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/AMS6415U AEROSPACE MATERIAL SPECIFICATION AMS6415 REV. U Issued 1940-01 Revised 2016-12Supersed
5、ing AMS6415T Steel, Bars, Forgings, and Tubing 0.80Cr - 1.8Ni - 0.25Mo (0.38 - 0.43C) (SAE 4340) (Composition similar to UNS G43406) RATIONALE AMS6415U results from a Five-Year Review and update of this specification that revises grain size requirement (3.3.2) and decarburization test procedures (3.
6、3.4.5), quality (3.4), and reporting (4.4). 1. SCOPE 1.1 Form This specification covers an aircraft-quality, low-alloy steel in the form of bars, forgings, mechanical tubing, and forging stock. 1.2 Application These products have been used typically for parts, 3.5 inches (89 mm) and under in nominal
7、 thickness at time of heat treatment, requiring a through-hardening steel capable of developing a minimum hardness of 40 HRC when properly hardened and tempered and also for parts of greater thickness, but requiring proportionately lower hardness. Usage is not limited to such applications. 1.2.1 Cer
8、tain design and 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 DOCUMENTS The issue of the following documents in effect on the date of the purchase order f
9、orms 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 th
10、at document shall apply. SAE INTERNATIONAL AMS6415U Page 2 of 9 2.1 SAE Publications Available 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 Bars A
11、MS2253 Tolerances Carbon and Alloy Steel Tubing AMS2259 Chemical Check Analysis Limits Wrought Low-Alloy and Carbon Steels AMS2301 Steel Cleanliness, Aircraft Quality Magnetic Particle Inspection Procedure AMS2370 Quality Assurance Sampling and Testing Carbon and Low-Alloy Steel Wrought Products and
12、 Forging Stock AMS2372 Quality Assurance Sampling and Testing Carbon and Low-Alloy Steel Forgings 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
13、of Steel Raw Materials 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 AS1182 Standard Stock Removal Allowance Aircraft-Quality and Premium Aircraft-Quality Steel
14、Bars and Mechanical Tubing 2.2 ASTM Publications Available 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 Steel ASTM A370 Mechanical Testing of Steel Products ASTM E112 Determini
15、ng Average Grain Size ASTM E140 Hardness Conversion Tables for Metals 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 Microindentation Hardness of Mat
16、erials SAE INTERNATIONAL AMS6415U Page 3 of 9 3. TECHNICAL REQUIREMENTS 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. Ta
17、ble 1 - Composition Element Min. Max. Carbon 0.38 0.43 Manganese 0.65 0.85 Silicon 0.15 0.35 Phosphorus - 0.025 Sulfur - 0.025 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
18、 or reported unless used to satisfy the average grain size requirements 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 and tensile strength shall be determined
19、 in accordance with ASTM A370: 3.2.1 Bars Bar shall not be cut from plate (also see 4.4.2). 3.2.1.1 Bars 0.500 Inch and Under in Nominal Diameter, or Least Distance between Parallel Sides Cold finished having tensile strength not higher than 125 ksi or hardness not higher than 27 HRC, or equivalent
20、(see 8.2). 3.2.1.2 Bars Over 0.500 Inch in Nominal Diameter, or Least Distance between Parallel Sides Hot finished and annealed, unless otherwise ordered, having hardness not higher than 235 HBW, or equivalent (see 8.2). Bars ordered cold finished may have hardness as high as 255 HBW, or equivalent
21、(see 8.2). 3.2.2 Forgings Normalized and tempered in accordance with AMS-H-6875 to a hardness not higher than 269 HBW, or equivalent, unless otherwise ordered (see 8.2). 3.2.3 Mechanical Tubing Cold finished, unless otherwise ordered, having hardness not higher than 25 HRC, or equivalent (see 8.2).
22、Tubing ordered hot finished and annealed shall have hardness not higher than 99 HRB, or equivalent (see 8.2). 3.2.4 Forging Stock As ordered by the forging manufacturer. SAE INTERNATIONAL AMS6415U Page 4 of 9 3.3 Properties The product shall conform to the following requirements; hardness testing sh
23、all 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 forging stock, etched in hot hydrochloric acid in accordance with ASTM E381, shall show no pipe or cracks. Porosity, segre
24、gation, inclusions, and other imperfections shall be no worse than the macrographs of ASTM E381 shown in Table 2. Table 2 - Macrostructure limits Cross-Sectional Area Square Inches Cross-Sectional Area Square Centimeters Macrographs Up to 36, incl Up to 232, incl S2 - R1 - C2 Over 36 to 100, incl Ov
25、er 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 and producer. The purchaser shall have written approval of the agreement from the cognizant engineering organization. 3.3.
26、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 as agreed upon by purchaser and producer. 3.3.2 Average Grain Size of Bars, Forgings and Tubing Average grain size shal
27、l 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 following are determined by heat analysis (see 8.6
28、): 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 Hardenability of Each Heat Shall be J 12/16 inch (19 mm) = 53 HRC minimum and
29、J 20/16 inch (32 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 F (871 C 6 C) and the test specimen austenitized at 1550 F 10 F (843 C 6 C). 3.3.4 Decarburization 3.3.4.1 Bars and tubing or
30、dered 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 of bars, billets, and tube rounds ordered for redrawing or forging
31、 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, shall not exceed the values shown in Table 3. SAE INTERNATIONAL AMS6415U Page 5 of 9 Table 3A - Maximum total depth of de
32、carburization, inch/pound units Nominal Diameter 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 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,
33、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 Diameter or Distance Between Parallel Sides Millimeters Total Depth of Decarburization Millimeters Up to 9.50, incl 0.25 Over
34、 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 0.76 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
35、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 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,
36、 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 Nominal Wall Thickness Millimeters Total Depth ID Millimeter Total Depth OD Millimeter Up to 2.75, incl 0.20 0.38 Over 2.75
37、 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 AMS6415U 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 Me
38、tallographic Method A cross section taken perpendicular to the surface shall be prepared, etched, and visually examined metallographically at a magnification not to exceed 100X. Optical indications of decarburiztion shall not show a layer of complete (ferrite) or partial decarburization exceeding th
39、e 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 in accordance with ASTM E384, at a magnification not exceeding 100X, conducted on a hardened, but untempered specimen, pro
40、tected 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 that surface where there is not further increase in hardness. Such measurements shall be far enough away from any adjacent
41、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, it is permissible to disregard local areas provided the decarburization of such areas does not exceed the above limits by
42、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 total depth of decarburization determined using the microindentation hardness traverse method shall govern. 3.4 Quality The product, as received by purchaser, shall be uniform in quality and
43、 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, except specimens containing nonmetallic inclusions over 1 inch (25 mm) in length, shall be subject to rejection. 3.4.2 Bars and
44、mechanical tubing shall be free from seams, laps, tears, 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 eviden
45、ce of reentrant grain flow. 3.5 Tolerances 3.5.1 Bars In accordance with AMS2251. 3.5.2 Mechanical Tubing In accordance with AMS2253. SAE INTERNATIONAL AMS6415U Page 7 of 9 4. QUALITY ASSURANCE PROVISIONS 4.1 Responsibility for Inspection The producer of the product shall supply all samples for prod
46、ucers 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 Tests 4.2.1 Acceptance Tests Compositio
47、n (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 rating (3.4.1), and tolerances (3.5) are acceptance tests and shall be performed on each heat or lot as applicable. If grain refining elements
48、(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 Tests If grain refining elements (3.3.2.2) 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 t
49、he producer (not to exceed 1 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 testing is specified by purchaser. 4.3 Sampling and Testing 4.3.1 Bars, Mechanical Tubing and Forging Stock In accordance with AMS2370. 4.3.2 Forgings In accordance with AMS2372
