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 2015 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:/www.sae.org/technical/standards/AMS6440S AEROSPACE MATERIAL SPECIFICATION AMS6440 REV. S Issued 1939-12 Revised 2
5、015-12 Superseding AMS6440R Steel, Bars, Forgings, and Tubing 1.45Cr (0.93 - 1.05C) (SAE 52100) For Bearing Applications (Composition similar to UNS G52986) RATIONALE AMS6440S results from a Five Year Review and update of this document that revises decarburization requirements and reporting. 1. SCOP
6、E 1.1 Form This specification covers a low-alloy steel in the form of bars, forgings, mechanical tubing, and forging stock. 1.2 Application These products have been used typically for bearing components requiring a through-hardening steel, usually with hardness of approximately 60 HRC and section th
7、ickness under 0.50 inch (12.7 mm), 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 the extent specified herein. The supplier may work to a subsequent revision
8、 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 Publications Available from SAE International, 400 Commonwealth Drive, Warrenda
9、le, 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 Analysis Limits, Wrought Low-Alloy and Carbon Steels AMS2301 Steel Cleanliness
10、, Aircraft-Quality Magnetic Particle Inspection Procedure SAE INTERNATIONAL AMS6440S Page 2 of 8 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 AMS2806 Id
11、entification Bars, Wire, Mechanical Tubing, and Extrusions, Carbon and Alloy Steels and Corrosion and Heat-Resistant Steels and Alloys AMS2808 Identification Forgings AS1182 Standard Stock Removal Allowance Aircraft-Quality and Premium Aircraft-Quality Steel Bars and Mechanical Tubing 2.2 ASTM Publi
12、cations 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 A370 Mechanical Testing of Steel Products ASTM E45 Determining the Inclusion Content of Steel ASTM E350 Chemical Analysis of Carbon Steel, Low-Allo
13、y Steel, Silicon Electrical Steel, Ingot Iron, and Wrought Iron ASTM E381 Macroetch Testing Steel Bars, Billets, Blooms, and Forgings ASTM E384 Knoop and Vickers Hardness of Materials 3. TECHNICAL REQUIREMENTS 3.1 Composition Shall conform to the percentages by weight shown in Table 1, determined by
14、 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 0.93 1.05 Manganese 0.25 0.45 Silicon 0.15 0.35 Phosphorus - 0.025 Sulfur - 0.015 Chromium 1.35 1.60 Nickel - 0.25 Moly
15、bdenum - 0.10 Copper Aluminum Oxygen - - - 0.30 0.050 0.0015 SAE INTERNATIONAL AMS6440S Page 3 of 8 3.1.1 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 sha
16、ll be determined in accordance with ASTM A370: 3.2.1 Bars Bar shall not be cut from plate (also see 4.4.2). Bars 0.500 Inch (12.70 mm) and Under in Nominal Diameter or Least Distance Between Parallel Sides Cold finished, with microstructure of spheroidized cementite in ferrite matrix, having tensile
17、 strength not higher than 120 ksi (827 MPa) or equivalent hardness (see 8.2). Bars Over 0.500 Inch (12.70 mm) in Nominal Diameter or Least Distance Between Parallel Sides Hot finished and annealed unless otherwise ordered, with microstructure of spheroidized cementite in ferrite matrix, having hardn
18、ess not higher than 207 HB, or equivalent (see 8.3). Bars ordered cold finished may have hardness as high as 248 HB, or equivalent (see 8.3). 3.2.2 Forgings As ordered. 3.2.3 Mechanical Tubing Cold finished unless otherwise ordered with microstructure of spheroidized cementite in ferrite matrix, hav
19、ing hardness not higher than 24 HRC, or equivalent (see 8.3). Tubing ordered hot finished and annealed shall have hardness not higher than 95 HRB, or equivalent (see 8.3). 3.2.4 Forging Stock As ordered by the forging manufacturer. 3.3 Properties The product shall conform to the following requiremen
20、ts; 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, and forging stock, etched in hot hydrochloric acid in accordance with ASTM E381, shall not show pipe or cracks. Porosity, s
21、egregation, inclusions, and other imperfections shall not be worse than the macrographs of ASTM E381 agreed upon by purchaser and producer. SAE INTERNATIONAL AMS6440S Page 4 of 8 3.3.2 Micro-Inclusion Rating At least one specimen from each ingot tested, as well as two-thirds of the total number of s
22、pecimens and the average of all specimens, shall not exceed the limits shown in Table 2, determined in accordance with ASTM E45, Method A. Table 2 - Micro-inclusion rating Type A B C D Thin 2.5 2.0 0.5 1.0 Heavy 1.5 1.0 0.5 1.0 3.3.3 Response to Heat Treatment of Bars, Forgings and Tubing Specimens
23、as in 4.3.3, protected by suitable means or treated in a neutral atmosphere or neutral salt to minimize scaling and prevent either carburization or decarburization, shall have substantially uniform hardness not lower than 63 HRC at any point below any permissible decarburization after being placed i
24、n a furnace that is at 1525 F 10 F (829 C 6 C), allowed to heat to 1525 F 10 F (829 C 6 C), held at heat for 20 minutes 2 minutes, and quenched in commercial paraffin oil (90 to 110 SUS at 100 F (38 C) at room temperature. 3.3.4 Decarburization Bars and tubing ordered ground, turned, or polished sha
25、ll be free from decarburization on the ground, turned, or polished surfaces. Decarburization on tubing ID shall not exceed the maximum depth specified in Table 3. Allowable decarburization of bars, billets, and tube rounds ordered for redrawing or forging or to specified microstructural requirements
26、 other than spheroidized cementite in ferrite matrix shall be as agreed upon by purchaser and producer. Decarburization of bars and of the ID and OD of tubes that 3.3.4.1 or 3.3.4.2 is not applicable shall be not greater than shown in Table 3. Table 3A - Maximum total depth of decarburization limits
27、, inch/pound units Nominal Diameter or Least Distance Between Parallel Sides Inches Total Depth of Decarburization Bars Hot Finished Inch Total Depth of Decarburization Bars Annealed Inch Total Depth of Decarburization Bars Cold Finished Inch Total Depth of Decarburization Tubes Annealed Inch Total
28、Depth of Decarburization Tubes Cold Finished Inch Up to 0.250, incl 0.005 0.015 0.003 0.012 0.010 Over 0.250 to 0.500, incl 0.006 0.015 0.004 0.012 0.010 Over 0.500 to 0.750, incl 0.008 0.015 0.006 0.012 0.010 Over 0.750 to 1.000, incl 0.010 0.015 0.008 0.012 0.010 Over 1.000 to 2.000, incl 0.017 0.
29、022 0.015 0.020 0.014 Over 2.000 to 3.000, incl 0.025 0.030 0.025 0.030 0.019 Over 3.000 to 4.000, incl 0.035 0.045 0.035 0.035 0.024 Over 4.000 to 5.000, incl 0.055 0.065 0.055 0.040 0.028 SAE INTERNATIONAL AMS6440S Page 5 of 8 Table 3B - Maximum total depth of decarburization limits, SI units Nomi
30、nal Diameter or Least Distance Between Parallel Sides Millimeters Total Depth of Decarburization Bars Hot Finished Millimeter Total Depth of Decarburization Bars Annealed Millimeter Total Depth of Decarburization Bars Cold Finished Millimeter Total Depth of Decarburization Tubes Annealed Millimeter
31、Total Depth of Decarburization Tubes Cold Finished Millimeter Up to 6.35, incl 0.13 0.38 0.08 0.30 0.25 Over 6.35 to 12.70, incl 0.15 0.38 0.10 0.30 0.25 Over 12.70 to 19.05, incl 0.20 0.38 0.15 0.30 0.25 Over 19.05 to 25.40, incl 0.25 0.38 0.20 0.30 0.25 Over 25.40 to 50.80, incl 0.43 0.56 0.38 0.5
32、1 0.36 Over 50.80 to 76.20, incl 0.64 0.76 0.64 0.76 0.48 Over 76.20 to 101.60, incl 0.89 1.14 0.89 0.89 0.61 Over 101.60 to 127.00, incl 1.40 1.65 1.40 1.02 0.71 Decarburization shall be evaluated by one of the methods of 3.3.4.5 or 3.3.4.6, Metallographic Method A cross section taken perpendicular
33、 to the surface 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 Table 3. Hardness Traverse Method The total depth of decarburization
34、shall be determined by a traverse method using microhardness 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. Tempering is generally not recommend
35、ed, but if tempered, the tempering temperature shall be not higher than 300 F (149 C). 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 a
36、ny adjacent surface to be uninfluenced by any decarburization on the adjacent surface. Acceptance shall be as listed in Table 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 mo
37、re than 0.005 inch (0.13 mm) and the width is 0.065 inch (1.65 mm) or less. In case of dispute, the total depth of decarburization determined using the microhardness traverse method shall govern. 3.4 Quality The product, as received by purchaser, shall be uniform in quality and condition, sound, and
38、 free from foreign materials and from imperfections detrimental to usage of the product. 3.4.1 Steel shall be aircraft-quality conforming to AMS2301. 3.4.2 Bars and tubing ordered hot rolled or cold finished, or ground, turned, or polished shall, after removal of the standard stock removal allowance
39、 in accordance with AS1182, be free from seams, laps, tears, and cracks open to the machined, ground, turned, or polished surface. 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 gr
40、ain flow. SAE INTERNATIONAL AMS6440S Page 6 of 8 3.5 Tolerances 3.5.1 Bars 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 sh
41、all 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 Composition (3.1), condition
42、 (3.2), macrostructure (3.3.1), micro-inclusion rating (3.3.2) response to heat treatment (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. 4.2.2 Periodic Tests Grain fl
43、ow 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
44、AMS2372. 4.3.3 Samples for response to heat treatment (see 3.3.3) shall be as follows: Specimens from bars shall be full cross-sections of the bar, except length and width need not exceed 1.5 inches (38 mm) respectively, ground on both faces normal to the axis so that length is 0.50 inch 0.010 inch
45、(12.7 mm 0.25 mm). Specimens from mechanical tubing shall be full cross-sections of the tubing, shall have wall thickness not over 0.625 inch (15.88 mm), with wall thicknesses over 0.625 inch (15.88 mm) being turned to 0.625 inch 0.010 inch (15.88 mm 0.25 mm), and shall be ground on both faces so th
46、at length is 0.50 inch 0.010 inch (12.7 mm 0.25 mm). SAE INTERNATIONAL AMS6440S Page 7 of 8 4.4 Reports 4.4.1 The producer of the bar, forgings, and tubing shall furnish with each shipment a report showing producer identity, country where the metal was melted (e.g., final melt in the case of metal p
47、rocessed by multiple melting operations), the results of tests for composition, micro-inclusion rating, and the frequency-severity rating of each heat and response to heat treatment of each lot, and stating that the product conforms to the other technical requirements. This report shall include the
48、purchase order number, heat and lot numbers, AMS6440S, 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
49、, report the nominal metallurgically worked size (also see 3.2.1). 4.4.3 The producer of forging stock shall furnish with each shipment a report showing producer identity, country where the metal was melted (e.g., final melt in the case of metal processed by multiple melting operations), the results of tests for composition, macrostructure, micro-inclusion rating, and the frequency-severity clea
