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 2017 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:/standards.sae.org/AMS4941G AEROSPACE MATERIAL SPECIFICATION AMS4941 REV. G Issued 1956-07 Revised 2017-08 Superse
5、ding AMS4941F Titanium Tubing, Welded 40 ksi (276 MPa) Yield Strength (Composition similar to UNS R50400) RATIONALE AMS4941G results from a Five-Year Review and update of this specification that revises composition analytical methods (3.1), removal of sample size allowance for hydrogen of Table 1 (c
6、overed by ASTM E1447).and revises reporting (4.4.2) and identification (5.1.1). 1. SCOPE 1.1 Form This specification covers one grade of commercially pure titanium in the form of welded tubing. 1.2 Application This tubing has been used typically for parts, such as low-pressure fluid-conducting lines
7、 and conduits, requiring strength up to 400 F (204 C) and oxidation resistance up to 600 F (316 C), 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 part of this specification to the extent
8、 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 document shall apply. 2.1 SAE Publications A
9、vailable 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. AMS2242 Tolerances, Corrosion and Heat Resistant Steel, Iron Alloy, Titanium, and Titanium Alloy Sheet, Strip, and Plate AMS224
10、4 Tolerances, Titanium and Titanium Alloy Tubing AMS2249 Chemical Check Analysis Limits, Titanium and Titanium Alloys AMS2368 Sampling and Testing of Wrought Titanium Raw Material, Except Forgings and Forging Stock AMS2750 Pyrometry SAE INTERNATIONAL AMS4941G Page 2 of 8 AMS2809 Identification, Tita
11、nium and Titanium Alloy Wrought Products AMS4902 Titanium Sheet, Strip, and Plate, Commercially-Pure, Annealed 40.0 ksi (276 MPa) Yield Strength AMS4951 Titanium Welding Wire Commercially Pure, Environment Controlled Packaging ARP1917 Clarification of Terms Used in Aerospace Metals Specifications 2.
12、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. ASTM E8/E8M Tension Testing of Metallic Materials ASTM E1409 Determination of Oxygen and Nitrogen in Titanium and Titanium Alloys by Inert G
13、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
14、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 2.3 AWS Publications Available from American Welding Society, 8669
15、 NW 36 Street, #130, Miami, FL 33166-6672, Tel: 1-800-443-9353 or 305-443-9353, www.aws.org. AWS A5.16 Specification for Titanium and Titanium Alloy Welding Electrodes and Rods AWS D17.1 Specification for Fusion Welding for Aerospace Applications 3. TECHNICAL REQUIREMENTS 3.1 Composition Shall confo
16、rm 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 or ASTM E2994. Other analytical methods may be used
17、if acceptable to the purchaser. SAE INTERNATIONAL AMS4941G Page 3 of 8 Table 1 - Composition Element Min Max Carbon - 0.08 Oxygen - 0.20 Iron - 0.30 Nitrogen - 0.05 (500 ppm) Hydrogen - 0.015 (150 ppm) Other Elements, each (3.1.1) - 0.10 Other Elements, total (3.1.1) - 0.30 Titanium remainder 3.1.1
18、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 produced by electron beam cold hearth or plasma arc cold hearth melting or shall be multiple melted. When multip
19、le melted, the first melt shall be made by vacuum consumable electrode, nonconsumable electrode, electron beam cold hearth, or plasma arc cold hearth melting practice. Subsequent melt or melts shall be made using vacuum arc remelting (VAR) practice. Alloy additions are not permitted in the final mel
20、t cycle. 3.2.1.1 The atmosphere for nonconsumable electrode melting shall be vacuum or shall be inert gas at a pressure not higher than 1000 mm of mercury. 3.2.1.2 The electrode tip for nonconsumable electrode melting shall be water-cooled copper. 3.2.2 Sheet and strip produced to AMS4902 is accepta
21、ble to satisfy the melting and composition requirements provided that the composition meets Table 1, except that hydrogen shall meet the requirements of 3.1 when sampled in accordance with 4.3.1. 3.3 Condition 3.3.1 Unless otherwise specified, tubing shall be furnished welded, cold drawn, annealed a
22、nd descaled. 3.3.2 When specified by purchase order (see 8.5), tubing may be furnished according to 3.3.3, 3.3.4, or 3.3.5. 3.3.3 As welded. 3.3.3.1 Welded tube shall be processed to either of the following conditions. 3.3.3.1.1 The weld reinforcements shall be planished or bead rolled to meet requi
23、rement of 3.7.2.2. Tube shall be chemically descaled to remove surface contamination. 3.3.3.1.2 Tubing may be welded from material with thickness greater than and with the diameter larger than the final required dimensions and then redrawn to achieve final diameter and wall thickness. Redrawn tubing
24、 shall meet the wall thickness requirements of AMS2242. 3.3.4 Welded, annealed and descaled. 3.3.5 Welded, stress relieved and descaled. 3.4 Welding process shall be Gas-Metal-Arc Welded (GMAW) or Gas-Tungsten-Arc Welded (GTAW) using automated equipment and with or without filler metal. Filler metal
25、 shall be in accordance with AMS4951 or ERTi-2 per AWS A5.16. SAE INTERNATIONAL AMS4941G Page 4 of 8 3.4.1 Welding shall be performed by a qualified operator using a written and qualified welding procedure per AWS D17.1. 3.5 Annealing Shall be as follows: 3.5.1 Heat to a temperature within the range
26、 1200 F to 1500 F (649 C to 816 C), hold at the selected temperature within 25 F (14 C) for 15 to 120 minutes, and cool as required. Annealing times for material processed in a continuous furnace may be shortened to 2 minutes minimum. Pyrometry shall be in accordance with AMS2750. 3.6 Stress Relieve
27、d Condition When specified, the tubing shall be stress relieved in accordance with 3.6.1.1 and shall be chemically descaled to remove surface contamination. 3.6.1.1 Heat to 1100 F 25 (593 C 14) and soak for 2 hours 30 minutes and air or furnace cool. Pyrometry shall be in accordance with AMS2750. 3.
28、7 Properties Tubing shall conform to the following requirements: 3.7.1 Tensile Properties Shall 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 maintained within a tolerance of 0.002 inch/inch/minute (0.
29、002 mm/mm/minute) through the 0.2% offset yield strain. Table 2 - Tensile properties Property Value Tensile Strength, minimum 50.0 ksi (345 MPa) Yield Strength at 0.2% Offset 40.0 to 65 ksi (276 to 448 MPa) Elongation in 2 inches (50.8 mm), minimum 20% 3.7.2 Flattening 3.7.2.1 Tubing with Nominal Wa
30、ll Thickness Less than or Equal to 10% of Nominal Outside Diameter A sample per 4.3.1.2 shall be flattened between platens under a gradually applied load until the distance between platens is equal to 5 times the nominal wall thickness of the tubing. The weld during flattening test shall be oriented
31、 at 90 degrees 5 to the application of flattening loads. The specimen shall flatten without cracking. Tubing failing to meet flattening requirement shall alternatively meet bending requirement of 3.7.3. 3.7.2.2 Tubing with Nominal Wall Thickness Greater than 10% of Nominal Outside Diameter The tubin
32、g shall not require a flattening test. The tubing shall meet the bend test requirement as specified in 3.7.3. 3.7.3 Bending 3.7.3.1 Shall not develop cracks, tears, breaks, or other flaws when bent per 3.7.3.2. 3.7.3.2 A sample per 4.3.1.2 shall be bent 90 at room temperature around a suitable bend
33、die having a centerline radius equal to three times the nominal outside diameter of the tubing. A center rod or ball type retractable mandrel inserted to the tangent of the bend or appropriate tube filler shall be used to support the inside of the tube during the tube bending operation to restrict f
34、lattening of the tube. Ovality of the specimen in the bend area shall not exceed 7%. SAE INTERNATIONAL AMS4941G Page 5 of 8 3.7.4 Flarability 3.7.4.1 Shall not develop cracks or other visible defects when flared per 3.7.4.2. 3.7.4.2 A sample per 4.3.2.1 shall be flared at room temperature by forcing
35、 it axially with a steady pressure over a hardened and polished tapered steel pin. The pin shall have a 74 included angle, to produce a flare having a permanent expanded outside diameter not less than 1.30 times the original nominal outside diameter. 3.7.5 Pressure Testing Tubing shall show no bulge
36、s, leaks, pin holes, cracks, or other defects when subjected to an internal hydrostatic pressure per 3.7.5.1. 3.7.5.1 A sample per 4.3.1.2 shall be tested with hydrostatic pressure (P) sufficient to cause a tensile stress (S) of 40.0 ksi (275 MPa) in the tubing wall except that a diametric permanent
37、 set of 0.002 inch per inch (0.002 mm/mm) of diameter is acceptable. The hydrostatic pressure (P) shall be determined from Equation 1. (Eq. 1) where: P = test pressure in ksi (MPa) S = 40.0 ksi (275 MPa) tensile stress D = nominal OD (Nominal OD plus tolerance) d = nominal ID (Nominal OD minus twice
38、 the minimum wall thickness) 3.7.6 Surface Contamination The surfaces of the tube shall be free of any oxygen-rich layer, such as alpha case (see 8.2), or other surface contamination when tested per 3.7.6.1. 3.7.6.1 A sample per 4.3.1.2 shall be metallographically examined to determine surface conta
39、mination, if any. The examination shall be of a metallographic cross section at 400X minimum magnification or by other method agreed upon by the purchaser. 3.7.7 Weld Quality 3.7.7.1 Welds on each tube following conditioning per 3.3 shall be tested per 3.7.7.2 and meet the acceptance criteria for Cl
40、ass A per AWS D17.1. 3.7.7.2 Weld on each tube in a lot shall be inspected visually, as well as, with a nondestructive inspection procedure established by the tubing manufacturer meeting any current industry specification (ultrasonic, radiographic, and/or eddy current). The procedure shall be demons
41、trated to be capable of detecting flaws larger than those specified for Class A per AWS D17.1. 3.8 General 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 tubing. It shall be smooth
42、and free from heavy 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, straightening marks, light mandrel and die marks, shallow pits, and scale pattern will not be consid
43、ered injurious if the imperfections are removable within the tolerances specified for wall thickness but removal of such imperfections is not required. P SD2d2D2d2+-=SAE INTERNATIONAL AMS4941G Page 6 of 8 3.9 Tolerances Each tube in the lot shall meet requirements specified here in. 3.9.1 Unless oth
44、erwise specified herein, tolerances shall conform to all applicable requirements of AMS2244; standard tolerances for diameter shall apply. 3.9.2 Wall Thickness 3.9.2.1 Thickness of the tubing in the area away from weld. The wall thickness of the tubing shall be as that of the sheet material thicknes
45、s used in the fabrication of the tubing. The thickness tolerance shall be in accordance with AMS2242. 3.9.2.2 Thickness of the tubing in the weld area. The face and root surface of the weld after planishing operation shall not be above the adjacent surface by more than 0.0025 inch. Neither face nor
46、root surface shall be below the adjacent surface. Undercut at the weld toe of the face and root sides shall not be acceptable. The measurement shall be performed on both ends of the specimens sectioned for the flattening, flaring, and pressure tests. 3.9.3 Ovality 3.9.3.1 Ovality shall not exceed 2%
47、 in any section of the tubing for tubing with diameter to thickness ratios less than or equal to 100. 3.9.3.2 Ovality shall not exceed 4% in any section of the tubing for tubing with diameter to thickness ratios greater than 100. 4. QUALITY ASSURANCE PROVISIONS 4.1 Responsibility for Inspection The
48、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 requirements. 4.2 Classi
49、fication of Tests 4.2.1 Acceptance Tests Composition (3.1), tensile properties (3.7.1), flattening (3.7.2) and/or bending (3.7.3), pressure test (3.7.5), surface contamination (3.7.6), weld quality (3.7.7), general quality (3.8) and tolerances (3.9) are acceptance tests and shall be performed on each heat or lot as applicable. 4.2.2 Periodic Tests Flarability (3.7.4) is a periodic test a
