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:/www.sae.org/technical/standards/AMS6274R AEROSPACE MATERIAL SPECIFICATION AMS6274 REV. R Issued 1942-09 Revised 2
5、016-06Superseding AMS6274P Steel, Bars, Forgings, and Tubing 0.50Cr - 0.55Ni - 0.20Mo (0.18 - 0.23C) (SAE 8620) (Composition similar to UNS G86200) RATIONALE AMS6274R results from a Five Year Review and update of this specification that revises macrostructure, grain size determination and reporting
6、and deletes decarburization requirements. 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 carburized parts that a high minimum core hardne
7、ss is required and a wide hardness range in sections 0.375 inch (9.52 mm) and under in nominal thickness is permitted, but usage is not limited to such applications. The core may or may not be machinable after hardening. 2. APPLICABLE DOCUMENTS The issue of the following documents in effect on the d
8、ate 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 document unless a specific document issue is specified. When the referenced document has been cancelled and no superseding document has been specified, the
9、 last published issue of that document shall apply. 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 AMS2253 Toler
10、ances, 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 SAE INTERNATIONAL AMS6274R Page 2 of 7 AMS2370 Quality Assurance Sampling and Testing, Carbon and Low-All
11、oy Steel Wrought Products and 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 Forgin
12、gs ARP1917 Clarification of Terms Used in Aerospace Metals Specifications 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 Conshoh
13、ocken, 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 Determining Average Grain Size ASTM E140 Hardness Conversion Tables for Metals ASTM E350 Chemical Analysis of Carbon Steel, Low-Alloy Steel, Si
14、licon Electrical Steel, Ingot Iron, and Wrought Iron ASTM E381 Macroetch Testing, Steel Bars, Billets, Blooms, and Forgings 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 spect
15、rochemical methods, or by other analytical methods acceptable to purchaser. Table 1 - Composition Element min max Carbon 0.17 0.23 Manganese 0.60 0.95 Silicon 0.15 0.35 Phosphorus - 0.025 Sulfur - 0.025 Chromium 0.35 0.65 Nickel 0.35 0.75 Molybdenum 0.15 0.25 Copper - 0.35 SAE INTERNATIONAL AMS6274R
16、 Page 3 of 7 3.1.1 Aluminum, vanadium and columbium are optional grain refining elements and need not be 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 Co
17、ndition The product shall be supplied in the following condition; hardness and tensile strength shall be 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 Pa
18、rallel Sides Cold finished having tensile strength not higher than 125 ksi (862 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 Sides Unless otherwise ordered, hot finished and annealed, having hardness not higher
19、 than 229 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, having hardness not higher than 25 HRC, or equivalent (see 8.3). Tubing ordered
20、hot finished and annealed shall have hardness not higher than 99 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 requirements; hardness testing shall be performed in accordance with ASTM A370: 3.3.1 M
21、acrostructure 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, segregation, inclusions, and other imperfections shall not be worse than the ma
22、crographs of ASTM E381 shown in Table 2. Table 2 - Macrostructure limits Section Size Square Inches Section Size 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
23、shall be agreed upon by purchaser and vendor. The purchaser shall have written approval of the agreement from the cognizant engineering organization. SAE INTERNATIONAL AMS6274R Page 4 of 7 3.3.1.1 If tubes are produced directly from ingots or large blooms, transverse sections may be taken form the t
24、ubes 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 Bar, 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
25、 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 8.5): 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 0.01
26、5 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 Shall be J1/16 inch (1.6 mm) = 48 HRC maximum and J3/16 inch (4.8 mm) = 32 HRC minimum, determined on the standard end-quench test specimen in accordance with ASTM A255 exc
27、ept that the steel shall be normalized at 1700 F 10 F (927 C 6 C) and the test specimen austenitized at 1700 F 10 F (927 C 6 C). 3.4 Quality 3.4.1 The product, as received by purchaser, shall be uniform in quality and condition, sound, and free from foreign materials and from imperfections detriment
28、al to usage of the product. 3.4.2 Steel shall be aircraft quality conforming to AMS2301. 3.4.3 Bars and mechanical tubing shall be free from seams, laps, tears, and cracks after removal of the standard stock removal allowance in accordance with AS1182. 3.4.4 Grain flow of die forgings, except in are
29、as that contain 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 AMS6274R Page 5 of 7 4. QUALITY ASSURANCE PR
30、OVISIONS 4.1 Responsibility 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 perform any confirmatory testing deemed necessary to ensure that the prod
31、uct conforms to 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), frequency-severity cleanliness ratings (3.4.2), and tolerances (3.5) are acceptance tests and shal
32、l 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 If grain refining elements (3.3.2.2) are present, the ASTM E112 grain size test (3.3.2.1) shall be cond
33、ucted on a periodic basis and shall be performed at a frequency selected by the producer (not to exceed one year) unless frequency of testing is specified by purchaser. Grain flow of die forgings (3.4.4) is a periodic test and shall be performed at a frequency selected by the producer unless a frequ
34、ency 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. 4.4 Reports 4.4.1 The producer of bars, forgings and tubing shall furnish with each shipment a report showing th
35、e producer identity, country where the metal was melted (e.g., final melt in the case of metal processed by multiple melting operations), results of composition, macrostructure, hardenability and frequency-severity cleanliness rating for each heat and for condition and, if measured, average grain si
36、ze of each lot, and stating that the product conforms to other technical requirements. This report shall include the purchase order number, heat and lot numbers, AMS6274R, product form and size (and/or part number, if applicable), and quantity. If forgings are supplied, the size and melt source of s
37、tock used to make the forgings shall also be included. If the grain size requirement of 3.3.2.1 is met by the aluminum, vanadium and/or columbium content, the aluminum, vanadium and/or columbium content shall be reported and a statement that the chemistry satisfies the grain size requirement shall b
38、e included. 4.4.2 If the ship size/shape is cut from a larger cross section, 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 the producer identity, country where the metal was melted (e.g., final m
39、elt in the case of metal processed by multiple melting operations), results of tests for composition, macrostructure, hardenability and frequency-severity cleanliness rating of each heat and the results of any additional property requirements imposed by the purchase order (see 8.6). This report shal
40、l include the purchase order number, heat number, AMS6274R, size and quantity. SAE INTERNATIONAL AMS6274R Page 6 of 7 4.5 Resampling and Retesting 4.5.1 Bars, Mechanical Tubing, and Forging Stock In accordance with AMS2370. 4.5.2 Forgings In accordance with AMS2372. 5. PREPARATION FOR DELIVERY 5.1 S
41、izes Except when exact lengths or multiples of exact lengths are ordered, straight bars and tubing will be acceptable in mill lengths of 6 to 20 feet (1.8 to 5.1 m), but not more than 10% of any shipment shall be supplied in lengths shorter than 10 feet (3 m). 5.2 Identification 5.2.1 Bars and Mecha
42、nical Tubing In accordance with AMS2806. 5.2.2 Forgings In accordance with AMS2808. 5.2.3 Forging Stock As agreed upon by purchaser and producer. 5.3 Protective Treatment Bars and mechanical tubing ordered cold drawn, cold rolled, ground, turned, or polished shall be protected from corrosion prior t
43、o shipment. 5.4 Packaging The product shall be prepared for shipment in accordance with commercial practice and in compliance with applicable rules and regulations pertaining to the handling, packaging, and transportation of the product to ensure carrier acceptance and safe delivery. 6. ACKNOWLEDGME
44、NT A producer shall include this specification number and its revision letter in all quotations and when acknowledging purchase orders. 7. REJECTIONS Product not conforming to this specification, or to modifications authorized by purchaser, will be subject to rejection. SAE INTERNATIONAL AMS6274R Pa
45、ge 7 of 7 8. NOTES 8.1 Revision Indicator A change bar (l) located in the left margin is for the convenience of the user in locating areas where technical revisions, not editorial changes, have been made to the previous issue of this document. An (R) symbol to the left of the document title indicate
46、s a complete revision of the document, including technical revisions. Change bars and (R) are not used in original publications, nor in documents that contain editorial changes only. 8.2 Tensile strength to hardness conversions are presented in ASTM A370. 8.3 Hardness conversion tables for metals ar
47、e presented in ASTM E140. 8.4 Terms used in AMS are clarified in ARP1917. 8.5 Dimensions and properties in inch/pound units and the Fahrenheit temperatures are primary; dimensions and properties in SI units and the Celsius temperatures are shown as the approximate equivalents of the primary units an
48、d are presented only for information. 8.6 Grain size The average grain size resulting from using the appropriate test procedures per ASTM E112 will satisfy an ASTM No. 5 or finer grain size when the elements defined in 3.3.2.2 as grain refiners are present. Other technical societies have adopted the
49、 verification of fine grain steel based on chemistry alone. Included are ASTM International (Documents A6, A20, and A29); American Society of Mechanical Engineers (Documents SA6, SA20, and SA29); American Bureau of Shipping; CSA Group (Canada); EuroNorm documents; American Association of State Highway and Transportation Officials. 8.7 Purchase documents should specify not less than the following: AMS6274R Product for
