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/AMS6477C AEROSPACE MATERIAL SPECIFICATION AMS6477 REV. C Issued 1988-04 Reaffirme
5、d 2006-02 Revised 2015-09 Superseding AMS6477B Steel, Bars, Forgings, and Tubing 0.80Cr (0.90 - 1.03C) For Bearing Applications (Composition similar to UNS G51985) RATIONALE AMS6477C is a Five Year Review and update of this specification and revises decarburization and reporting. 1. SCOPE 1.1 Form T
6、his 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 thickness under
7、 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 of a documen
8、t 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, Warrendale, PA 15096-
9、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 AMS2370 Quality Assurance Sampling and
10、 Testing, Carbon and Low-Alloy Steel Wrought Products and Forging Stock SAE INTERNATIONAL AMS6477C Page 2 of 8 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 Corros
11、ion 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 Publications Available from ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Consho
12、hocken, PA 19428-2959, Tel: 610-832-9585, www.astm.org. ASTM A370 Mechanical Testing of Steel Products ASTM E45 Determining the Inclusion Content of Steels ASTM E350 Chemical Analysis of Carbon Steel, Low-Alloy Steel, Silicon Electrical Steel, Ingot Iron, and Wrought Iron ASTM E381 Macroetch Testing
13、 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 wet chemical methods in accordance with ASTM E350 or by spectrochemical or other analytica
14、l methods acceptable to purchaser. Table 1 - Composition Element min max Carbon Manganese Silicon Phosphorus Sulfur Chromium Nickel Molybdenum Copper 0.90 0.75 0.15 - - 0.70 - - - 1.03 1.00 0.35 0.025 0.025 0.90 0.25 0.10 0.35 3.1.1 Check Analysis Composition variations shall meet the applicable req
15、uirements of AMS2259. 3.2 Condition The product shall be supplied in the following condition; hardness and tensile strength shall be determined in accordance with ASTM A370: SAE INTERNATIONAL AMS6477C Page 3 of 8 3.2.1 Bars 3.2.1.1 Bars 0.500 Inch (12.70 mm) and Under in Nominal Diameter or Least Di
16、stance Between Parallel Sides Cold finished, with microstructure of spheroidized cementite in ferrite matrix, having tensile strength not higher than 120 ksi (825 MPa), or equivalent hardness (see 8.2). 3.2.1.2 Bars Over 0.500 Inch (12.70 mm) in Nominal Diameter or Least Distance Between Parallel Si
17、des Hot finished and annealed, unless otherwise ordered, with microstructure of spheroidized cementite in ferrite matrix, having hardness not higher than 207 HB, or equivalent (see 8.3). Bars ordered cold finished may have hardness as high as 248 HB, or equivalent. 3.2.1.3 Bar shall not be cut from
18、plate (also see 4.4.2). 3.2.2 Forgings As ordered. 3.2.3 Mechanical Tubing Cold finished and annealed, unless otherwise ordered, with microstructure of spheroidized cementite in ferrite matrix. Tubing ordered hot finished and annealed shall have hardness not higher than 95 HRB, or equivalent (see 8.
19、3). 3.2.4 Forging 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: 3.3.1 Macrostructure Visual examination of transverse full cross-sections from bars, billets, tube
20、 rounds, or 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 agreed upon by purchaser and producer (see 8.6). 3.3.2 Micro-Inclusion
21、 Rating of Each Heat At least one specimen from each ingot tested, as well as two-thirds of the total number of specimens 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 limits Type A B
22、 C D Thin Heavy 2.5 1.5 2.0 1.0 0.5 0.5 1.0 1.0 3.3.3 Response to Heat Treatment of Bars, Forgings and Tubing Specimens as in 4.3.3, protected by suitable means or treated in a neutral atmosphere to minimize scaling and prevent either carburization or decarburization, shall have substantially unifor
23、m hardness not lower than 63 HRC at any point below any permissible decarburization after being heated to 1525 F 10 F (829 C 6 C), held at heat for 20 minutes 2 minutes, and quenched in commercial paraffin oil (90-110 SUS at 100 F (38 C) at room temperature. SAE INTERNATIONAL AMS6477C Page 4 of 8 3.
24、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 specified in Table 4. 3.3.4.2 Allowable decarburization of bars, billets, an
25、d tube rounds ordered for redrawing or forging or to specified microstructural requirements other than spheroidized cementite in ferrite matrix shall be as agreed upon by purchaser and producer. 3.3.4.3 Decarburization of bars for anti-friction balls and rollers that 3.3.4.1 or 3.3.4.2 is not applic
26、able shall be not greater than shown in Table 3. Table 3A Maximum total depth of Decarburization limits, inch/pound units Nominal Diameter or Distance Between Parallel Sides Inch Total Depth of Decarburization Inch Hot Finished Total Depth of Decarburization Inch Cold Finished Up to 0.250, incl Over
27、 0.250 to 0.500, incl Over 0.500 to 0.750, incl Over 0.750 to 1.000, incl 0.005 0.006 0.008 0.010 0.003 0.004 0.006 0.008 Table 3B - Maximum total depth of decarburization limits, SI units Nominal Diameter or Distance Between Parallel Sides Millimeters Total Depth of Decarburization Millimeters Hot
28、Finished Total Depth of Decarburization Millimeters Cold Finished Up to 6.35, incl Over 6.35 to 12.70, incl Over 12.70 to 19.05, incl Over 19.05 to 25.40, incl 0.13 0.15 0.20 0.25 0.08 0.10 0.15 0.20 3.3.4.4 Decarburization of bars and of the ID and OD of tubes that 3.3.4.1, 3.3.4.2, or 3.3.4.3 is n
29、ot applicable shall be not greater than shown in Table 4. Table 4A - Maximum total depth of decarburization limits, inch/pound units Nominal Diameter or Distance Between Parallel Sides Inches Total Depth of Decarburization Bars, Hot Finished Inch Total Depth of Decarburization Bars Annealed Inch Tot
30、al Depth of Decarburization Bars, Cold Finished Inch Total Depth of Decarburization Tubes Annealed Inch Total Depth of Decarburization Tubes, Cold Finished Inch Up to 1.000, incl Over 1.000 to 2.000, incl Over 2.000 to 3.000, incl Over 3.000 to 4.000, incl Over 4.000 to 5.000, incl 0.012 0.017 0.025
31、 0.035 0.055 0.015 0.022 0.030 0.045 0.065 0.012 0.015 0.025 0.035 0.055 0.012 0.020 0.030 0.035 0.040 0.010 0.014 0.019 0.024 0.028 SAE INTERNATIONAL AMS6477C Page 5 of 8 Table 4B - Maximum total depth of decarburization limits, SI units Nominal Diameter or Distance Between Parallel Sides Millimete
32、rs Total Depth of Decarburization Bars, Hot Finished Millimeters Total Depth of Decarburization Bars Annealed Millimeters Total Depth of Decarburization Bars, Cold Finished Millimeters Total Depth of Decarburization Tubes Annealed Millimeters Total Depth of Decarburization Tubes, Cold Finished Milli
33、meters Up to 25.40, incl Over 25.40 to 50.80, incl Over 50.80 to 76.20, incl Over 76.20 to 101.60, incl Over 101.60 to 127.00, incl 0.30 0.43 0.64 0.89 1.40 0.38 0.56 0.76 1.14 1.65 0.30 0.38 0.64 0.89 1.40 0.30 0.51 0.76 0.89 1.02 0.25 0.36 0.48 0.61 0.71 3.3.4.5 Decarburization shall be evaluated
34、by one of the two methods of 3.3.4.6 or 3.3.4.7. 3.3.4.6 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. The product shall not show a layer of complete (ferrite) or par
35、tial decarburization exceeding the limits of Tables 3 or 4. 3.3.4.7 Hardness Traverse Method The total depth of decarburization 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 untemp
36、ered specimen protected during heat treatment to prevent changes in surface carbon content. Tempering is generally not recommended, 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
37、 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 as listed in Tables 3 or 4. 3.3.4.8 When determining the depth of
38、 decarburization, it is permissible to disregard local areas provided the decarburization of such areas does not exceed the limits of Tables 3 or 4 by more than 0.005 inch (0.13 mm) and the width is 0.065 inch (1.65 mm) or less. 3.3.4.9 In case of dispute, the total depth of decarburization determin
39、ed 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 free from foreign materials and from imperfections detrimental to usage of the product. 3.4.1 Bars and mechanical tubing ordered hot rolle
40、d 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. 3.4.2 Grain flow of die forgings, except in areas that contai
41、n 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 Bars In accordance with AMS2251. 3.5.2 Mechanical Tubing In accordance with AMS2253. SAE INTERNATIONAL AMS6477C Page 6 of 8 4. QUALITY ASSURANCE PROVISIONS 4.1 R
42、esponsibility 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 conform
43、s to specified requirements. 4.2 Classification of Tests 4.2.1 Acceptance Tests Composition (3.1), condition (3.2), macrostructure (3.3.1), micro-inclusion ratings (3.3.2), response to heat treatment (3.3.3), decarburization (3.3.4), and tolerances (3.5) are acceptance tests and shall be performed o
44、n each heat or lot as applicable. 4.2.2 Periodic Tests Grain flow of die forgings (3.4.2) 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
45、 In accordance with AMS2370. 4.3.2 Forgings In accordance with AMS2372. 4.3.3 Samples for response to heat treatment (3.3.3) shall be as follows: 4.3.3.1 Specimens from bars shall be full cross-sections of the bar, machined or ground on both faces normal to the axis so that length is 0.50 inch 0.010
46、 inch (12.7 mm 0.25 mm). 4.3.3.2 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 machined or
47、ground on both faces so that length is 0.50 inch 0.010 inch (12.7 mm 0.25 mm). 4.4 Reports 4.4.1 The producer of bars, forgings and tubing shall furnish with each shipment a report showing the producer identity, country where the metal was melted (e.g., final melt in the case of metal processed by m
48、ultiple melting operations), results of tests for composition, macrostructure and micro-inclusion rating for each heat, and for response to 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
49、 and lot numbers, AMS6477C, product form and size or part number, 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 Report the nominal metallurgically worked cross sectional size and the cut size, if different (also see 3.2.1.3). 4.4.3 The producer of forging stock shall furnish with each shipment a report show
