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/AMS6496AAEROSPACE MATERIAL SPECIFICATIONAMS6496 REV. AIssued 2009-09Revised 2013-11Steel Bars
5、 Forgings, and Tubing, Nitriding1.4Cr - 1.2Mo - 0.3V (0.29 - 0.36C)Aircraft-Quality for Bearing Applications(Composition similar to UNS K23280)RATIONALEAMS6496A results from a Five Year Review and update of this specification.1. SCOPE1.1 FormThis specification covers a nitriding grade of aircraft-q
6、uality, low-alloy steel in the form of bars, forgings, mechanical tubing, and forging stock. AMS6497 and AMS6498 cover UNS K23280 having other quality levels.1.2 ApplicationThese products have been used typically for nitrided parts such as bearings, operating under heavy loads and high speeds at mod
7、erate temperatures, and subject to rigid inspection standards, and requiring highest surface hardness, high core toughness, and less distortion than parts made from steel requiring quenching to case harden, but usage is not limited to such applications.2. APPLICABLE DOCUMENTSThe issue of the followi
8、ng 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 superseding d
9、ocument 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 Canada) or 724-776-4970 (outside USA), www.sae.org.AMS2251 Tolerances, Low-Allo
10、y Steel BarsAMS2253 Tolerances, Carbon and Alloy Steel TubingAMS2259 Chemical Check Analysis Limits, Wrought Low-Alloy and Carbon SteelsAMS2301 Steel Cleanliness, Aircraft-Quality, Magnetic Particle Inspection ProcedureSAE INTERNATIONAL AMS6496A Page 2 of 8AMS2370 Quality Assurance Sampling and Test
11、ing, Carbon and Low-Alloy Steel Wrought Products and Forging StockAMS2372 Quality Assurance Sampling and Testing, Carbon and Low-Alloy Steel, Forgings AMS2806 Identification, Bars, Wire, Mechanical Tubing, and Extrusions, Carbon and Alloy Steels and Corrosion and Heat-Resistant Steels and AlloysAMS2
12、808 Identification, ForgingsAS1182 Standard Stock Removal Allowance, Aircraft-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.a
13、stm.org.ASTM A 255 Determining Hardenability of SteelASTM A 370 Mechanical Testing of Steel ProductsASTM E 381 Macroetch Testing Steel Bars, Billets, Blooms and ForgingsASTM E 112 Determining Average Grain SizeASTM E 350 Chemical Analysis of Carbon Steel, Low-Alloy Steel, Silicon Electrical Steel,In
14、got Iron, and Wrought IronASTM E 384 Knoop and Vickers Hardness of Materials3. TECHNICAL REQUIREMENTS3.1 CompositionShall conform to the following percentages by weight shown in Table 1, determined by wet chemical methods in accordance with ASTM E 350, by spectrochemical methods, or by other analyti
15、cal methods acceptable to purchaser.TABLE 1 COMPOSITIONElement min maxCarbon 0.29 0.36Manganese 0.70 1.20Silicon - 0.30Phosphorus - 0.015Sulfur - 0.005Chromium 1.10 1.60Nickel 0.50 1.00Molybdenum 0.90 1.40Vanadium 0.20 0.40Aluminum 0.10 0.303.1.1 Check AnalysisComposition variations shall meet the a
16、pplicable requirements of AMS2259.3.2 ConditionThe product shall be supplied in the following condition; hardness and tensile strength shall be determined in accordance with ASTM A 370:SAE INTERNATIONAL AMS6496A Page 3 of 83.2.1 Bars3.2.1.1 Bars 0.500 inch (12.70 mm) and Under in Nominal Diameter or
17、 Least Distance Between Parallel SidesCold finished having tensile strength not higher than 138 ksi (950 MPa) or hardness not higher than 285 HB or equivalent (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, unle
18、ss otherwise ordered, having hardness not higher than 285 HB or equivalent (See 8.2). Bars ordered cold finished may have hardness as high as 310 HB or equivalent (See 8.2).3.2.1.3 Bars shall not be cut from plate.3.2.2 ForgingsAs ordered.3.2.3 Mechanical TubingCold finished, unless otherwise ordere
19、d, having hardness not higher than 285 HB, or equivalent (See 8.2). Tubing ordered hot finished and annealed or tempered shall have hardness not higher than 285 HB or equivalent (See 8.2).3.2.4 Forging StockAs ordered by the forging manufacturer.3.3 PropertiesThe product shall conform to the followi
20、ng requirements; hardness, tensile, and impact testing shall be performed in accordance with ASTM A 370:3.3.1 MacrostructureVisual 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 sh
21、ow no pipe or cracks. Porosity, segregation, inclusions, and other imperfections shall be no worse than the macrographs of ASTM E 381 shown in Table 2.TABLE 2 - MACROSTRUCTURE LIMITSCross-Section AreaSquare InchesCross-Section AreaSquare Centimeters MacrographsUp to 36, incl Up to 232, incl S2 -R1 -
22、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 agreed 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 fr
23、om ingots or large blooms, transverse sections may be taken from the tubes rather than tube rounds. Macroetch standards for such tubes shall be agreed upon by purchaser and vendor.3.3.2 Average Grain SizeShall be ASTM No. 6 or finer determined in accordance with ASTM E 112.SAE INTERNATIONAL AMS6496A
24、 Page 4 of 83.3.3 Response to Heat Treatment3.3.3.1 Bars, Forgings and Mechanical TubingSpecimens from product shall have the properties shown in Table 4 after being austenitized by heating to 1720 F 25 (938 C 14), holding at heat for a time commensurate with section thickness, heating equipment, an
25、d procedure used, oil quenched to below 90 F (32 C) followed by tempering for 2 hours minimum at no lower than 1110 F (599 C).TABLE 4 LONGITUDINAL MECHANICAL PROPERTIESPROPERTY VALUETensile Strength, min 181 ksi (1250 MPa)Yield Strength 0.2%, min 155 ksi (1070 MPa)Elongation in 4D, min 10%Charpy Vno
26、tch, min 15 ft-lb (20 J)Hardness 375 to 450 HB, or equivalent (See 8.2)3.3.3.2 Forging StockWhen a sample of stock is forged to a test coupon and heat treated as in 3.3.3.1, specimens taken from the heat treated coupon shall conform to the requirements of 3.3.3.1. If specimens taken from the stock a
27、fter heat treatment as in 3.3.3.1 conform to the requirements of 3.3.3.1, tests shall be accepted as equivalent to tests of a forged coupon.3.3.4 Decarburization3.3.4.1 Bars and tubing ordered ground, turned, or polished shall be free from decarburization on the ground, turned or polished surfaces.
28、Decarburization on tubing ID shall not exceed the maximum depth specified in Table 6.3.3.4.2 Allowable decarburization of bars, billets, and tube rounds ordered for redrawing or forging or to specified microstructural requirements shall be as agreed upon purchaser and vendor.3.3.4.3 Decarburization
29、of bars to which 3.3.4.1 or 3.3.4.2 is not applicable shall be not greater than shown in Table 5.TABLE 5A - MAXIMUM TOTAL DEPTH OF DECARBURIZATION, BARS, INCH/POUND UNITSNominal Diameter or DistanceBetween Parallel SidesInchesTotal Depthof DecarburizationInchUp to 0.500, incl 0.030Over 0.500 to 1.00
30、0, incl 0.035Over 1.000 to 1.500, incl 0.040Over 1.500 to 2.000, incl 0.050Over 2.000 to 2.500, incl 0.060Over 2.500 to 3.000, incl 0.070Over 3.000 0.080TABLE 5B - MAXIMUM TOTAL DEPTH OF DECARBURIZATION, BARS, SI UNITSNominal Diameter or DistanceBetween Parallel SidesMillimetersTotal Depthof Decarbu
31、rizationMillimetersUp to 12.70, incl 0.76Over 12.70 to 25.40, incl 0.89Over 25.40 to 38.10, incl 1.02Over 38.10 to 50.80, incl 1.27Over 50.80 to 63.50, incl 1.52Over 63.50 to 76.20, incl 1.78Over 76.20 2.04SAE INTERNATIONAL AMS6496A Page 5 of 83.3.4.4 Decarburization of tubing to which 3.3.4.1 or 3.
32、3.4.2 is not applicable shall be not greater than shown in Table 6.TABLE 6A - MAXIMUM TOTAL DEPTH OF DECARBURIZATION, TUBING, INCH/POUND UNITSNominal Wall ThicknessInchesTotal Depth of DecarburizationInchIDTotal Depth of DecarburizationInchODUp to 0.109, incl 0.008 0.015Over 0.109 to 0.203, incl 0.0
33、10 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 6B - MAXIMUM TOTAL DEPTH OF DECARBURIZATION, TUBING, SI UNITSNominal Wall ThicknessMillimetersTotal Depth of DecarburizationMillimeterIDTotal Depth of De
34、carburizationMillimetersODUp 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 traverse met
35、hod 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 defin
36、ed 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 depth of d
37、ecarburization 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 (0.12 mm) and the wid
38、th 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 Product
39、ordered hot finished or cold finished 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 die forgings, except
40、in areas that contain flash-line end grain, shall follow the general contour of the forgings showing no evidence of reentrant grain flow.3.5 Tolerances3.5.1 BarsIn accordance with AMS2251.SAE INTERNATIONAL AMS6496A Page 6 of 83.5.2 Mechanical TubingIn accordance with AMS2253.4. QUALITY ASSURANCE PRO
41、VISIONS4.1 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 deemed necessary to ensure that the product
42、conforms to specified requirements.4.2 Classification of Tests4.2.1 Acceptance Tests4.2.1.1 Composition (3.1), condition (3.2), macrostructure (3.3.1), average grain size (3.3.2), response to heat treatment (3.3.3.1), frequency-severity cleanliness rating (3.4.1) and tolerances (3.5) are acceptance
43、tests and shall be performed on each heat or lot as applicable.4.2.1.2 When specified, decarburization (3.3.4).4.2.2 Periodic TestsGrain flow of die forgings (3.4.3) and response to heat treatment of forging stock (3.3.3.2) are periodic tests and shall be performed at a frequency selected by the ven
44、dor unless frequency of testing is specified by purchaser.4.3 Sampling and Testing4.3.1 Bars, Mechanical Tubing, and Forging Stock In accordance with AMS2370.4.3.2 ForgingsIn accordance with AMS2372.4.4 Reports4.4.1 The producer of bars, forgings and tubing shall furnish with each shipment a report
45、showing producer identity and country where the metal was melted (i.e., final melt in the case of metal processed by multiple melting operations) and the the results of tests for composition, macrostructure and frequency-severity cleanliness rating of each heat, and for condition, average grain size
46、 and response to heat treatment of each lot, and stating that the product conforms to the other technical requirements. This report shall include the purchase order number, heat and lot numbers, AMS6496A, product form and size or part number, and quantity. If forgings are supplied, the size and mel
47、t source of stock used to make the forgings shall also be included.4.4.2 Report the nominal metallurgically worked cross sectional size and the cut size, if different (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
48、 where the metal was melted (e. g., final melt in the case of metal processed by multiple melting operations) and the composition, macrostructure and frequency-severity cleanliness rating of each heat. This report shall include the purchase order number, heat number, AMS6496A, size and quantity.4.5
49、Resampling and Retesting4.5.1 Bars, Mechanical Tubing, and Forging StockIn accordance with AMS2370.SAE INTERNATIONAL AMS6496A Page 7 of 84.5.2 ForgingsIn accordance with AMS2372.5. PREPARATION FOR DELIVERY5.1 SizesExcept when exact lengths or multiples of exact lengths are ordered, 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
