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 ther
2、efrom, 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 2017 SAE International All rights reserved. No part of this
3、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: 877-606-7323 (inside USA and Canada) Tel: +1 724-776-49
4、70 (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/AMS6407K AEROSPACE MATERIAL SPECIFICATION AMS6407 REV. K Issued 1995-03 Revised 2017-09 Supers
5、eding AMS6407J Steel, Bars, Forgings, and Tubing 1.2Cr - 2.0Ni - 0.45Mo (0.27 - 0.33C) (Composition similar to UNS K33020) RATIONALE AMS6407K results from a Five-Year Review and update of this specification that revises grain size determination (3.1.1 and 3.3.2), decarburization testing methods (3.3
6、.5.4), surface quality (3.4.2), testing frequency (4.2), reporting (4.4) and identification (5.2). 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 prima
7、rily for parts requiring high tensile strength and hardness with good ductility and moderate impact strength, but usage is not limited to such applications. 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
8、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 apply. 2.1 SAE Publ
9、ications 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 AMS2253 Tolerances Carbon and Alloy Steel Tubing AMS2259 Chemical Check Analy
10、sis Limits Wrought Low-Alloy and Carbon Steels AMS2301 Steel Cleanliness, Aircraft Quality Magnetic Particle Inspection Procedure SAE INTERNATIONAL AMS6407K Page 2 of 9 AMS2370 Quality Assurance Sampling and Testing Carbon and Low-Alloy Steel Wrought Products and Forging Stock AMS2372 Quality Assura
11、nce 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 ARP1917 Clarification of Terms Used in Aerospace Metals Specifi
12、cations AS1182 Standard Stock Removal Allowance Aircraft-Quality and Premium Aircraft-Quality Steel 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 D
13、etermining the Hardenability of Steel ASTM A370 Mechanical Testing of Steel Products ASTM E23 Notched Bar Impact Testing of Metallic Materials ASTM E112 Determining Average Grain Size ASTM E140 Hardness Conversion Tables for Metals Relationship Among Brinell Hardness, Vickers Hardness, Rockwell Hard
14、ness, Superficial Hardness, Knoop Hardness, Scleroscope Hardness, and Leeb Hardness 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 H
15、ardness of Materials 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. Table 1 - Composition Eleme
16、nt Min Max Carbon 0.27 0.33 Manganese 0.60 0.80 Silicon 0.40 0.70 Phosphorus - 0.025 Sulfur - 0.025 Chromium 1.00 1.35 Nickel 1.85 2.25 Molybdenum 0.35 0.55 Copper - 0.35 SAE INTERNATIONAL AMS6407K Page 3 of 9 3.1.1 Aluminum, vanadium and columbium are optional grain refining elements and need not b
17、e determined 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 b
18、e determined 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 (12.70 mm) and Under in Nominal Diameter or Least Distance Between Parallel Sides Cold finished having tensile strength not higher than 125 ksi (862 MPa) or equivalent hard
19、ness (see 8.2). 3.2.1.2 Bars Over 0.500 Inch (12.70 mm) in Nominal Diameter or Least Distance Between Parallel Sides Hot finished and annealed, unless otherwise ordered, having hardness not higher than 241 HB, or equivalent (see 8.3). Bars ordered cold finished may have hardness as high as 248 HB, o
20、r equivalent (see 8.3). 3.2.2 Forgings As ordered. 3.2.3 Mechanical Tubing Cold finished, unless otherwise ordered, having hardness not higher than 25 HRC, or equivalent (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 For
21、ging Stock As ordered by the forging manufacturer. 3.3 Properties The product shall conform to the following requirements; hardness testing shall be performed in accordance with ASTM A370: SAE INTERNATIONAL AMS6407K Page 4 of 9 3.3.1 Macrostructure Visual examination of transverse full cross section
22、s 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, segregation, inclusions, and other imperfections shall be no worse than the macrographs of ASTM E381 shown in Table 2. Table
23、 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 133, incl Over 232 to 858, incl S2 - R2 C3 Over 133 Over 858 Note 1 Note 1: Limits for larger sizes shall be agreed upon by purchas
24、er and 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 sha
25、ll be 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
26、 have 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
27、 A columbium content of 0.02 to 0.05%. 3.3.3 Hardenability of Each Heat Shall be J4/16 inch (6.35 mm) = 48 HRC minimum and J20/16 inch (31.7 mm) = 47 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 10 F
28、 (927 C 6 C) and the test specimen austenitized at 1600 F 10 F (871 C 6 C). 3.3.4 Impact Strength of Bars, Forgings, and Tubing The Izod impact value shall be not less than 15 ft-lb force (20 Nm), determined at room temperature in accordance with ASTM E23 using a V-notched specimen as in 4.3.3. Spec
29、imens, before testing, shall have hardness not lower than 46 HRC after being quenched in oil from 1600 F 10 F (871 C 6 C) and tempered at not lower than 400 F (204 C). Specimens, before heat treatment, shall be to size or approximately to size except for the notch. 3.3.5 Decarburization 3.3.5.1 Bars
30、 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 4. SAE INTERNATIONAL AMS6407K Page 5 of 9 3.3.5.2 Decarburization of bars that 3.3.5.1 is
31、 not applicable shall be not greater than shown in Table 3. Table 3 Table 3A - Maximum allowable depth of decarburization, 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 0.5
32、00 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 allowable depth of decarburization, SI units Nominal Diameter or
33、Distance Between Parallel Sides Millimeters Total Depth of Decarburization, Millimeters Up to 9.52, incl 0.25 Over 9.52 to 12.70, incl 0.30 Over 12.70 to 15.88, incl 0.36 Over 15.88 to 25.40, incl 0.43 Over 25.40 to 38.10, incl 0.51 Over 38.10 to 50.80, incl 0.64 Over 50.80 to 63.50, incl 0.76 Over
34、63.50 to 76.20, incl 0.89 Over 76.20 to 101.60, incl 1.14 3.3.5.3 Decarburization of tubing that 3.3.5.1 is not applicable shall be not greater than shown in Table 4. Table 4 Table 4A - Maximum allowable depth of decarburization, inch/pound units Nominal Wall Thickness Inch Total Depth of Decarburiz
35、ation, Inch ID Total Depth of Decarburization, Inch OD 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 SAE INTERNATIONAL AMS6407K Page 6 of 9 T
36、able 4B - Maximum allowable depth of decarburization, SI units Nominal Wall Thickness Millimeters Total Depth of Decarburization, Millimeter ID Total Depth of Decarburization, Millimeters OD Up to 2.77, incl 0.20 0.38 Over 2.77 to 5.16, incl 0.25 0.51 Over 5.16 to 10.16, incl 0.30 0.64 Over 10.16 to
37、 15.24, incl 0.38 0.76 Over 15.24 to 25.40, incl 0.43 0.89 Over 25.40 0.51 1.02 3.3.5.4 Decarburization shall be evaluated by one of the two methods of 3.3.5.4.1 or 3.3.5.4.2, selected at the discretion of the producer. 3.3.5.4.1 Metallographic Method A cross section taken perpendicular to the surfa
38、ce shall be prepared, etched, and visually examined metallographically at a magnification not to exceed 100X. The product shall not show a layer of complete (ferrite) or partial decarburization exceeding the limits of Tables 3 or 4. 3.3.5.4.2 Hardness Traverse Method The total depth of decarburizati
39、on 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 protected during heat treatment to prevent changes in surface carbon content. Depth of decarburizat
40、ion 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 adjacent surface. Acceptance shall be a
41、s listed in Tables 3 or 4. 3.3.5.4.3 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) or less. 3.3.5.4.4 In cas
42、e 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 condition, sound, and free from foreign materials and from imperfections detrimental to usa
43、ge of the product. 3.4.1 Steel shall be aircraft-quality conforming to AMS2301. 3.4.2 Bars and 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 which contain fla
44、sh-line end grain, shall follow the general contour of the forgings showing no evidence 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 AMS6407K Page 7 of 9 4. QUALITY ASSURANCE PROVISIONS 4.1 Respon
45、sibility 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 reserves the right to sample and to perform any confirmatory testing deemed necessary to ensure that the product conforms to
46、specified requirements. 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), impact strength (3.3.4), decarburization (3.3.5), frequency-severity cleanliness ratings (3.4.1), and tolerances (
47、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 Tests Grain flow of die forgings (3.4.3) is a periodic test and shall be pe
48、rformed at a frequency selected by the producer, unless a frequency is specified by the purchaser. 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 the producer (not to e
49、xceed 1 year) 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. 4.3.3 Samples for impact testing (3.3.4) shall be taken longitudinally from sections rolled or forged from full cross-section or quarter-section to not over 2 inches (51 mm) round or square.
