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 (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/AMS6412NAEROSPACEMATERIAL SPECIFICATIONAMS6412 REV. NIssued 1940-01Reaffirmed 2006-02Revised
5、2015-12Superseding AMS6412MSteel, Bars and Forgings0.80Cr - 1.8Ni - 0.25Mo (0.35 - 0.40C) (4337)(Composition similar to UNS G43370)RATIONALEAMS6412N results from a Five Year Review and update of this document that revises macrostructure, grain size, decarburization testing methods and reporting.1. S
6、COPE1.1 FormThis specification covers an aircraft-quality, low-alloy steel in the form of bars, forgings, and forging stock.1.2 ApplicationThese products have been used typically for parts, 0.875 inch (22.22 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 for 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
8、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 document has been specified, the last published issue of that do
9、cument 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 BarsAMS2259 Chemical Check Analysis Limits, Wrought
10、Low-Alloy and Carbon SteelsAMS2301 Steel Cleanliness, Aircraft Quality, Magnetic Particle Inspection ProcedureSAE INTERNATIONAL AMS6412N Page 2 of 7AMS2370 Quality Assurance Sampling and Testing, Carbon and Low-Alloy Steel, Wrought Products and Forging StockAMS2372 Quality Assurance Sampling and Tes
11、ting, 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 ForgingsAS1182 Standard Stock Removal Allowance, Aircraft-Quality and Premium Aircraft-Quali
12、ty 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 Determining Hardenability of SteelASTM A370 Mechanical Testing of Steel ProductsASTM E112 Deter
13、mining 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 ForgingsASTM E384 Knoop and Vickers Hardness of Materials3. TECHNICAL REQUIREMENTS3.1 CompositionS
14、hall 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.Table 1 - CompositionElement min maxCarbon 0.35 0.40Manganese 0.65 0.85Silicon 0.15 0.35Phos
15、phorus - 0.025Sulfur - 0.025Chromium 0.70 0.90Nickel 1.65 2.00Molybdenum 0.20 0.30Copper - 0.353.1.1 Aluminum, vanadium and columbium are optional grain refining elements and need not be determined or reported unless used to satisfy average grain size requirements of 3.3.2. 3.1.2 Check AnalysisCompo
16、sition variations shall meet the applicable requirements of AMS2259.SAE INTERNATIONAL AMS6412N Page 3 of 73.2 ConditionThe product shall be supplied in the following condition; hardness and tensile strength shall be determined in accordance with ASTM A370.3.2.1 BarsBar shall not be cut from plate.3.
17、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 Over 0.500 Inch (12.70 mm) in Nominal Diameter or Least Distance Between Parall
18、el 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 248 HB, or equivalent (see 8.3).3.2.2 ForgingsAs ordered.3.2.3 Forging StockAs ordered by the forging manufacturer.3.3
19、 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, and forging stock, etched in hot hydrochloric acid in accordance with ASTM
20、 E381, shall show no pipe or cracks. Porosity, segregation, inclusions, and other imperfections shall be no worse than the macrographs of ASTM E381 shown in Table 2.Table 2 - Macrostructure limitsCross-Sectional Area Square InchesCross-Sectional AreaSquare Centimeters MacrographsUp to 36, incl Up to
21、 232, incl S2 - R1 - C2Over 36 to 100, incl Over 232 to 645, incl S2 - R2 - C3Over 133 Over 858 Note 1Note 1: Limits for larger sizes shall be agreed upon by purchaser and producer. The purchaser shall have written approval of the agreement from the cognizant engineering organization.3.3.2 Average G
22、rain Size of Bars and ForgingsAverage 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 if one or more of the
23、 following are determined by heat analysis (see 8.6).3.3.2.2.1 A total aluminum content of 0.020% to 0.050%.SAE INTERNATIONAL AMS6412N Page 4 of 73.3.2.2.2 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 0.0
24、5%.3.3.3 Hardenability of each heatShall be J10/16 inch (15.9 mm) = 50 HRC minimum and J18/16 inch (28.6 mm) = 44 HRC minimum, determined on the standard end-quench test specimen in accordance with ASTM A255 except that the steel shall be normalized at 1700 F 25 F (927 C 14 C) and the test specimen
25、austenitized at 1500 F 25 F (816 C 14 C).3.3.4 Decarburization3.3.4.1 Bars ordered ground, turned, or polished shall be free from decarburization on the ground, turned, or polished surfaces.3.3.4.2 Allowable decarburization of bars and billets ordered for redrawing or forging or to specified microst
26、ructural 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 decarburization, inch/pound unitsNominal Diameter or DistanceBetween Parallel SidesInchesTot
27、al Depth ofDecarburizationInchUp to 0.375, incl 0.010Over 0.375 to 0.500, incl 0.012Over 0.500 to 0.625, 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 0.04
28、5Table 3B - Maximum decarburization, SI unitsNominal Diameter or DistanceBetween Parallel 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
29、50.80, incl 0.64Over 50.80 to 63.50, incl 0.76Over 63.50 to 76.20, incl 0.89Over 76.20 to 101.60, incl 1.143.3.4.4 Decarburization shall be evaluated by one of the two methods of 3.3.4.4.1 or 3.3.4.4.2.3.3.4.4.1 Metallographic MethodA cross section taken perpendicular to the surface shall be prepare
30、d, etched, and visually examined metallographically at a magnification not to exceed 100X. Optical indications of decarburization (including complete decarburization ferrite plus partial decarburization shall not exceed the limits of Table 3.SAE INTERNATIONAL AMS6412N Page 5 of 73.3.4.4.2 Hardness T
31、raverse MethodThe 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 changes in surface car
32、bon content. Depth of decarburization is defined as the perpendicular distance from the surface to the depth under that surface where there is not further increase in hardness. Such measurements shall be far enough away from any adjacent surface to be uninfluenced by any decarburization on the adjac
33、ent surface. Acceptance shall be as listed in Table 3.3.3.4.5 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 the width is 0.065 inch (1.65 mm)
34、or less. 3.3.4.6 In case of dispute, the total depth of decarburization determined using the microhardness traverse method shall govern.3.4 QualityThe product, as received by purchaser, shall be uniform in quality and condition, sound, and free from foreign materials and from imperfections detriment
35、al to usage of the product.3.4.1 Steel shall be aircraft quality conforming to AMS2301.3.4.2 Bars 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
36、to the machined, ground, turned, or polished surfaces.3.4.3 Grain flow of die forgings, except 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 TolerancesBars shall conform to all applicable requirements of A
37、MS2251.4. QUALITY ASSURANCE PROVISIONS4.1 Responsibility for InspectionThe producer of the product shall supply 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 ne
38、cessary to ensure that the product conforms to specified requirements.4.2 Classification of Tests4.2.1 Acceptance TestsComposition (3.1), condition/hardness (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 cl
39、eanliness rating (3.4.1), and tolerance (3.5) are acceptance tests and shall be performed on each heat or lot as applicable. 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.4.2.2 Periodic TestsIf grain refining elements (3.
40、3.2.2) are present, the ASTM E112 grain size test (3.3.2.1) shall be conducted 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
41、shall be performed at a frequency selected by the producer unless frequency of testing is specified by purchaser.SAE INTERNATIONAL AMS6412N Page 6 of 74.3 Sampling and Testing4.3.1 Bars and Forging StockIn accordance with AMS2370.4.3.2 ForgingsIn accordance with AMS2372.4.4 Reports4.4.1 The producer
42、 of bar and forgings shall furnish with each shipment a report showing producer identity, country where 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-severit
43、y cleanliness rating of each heat and for hardness and average grain size, if measured, of each lot, and stating that the product conforms to the other technical requirements, the purchase order number, heat and lot numbers, AMS6412N, product form and size or part number and quantity. If forgings ar
44、e 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 aluminum, vanadium and/or columbium content, the aluminum, vanadium and/or columbium content shall be reported and a statement that the chemistry sat
45、isfies the grain size requirement shall be included.4.4.2 The producer of forging stock shall furnish with each shipment a report showing producer identity, country where the metal was melted (e.g., final melt in the case of metal processed by multiple melting operations), the results of tests for c
46、omposition, macrostructure, hardenability and frequency-severity cleanliness rating of each heat. This report shall include the purchase order number, heat number, AMS6412N, size and quantity.4.5 Resampling and Retesting4.5.1 Bars and Forging StockIn accordance with AMS2370.4.5.2 ForgingsIn accordan
47、ce with AMS2372.5. PREPARATION FOR DELIVERY5.1 SizesExcept when exact lengths or multiples of exact lengths are ordered, straight bars will be acceptable in mill lengths of 6 to20 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 I
48、dentification5.2.1 BarsIn accordance with AMS2806.5.2.2 ForgingsIn accordance with AMS2808.5.2.3 Forging StockAs agreed upon by purchaser and producer.SAE INTERNATIONAL AMS6412N Page 7 of 75.3 Protective TreatmentBars ordered cold drawn, cold rolled, ground, turned, or polished shall be protected fr
49、om corrosion prior to shipment.5.4 PackagingThe product shall be prepared for shipment in 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 producer shall include this specification number and its revision letter in all qu
