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 2015 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 (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/AMS6312JAEROSPACEMATERIAL SPECIFICATIONAMS6312 REV. JIssued 1939-12Revised 2015-12Superseding
5、AMS6312HSteel Bars, Forgings, and Tubing1.8Ni - 0.25Mo (0.38 - 0.43C) (4640)(Composition similar to UNS K22440)RATIONALEAMS6312J results from a Five Year Review and update of this specification that revises macrostructure, grain size,decarburization testing methods and reporting.1. SCOPE1.1 FormThis
6、 specification covers an aircraft-quality, low-alloy steel in the form of bars, forgings, mechanical tubing, and forging stock.1.2 ApplicationThese products have been used typically for parts 0.250 inch (6.35 mm) and under in nominal section thickness at time of heat treatment requiring a through-ha
7、rdening steel capable of developing hardness as high as 50 HRC, and also parts of greater thickness 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
8、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 document has been specified, the last published issue of that docu
9、ment 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 +1 724-776-4970 (outside USA), www.sae.org.AMS2251 Tolerances, Low-Alloy Steel BarsAMS2253 Tolerances, Carbon and Alloy Steel TubingA
10、MS2259 Chemical Check Analysis Limits, Wrought Low-Alloy and Carbon SteelsAMS2301 Steel Cleanliness, Aircraft Quality Magnetic Particle Inspection ProcedureSAE INTERNATIONAL AMS6312J Page 2 of 9AMS2370 Quality Assurance Sampling and Testing, Carbon and Low-Alloy Steel Wrought Products and Forging St
11、ockAMS2372 Quality Assurance Sampling and Testing 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 Steel Raw M
12、aterialsAS1182 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.astm.org.ASTM A255 Dete
13、rmining Hardenability of SteelASTM A370 Mechanical Testing of Steel ProductsASTM E112 Determining Average Grain SizeASTM E350 Chemical Analysis of Carbon Steel, Low-Alloy Steel, Silicon Electrical Steel, Ingot Iron, and Wrought IronASTM E381 Macroetch Testing Steel Bars, Billets, Blooms, and Forging
14、sASTM E384 Knoop and Vickers Hardness of Materials3. TECHNICAL REQUIREMENTS3.1 CompositionShall conform to the percentages by weight shown in Table 1, determined by wet chemical methods in accordance with ASTM E350, by spectrochemical methods, or by other analytical methods acceptable to purchaser.T
15、able 1 - CompositionElement min maxCarbonManganeseSiliconPhosphorusSulfurNickelMolybdenumChromiumCopper0.380.600.15-1.650.20-0.43 0.80 0.35 0.0250.0252.00 0.30 0.20 0.35 3.1.1 Aluminum, vanadium and columbium are optional grain refining elements and need not be determined or reported unless used to
16、satisfy the average grain size requirements of 3.3.2.2.3.1.2 Check AnalysisComposition variations shall meet the applicable requirements of AMS2259.SAE INTERNATIONAL AMS6312J Page 3 of 93.2 ConditionThe product shall be supplied in the following condition; hardness and tensile strength shall be dete
17、rmined in accordance with ASTM A370:3.2.1 BarsBar shall not be cut from plate.3.2.1.1 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 130 ksi (896 MPa) or equivalent hardness (see 8.2).3.2.1.2 Bars
18、 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 229 HB, or equivalent (see 8.3). Bars ordered cold finished may have hardness as high as 241 HB, or equivalent (see 8.3).3.2.2
19、ForgingsNormalized and tempered in accordance with AMS-H-6875.3.2.3 Mechanical TubingCold finished, unless otherwise ordered, having hardness not higher than 25 HRC, or equivalent (see 8.3). Tubing ordered hot finished and annealed shall have hardness not higher than 99 HRB, or equivalent (see 8.3).
20、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 A370:3.3.1 MacrostructureVisual examination of transverse full cross-sections from bars, billets, tube rounds,
21、and forging stock, etched in hot hydrochloric acid in accordance with ASTM E381, shall not show pipe or cracks. Porosity, segregation, inclusions, and other imperfections shall not be worse than the macrographs of ASTM E381 shown in Table 2.Table 2 - Macrostructure limitsSection SizeSquare InchesSec
22、tion SizeSquare Centimeters MacrographsUp to 36, inclOver 36 to 133, inclOver 133Up to 232, inclOver 232 to 858, inclOver 858S2 - R1 - C2S2 - R2 - C3Note 1Note 1 Limits for larger sizes shall be agreed upon by purchaser and purchaser. The purchaser shall have written approval of the agreement from t
23、he 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 such tubes shall be agreed upon by purchaser and producer.SAE INTERNATIONAL AMS6312J Page 4 of 93
24、.3.2 Average Grain Size of Bars, Forgings and TubingAverage grain size shall be determined by either 3.3.2.1 or 3.3.2.2.3.3.2.1 Shall be ASTM No. 5 or finer, determined in accordance with ASTM E112.3.3.2.2 The product of a heat shall be considered to have an ASTM No. 5 or finer austenitic grain size
25、 if one or more of the following are determined by heat analysis (see 8.6):3.3.2.2.1 A total aluminum content of 0.020 to 0.050%.3.3.2.2.2 An acid soluble aluminum content of 0.015 to 0.050%.3.3.2.2.3 A vanadium content of 0.02 to 0.08%.3.3.2.2.4 A columbium content of 0.02 to 0.05%.3.3.3 Hardenabil
26、ity of each HeatShall be J 3/16 inch (4.8 mm) = 50 HRC minimum and J 9/16 inch (14.3 mm) = 35 HRC minimum, determined on the standard end-quench test specimen in accordance with ASTM A255 except that the steel shall be normalized at 1550 F 10 F (843 C 6 C) and the test specimen austenitized at 1500
27、F 10 F (816 C 6 C). 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. Decarburization on tubing ID shall not exceed the maximum depth specified in Table 4.3.3.4.2 Allowable decarburization
28、of bars, billets, and tube rounds ordered for redrawing or forging or to specified microstructural requirements shall be as agreed upon by purchaser and producer.3.3.4.3 Decarburization of bars that 3.3.4.1 or 3.3.4.2 is not applicable shall be not greater than shown in Table 3.Table 3A - Maximum to
29、tal depth of decarburization, inch/pound unitsNominal Diameter or DistanceBetween Parallel SidesInchesTotal Depth ofDecarburizationInchUp to 0.375, inclOver 0.375 to 0.500, inclOver 0.500 to 0.625, inclOver 0.625 to 1.000, inclOver 1.000 to 1.500, inclOver 1.500 to 2.000, inclOver 2.000 to 2.500, in
30、clOver 2.500 to 3.000, inclOver 3.000 to 4.000, incl0.0100.0120.0140.0170.0200.0250.0300.0350.045SAE INTERNATIONAL AMS6312J Page 5 of 9Table 3B - Maximum total depth of decarburization, SI unitsNominal Diameter or DistanceBetween Parallel SidesMillimetersTotal Depth ofDecarburizationMillimetersUp to
31、 9.52, inclOver 9.52 to 12.70, inclOver 12.70 to 15.88, inclOver 15.88 to 25.40, inclOver 25.40 to 38.10, inclOver 38.10 to 50.80, inclOver 50.80 to 63.50, inclOver 63.50 to 76.20, inclOver 76.20 to 101.60, incl0.250.300.360.430.510.640.760.891.143.3.4.4 Decarburization of tubing that 3.3.4.1 is not
32、 applicable shall be not greater than shown in Table 4.Table 4A - Maximum total depth of decarburization, inch/pound unitsNominal Wall ThicknessInchesTotal Depth ofDecarburizationInchIDTotal Depth ofDecarburizationInchODUp to 0.109, inclOver 0.109 to 0.203, inclOver 0.203 to 0.400, inclOver 0.400 to
33、 0.600, inclOver 0.600 to 1.000, inclOver 1.000 0.0080.0100.0120.0150.0170.0200.0150.0200.0250.0300.0350.040Table 4B - Maximum total depth of decarburization, SI unitsNominal Wall ThicknessMillimetersTotal Depth ofDecarburizationMillimeterIDTotal Depth ofDecarburizationMillimetersODUp to 2.77, inclO
34、ver 2.77 to 5.16, inclOver 5.16 to 10.16, inclOver 10.16 to 15.24, inclOver 15.24 to 25.40, inclOver 25.40 0.200.250.300.380.430.510.380.510.640.760.891.023.3.4.5 Decarburization shall be evaluated by one of the two methods of 3.3.4.5.1 or 3.3.4.5.2.3.3.4.5.1 Metallographic MethodA cross section tak
35、en perpendicular to the surface shall be prepared, etched, and visually examined metallographically at a magnification not to exceed 100X. The product shall not show a layer of complete (ferrite) or partial decarburization exceeding the limits of Tables 3 and 4.SAE INTERNATIONAL AMS6312J Page 6 of 9
36、3.3.4.5.2 Hardness Traverse Method The total depth of decarburization shall be determined by a traverse method using microhardness testing in accordance with ASTM E384, at a magnification not exceeding 100X, conducted on a hardened but untempered specimen protected during heat treatment to prevent c
37、hanges in surface carbon content. Tempering is generally not recommended, but if tempered, the tempering temperature shall be not higher than 300 F (149 C). Depth of decarburization is defined as the perpendicular distance from the surface to the depth under that surface where there is not further i
38、ncrease in hardness. Such measurements shall be far enough away from any adjacent surface to be uninfluenced by any decarburization on the adjacent surface. Acceptance shall be as listed in Tables 3 and 4.3.3.4.5.3 When determining the depth of decarburization, it is permissible to disregard local a
39、reas provided the decarburization of such areas does not exceed the above limits by more than 0.005 inch (0.13 mm) and the width is 0.065 inch (1.65 mm) or less.3.3.4.5.4 In case of dispute, the total depth of decarburization determined using the microhardness traverse method shall govern.3.4 Qualit
40、yThe 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 Bars and tubing ordered hot rolled or cold drawn, or
41、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 in areas that contain flashline end grai
42、n, shall follow the general contour of the forgings, showing no evidence of reentrant grain flow.3.5 Tolerances3.5.1 BarsIn accordance with AMS2251.3.5.2 Mechanical TubingIn accordance with AMS2253.4. QUALITY ASSURANCE PROVISIONS4.1 Responsibility for InspectionThe producer of the product shall supp
43、ly 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 product conforms to specified requirements.4.2 Classification of Tests4.2.1 Accept
44、ance TestsComposition (3.1), condition (3.2), macrostructure (3.3.1), average grain size (3.3.2), hardenability (3.3.3), decarburization(3.3.4), quality (3.4), frequency-severity cleanliness rating (3.4.1), and tolerances (3.5) are acceptance tests and shall be performed on each heat or lot, as appl
45、icable. If grain refining elements (3.3.2.2) are not present, the ASTM E112 grain size test (3.3.2.1) shall be conducted on each lot.SAE INTERNATIONAL AMS6312J Page 7 of 94.2.2 Periodic TestsIf grain refining elements (3.3.2.2) are present, the ASTM E112 grain size test (3.3.2.1) shall be conducted
46、on a periodic basis and shall be performed at a frequency selected by the producer (not to exceed one year) unless frequency of testing is specified by purchaser. Grain flow of die forgings (3.4.3) is a periodic test and shall be performed at a frequency selected by the producer unless frequency of
47、testing is specified by purchaser.4.3 Sampling4.3.1 Bars, Mechanical Tubing, and Forging StockIn 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 showing producer identity, country w
48、here the metal was melted (e.g., final melt in the case of metal processed by multiple melting operations) and the results of tests for composition, macrostructure, hardenability, and frequency-severity cleanliness rating of each heat and for condition and, if measured, average grain size for each l
49、ot, and stating that the product conforms to the other technical requirements. This report shall include the purchase order number, heat and lot numbers, AMS6312J, product form and 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 also be included. If the grain size requirement of 3.3.2.2 is met by the
