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 andsuggestions.Copyright 2015 SAE InternationalAll rights reserved. No part of this public
3、ation 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 (outs
4、ide 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/AS7461DAEROSPACESTANDARDAS7461 REV. DIssued 1992-05Reaffirmed 2001-10Revised 2015-08Supersedin
5、g AS7461CBolts and Screws, Titanium Alloy6Al-4V, UNS R56400Fatigue-Rated, Procurement Specification ForFSC 55306RATIONALEParagraph 3.6.3.2.4, delete reference to 3.6.2.3 and add reference to 3.6.2.4.1. SCOPE1.1 TypeThis procurement specification covers aircraft-quality bolts and screws made from 6Al
6、-4V titanium alloy of the type identified under the Unified Numbering System as UNS R56400. The following specification designation and its properties are covered:AS7461 160 ksi minimum ultimate tensile strength at room temperature.77 ksi tension to 19.2 ksi tension fatigue at room temperature.1.2 A
7、pplicationPrimarily for aerospace propulsion system applications where high strength, light weight, fatigue rated fasteners are required for use up to approximately 600 F.1.3 Safety - Hazardous MaterialsWhile the materials, methods, applications, and processes described or referenced in this specifi
8、cation may involve the use of hazardous materials, this specification does not address the hazards which may be involved in such use. It is the sole responsibility of the user to ensure familiarity with the safe and proper use of any hazardous materials and to take necessary precautionary measures t
9、o ensure the health and safety of all personnel involved.SAE INTERNATIONAL AS7461D Page 2 of 212. REFERENCES2.1 Applicable DocumentsThe following publications form a part of this document to the extent specified herein. The latest issue of SAE publicationsshall apply. The applicable issue of other p
10、ublications shall be the issue in effect on the date of the purchase order. In theevent of conflict between the text of this document and references cited herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specif
11、ic exemption has been obtained.2.1.1 SAE PublicationsAvailable 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.2.1.1.1 Aerospace Material SpecificationsAMS2750 PyrometryAMS4967 Titanium
12、 Alloy, Bars, Wire, Forgings, and Rings, 6.0Al - 4.0V, Annealed, Heat Treatable2.1.1.2 Aerospace StandardsAS1132 Bolts, Screws and Nuts - External Wrenching, UNJ Thread, Inch - Design StandardAS1814 Terminology for Titanium MicrostructuresAS3062 Bolts, Screws and Studs, Screw Thread RequirementsAS30
13、63 Bolts, Screws, and Studs, Geometric Control RequirementsAS8879 Screw Threads - UNJ Profile, Inch, Controlled Radius Root with Increased Minor Diameter2.1.2 AIA/NAS PublicationsAvailable from Aerospace Industries Association, 1000 Wilson Boulevard, Suite 1700, Arlington, VA 22209-3928, Tel: 703-35
14、8-1000, www.aia-aerospace.org.NASM1312-6 Fastener Test Methods, Method 6, HardnessNASM1312-8 Fastener Test Methods, Tensile StrengthNASM1312-11 Fastener Test Methods, Tension Fatigue2.1.3 U.S. Government PublicationsCopies of these documents are available online at http:/quicksearch.dla.mil.2.1.3.1
15、Military StandardsMIL-STD-2073-1 Standard Practice for Military PackagingSAE INTERNATIONAL AS7461D Page 3 of 212.1.4 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 B600 Descaling and Cl
16、eaning Titanium and Titanium Alloy SurfacesASTM E8/E8M Standard Test Methods for Tension Testing of Metallic Materials.ASTM E340 Standard Test Method for Macroetching Metals and AlloysASTM E407 Standard Test Practice for Microetching Metals and AlloysASTM E1417/E1417M Standard Practice for Liquid Pe
17、netrant TestingASTM E1447 Standard Test Method for Determination of Hydrogen in Titanium and Titanium Alloys, by Inert Gas Fusion Thermal Conductivity/Infrared Detection Method2.1.5 ASME PublicationAvailable from ASME, P.O. Box 2900, 22 Law Drive, Fairfield, NJ 07007-2900, Tel: 800-843-2763 (U.S./Ca
18、nada), 001-800-843-2763 (Mexico), 973-882-1170 (outside North America), www.asme.org.ASME B46.1 Surface Texture (Surface Roughness, Waviness, and Lay)2.2 DefinitionsPRODUCTION INSPECTION LOT: Shall be all finished parts of the same part number, made from a single heat of alloy, heat treated at the s
19、ame time to the same specified condition, produced as one continuous run, and submitted for vendors inspection at the same time.Refer to AS1814 for titanium microstructure terms and definitions.2.3 Unit Symbols Baume - hydrometer scale unit for measuring specific gravity of liquidsF - degree Fahrenh
20、eit% - percent (1% = 1/100)lbf - pound-forceksi - kips (1000 pounds) per square inchsp gr - specific gravity3. TECHNICAL REQUIREMENTS3.1 MaterialShall be AMS4967 titanium alloy.SAE INTERNATIONAL AS7461D Page 4 of 213.2 DesignFinished (completely manufactured) parts shall conform to the following req
21、uirements:3.2.1 DimensionsThe dimensions of finished parts, after all processing, shall conform to the part drawing. Dimensions apply before any required coating with dry film lubricants.3.2.2 Surface TextureSurface texture of finished parts, prior to any required coating, shall conform to the requi
22、rements as specified on the part drawing, determined in accordance with ASME B46.1.3.2.3 ThreadsScrew thread UNJ profile and dimensions shall be in accordance with AS8879, unless otherwise specified on the part drawing.3.2.3.1 Incomplete ThreadsIncomplete threads are permissible at the chamfered end
23、 and the juncture of the unthreaded portion of the shank or adjacent to the head as specified in AS3062.3.2.3.2 ChamferThe entering end of the thread shall be chamfered as specified on the part drawing.3.2.4 Geometric TolerancesPart features shall be within the geometric tolerances specified on the
24、part drawing and, where applicable, controlled in accordance with AS3063.3.3 Fabrication3.3.1 BlanksHeads shall be formed by hot forging.3.3.1.1 CleaningBlanks shall be cleaned prior to heat treatment in accordance with ASTM B600, or other methods approved by the purchaser. Blank surfaces shall be f
25、ree of halogen compounds, such as residue from halogenated solvents and coolants, and salt from sweaty hands. Surfaces of parts, fixtures, racks, etc., shall be clean and free of dirt, water, oil, grease, paint, ink, crayon markings, dye pickup, finger prints, and other foreign materials. After clea
26、ning and prior to heat treatment, personnel handling blanks shall wear clean white cotton gloves or equivalent.3.3.2 Heat TreatmentHeaded blanks after cleaning as in 3.3.1.1 shall, before finishing the shank and the bearing surface of the head, cold working the head-to-shank fillet radius, and rolli
27、ng the threads, be heat treated as follows:SAE INTERNATIONAL AS7461D Page 5 of 213.3.2.1 Heating EquipmentFurnaces may be any type ensuring uniform temperature throughout the blanks being heated and shall be equipped with, and operated by, automatic temperature controllers and data recorders conform
28、ing to AMS2750. The heating medium or atmosphere shall cause neither surface hardening nor embrittlement.3.3.2.2 Solution Heat TreatmentBlanks shall be uniformly heated to a temperature within the range 1650 to 1750 F, held at the selected temperature within 25 F for 30 to 60 minutes, and quenched i
29、n water.3.3.2.3 Precipitation Heat TreatmentSolution heat treated blanks shall be heated to a temperature within the range 900 to 1100 F, held at the selected temperature within 10 F for 4 to 8 hours, and cooled in air.3.3.3 Contamination RemovalThe solution and precipitation heat treated blanks, be
30、fore cold working the fillet radius and rolling the threads, shall have the full body, head-to-shank fillet, and bearing surface of the head free from surface contamination and contamination penetration caused by prior heat treatment. The removal process shall produce no intergranular attack or corr
31、osion, or changes of structure of the blanks. The metal removed from the bearing surface of the head and the full body diameter of the shank shall be as little as practicable to obtain a clean, smooth surface, and in no case shall be so great as to producemore cutting of flow lines in the head-to- s
32、hank junction. 3.3.4 Cold Rolling of Fillet RadiusAfter removal of contamination as in 3.3.3, the head-to-shank fillet radius of headed parts having the radius complete throughout the circumference of the part shall be cold worked. The fillet shall be cold worked sufficiently to remove all visual ev
33、idence of grinding or tool marks. If there is no visual evidence of grinding or tool marks prior to cold working, thefillet shall still be cold worked. Distortion due to cold rolling shall conform to Figure 1, unless otherwise specified on the part drawing. It shall not raise metal more than 0.002 i
34、nch above the contour at “A“ or depress metal more than 0.002 inch below the contour at “B“ as shown in Figure 1. In configurations having an undercut associated with the fillet radius, the cold rolling will be required only for 90 degrees of fillet arc, starting at the point of tangency of the fill
35、et radius and the bearing surface of the head. For shouldered bolts having an unthreaded shank diameter larger than the thread major diameter and having an undercut associated with a fillet between the threaded shank and the shoulder of the unthreaded shank, the cold rolling will be required only fo
36、r 90 degrees of fillet arc, starting at the point of tangency of the fillet radius and the shouldered surface of the unthreaded shank. For parts with compound fillet radii between head and shank, cold roll only the radius that blends with the head. The shank diameter on close tolerance full shank bo
37、lts shall not exceed its maximum diameter limit after cold rolling the head-to-hank fillet radius.3.3.5 Thread RollingThreads shall be formed on the heat treated and finished blanks by a single rolling process after removal of contamination as in 3.3.3.3.4 Product MarkingEach part shall be identific
38、ation marked as specified on the part drawing. The markings may be formed by forging or stamping, raised or depressed 0.010 inch maximum, with rounded root form on depressed characters.SAE INTERNATIONAL AS7461D Page 6 of 213.5 Mechanical PropertiesParts shall conform to the requirements of 3.5.1 and
39、 3.5.2. Threaded members of gripping fixtures for tensile and fatigue tests shall be of sufficient size and strength to develop the full strength of the part without stripping the thread. The loaded portion of the shank shall have a minimum of three full thread turns from the thread runout exposed b
40、etween the loading fixtures during the tensile and fatigue tests. Finished parts shall be tested in accordance with the following applicable test methods:a. Room Temperature Ultimate Tensile Strength: MIL-STD-1312-8 in accordance with NASM1312-8b. Fatigue Strength: MIL-STD-1312-11 in accordance with
41、 NASM1312-113.5.1 Ultimate Tensile Strength at Room Temperature3.5.1.1 Finished PartsTension bolts, such as hexagon, double hexagon, and spline drive head, shall have an ultimate tensile load not lower than that specified in Table 2A and shall be tested to failure in order to observe fracture locati
42、on, first measuring and recordingthe maximum tensile load achieved. Screws, such as 100 degree flush head, pan head, and fillister head, shall have an ultimate tensile load not lower than that specified in Table 2B, screws need not be tested to failure, however the maximum tensile load achieved shal
43、l be measured and recorded. If the size or shape of the part is such that failure would occur outside the threaded section but the part can be tested satisfactorily, such as parts having a shank diameter equal to or less than the thread root diameter or having an undercut, parts shall conform to onl
44、y the ultimate tensile strength requirements of 3.5.1.2; for such parts, the diameter of the area on which stress is based shall be the actual measured minimum diameter of the part. Tension fasteners with either standard double hexagon drive or hexagon-type heads having a minimum metal condition in
45、the head equal to the design parameters specified in AS1132 shall not fracture in the head-to-shank fillet radius except when this radius is associated with an undercut or with a shank diameter less than the minimum pitch diameter of the thread.3.5.1.2 Machined Test SpecimensIf the size or shape of
46、the part is such that a tensile test cannot be made on the part, tensile tests shall be conducted in accordance with ASTM E8 on specimens prepared as in 4.5.6. Tests on such specimens shall be conducted at a strain rate of 0.003 to 0.007 inch/inch/minute through the 0.2% offset after which the rate
47、shall be increased so as to produce failure in approximately 1 minute. Specimens may be required by the purchaser to perform confirmatory tests. Specimens shall meet the following requirements:a. Ultimate Tensile Strength, minimum: 160 ksib. Elongation in 2 inches or 4D, minimum: 8%c. Reduction of A
48、rea, minimum: 20%3.5.2 Fatigue StrengthFinished parts tested in tension-tension fatigue at room temperature with maximum load as specified in Table 2 and minimum load equal to 25% of maximum load shall have average life of not less than 30 000 cycles with no part having life less than 15 000 cycles.
49、 Tests need not be run beyond 60 000 cycles for purposes of computing average life. If the shank diameter of the part is less than the minimum pitch diameter of the thread, parts shall withstand fatigue testing as above using loads sufficient to produce a maximum stress of 77 ksi and a minimum stress of 19.2 ksi. The above requirements apply only to parts 0.138 inch and larger in nominal thread size with round, square, hexagonal, or
