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 2013 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/AMS6448LAEROSPACE MATERIAL SPECIFICATIONAMS6448 REV. LIssued 1942-03Revised 2013-11Supersedin
5、g AMS6448KSteel, Bars, Forgings, and Tubing0.95Cr - 0.22V (0.48 - 0.53C) (SAE 6150)(Composition similar to UNS G61500)RATIONALEAMS6448L results from a Five Year Review and update of this specification 1. SCOPE1.1 FormThis specification covers an aircraft-quality, low-alloy steel in the form of bars,
6、 forgings, mechanical tubing, and forging stock.1.2 ApplicationThese products have been used typically for parts 0.500 inch (12.70 mm) and under in nominal section thickness at time of heat treatment requiring a through-hardening steel capable of developing hardness as high as 52 HRC when properly h
7、ardened and tempered and also parts of greater thickness but requiring proportionately lower hardness, but usage is not limited 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 exten
8、t 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 PublicationsAv
9、ailable from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org.AMS2251 Tolerances, Low-Alloy Steel BarsAMS2253 Tolerances, Carbon and Alloy Steel TubingAMS2259 Chemical Check Analysis Limits, Wro
10、ught Low-Alloy and Carbon SteelsAMS2301 Cleanliness, Aircraft Quality, Magnetic Particle Inspection ProcedureSAE INTERNATIONAL AMS6448L Page 2 of 8AMS2370 Quality Assurance Sampling and Testing, Carbon and Low-Alloy Steel Wrought Products and Forging StockAMS2372 Quality Assurance Sampling and Testi
11、ng, Carbon and Low-Alloy Steel ForgingsAMS2806 Identification, Bars, Wire, Mechanical Tubing, and Extrusions, Carbon and Alloy Steels and Corrosion and Heat-Resistant Steels and AlloysAMS2808 Identification, ForgingsAMS-H-6875 Heat Treatment of SteelAS1182 Standard Stock Removal Allowance, Aircraft-
12、Quality and Premium Aircraft-Quality Steel Bars and Mechanical Tubing2.2 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 A 255 Determining Hardenability of SteelASTM A 370 Mechanical Testi
13、ng of Steel ProductsASTM E 112 Determining Average Grain SizeASTM E 350 Chemical Analysis of Carbon Steel, Low-Alloy Steel, Silicon Electrical Steel, Ingot Iron, and Wrought IronASTM E 381 Macroetch Testing Steel Bars, Billets, Blooms, and ForgingsASTM E 384 Knoop and Vickers Hardness of Materials3.
14、 TECHNICAL REQUIREMENTS3.1 CompositionShall conform to the percentages by weight shown in Table 1, determined by wet chemical methods in accordance with ASTM E 350, by spectrochemical methods, or by other analytical methods approved by purchaser.TABLE 1 - COMPOSITIONElement min maxCarbon 0.48 0.53Ma
15、nganese 0.70 0.90Silicon 0.15 0.35Phosphorus - 0.025Sulfur - 0.025Chromium 0.80 1.10Vanadium 0.15 0.30Nickel - 0.25Molybdenum - 0.06Copper - 0.353.1.1 Check AnalysisComposition variations shall meet the applicable requirements of AMS2259.SAE INTERNATIONAL AMS6448L Page 3 of 83.2 ConditionThe product
16、 shall be supplied in the following condition; hardness and tensile strength shall be determined in accordance with ASTM A 370:3.2.1 Bars3.2.1.1 Bars 0.500 inch (12.70 mm) and Under in Nominal Diameter or Least Distance Between Parallel SidesCold finished having tensile strength not higher than 125
17、ksi (862 MPa) or equivalent hardness (See 8.2).3.2.1.2 Bars Over 0.500 inch (12.70 mm) in Nominal Diameter or Least Distance Between Parallel SidesHot finished and annealed, unless otherwise ordered, having hardness not higher than 235 HB, or equivalent. Bars ordered cold finished may have hardness
18、as high as 248 HB, or equivalent (See 8.3).3.2.1.3 Bar shall not be cut from plate (Also see 4.4.2).3.2.2 ForgingsAnnealed in accordance with AMS-H-6875.3.2.3 Mechanical TubingCold finished, unless otherwise ordered, having hardness not higher than 25 HRC, or equivalent. Tubing ordered hot finished
19、and annealed shall have hardness not higher than 99 HRB, or equivalent (See 8.3).3.2.4 Forging StockAs ordered by the forging manufacturer.3.3 PropertiesThe product shall conform to the following requirements; hardness testing shall be performed in accordance with ASTM A 370:3.3.1 MacrostructureVisu
20、al examination of transverse full cross-sections from bars, billets, tube rounds, and forging stock, etched in hot hydrochloric acid in accordance with ASTM E 381, shall show no pipe or cracks. Porosity, segregation, inclusions, and other imperfections shall be no worse than the macrographs of ASTM
21、E 381 shown in Table 2.TABLE 2 - MACROSTRUCTURE LIMITSCross-Sectional AreaSquare InchesCross-Sectional AreaSquare Centimeters MacrographsUp to 36, incl Up to 232, incl S2 -R1 -C2Over 36 to 133, incl Over 232 to 858, incl S2 -R2 -C3Over 133 Over 858 Note 1Note 1 Limits for larger sizes shall be agree
22、d upon by purchaser and vendor. The purchaser shall have written approval of the agreement from the cognizant engineering organization.3.3.1.1 If tubes are produced directly from ingots or large blooms, transverse sections may be taken from the tubes rather than tube rounds. Macroetch standards for
23、such tubes shall be agreed upon by purchaser and vendor.3.3.2 Average Grain SizeShall be ASTM No. 5 or finer, determined in accordance with ASTM E 112.SAE INTERNATIONAL AMS6448L Page 4 of 83.3.3 HardenabilityShall be J 6/16 inch (9.5 mm) = HRC 53 minimum and J 8/16 inch (12.7 mm) = HRC 47 minimum, d
24、etermined on the standard end-quench test specimen in accordance with ASTM A 255 except that the steel shall be normalized at 1700 F 10 (927 C 6) and the test specimen austenitized at 1550 F 10 (843 C 6). 3.3.4 Decarburization3.3.4.1 Bars and tubing ordered ground, turned, or polished shall be free
25、from decarburization on the ground, turned, or polished surfaces. 3.3.4.2 Allowable decarburization of bars, billets, and tube rounds ordered for redrawing or forging or to specified microstructural requirements shall be as agreed upon by purchaser and vendor.3.3.4.3 Decarburization of bars to which
26、 3.3.4.1 or 3.3.4.2 is not applicable shall be not greater than shown in Table 3.TABLE 3A - MAXIMUM DEPTH OF DECARBURIZATION, INCH/POUND UNITSNominal Diameter or DistanceBetween Parallel SidesInchesTotal Depth ofDecarburizationInchUp to 0.375, incl 0.010Over 0.375 to 0.500, incl 0.012Over 0.500 to 0
27、.625, incl 0.014Over 0.625 to 1.000, incl 0.017Over 1.000 to 1.500, incl 0.020Over 1.500 to 2.000, incl 0.025Over 2.000 to 2.500, incl 0.030Over 2.500 to 3.000, incl 0.035Over 3.000 to 4.000, incl 0.045TABLE 3B - MAXIMUM DEPTH OF DECARBURIZATION, SI UNITSNominal Diameter or DistanceBetween Parallel
28、SidesMillimetersTotal Depth ofDecarburizationMillimetersUp to 9.52, incl 0.25Over 9.52 to 12.70, incl 0.30Over 12.70 to 15.88, incl 0.36Over 15.88 to 25.40, incl 0.43Over 25.40 to 38.10, incl 0.51Over 38.10 to 50.80, incl 0.64Over 50.80 to 63.50, incl 0.76Over 63.50 to 76.20, incl 0.89Over 76.20 to
29、101.60, incl 1.143.3.4.4 Decarburization of tubing to which 3.3.4.1 or 3.3.4.2 is not applicable shall be not greater than shown in Table 4.SAE INTERNATIONAL AMS6448L Page 5 of 8TABLE 4A - MAXIMUM DEPTH OF DECARBURIZATION, INCH/POUND UNITSNominal WallThicknessInchesTotal DepthIDInchTotal DepthODInch
30、Up to 0.109, incl 0.008 0.015Over 0.109 to 0.203, incl 0.010 0.020Over 0.203 to 0.400, incl 0.012 0.025Over 0.400 to 0.600, incl 0.015 0.030Over 0.600 to 1.000, incl 0.017 0.035Over 1.000 0.020 0.040TABLE 4B - MAXIMUM DEPTH OF DECARBURIZATION, SI UNITSNominal WallThicknessMillimetersTotal DepthIDMil
31、limetersTotal DepthODMillimetersUp to 2.77, incl 0.20 0.38Over 2.77 to 5.16, incl 0.25 0.51Over 5.16 to 10.16, incl 0.30 0.64Over 10.16 to 15.24, incl 0.38 0.76Over 15.24 to 25.40, incl 0.43 0.89Over 25.40 0.51 1.023.3.4.5 Decarburization shall be measured by the metallographic method or by a traver
32、se method using microhardness testing in accordance with ASTM E 384. The microhardness method shall be conducted on a hardened but untempered specimen protected during heat treatment to prevent changes in surface carbon content. Depth of decarburization, when measured by the microhardness method, is
33、 defined as the perpendicular distance from the surface to the depth under that surface where there is no further increase in hardness. Such measurements shall be far enough away from any adjacent surface to be uninfluenced by any decarburization on the adjacent surface. In case of dispute, the dept
34、h of decarburization determined using the microhardness traverse method shall govern.3.3.4.5.1 When determining the depth of decarburization, it is permissible to disregard local areas provided the decarburization of such areas does not exceed the above limits by more than 0.005 inch (0.13 mm) and t
35、he width is 0.065 inch (1.65 mm) or less.3.4 QualityThe product, 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 product.3.4.1 Steel shall be aircraft quality conforming to AMS2301.3.4.2 Ba
36、rs and mechanical tubing ordered hot rolled or cold drawn, or ground, turned, or polished shall, after removal of the standard stock removal allowance in accordance with AS1182, be free from seams, laps, tears, and cracks open to the machined, ground, turned, or polished surface.3.4.3 Grain flow of
37、die forgings, except in areas which contain flash-line end grain, shall follow the general contour of the forgings showing no evidence of reentrant grain flow.3.5 TolerancesShall be as follows:3.5.1 BarsIn accordance with AMS2251.SAE INTERNATIONAL AMS6448L Page 6 of 83.5.2 Mechanical TubingIn accord
38、ance with AMS2253.4. QUALITY ASSURANCE PROVISIONS4.1 Responsibility for InspectionThe vendor of the product shall supply all samples for vendors tests and shall be responsible for the performance of all required tests. Purchaser reserves the right to sample and to perform any confirmatory testing de
39、emed necessary to ensure that the product conforms to specified requirements. 4.2 Classification of Tests4.2.1 Acceptance TestsComposition (3.1), condition (3.2), macrostructure (3.3.1), average grain size (3.3.2), hardenability (3.3.3), decarburization (3.3.4), frequency-severity cleanliness rating
40、 (3.4.1), and tolerances (3.5) are acceptance tests and shall be performed on each heat or lot as applicable.4.2.2 Periodic TestsGrain flow of die forgings (3.4.3) is a periodic test and shall be performed at a frequency selected by the vendor unless frequency of testing is specified by purchaser. 4
41、.3 Sampling and TestingShall be as follows:4.3.1 Bars, Mechanical Tubing, and Forging Stock In accordance with AMS2370.4.3.2 Forgings In accordance with AMS2372.4.4 Reports4.4.1 The producer of bars, forgings, and mechanical tubing shall furnish with each shipment a report showing theproducer identi
42、ty and country where the metal was melted (e. g., final melt in the case of metal processed by multiple melting operations) and results of tests for composition, macrostructure, hardenability, and frequency-severity cleanliness rating of each heat, and for average grain size of each lot, and stating
43、 that the product conforms to the other technical requirements. This report shall include the purchase order number, heat and lot numbers, AMS6448L, size (and/or part number, if applicable), and quantity. If forgings are supplied, the size and melt source of stock used to make the forgings shall als
44、o be included.4.4.2 Report the nominal metallurgically worked cross sectional size and the cut size, if different (Also see 3.2.1.3).4.4.3 The producer of forging stock shall furnish with each shipment a report showing the producer identity and country where the metal was melted (e. g., final melt i
45、n the case of metal processed by multiple melting operations) and the composition, macrostructure, hardenability and frequency-severity cleanliness rating of each heat. This report shall include the purchase order number, heat number, AMS6448L, size (and/or part number, if applicable) and quantity.S
46、AE INTERNATIONAL AMS6448L Page 7 of 84.5 Resampling and RetestingShall be as follows:4.5.1 Bars, Mechanical Tubing, and Forging StockIn accordance with AMS2370.4.5.2 Forgings In accordance with AMS2372.5. PREPARATION FOR DELIVERY5.1 SizesExcept when exact lengths or multiples of exact lengths are or
47、dered, straight bars and tubing will be acceptable in mill lengths of 6 to 20 feet (1.8 to 6.1 m) but not more than 10% of any shipment shall be supplied in lengths shorter than 10 feet (3 m).5.2 IdentificationShall be as follows:5.2.1 Bars and Mechanical TubingIn accordance with AMS2806.5.2.2 Forgi
48、ngsIn accordance with AMS2808.5.2.3 Forging StockAs agreed upon by purchaser and vendor.5.3 Protective TreatmentBars and tubing ordered cold drawn, cold rolled, ground, turned, or polished shall be protected from corrosion prior to shipment.5.4 PackagingThe product shall be prepared for shipment in
49、accordance with commercial practice and in compliance with applicable rules and regulations pertaining to the handling, packaging, and transportation of the product to ensure carrier acceptance and safe delivery.6. ACKNOWLEDGMENTA vendor shall include this specification number and its revision letter in all quotations and when acknowledging purchase orders.7. REJECTIONSProduct not conforming to this specificatio
