1、AEROSPACE MATERIAL SPECIFICATIONAMS6428 REV. KIssued 1953-06Revised 2014-07Superseding AMS6428JSteel, Bars, Forgings, and Tubing0.78Cr - 1.8Ni - 0.35Mo - 0.20V (0.32 - 0.38C) (4335 Mod)(Composition similar to UNS K33517)RATIONALEAMS6428K results from a Five Year Review and update of this specificati
2、on that revises the title, cutting restrictions, macrostructure, decarburization, and reporting requirements.1. SCOPE1.1 FormThis 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
3、 typically for heat treated parts up to 4 inches (1102 mm) round or equivalent cross-section that require through hardening to tensile strength not lower than 180 ksi (1241 MPa) and that may require welding after heat treatment, but usage is not limited to such applications.1.2.1 Certain design and
4、processing procedures may cause these products to become susceptible to stress-corrosion cracking after heat treatment. ARP1110 recommends practices to minimize such conditions.2. APPLICABLE DOCUMENTSThe issue of the following documents in effect on the date of the purchase order forms a part of thi
5、s 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 document shall
6、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-Alloy Steel BarsAMS2253 Tolerances, Carbon and Alloy Steel TubingAMS2259 Chemica
7、l Check Analysis Limits, Wrought Low-Alloy and Carbon Steels_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 part
8、icular use, including any patent infringement arising therefrom, 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 2014
9、 SAE InternationalAll rights reserved. No part of this publication 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: 8
10、77-606-7323 (inside USA and Canada)Tel: +1 724-776-4970 (outside 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/AMS6428KSAE INTERNATIONAL AMS6428
11、K Page 2 of 8AMS2301 Steel Cleanliness, Aircraft Quality, Magnetic Particle Inspection ProcedureAMS2370 Quality Assurance Sampling and Testing, Carbon and Low-Alloy Steel Wrought Products and Forging StockAMS2372 Quality Assurance Sampling and Testing, Carbon and Low-Alloy Steel ForgingsAMS2806 Iden
12、tification, Bars, Wire, Mechanical Tubing, and Extrusions, Carbon and Alloy Steels and Corrosion and Heat-Resistant Steels and AlloysAMS2808 Identification, ForgingsARP1110 Minimizing Stress Corrosion Cracking in Wrought Forms of Steels and Corrosion-Resistant Steels and AlloysAS1182 Standard Stock
13、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 A 255 Determining Hardenability of Ste
14、elsASTM A 370 Mechanical Testing 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 Vi
15、ckers 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 E 350, by spectrochemical methods, or by other analytical methods acceptable to purchaser.TABLE 1 - COMPOSITIONEl
16、ement min maxCarbon 0.32 0.38Manganese 0.60 0.80Silicon 0.15 0.35Phosphorous - 0.025Sulfur - 0.025Chromium 0.65 0.90Nickel 1.65 2.00Molybdenum 0.30 0.40Vanadium 0.17 0.23Copper - 0.35SAE INTERNATIONAL AMS6428K Page 3 of 83.1.1 Check AnalysisComposition variations shall meet the applicable requiremen
17、ts 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 370:3.2.1 Bars3.2.1.1 Bars 0.500 Inch (12.70 mm) and Under in Nominal Diameter or Least Distance Between Parallel SidesAnnealed and cold fi
18、nished 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 Parallel SidesHot finished and annealed, unless otherwise ordered, having hardness not higher than 248 HB, or equiva
19、lent (See 8.3). Bars ordered cold finished may have hardness as high as 262 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 ForgingsAs ordered.3.2.3 Mechanical TubingCold finished, unless otherwise ordered, having hardness not higher than 25 HRC, or equival
20、ent (See 8.3). Tubing ordered hot finished 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 accordan
21、ce 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 show no pipe or cracks. Porosity, segregation, inclusions, and other imperfections shal
22、l be no worse than the macrographs of ASTM 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
23、 1Note 1: Limits for larger sizes shall be agreed upon by purchaser and vendor. The purchaser shall have written approval from the cognizant engineering organization3.3.2 Average Grain Size of Bars, Forgings and TubingShall be ASTM No. 5 or finer, determined in accordance with ASTM E 112.SAE INTERNA
24、TIONAL AMS6428K Page 4 of 83.3.3 Hardenability of Each HeatShall be J 1/16 inch (1.6 mm) = 58 HRC minimum and J 15/16 inch (23.8 mm) = 48 HRC minimum, determined 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) an
25、d the test specimen austenitized at 1625 F 10 (885 C 6).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
26、4.3.3.4.2 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 3.3.4.1 or 3.3.4.2 is not applicable shall be not greater than
27、shown in Table 3.TABLE 3A - MAXIMUM TOTAL 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 0.625, incl 0.014Over 0.625 to 1.000, incl 0.017Over 1.000
28、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 TOTAL DEPTH OF DECARBURIZATION, SI UNITSNominal Diameter or DistanceBetween Parallel SidesMillimetersTotal Depth ofDecarburizationMillime
29、tersUp 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 101.60, incl 1.143.3.4.4 Decarburization of tubing t
30、o which 3.3.4.1 or 3.3.4.2 is not applicable shall be not greater than shown in Table 4.SAE INTERNATIONAL AMS6428K Page 5 of 8TABLE 4A - MAXIMUM TOTAL DEPTH OF DECARBURIZATION, INCH/POUND UNITSNominal Wall ThicknessInchesTotal Depth ofDecarburizationInchIDTotal Depth ofDecarburizationInchODUp to 0.1
31、09, 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 TOTAL DEPTH OF DECARBURIZATION, SI UNITSNominal Wall ThicknessMillimetersTotal Depth ofDeca
32、rburizationMillimeterIDTotal Depth ofDecarburizationMillimetersODUp 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 met
33、allographic method or by the microhardness traverse 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 decarburizati
34、on, when measured by a microhardness method, is 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
35、 adjacent surface. In case of dispute, the depth 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
36、 limits by more than 0.005 inch (0.13 mm) and the 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
37、aircraft quality conforming to AMS2301.3.4.2 Bars and 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 ground, turned, or polished sur
38、face.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 Tolerances3.5.1 BarsIn accordance with AMS2251.SAE INTERNATIONAL AMS6428K Page 6 of 83.5.2 Mechanical TubingIn ac
39、cordance 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 testin
40、g deemed 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 rat
41、ing (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
42、.4.3 Sampling and Testing4.3.1 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 the producer identity, country where the metal was
43、 melted (e. g., final melt in the case of metal processed by multiple meltingoperations), the results of tests for composition, macrostructure, hardenability, and frequency-severity cleanliness rating of each heat and for condition and average grain size of each lot, and stating that the product con
44、forms to the other technical requirements. This report shall include the purchase order number, heat and lot numbers, AMS6428K, product form and size (and/or part number, if applicable), and quantity. If forgings are supplied, size and melt source of stock used to make the forgings shall also be inc
45、luded.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 vendor of forging stock shall furnish with each shipment a report showing the producer identity, country where the metal was melted (e. g., final melt in the case of
46、 metal processed by multiple melting operations) and the results of tests for composition, macrostructure, hardenability, and frequency-severity cleanliness rating of each heat. This report shall include the purchase order number, heat number, AMS6428K, size and quantity4.5 Resampling and Retesting4
47、.5.1 Bars, Mechanical Tubing, and Forging StockIn accordance with AMS2370.SAE INTERNATIONAL AMS6428K 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 acceptabl
48、e 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 Identification5.2.1 Bars and Mechanical TubingIn accordance with AMS2806.5.2.2 ForgingsIn accordance with AMS2808.5.2.3 Forging StockAs agreed upon by pu
49、rchaser 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 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 acc
