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 2014 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/AMS4991EAEROSPACE MATERIAL SPECIFICATIONAMS4991 REV. EIssued 1980-07Revised 2014-04Supersedin
5、g AMS4991DTitanium Alloy Castings, Investment6Al - 4VHot Isostatic Pressed, Anneal Optional(Composition similar to UNS R56401)RATIONALEAMS4991E results from a Five Year Review and update of this specification that aligns hydrogen sample mass with ASTM E 1447 and standardizes reporting requirements.1
6、. SCOPE1.1 FormThis specification covers a titanium alloy in the forms of investment castings having four grades of permissible discontinuities.1.2 ApplicationThese castings have been used typically for parts of intricate design requiring a combination of good strength-to-weight ratio, creep and fat
7、igue properties, and corrosion resistance up to 750 F (399 C), but usage is not limited to such applications.1.3 ClassificationQuality grades A, B, C, and D are defined in 3.7. If a specific grade is not specified (See 8.2.1), Grade C or better shall besupplied.2. APPLICABLE DOCUMENTSThe issue of th
8、e 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 specified. When the referenced document has been cancelled and no supe
9、rseding document has been specified, the last published issue of that document shall apply.SAE INTERNATIONAL AMS4991E Page 2 of 172.1 SAE PublicationsAvailable from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outsid
10、e USA), www.sae.org.AMS2249 Chemical Check Analysis Limits, Titanium and Titanium AlloysAMS2750 PyrometryAMS2694 Repair Welding of Aerospace CastingsAMS2804 Identification, Castings2.2 ASTM PublicationsAvailable from ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 194
11、28-2959, Tel: 610-832-9585, www.astm.org.ASTM B 600 Descaling and Cleaning Titanium and Titanium Alloy SurfacesASTM E 8 / E 8M Tension Testing of Metallic MaterialsASTM E 539 Analysis of Titanium Alloys by X-Ray Fluorescence SpectrometryASTM E 1320 Reference Radiographs for Titanium CastingsASTM E 1
12、409 Determination of Oxygen and Nitrogen in Titanium and Titanium Alloys by the Inert Gas Fusion TechniqueASTM E 1417 Liquid Penetrant TestingASTM E 1447 Determination of Hydrogen in Titanium and Titanium Alloys by the Inert Gas Fusion Thermal Conductivity/Infrared Detection MethodASTM E 1742 Radiog
13、raphic ExaminationASTM E 1941 Determination of Carbon in Refractory and Reactive Metals and Their Alloys by Combustion AnalysisASTM E 2371 Analysis of Titanium and Titanium Alloys by Direct Current Plasma and Inductively Coupled Atomic Emission Spectrometry3. TECHNICAL REQUIREMENTS3.1 CompositionSha
14、ll conform to the percentages by weight shown in Table 1; carbon shall be determined in accordance with ASTM E 1941, hydrogen in accordance with ASTM E 1447, oxygen and nitrogen in accordance with ASTM E 1409, and other elements in accordance with ASTM E 539 or ASTM E 2371. Other analytical methods
15、may be used if acceptable to the purchaser (See 8.2.2 and 8.2.3).SAE INTERNATIONAL AMS4991E Page 3 of 17TABLE 1 - COMPOSITIONElement min maxAluminum 5.50 6.75Vanadium 3.50 4.50Iron - 0.30Oxygen - 0.20Carbon - 0.10Nitrogen - 0.05 (500 ppm)Hydrogen - 0.015 (150 ppm)Yttrium (3.1.1) - 0.005 ( 50 ppm)Oth
16、er Elements, each (3.1.1) - 0.10Other Elements, total (3.1.1) - 0.40Titanium remainder3.1.1 Determination not required for routine acceptance.3.1.2 Check AnalysisComposition variations shall meet the applicable requirements of AMS2249.3.2 Melting Practice3.2.1 Castings and specimens shall be poured
17、at the casting vendors facility either from a remelt (See 8.2.4) of a master heat or directly from a master heat (See 3.2.3).3.2.1.1 Remelt for CastingCastings and specimens shall be remelted and poured under inert gas pressure in accordance with 3.2.2.1, or under vacuum without loss of vacuum betwe
18、en melting and pouring.3.2.1.2 If authorized by purchaser (See 8.2.5), portions of two or more qualified master heats of 3.2.3 may be remelted together and poured into castings using a procedure acceptable to purchaser.3.2.1.3 Remelt for casting shall be performed using consumable electrode practice
19、 or other method authorized by purchaser.3.2.2 Master Heat PreparationA master heat shall be prepared from any combination of elemental and revert materials that are melted and refined as necessary in a single furnace charge. Single or multiple melting shall be accomplished using consumable electrod
20、e, nonconsumable electrode, electron beam, or plasma arc practices.3.2.2.1 The atmosphere for melting shall be vacuum or shall be argon and/or helium at an absolute pressure not higherthan 1000 millimeters of mercury.3.2.2.2 Revert (gates, sprues, risers, and rejected castings) may be used in the pr
21、eparation of master heats.3.2.2.3 Solidification of the master heat into pigs or ingots before remelting and pouring of castings is permitted.3.2.2.4 The master heat source shall establish effective control procedures, including parameters for the critical variables that will consistently produce ma
22、terial suitable for remelting of castings meeting the requirements of this specification. Control procedures shall be acceptable to purchaser and casting vendor.3.2.3 Master Heat QualificationEach master heat shall be qualified by evaluation of chemical and tensile specimens.SAE INTERNATIONAL AMS499
23、1E Page 4 of 173.2.3.1 Specimens shall be either separately-cast, integrally-cast (See 8.2.6), or machined-from- casting, and shall conform to 3.2.1.3.2.3.2 If specimens are separately-cast, vendor shall have a written procedure acceptable to purchaser. Control factors of 4.4.2.2 shall apply.3.2.3.3
24、 The acceptance tests of 4.2.1 may be used to satisfy the qualification requirements of 3.2.3.3.3 Condition3.3.1 Castings shall be hot isostatically pressed.3.3.2 A separate annealing operation may be performed, but is not required.3.3.3 The vendor shall record the type of thermal processing perform
25、ed as a control factor of 4.4.2.2.3.4 Test Specimens3.4.1 Chemical Analysis SpecimensShall be of any convenient size and shape.3.4.2 Tensile SpecimensShall be of standard proportions in accordance with ASTM E 8 / E 8M with 0.250 inch (6.35 mm) diameter at the reduced parallel gage section.3.4.2.1 Se
26、parately-cast and integrally-cast specimens may be either cast to size or cast oversize and subsequently machined to 0.250 inch (6.35 mm) diameter.3.4.2.1.1 After machining or chemical cleaning, tensile specimens shall be free of oxygen-rich layer, such as alpha case, or other surface contamination.
27、3.4.2.2 When integrally-cast specimens and specimens machined from castings are specified, specimen size and location shall be agreed upon by purchaser and vendor (See 8.2.7 and 8.4).3.5 Thermal ProcessingCastings and representative specimens shall be hot isostatically pressed in accordance with 3.5
28、.1, unless alternative cycle parameters are specified by customer. When performed, annealing shall be in accordance with 3.5.2.3.5.1 Hot Isostatic PressProcess in inert atmosphere at not less than 14.5 ksi (100 MPa) within the range of 1650 to 1750 F (899 to 954 C), hold at the selected temperature
29、within 25 F (14 C) for 2 to 4 hours, and cool under inert atmosphere in the autoclave to below 800 F (427 C).3.5.2 AnnealProcess in vacuum or inert atmosphere (See 4.3.1) at a temperature within the range of 1300 to 1550 F (704 to 843 C), hold at the selected temperature within 25 F (14 C) for 2 to
30、4 hours, cool in the furnace to below 1000 F (538 C). Pyrometry shall be in accordance with AMS27503.6 PropertiesCastings and representative tensile specimens shall conform to the following requirements; conformance of separately cast tensile specimens to the requirements of 3.6.1.1 shall be used fo
31、r acceptance of castings except when purchaser specifies that integrally-cast specimens to the requirements of 3.6.1.1 or specimens machined-from-casting to the requirements of 3.6.1.2 shall apply.SAE INTERNATIONAL AMS4991E Page 5 of 173.6.1 Room Temperature Tensile PropertiesShall be as specified i
32、n 3.6.1.1 or 3.6.1.2, determined in accordance with ASTM E 8 / E 8M 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 (0.002 mm/mm/minute) through the 0.2% offset yield strain.3.6.1.1 Separately-Cast or Cut from Int
33、egrally-Cast CouponsShall be as shown in Table 2.TABLE 2 - MINIMUM TENSILE PROPERTIESProperty ValueTensile Strength 130 ksi (896 MPa)Yield Strength at 0.2% Offset 120 ksi (827 MPa)Elongation in 4D 6%3.6.1.2 Machined-from-Casting Specimens3.6.1.2.1 Machined-from-Casting Specimens from Designated Area
34、sShall be as shown in Table 3.TABLE 3 - MINIMUM TENSILE PROPERTIESProperty ValueTensile Strength 130 ksi (896 MPa)Yield Strength at 0.2% Offset 120 ksi (827 MPa)Elongation in 4D 6%3.6.1.2.2 Machined-from-Casting Specimens from Non-designated AreasShall be as shown in Table 4.TABLE 4 - MINIMUM TENSIL
35、E PROPERTIESProperty ValueTensile Strength 127 ksi (876 MPa)Yield Strength at 0.2% Offset 110 ksi (758 MPa)Elongation in 4D 4.5%3.6.2 Surface ContaminationCastings shall be free of any oxygen-rich layer, such as alpha case, compounds such as residue from halogenated solvents and quenchants, or other
36、 surface contamination.3.6.2.1 Cleaning shall be performed in accordance with ASTM B 600 or other method(s) acceptable to purchaser.3.6.2.2 After cleaning and prior to any subsequent processing involving temperatures over 500 F (260 C), castings shall be handled in a manner to preclude surface conta
37、mination. Handling with clean, dry, white cotton gloves is recommended.3.7 Quality3.7.1 Castings, 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 castings.3.7.1.1 Castings shall have smooth
38、 surfaces and shall be cleaned sufficiently to permit nondestructive inspection. Metallic shot or grit shall not be used for final cleaning.SAE INTERNATIONAL AMS4991E Page 6 of 173.7.1.2 When specified, additional nondestructive testing shall be performed as follows:3.7.1.2.1 Fluorescent penetrant t
39、esting in accordance with ASTM E 1417 or other method specified by purchaser.3.7.1.3 Acceptance standards other than those specified herein for radiographic, fluorescent penetrant, visual, surface contamination, and other inspections shall be as agreed upon by purchaser and vendor.3.7.1.4 Discontinu
40、ities for which specific limits are not defined herein, such as hot tears, cracks, cold shuts, and missruns, are not acceptable. Any type of discontinuity appearing on opposite sides of a wall, and that is interconnected, is not acceptable.3.7.2 Visual and, If Specified, Fluorescent Penetrant Inspec
41、tion3.7.2.1 Positive (Raised) Material on Cast SurfacesShall be acceptable as follows:3.7.2.1.1 NodulesThree nodules, 0.020 inch (0.51 mm) and under in height above the parent surface and 0.020 inch (0.51 mm) and under in length, are permissible in a 1-inch (25-mm) square; or one nodule, 0.020 inch
42、(0.51 mm) and under in height and 0.150 inch (3.81 mm) and under in length, in a 2-inch (51-mm) square.3.7.2.1.2 Parting Lines and Gating MaterialPositive material less than 0.015 inch (0.38 mm) in height, in the form of parting lines, gates, risers, or material due to wax welds.3.7.2.1.3 Areas to b
43、e Final FinishedPositive material less than 0.060 inch (1.52 mm) in height in areas to be finish machined.3.7.2.2 FlowlinesFlowlines on cast surfaces are acceptable as follows:3.7.2.2.1 Flowlines shall have well-rounded contours.3.7.2.2.2 The width of the flowline shall be equal to, or greater than,
44、 twice the depth of the flowline below the parent surface.3.7.2.2.3 Flowlines shall not be associated with cold shuts or miss runs.3.7.2.2.4 In Grade A areas, flowlines are not permitted.3.7.2.2.5 In Grade B, C, and D areas, flowlines 0.005 inch (0.13 mm) and under in depth below the parent surface
45、are permissible without length or number restriction.3.7.2.2.6 In Grade C and D areas, flowlines 0.010 inch (0.25 mm) and under in depth below the parent surface are permissible provided that not more than two such flowlines exist in a 1-inch (25-mm) square and that the flowlines are 0.250 inch (6.3
46、5 mm) and under in length.3.7.2.3 Permissible Negative Surface DiscontinuitiesSize and quantity of discrete and clustered negative discontinuities shall not exceed those specified in Table 5.SAE INTERNATIONAL AMS4991E Page 7 of 17TABLE 5A - NEGATIVE SURFACE DISCONTINUITY LIMITS, INCH/POUND UNITSArea
47、GradeMaximum Numberof Discontinuities(See 8.2.11)Maximum DiscreteDiscontinuity LengthInchLinearMaximum DiscreteDiscontinuity LengthInchNonlinearMaximumClusterLength1InchA 4 discrete discontinuitiesin a 1-inch squareNoneAllowed0.015 NoneAllowedB 4 discrete discontinuitiesin a 1-inch squareOne cluster
48、 in a 2-inchsquareNoneAllowedNoneAllowed0.0200.010(2)-0.125C 8 discrete discontinuitiesin a 1-inch squareOne cluster in a 2-inchsquare0.020One max0.0100.0300.030(2)-0.375D 8 discrete discontinuitiesin a 1-inch square0.045Two max0.040 -1 Clusters shall be nonlinear. An area of shrinkage appearing on
49、a finished surface may be considered a cluster.2 One discrete nonlinear discontinuity is permitted within the cluster.TABLE 5B - NEGATIVE SURFACE DISCONTINUITY LIMITS, SI UNITSAreaGradeMaximum Numberof Discontinuities(See 8.2.11)Maximum DiscreteDiscontinuity LengthMillimetersLinearMaximum DiscreteDiscontinuity LengthMillimetersNonlinearMaximumClusterLength1MillimetersA 4 discrete discontinuitiesin a 25-mm square
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