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 reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions.Copyright 2012 SAE InternationalAll rights reserved. No part of this publication may b
3、e 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 (outside USA)Fax
4、: 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/AMS6408DAEROSPACEMATERIALSPECIFICATIONAMS6408 REV. DIssued 1989-01Revised 2013-01Superseding AMS6408CStee
5、l, Hotwork Tool, Bars and Forgings5.25Cr 1.5Mo 1.0V (0.35-0.45C) (H-13)Electroslag Remelted (ESR) or Consumable Electrode Vacuum Arc Remelted (VAR)Annealed(Composition similar to UNS T20813)RATIONALEAMS6408D is a five year review and update of this specification.1. SCOPE1.1 FormThis specification co
6、vers a premium aircraft-quality, low-alloy steel in the form of bars, forgings, and forging stock.1.2 ApplicationThese products have been used typically for hotwork tooling or for parts requiring a steel capable of through-hardening to a minimum hardness of 50 HRC in section thicknesses up to 12 inc
7、hes (305 mm) with relatively high levels of strength, fatigue resistance, ductility, and thermal stability for use in service from -100 to +1000 F (-73 to +538 C) and where such parts may require welding, but usage is not limited to such applications.1.2.1 Certain design and processing procedures ma
8、y 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 this document to the extent
9、 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.SAE AMS6408D Page 2 of
10、82.1 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 BarsAMS2259 Chemical Check Analysis Limits, Wrought Low-Alloy and Carbon
11、SteelsAMS2300 Steel Cleanliness, Premium 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 Id
12、entification, 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 Heat Treatable Wrought Low-Alloy and Martensitic Corrosion-Resistant SteelsAS1182 Sta
13、ndard 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 A 370 Mechanical Testing o
14、f Steel ProductsASTM A 604 Macroetch Testing of Consumable Electrode Remelted Steel Bars and BilletsASTM E 45 Determining the Inclusion Content of SteelsASTM E 112 Determining Average Grain SizeASTM E 350 Chemical Analysis of Carbon Steel, Low-Alloy Steel, Silicon Electrical Steel, Ingot Iron, and W
15、rought IronASTM E 384 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 E 350, by spectrochemical methods, or by other analytical methods acceptable to
16、 purchaser.SAE AMS6408D Page 3 of 8TABLE 1 - COMPOSITIONElement min maxCarbon 0.35 0.45Manganese 0.20 0.50Silicon 0.85 1.20Phosphorus - 0.020Sulfur - 0.008Chromium 5.00 5.50Molybdenum 1.20 1.75Vanadium 0.85 1.203.1.1 Check AnalysisComposition variations shall meet the applicable requirements of AMS2
17、259.3.2 Melting PracticeSteel shall be multiple melted using either electroslag remelting (ESR) practice or consumable electrode vacuum arc remelting (VAR) practice as the final melting process.3.3 ConditionThe product shall be supplied in the following condition; hardness and tensile strength shall
18、 be determined in accordance with ASTM A 370:3.3.1 BarsBars shall not be cut from plate. (Also see 4.4.2.)3.3.1.1 Bars 0.500 Inch (12.70 mm) and Under in Nominal Diameter or Least Distance Between Parallel SidesCold finished and annealed having hardness not higher than 262 HB, or equivalent (See 8.2
19、).3.3.1.2 Bars Over 0.500 Inch (12.70 mm) in Nominal Diameter or Least Distance Between Parallel SidesHot or cold finished and annealed having hardness not higher than 235 HB, or equivalent (See 8.2).3.3.2 ForgingsAnnealed having hardness not higher than 217 HB, or equivalent (See 8.2).3.3.3 Forging
20、 StockAs ordered by the forging manufacturer.3.4 PropertiesThe product shall conform to the following requirements; hardness and tensile testing shall be performed in accordance with ASTM A 370:3.4.1 MacrostructureVisual examination of transverse full cross-sections from bars, billets, and forging s
21、tock, etched in hot hydrochloric acid in accordance with ASTM A 604, shall show no pipe or cracks. Porosity, segregation, inclusions, and other imperfections shall be no worse than the macrographs of ASTM A 604 shown in Table 2.SAE AMS6408D Page 4 of 8TABLE 2 - MACROSTRUCTURE LIMITSClass Condition S
22、everity1Freckles A2 White Spots B3 Radial Segregation B4 Ring Pattern B3.4.2 Micro-Inclusion Rating of Each HeatNo specimen shall exceed the limits shown in Table 3, determined in accordance with ASTM E 45, Method D.3.4.2.1 A rateable field is defined as one that has a Type A, B, C, or D inclusion r
23、ating of at least No. 1.0 thin or heavy in accordance with the Jernkontoret chart, Plate I-r, ASTM E 45.TABLE 3 - MICRO-INCLUSION RATING LIMITSAThinAHeavyBThinBHeavyCThinCHeavyDThinDHeavyWorst Field Severity 1.5 1.0 1.5 1.0 1.5 1.0 2.0 1.0Worst Field Frequency,maximuma1 a 1 a 1 3 1Total Rateable Fie
24、lds,Frequency, maximumb1 b 1 b 1 8 1a - Combined A+B+C, not more than 3 fieldsb - Combined A+B+C, not more than 8 fields3.4.3 Decarburization3.4.3.1 Bars ordered ground, turned, or polished shall be free from decarburization on the ground, turned, or polished surfaces.3.4.3.2 Allowable decarburizati
25、on of bars and billets ordered for redrawing or forging or to specified microstructural requirements shall be as agreed upon by purchaser and vendor.3.4.3.3 Decarburization of bars when 3.4.3.1 or 3.4.3.2 is not applicable shall be not greater than shown in Table 4.TABLE 4A - MAXIMUM DEPTH OF DECARB
26、URIZATION, INCH/POUND UNITSNominal Diameter or DistanceBetween Parallel SidesInchesTotal Depth of DecarburizationInchUp to 0.375, incl 0.010Over 0.375 to 0.500, incl 0.015Over 0.500 to 0.625, incl 0.020Over 0.625 to 1.000, incl 0.025Over 1.000 to 2.000, incl 0.035Over 2.000 to 3.000, incl 0.048Over
27、3.000 to 4.000, incl 0.062Over 4.000 to 5.000, incl 0.094Over 5.000 0.125SAE AMS6408D Page 5 of 8TABLE 4B - MAXIMUM DEPTH OF DECARBURIZATION, SI UNITSNominal Diameter or DistanceBetween Parallel SidesMillimetersTotal Depth of DecarburizationMillimetersUp to 9.52, incl 0.25Over 9.52 to 12.70, incl 0.
28、38Over 12.70 to 15.88, incl 0.51Over 15.88 to 25.40, incl 0.64Over 25.40 to 50.80, incl 0.89Over 50.80 to 76.20, incl 1.22Over 76.20 to 101.60, incl 1.57Over 101.60 to 127.00, incl 2.39Over 127.00 3.183.4.3.4 Decarburization shall be measured by the metallographic method, by the HR30N scale hardness
29、 testing method, or by a traverse method using microhardness testing in accordance with ASTM E 384. The hardness method(s) 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
30、 a hardness method, is defined as the perpendicular distance from the surface to the depth under that surface below which 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.
31、In case of dispute, the depth of decarburization determined using the microhardness traverse method shall govern.3.4.3.4.1 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 tha
32、n 0.005 inch (0.13 mm) and the width is 0.065 inch (1.65 mm) or less.3.4.4 Response to Heat TreatmentExtracted specimens as in 3.4.4.1 shall conform to the following requirements after being austenitized by heating to 1850 F 25 (1010 C 14), holding at heat for 15 to 45 minutes, cooling to room tempe
33、rature at a rate equivalent to air cooling, and double tempered by heating to a temperature not lower than 1100 F (593 C), holding at heat for 2 to 3 hours, and cooling in air:3.4.4.1 Longitudinal Tensile PropertiesThe requirements shown in Table 5 apply to specimens taken from bars and forging stoc
34、k 25 square inches (161 cm2) and under in cross-sectional area, from forgings with axis approximately parallel to the forging flow lines, and to specimens from coupons of stock over 25 square inches (161 cm2) in cross-sectional area that has been forged to 25 square inches (161 cm2) in cross-section
35、al area prior to heat treatment as in 3.4.4.TABLE 5 - MINIMUM TENSILE PROPERTIESRequirement ValueTensile Strength 205 ksi (1413 MPa)Yield Strength at 0.2% Offset 180 ksi (1241 MPa)Elongation in 4D 8%Reduction of Area 20%3.4.4.2 HardnessShall be 44 to 50 HRC, or equivalent (See 8.2).SAE AMS6408D Page
36、 6 of 83.4.4.3 Average Grain Size of Bars and ForgingsShall be as follows, determined in accordance with ASTM E 112:3.4.4.3.1 Bars and Forgings Up to 2.50 Inches (63.5 mm) in Nominal Diameter, Distance Between Parallel Sides, or Cross-Sectional DimensionShall be ASTM No. 7 or finer.3.4.4.3.2 Bars an
37、d Forgings Over 2.50 Inches (63.5 mm) in Nominal Diameter, Distance Between Parallel Sides, or Cross-Sectional DimensionShall be ASTM No. 5 or finer.3.5 QualityThe product, as received by purchaser, shall be uniform in quality and condition, sound, and free from foreign materials and from imperfecti
38、ons detrimental to usage of the product.3.5.1 Steel shall be premium aircraft-quality conforming to AMS2300.3.5.2 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.3.5.3 Bars ord
39、ered 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.3.6 TolerancesBars shall conform to all applicabl
40、e requirements of AMS2251.4. 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 te
41、sting deemed necessary to ensure that the product conforms to specified requirements.4.2 Classification of Tests4.2.1 Acceptance TestsComposition (3.1), condition (3.3), macrostructure (3.4.1), micro-inclusion rating (3.4.2), response to heat treatment (3.4.4), average grain size (3.4.4.3), and tole
42、rances (3.6), are acceptance tests and shall be performed on each heat or lot as applicable.4.2.2 Periodic TestsFrequency-severity cleanliness rating (3.5.1) and grain flow of forgings (3.5.2) are periodic tests and shall be performed at a frequency selected by the vendor unless frequency of testing
43、 is specified by purchaser.SAE AMS6408D Page 7 of 84.3 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 vendor of bars and forgings shall furnish with each shipment a report showing the results of tests for compo
44、sition, macrostructure, and micro-inclusion rating of each heat, and for the average grain size, tensile properties, and hardness after 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
45、 lot numbers, AMS6408D, 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.4.4.2 If the ship size/shape is cut from a larger cross section, report the nominal metallurgi
46、cally worked size (See 3.3.1).4.4.3 The vendor of forging stock shall furnish with each shipment a report showing the results of tests for composition, macrostructure, micro-inclusion rating and response to heat treatment of each heat. This report shall include the purchase order number, heat number
47、, AMS6408D, size and quantity.4.5 Resampling and Retesting4.5.1 Bars and Forging StockIn accordance with AMS2370.4.5.2 ForgingsIn accordance 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
48、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 BarsIn accordance with AMS2806.5.2.2 ForgingsIn accordance with AMS2808.5.2.3 Forging StockAs agreed upon by purchaser and vendor.SAE AMS6408D
49、 Page 8 of 85.3 Protective TreatmentBars 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 acceptance and safe delivery.6. ACKNO
