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 reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions. Copyright 2011 SAE International All rights reserved. No part of this publication m
3、ay 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: +1 724-776-4970 (outside U
4、SA) 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/AMS6274PAEROSPACEMATERIALSPECIFICATIONAMS6274 REV. P Issued 1942-09 Revised 2011-06Supersedin
5、g AMS6274N Steel, Bars, Forgings, and Tubing 0.50Cr - 0.55Ni - 0.20Mo (0.18 - 0.23C) (SAE 8620) (Composition similar to UNS G86200) RATIONALE AMS6274P results from a Five Year Review and update of this specification. 1. SCOPE 1.1 Form This specification covers an aircraft-quality, low-alloy steel in
6、 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 hardness is required and a wide hardness range in sections 0.375 inch (9.52 mm) and under in nominal thickness is permitted, but us
7、age is not limited to such applications. The core may or may not be merchantable after hardening. 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 sub
8、sequent 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 SAE International, 400 Commonwealth
9、 Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 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
10、 Cleanliness, Aircraft Quality Magnetic Particle Inspection Procedure AMS2370 Quality Assurance Sampling and Testing, Carbon and Low-Alloy Steel Wrought Products and Forging Stock Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted
11、without license from IHS-,-,-SAE AMS6274P Page 2 of 7 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 Identifi
12、cation, 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 Conshohocken, PA 19428-2959, Tel: 610-832-9585, www.astm.org.A
13、STM A 255 Determining Hardenability of Steel ASTM A 370 Mechanical Testing of Steel Products ASTM E 112 Determining Average Grain Size ASTM E 350 Chemical Analysis of Carbon Steel, Low-Alloy Steel, Silicon Electrical Steel, Ingot Iron, and Wrought Iron ASTM E 381 Macroetch Testing, Steel Bars, Bille
14、ts, Blooms, and Forgings ASTM E 384 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 E 350, by spectrochemical methods, or by other analytical meth
15、ods acceptable to purchaser. TABLE 1 - COMPOSITION Element min max Carbon 0.17 0.23 Manganese 0.60 0.95Silicon 0.15 0.35 Phosphorus - 0.025Sulfur - 0.025Chromium 0.35 0.65 Nickel 0.35 0.75Molybdenum 0.15 0.25 Copper - 0.353.1.1 Check Analysis Composition variations shall meet the applicable requirem
16、ents 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 A 370: Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without li
17、cense from IHS-,-,-SAE AMS6274P Page 3 of 7 3.2.1 Bars Bar shall not be cut from plate. 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 hardness (See 8.2).
18、 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 than 229 HB, or equivalent (See 8.3). Bars ordered cold finished may have hardness as high as 248 HB, or equivalent (S
19、ee 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 Forging Stock As o
20、rdered by the forging manufacturer. 3.3 Properties The product shall conform to the following requirements; hardness testing shall be performed in accordance with ASTM A 370: 3.3.1 Macrostructure Visual examination of transverse full cross-sections from bars, billets, tube rounds and forging stock,
21、etched in hot hydrochloric acid in accordance with ASTM E 381, shall not show pipe or cracks. Porosity, segregation, inclusions, and other imperfections shall not be worse than the macrographs of ASTM E 381 shown in Table 2. TABLE 2 - MACROSTRUCTURE LIMITS Section Size Square Inches Section Size Squ
22、are Centimeters Macrographs Up to 36, incl Up to 232, incl S2 - R1 - C2 Over 36 to 100, incl Over 232 to 645, incl S2 - R2 - C3 3.3.1.1 If tubes are produced directly from ingots or large blooms, transverse sections may be taken form the tubes rather than tube rounds. Macroetch standards for such tu
23、bes shall be as agreed upon by purchaser and vendor. 3.3.2 Average Grain Size of Bar, Forgings and Tubing Shall be ASTM No. 5 or finer, determined in accordance with ASTM E 112. 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
24、 the standard end-quench test specimen in accordance with ASTM A 255 except that the steel shall be normalized at 1700 F 10 (927 C 6) and the test specimen austenitized at 1700 F 10 (927 C 6). Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networki
25、ng permitted without license from IHS-,-,-SAE AMS6274P Page 4 of 7 3.3.4 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 specifi
26、ed in Table 4 3.3.4.2 Allowable decarburization of bars, billets, and tube rounds ordered for redrawing or forging or to specified microstructural requirements, shall be as agreed upon by purchaser and vendor. 3.3.4.3 Decarburization of bars to which 3.3.4.1 or 3.3.4.2 is not applicable shall be not
27、 greater than shown in Table 3. TABLE 3A - MAXIMUM DECARBURIZATION, INCH/POUND UNITS Nominal Diameter or Distance Between Parallel Sides Inches Total Depth of DecarburizationInch Up to 0.500, incl 0.015 Over 0.500 to 1.000, incl 0.030 Over 1.000 to 2.000, incl 0.040 Over 2.000 to 3.000, incl 0.050 O
28、ver 3.000 to 4.000, incl 0.065 Over 4.000 to 5.000, incl 0.095 TABLE 3B - MAXIMUM DECARBURIZATION, SI UNITS Nominal Diameter or Distance Between Parallel Sides MillimetersTotal Depth of DecarburizationMillimetersUp to 12.70, incl 0.38 Over 12.70 to 25.40, incl 0.76 Over 25.40 to 50.80, incl 1.02 Ove
29、r 50.80 to 76.20, incl 1.27 Over 76.20 to 101.60, incl 1.65 Over 101.60 to 127.00, incl 2.41 3.3.4.4 Decarburization of tubing to which 3.3.4.1 or 3.3.4.2 is not applicable shall not be greater than shown in Table 4. TABLE 4A - MAXIMUM DECARBURIZATION, INCH/POUND UNITS Nominal Outside Diameter Inche
30、s Total Depth of DecarburizationInch Up to 1.000, incl 0.025 Over 1.000 to 2.000, incl 0.035 Over 2.000 to 3.000, incl 0.045 Over 3.000 to 4.000, incl 0.055 Over 4.000 to 5.000, incl 0.080 TABLE 4B - MAXIMUM DECARBURIZATION, SI UNITS Nominal Outside Diameter MillimetersTotal Depth of Decarburization
31、MillimetersUp to 25.40, incl 0.64 Over 25.40 to 50.80, incl 0.89 Over 50.80 to 76.20, incl 1.14 Over 76.20 to 101.60, incl 1.40 Over 101.60 to 127.00, incl 2.03 Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license fro
32、m IHS-,-,-SAE AMS6274P Page 5 of 7 3.3.4.5 Decarburization shall be measured by the metallographic method, by the HR30N scale hardness testing method, or by a traverse method using microhardness testing in accordance with ASTM E 384. The hardness method(s) shall be conducted on a hardened but untemp
33、ered specimen protected during heat treatment to prevent changes in surface carbon content. Depth of decarburization, when measured by a hardness method, is defined as the perpendicular distance from the surface to the depth under that surface below which there is no further increase in hardness. Su
34、ch measurements shall be far enough away from any adjacent surface to be uninfluenced by any decarburization on the adjacent surface. In case of dispute, the depth of decarburization determined using the microhardness traverse method shall govern. 3.3.4.5.1 When determining the depth of decarburizat
35、ion, 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. 3.4 Quality 3.4.1 The product, as received by purchaser, shall be uniform in quality and condit
36、ion, sound, and free from foreign materials and from imperfections detrimental to usage of the product. 3.4.2 Steel shall be aircraft quality conforming to AMS2301. 3.4.3 Bars and mechanical tubing ordered hot rolled or cold drawn, or ground, turned, or polished shall, after removal of the standard
37、stock removal allowance in accordance with AS1182, be free from seams, laps, tears, and cracks open to the ground, turned, or polished surface. 3.4.4 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
38、 reentrant grain flow. 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 vendor of the product shall supply all samples for vendors tests and shall be responsible for the per
39、formance of all required tests. Purchaser reserves the right to sample and 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 (3.2), macrostructure (3.3.1), a
40、verage grain size (3.3.2), hardenability (3.3.3), decarburization (3.3.4), frequency-severity cleanliness ratings (3.4.2), and tolerances (3.5) are acceptance tests and shall be performed on each heat or lot as applicable. Copyright SAE International Provided by IHS under license with SAENot for Res
41、aleNo reproduction or networking permitted without license from IHS-,-,-SAE AMS6274P Page 6 of 7 4.2.2 Periodic Tests Grain flow of die forgings (3.4.4) is a periodic test and shall be performed at a frequency selected by the vendor unless a frequency of testing is specified by purchaser. 4.3 Sampli
42、ng 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 vendor of bars, forgings and tubing shall furnish with each shipment a report showing the results of composition, macrostructure, hardenability
43、 and frequency-severity cleanliness rating for each heat and for condition and average grain size 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, AMS6274P, product form and size (and/or par
44、t 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, report the nominal metallurgically worked size (See 3.2.1). 4.4.3 The vendor of forgi
45、ng stock shall furnish with each shipment a report showing the 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 shall inc
46、lude the purchase order number, heat number, AMS6274P, size and quantity. 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 Sizes Except when exact lengths or multiples
47、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 Mechanical Tubing In accordance with AMS2806. Cop
48、yright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE AMS6274P Page 7 of 7 5.2.2 Forgings In accordance with AMS2808. 5.2.3 Forging Stock As agreed upon by purchaser and vendor. 5.3 Protective Treatment Bars and mechanical tubing ordered cold drawn, cold rolled, ground, turned, or polished shall be protected from corrosion prior to shipment. 5.4 Packaging The product shall be prepared for shipment in accordance with commercial practice and in
