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 there
2、from, 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 2016 SAE International All rights reserved. No part of this p
3、ublication 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: +1 724-776-497
4、0 (outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To provide feedback on this Technical Report, please visit http:/standards.sae.org/AMS6409E AEROSPACE MATERIAL SPECIFICATION AMS6409 REV. E Issued 1987-01 Revised 2016-12Supersed
5、ing AMS6409D Steel, Bars, Forgings, and Tubing 0.80Cr - 1.8Ni - 0.25Mo (0.38 - 0.43C) (SAE 4340) Special Aircraft Quality Cleanliness Normalized and Tempered (Composition similar to UNS G43406) RATIONALE AMS6409E results from a Five Year Review and update of this specification that revises grain siz
6、e requirements (3.1.1 and 3.3.2), hardness testing of condition (3.2.1), decarburization testing methods (3.3.4.5), quality (3.4) and reporting (4.4). 1. SCOPE 1.1 Form This specification covers a low-alloy steel in the form of bars, forgings, mechanical tubing, and forging stock. 1.2 Application Th
7、ese products have been used typically for parts required to meet stringent magnetic particle inspection criteria, having sections 3.5 inches (89 mm) and under in nominal thickness at time of heat treatment, and requiring a through-hardening steel capable of developing a minimum hardness of 40 HRC wh
8、en properly hardened and tempered and also for parts of greater thickness, but requiring proportionately lower hardness, but usage is not limited to such applications. 1.2.1 Certain design and processing procedures may cause these products to become susceptible to stress-corrosion cracking after hea
9、t treatment; ARP1110 recommends practices to minimize such conditions. 1.2.2 These products are not recommended for use in parts heat treated to a hardness greater than 46 HRC (ultimate tensile strength over 220 ksi (1517 MPa) or where the high transverse properties of remelted steel are required (s
10、ee 8.2). 2. APPLICABLE DOCUMENTS The issue of the following 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 re
11、ferenced document has been cancelled and no superseding document has been specified, the last published issue of that document shall apply. SAE INTERNATIONAL AMS6409E Page 2 of 9 2.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-73
12、23 (inside USA and Canada) or +1 724-776-4970 (outside USA), www.sae.org. AMS2251 Tolerances Low-Alloy Steel Bars AMS2253 Tolerances Carbon and Alloy Steel Tubing AMS2259 Chemical Check Analysis Limits Wrought Low-Alloy and Carbon Steels AMS2304 Steel Cleanliness, Special Aircraft-Quality Magnetic P
13、article Inspection Procedure AMS2370 Quality Assurance Sampling and Testing Carbon and Low-Alloy Steel Wrought Products and Forging Stock AMS2372 Quality Assurance Sampling and Testing Carbon and Low-Alloy Steel Forgings AMS2759/1 Heat Treatement of Carbon and Low-Alloy Steel Parts Minimum Tensile S
14、trength Below 220 ksi (1517 MPa) AMS2806 Identification Bars, Wire, Mechanical Tubing, and Extrusions Carbon and Alloy Steels and Corrosion and Heat-Resistant Steels and Alloys AMS2808 Identification Forgings AMS-H-6875 Heat Treatment of Steel Raw Materials AS1182 Standard Stock Removal Allowance Ai
15、rcraft-Quality and Premium Aircraft-Quality Steel Bars and Mechanical Tubing ARP1110 Minimizing Stress Corrosion Cracking in Wrought Forms of Steels and Corrosion Resistant Steels and Alloys ARP1917 Clarification of Terms Used in Aerospace Metals Specifications 2.2 ASTM Publications Available from A
16、STM 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 Steel ASTM A370 Mechanical Testing of Steel Products ASTM E112 Determining Average Grain Size ASTM E140 Hardness Conversion Tables for Me
17、tals ASTM E350 Chemical Analysis of Carbon Steel, Low-Alloy Steel, Silicon Electrical Steel, Ingot Iron, and Wrought Iron ASTM E381 Macroetch Testing Steel Bars, Billets, Blooms, and Forgings ASTM E384 Microindentration Hardness of Materials SAE INTERNATIONAL AMS6409E Page 3 of 9 3. TECHNICAL REQUIR
18、EMENTS 3.1 Composition Shall 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 - Composition Element Min. Max. Carbon 0.38 0.43 Manganese
19、0.65 0.85 Silicon 0.15 0.35 Phosphorus - 0.015 Sulfur - 0.008 Chromium 0.70 0.90 Nickel 1.65 2.00 Molybdenum 0.20 0.30 Copper - 0.35 3.1.1 Aluminum, vanadium and columbium are optional grain refining elements and need not be determined or reported unless used to satisfy the average grain size requir
20、ements of 3.3.2.2. 3.1.2 Check Analysis Composition variations shall meet the applicable requirements of AMS2259. 3.2 Condition The product shall be supplied in the following condition; hardness shall be determined in accordance with ASTM A370: 3.2.1 Bars Normalized at 1650 F 25 F (899 C 14 C) and t
21、empered, having hardness at mid-radius not higher than 322 HBW, or equivalent (see 8.3). Bars shall have a turned, ground, polished, or burnished surface; surface hardness shall be not more than 3 points HRC harder than mid-radius hardness. Bars with a mid-radius hardness less than 20 HRC shall not
22、have a surface hardness greater than that of the mid-radius hardness by the equivalent of 20 HBW. 3.2.1.1 When hot finished or cold drawn bars are specified, the surface hardness shall be not more than 3 points HRC harder than the mid-radius hardness as in 3.2.1. Bars with a mid-radius hardness less
23、 than 20 HRC shall not have a surface hardness greater than that of the mid-radius hardness by the equivalent of 20 HBW. 3.2.1.2 Bar shall not be cut from plate (also see 4.4.2). 3.2.2 Forgings Normalized and tempered in accordance with AMS-H-6875 having hardness not higher than 322 HBW, or equivale
24、nt (see 8.3). 3.2.3 Mechanical Tubing Normalized and tempered having hardness not higher than 322 HBW, or equivalent (see 8.3). Tubing 1.0 inch (25 mm) and under in nominal OD shall be cold reduced; larger sizes shall be hot rolled. 3.2.4 Forging Stock As ordered by the forging manufacturer. SAE INT
25、ERNATIONAL AMS6409E Page 4 of 9 3.3 Properties The product shall conform to the following requirements; hardness testing shall be performed in accordance with ASTM A370: 3.3.1 Macrostructure Visual examination of transverse full cross-sections from bars, billets, tube rounds (solid, not hollow), and
26、 forging stock, etched in hot hydrochloric acid in accordance with ASTM 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 limits Cross-Section Area Square Inche
27、s Cross-Sectional Area Square Centimeters Macrographs Up to 36, incl Up to 232, incl S2 - R1 - C2 Over 36 to 100, incl Over 232 to 645. incl S2 - R2 C2 Over 100 to 133. incl Over 645 to 858, incl S2 - R2 - C3 Over 133 Over 858 Note 1 Note 1 Limits for larger sizes shall be agreed upon by purchaser a
28、nd producer. The purchaser shall have written approval of the agreement from the 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 b
29、e as agreed upon by purchaser and producer. 3.3.2 Average Grain Size of Bars, Forgings and Tubing Average 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 h
30、ave an ASTM No. 5 or finer austenitic grain size if one or more of the following are determined by heat analysis (see 8.7): 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
31、 columbium content of 0.02 to 0.05%. 3.3.3 Hardenability of Each Heat Shall be J 12/16 inch (J19 mm) = 53 HRC, minimum, and J 20/16 inch (J32 mm) = 50 HRC, minimum, determined on the standard end-quench test specimen in accordance with ASTM A255 except that the steel shall be normalized at 1600 F 10
32、 F (871 C 6 C) and the specimen austenitized at 1550 F 10 F (843 C 6 C ). 3.3.4 Decarburization 3.3.4.1 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
33、specified in Table 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 producer. 3.3.4.3 Decarburization of bars, for which 3.3.4.1 or 3.3.4.2 are not applicable,
34、 shall not exceed the values shown in Table 3. SAE INTERNATIONAL AMS6409E Page 5 of 9 Table 3A - Maximum total depth of decarburization, inch/pound units Nominal Thickness or Distance Between Parallel Sides Inches Total Depth of Decarburization Inch Up to 0.375, incl 0.010 Over 0.375 to 0.500, incl
35、0.012 Over 0.500 to 0.625, incl 0.014 Over 0.625 to 1.000, incl 0.017 Over 1.000 to 1.500, incl 0.020 Over 1.500 to 2.000, incl 0.025 Over 2.000 to 2.500, incl 0.030 Over 2.500 to 3.000, incl 0.035 Over 3.000 to 4.000, incl 0.045 Table 3B - Maximum total depth of decarburization, SI units Nominal Di
36、ameter or Distance Between Parallel Sides Millimeters Total Depth of Decarburization Millimeters Up to 9.50, incl 0.25 Over 9.50 to 12.50, incl 0.30 Over 12.50 to 15.65, incl 0.36 Over 15.65 to 25.00, incl 0.43 Over 25.00 to 37.50, incl 0.51 Over 37.50 to 50.00, incl 0.64 Over 50.00 to 62.50, incl 0
37、.76 Over 62.50 to 75.00, incl 0.89 Over 75.00 to 100.00, incl 1.14 3.3.4.4 Decarburization of tubing, for which 3.3.4.1 or 3.3.4.2 are not applicable, shall not exceed the values shown in Table 4. Table 4A - Maximum total depth of decarburization, inch/pound units Nominal Wall Thickness Inches Total
38、 Depth ID Inch Total Depth OD Inch Up to 0.109, incl 0.008 0.015 Over 0.109 to 0.203, incl 0.010 0.020 Over 0.203 to 0.400, incl 0.012 0.025 Over 0.400 to 0.600, incl 0.015 0.030 Over 0.600 to 1.000, incl 0.017 0.035 Over 1.000 0.020 0.040 Table 4B - Maximum total depth of decarburization, SI units
39、Nominal Wall Thickness Millimeters Total Depth ID Millimeter Total Depth OD Millimeter Up to 2.75, incl 0.20 0.38 Over 2.75 to 5.00, incl 0.25 0.51 Over 5.00 to 10.00, incl 0.30 0.64 Over 10.00 to 15.00, incl 0.35 0.76 Over 15.00 to 25.00, incl 0.40 0.89 Over 25.00 0.50 1.02 SAE INTERNATIONAL AMS640
40、9E Page 6 of 9 3.3.4.5 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 Method A cross section taken perpendicular to the surface shall be prepared, etched, and visually examined metallographically at a magnification not to exceed 100X.
41、 Optical indications of decarburiztion shall not show a layer of complete (ferrite) or partial decarburization exceeding the limits of Tables 3 or 4. 3.3.4.5.2 Hardness Traverse Method The total depth of decarburization shall be determined by a traverse method using microindentation hardness testing
42、 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 carbon content. Depth of decarburization is defined as the perpendicular distance from the surface to the depth under
43、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 adjacent surface. Acceptance shall be as listed in Tables 3 or 4. 3.3.4.6 When determining the depth of decarburization,
44、 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) or less. 3.3.4.7 In case of dispute, the depth of decarburization determined using the microindentation hard
45、ness traverse method shall govern. 3.3.5 Tensile Properties After being heat treated in accordance with AMS2759/1 to an ultimate tensile strength range of 180 to 200 ksi (1241 to 1379 MPa), product shall have a transverse reduction of area not lower than 15% (see 1.2.2). 3.4 Quality The product, as
46、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 special aircraft-quality conforming to AMS2304. 3.4.2 Bars and mechanical tubing shall be free from seams, laps, t
47、ears, and cracks after removal of the standard stock removal allowance in accordance with AS1182. 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 Tolerances 3.5.1 Ba
48、rs In accordance with AMS2251. 3.5.2 Mechanical Tubing In accordance with AMS2253. 4. QUALITY ASSURANCE PROVISIONS 4.1 Responsibility for Inspection The producer of the product shall supply all samples for producers tests and shall be responsible for the performance of all required tests. Purchaser
49、reserves the right to sample and to perform any confirmatory testing deemed necessary to ensure that the product conforms to specified requirements. SAE INTERNATIONAL AMS6409E Page 7 of 9 4.2 Classification of Tests 4.2.1 Acceptance Tests Composition (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 c
