to 0.749, incl 0.004 0.000Over 0.749 to 0.999, incl 0.004 0.001Over 0.999 to
40、 1.499, incl 0.004 0.002Over 1.499 to 1.999, incl 0.005 0.002SAE INTERNATIONAL AMS4944L Page 6 of 9Table 4B - Tolerances, outer diameter, SI unitsNominal ODMillimetersToleranceMillimeterPlusToleranceMillimeterMinusOver 2.36 to 4.75, incl 0.05 0.00Over 4.75 to 12.67, incl 0.08 0.00Over 12.67 to 19.02
41、 incl 0.10 0.00Over 19.02 to 25.37, incl 0.10 0.025Over 25.37 to 38.07, incl 0.10 0.05Over 38.07 to 50.77, incl 0.13 0.053.6.1.1 Diameter tolerances for tubing 0.093 inch (2.36 mm) and under or over 1.999 inches (50.77 mm) in nominal OD shall be as agreed upon by purchaser and producer. 3.6.2 Wall
42、ThicknessAll tubing 1.500 inches (38.10 mm) and under in nominal OD shall not vary more than +10%, -5% from nominal; tubing over 1.500 inches (38.10 mm) in nominal OD shall not vary more than 10%.3.6.3 Length and StraightnessShall conform to AMS2244.4. QUALITY ASSURANCE PROVISIONS 4.1 Responsibility
43、 for Inspection The producer of tubing shall supply all samples for producers tests 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 tubing conforms to specified requ
44、irements.4.2 Classification of Tests 4.2.1 Acceptance TestsAll technical requirements, except pressure testing (3.4.3), are acceptance tests and shall be performed on each heat or lot as applicable.4.2.2 Periodic TestsPressure testing (3.4.3) is a periodic test and shall be performed at a frequency
45、selected by the producer unless frequency of testing is specified by purchaser.4.2.3 Preproduction TestsAll technical requirements are preproduction tests and shall be performed prior to or on the initial shipment of tubing to a purchaser, when a change in material and/or processing requires reappro
46、val as in 4.4.2, and when purchaser deems confirmatory testing to be required.4.3 Sampling and Testing Shall be in accordance with the following; a lot shall be all tubing of the same nominal size from the same heat, same processing, and finishing operations, and stress relieved in the same furnace
47、charge:SAE INTERNATIONAL AMS4944L Page 7 of 94.3.1 CompositionOne sample from each heat, except that for hydrogen determinations one sample from each lot obtained after thermal and chemical processing is completed. An ingot analysis obtained from the alloy producer may be utilized to substantiate he
48、at requirements.4.3.2 Tensile PropertiesOne sample for each 1000 feet (305 mm) or 3 samples from each lot, whichever is greater.4.3.3 FlarabilityOne sample for each 1000 feet (305 mm) or 3 samples from each lot, whichever is greater.4.3.3.1 Specimens for flarability (3.4.2) test shall be full tubes
49、or sections cut from a tube. The end of the specimens to be flared shall be cut square, with the cut end smooth and free from burrs, but not rounded.4.3.4 Pressure TestAs agreed upon by purchaser and producer.4.3.5 BendingTwo samples from each lot.4.3.6 FlatteningOne sample for each 135 feet (41 m) of tubing or 10 samples from each lot, whichever is less. Each specimen shall be notless th
