1、_ SAE Technical Standards Board Rules provide that: 7KLVUHSRUWLVSXEOLVKHGE6$(WRDGYDQFHWKHVWDWHRIWHFKQLFDO DQGHQJLQHHULQJVFLHQFHV7KHXVHRIWKLVUHSRUWLVHQWLUH ly voluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefrom, iVWKHVROHUHVSRQV
2、LELOLWRIWKHXVHU 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 publication may be reproduced, s
3、tored 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: +1 724-776-4970 (outside USA) Fax: 724-776-07
4、90 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/AMS6447H AEROSPACE MATERIAL SPECIFICATION AMS6447 REV. H Issued 1963-07 Revised 2016-02 Superseding AMS6447G Ste
5、el, Bars, Forgings, and Tubing 1.4Cr (0.93-1.05C) (SAE 52100) Electroslag Remelted (Composition similar to UNS G52986) RATIONALE AMS6447H results from a Five Year Review and update of this document that revises micro-inclusion rating, decarburization testing, and reporting. 1. SCOPE 1.1 Form This sp
6、ecification covers a premium 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 bearing components requiring a through-hardening steel usually with hardness of approximately 60 HRC, sectio
7、n thickness under 0.50 inch (12.7 mm), and subject to very rigid inspection standards, 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 he
8、rein. 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 Publications Available from
9、 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 Analysis Limits, Wrought L
10、ow-Alloy and Carbon Steels SAE INTERNATIONAL $06 H Page 2 of 8 AMS2300 Steel Cleanliness, Premium Aircraft-Quality Magnetic Particle Inspection Procedure AMS2370 Quality Assurance Sampling and Testing, Carbon and Low-Alloy Steel Wrought Products and Forging Stock AMS2372 Quality Assurance Sampling a
11、nd 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 AS1182 Standard Stock Removal Allowance Aircraft-Quality and Premium Aircraf
12、t-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 A370 Mechanical Testing of Steel Products ASTM A604 Macroetch Testing of Consumable Electr
13、ode Remelted Steel Bars and Billets ASTM E45 Determining the Inclusion Content of Steel ASTM E350 Chemical Analysis of Carbon Steel, Low-Alloy Steel, Silicon Electrical Steel, Ingot Iron, and Wrought Iron ASTM E384 Knoop and Vickers Hardness Testing of Materials 3. TECHNICAL REQUIREMENTS 3.1 Composi
14、tion 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 0.93 1.05 Manganese 0.25 0.45 Silicon 0.
15、15 0.35 Phosphorus - 0.015 Sulfur - 0.015 Chromium 1.30 1.60 Nickel - 0.25 Molybdenum - 0.10 Copper - 0.35 3.1.1 Check Analysis Composition variations shall meet the applicable requirements of AMS2259. 3.2 Melting Practice Steel shall be multiple melted using electroslag melting practice (ESR) in th
16、e remelt cycle. SAE INTERNATIONAL $06 H Page 3 of 8 3.3 Condition The product shall be supplied in the following condition; hardness and tensile strength shall be determined in accordance with ASTM A370: 3.3.1 Bars Bar shall not be cut from plate (also see 4.4.2.) 3.3.1.1 Bars 0.500 Inch (12.70 mm)
17、and Under in Nominal Diameter or Least Distance Between Parallel Sides Cold finished, with microstructure of spheroidized cementite in a ferrite matrix, having tensile strength not higher than 120 ksi (827 MPa) or equivalent hardness (see 8.2). 3.3.1.2 Bars Over 0.500 Inch (12.70 mm) in Nominal Diam
18、eter or Least Distance Between Parallel Sides Hot finished and annealed, unless otherwise ordered, with microstructure of spheroidized cementite in a 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 eq
19、uivalent (see 8.3). 3.3.2 Forgings As ordered. 3.3.3 Mechanical Tubing Cold finished, unless otherwise ordered, with microstructure of spheroidized cementite in a ferrite matrix, having hardness not higher than 24 HRC, or equivalent (see 8.3). Tubing ordered hot finished and annealed shall have hard
20、ness not higher than 95 HRB, or equivalent (see 8.3). 3.3.4 Forging Stock As ordered by the forging manufacturer. 3.4 Properties The product shall conform to the following requirements; hardness testing shall be performed in accordance with ASTM A370: 3.4.1 Macrostructure Visual examination of trans
21、verse full cross sections from bars, billets, tube rounds or forging stock, etched in hot hydrochloric acid in accordance with ASTM A604, shall show no pipe or cracks. Porosity, segregation, inclusions, and other imperfections shall be no worse than the macrographs of ASTM A604 shown in Table 2. Tab
22、le 2 - Macrostructure limits Class Condition Severity 1 Freckles A 2 White Spots B 3 Radial Segregation B 4 Ring Pattern B SAE INTERNATIONAL $06 H Page 4 of 8 3.4.2 Micro-Inclusion Rating At least one specimen from each ingot tested as well as two-thirds of the total number of specimens and the aver
23、age of all specimens shall not exceed the limits shown in Table 3, determined in accordance with ASTM E45, Method D, except that the length of any inclusion shall be not greater than 0.015 inch (0.38 mm): Table 3 - Micro-inclusion rating Limits A Thin A Heavy B Thin B Heavy C Thin C Heavy D Thin D H
24、eavy Worst Field Severity 2.0 1.0 1.5 1.0 1.5 1.0 1.5 1.0 Worst Field Frequency, maximum (a) 1 (a) 1 (a) 1 3 1 Total Rateable Fields Frequency, maximum (b) 1 (b) 1 (b) 1 8 1 (a) - Combined A+B+C, not more than 3 fields (b) - Combined A+B+C, not more than 8 fields 3.4.2.1 A rateable field is defined
25、as one that has a type A, B, C, or D inclusion rating of at least 1.0 thin or heavy in accordance with ASTM E45. 3.4.3 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 or neutral salt to minimize scaling an
26、d prevent either carburization or decarburization, shall have substantially uniform 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 that temperature for 20 minutes 2 minutes, and quenched in commercial paraffin
27、oil (90 to 110 SUS at 100 F (38 C) at room temperature. 3.4.4 Decarburization 3.4.4.1 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
28、 4. 3.4.4.2 Allowable decarburization of bars, billets, and tube rounds ordered for redrawing or forging or to specified microstructural requirements other than spheroidized cementite in a ferrite matrix shall be as agreed upon by purchaser and producer. 3.4.4.3 Decarburization of bars that 3.4.4.1
29、or 3.4.4.2 is not applicable shall be not greater than shown in Table 4. 3.4.4.4 Decarburization on the ID and OD of tubes that 3.4.4.1 or 3.4.4.2 is not applicable shall be not greater than that shown in Table 4. Table 4A - Maximum total depth decarburization limits, inch/pound units Nominal Diamet
30、er or 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 Depth of Decarburization Tubes Cold Fin
31、ished 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 0.022 0.015 0.020 0.014 Over 2.000 to 3.0
32、00, 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 $06 H Page 5 of 8 Table 4B - Maximum total depth decarburization limits, SI units Nominal Diameter or Distance Between Parallel Sid
33、es 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 Total Depth of Decarburization Tubes Cold Finished
34、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 0.51 0.36 Over 50.80 to 76.20, incl 0.64 0.76 0.64 0.7
35、6 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 3.4.4.5 Decarburization shall be evaluated by one of the methods of 3.4.4.5.1 or 3.4.4.5.2. 3.4.4.5.1 Metallographic Method A cross section taken perpendicular to the surface shall be prep
36、ared, 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 4. 3.4.4.5.2 Hardness Traverse Method The total depth of decarburization shall be determined
37、 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 recommended, but if tempered
38、, 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 any adjacent surface
39、 to be uninfluenced by any decarburization on the adjacent surface. Acceptance shall be as listed in Table 4. 3.4.4.6 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 more than 0.0
40、05 inch (0.13 mm) and the width is 0.065 inch (1.65 mm) or less. 3.4.4.7 In the case of dispute, the total depth of decarburization determined using the microhardness traverse method shall govern. 3.5 Quality The product, as received by purchaser, shall be uniform in quality and condition, sound, an
41、d free from foreign materials and from imperfections detrimental to usage of the product. 3.5.1 Steel shall be premium aircraft-quality conforming to AMS2300. 3.5.2 Bars and tubing ordered hot rolled or cold drawn, or machined, ground, turned, or polished shall, after removal of the standard stock r
42、emoval allowance in accordance with AS1182, be free from seams, laps, tears, and cracks open to the machined, ground, turned, or polished surface. 3.5.3 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
43、 of reentrant grain flow. SAE INTERNATIONAL $06 H Page 6 of 8 3.6 Tolerances 3.6.1 Bars In accordance with AMS2251. 3.6.2 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 producerV
44、WHVWVDQGVKDOOEHUHVSRQVLEOHIRUWKHSHUIRUPDQFHRIDOOrequired 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), conditi
45、on (3.3), macrostructure (3.4.1), micro-inclusion rating (3.4.2), response to heat treatment (3.4.3), decarburization (3.4.4), frequency-severity cleanliness rating (3.5.1) and tolerances (3.6) are acceptance tests and shall be performed on each heat or lot as applicable. 4.2.2 Periodic Tests Grain
46、flow of die forgings (3.5.3) 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 wit
47、h AMS2372. 4.3.3 Samples for Response to Heat Treatment (see 3.4.3) shall be as follows: 4.3.3.1 Specimens from bars shall be full cross-sections of the bar, except length and width need not exceed 1.5 inches (38 mm) respectively, or not more than 2 in2 (12.9 cm2) of the bar ground on both faces nor
48、mal to the axis so that the length is 0.50 inch 0.010 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 ground on both faces so that the lengt
