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/AMS6250M AEROSPACE MATERIAL SPECIFICATION AMS6250 REV. M Issued 1939-12 Revised 2
5、015-12 Superseding AMS6250L Steel Bars, Forgings, and Tubing 1.5Cr - 3.5Ni (0.07 - 0.13 C) (3310) (Composition similar to UNS K44910) RATIONALE AMS6250M results from a Five Year Review and update of this specification that revises macroetch, grain size and reporting requirements. 1. SCOPE 1.1 Form T
6、his 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, including gears, that require high minimum core hardness with narrow range, but usage is no
7、t limited to such applications. 1.2.1 The core is machinable 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 subsequent revision of
8、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, Warrendale,
9、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, Ai
10、rcraft Quality, Magnetic Particle Inspection Procedure SAE INTERNATIONAL AMS6250M Page 2 of 7 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 Iden
11、tification 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 Publica
12、tions 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 A255 Determining Hardenability of Steel ASTM A370 Mechanical Testing of Steel Products ASTM E112 Determining Average Grain Size ASTM E350 Chemical An
13、alysis of Carbon Steel, Low-Alloy Steel, Silicon Electrical Steel, Ingot Iron, and Wrought Iron ASTM E381 Macroetch Testing, Inspection, and Rating Steel Products Comprising Bars, Billets, Blooms, and Forgings 3. TECHNICAL REQUIREMENTS 3.1 Composition Shall conform to the percentages by weight shown
14、 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 Manganese Silicon Phosphorus Sulfur Chromium Nickel Molybdenum Copper 0.07 0.40 0.15 - - 1.25
15、 3.25 - - 0.13 0.70 0.35 0.025 0.025 1.75 3.75 0.06 0.35 SAE INTERNATIONAL AMS6250M 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 Analys
16、is 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 shall be determined in accordance with ASTM A370: 3.2.1 Bars Bar shall not be cut from plate. 3.2.1.1 Bars 0.500 Inch (12
17、.70 mm) and Under in Nominal Diameter or Least Distance Between Parallel Sides Cold finished having tensile strength not higher than 125.0 ksi (862 MPa) or equivalent hardness (see 8.3). 3.2.1.2 Bars Over 0.500 Inch (12.70 mm) in Nominal Diameter or Least Distance Between Parallel Sides Hot finished
18、 and annealed or tempered, unless otherwise ordered, having hardness not higher than 229 HB, or equivalent (see 8.2). Bars ordered cold finished may have hardness as high as 248 HB, or equivalent (see 8.2). 3.2.2 Forgings As ordered. 3.2.3 Mechanical Tubing Cold finished, unless otherwise ordered, h
19、aving hardness not higher than 25 HRC, or equivalent (see 8.2). Tubing ordered hot finished and annealed shall have hardness not higher than 99 HRB, or equivalent (see 8.2). 3.2.4 Forging Stock As ordered by the forging manufacturer. 3.3 Properties The product shall conform to the following requirem
20、ents; hardness testing shall be performed in accordance with ASTM A370: SAE INTERNATIONAL AMS6250M Page 4 of 7 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, sh
21、all show no pipe or cracks. Porosity, segregation, inclusions, and other imperfections shall be no worse than the macrographs of ASTM E381 shown in Table 2. Table 2 - Macrostructure limits Cross-Sectional Area Square Inches Cross-Sectional Area Square Centimeters Macrographs Up to 36, incl Over 36 t
22、o 133, incl Over 133 Up to 232, incl Over 232 to 858, incl Over 858 S2 - R1 - C2 S2 - R2 - C3 Note 1 Note 1: Limits for larger sizes shall be agreed upon by the purchaser and producer. The purchaser shall have written approval of the agreement from the cognizant engineering organization. 3.3.1.1 If
23、tubes are produced directly from ingots or large blooms, transverse sections may be taken from the tubes rather than tube rounds. Macroetch standards for such tubes shall be agreed upon by purchaser and producer. 3.3.2 Average Grain Size of Bars, Forgings and Tubing Average grain size shall be deter
24、mined 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 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
25、.1 A total aluminum content of 0.020 to 0.050%. 3.3.2.2.2 An acid soluble aluminum content of 0.015 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 of Each Heat Shall be J 1/16 inch (1.588 mm) = 41 HRC max and J 6/16 inch
26、(9.525 mm) = 32 HRC min, determined on the standard end-quench test specimen in accordance with ASTM A255 except that the steel shall be normalized at 1700 F 10 F (927 C 5 C) and the test specimen austenitized at 1500 F 10 F (816 C 5 C). 3.4 Quality The product shall be uniform in quality and condit
27、ion, sound, and 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 drawn, or ground, turned, or polished shall be free from seams, laps, tears, and crack
28、s open to the machined, ground, turned, or polished surface after removal of the standard stock removal allowance in accordance with AS1182. 3.4.3 Grain flow of die forgings, except in areas that contain flash-line end grain, shall follow the general contour of the forging showing no evidence of ree
29、ntrant grain flow. 3.5 Tolerances SAE INTERNATIONAL AMS6250M Page 5 of 7 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 tes
30、ts 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 conforms to specified requirements. 4.2 Classification of Tests 4.2.1 Acceptance Tests Composition (3.1),
31、condition (3.2), macrostructure (3.3.1), average grain size (3.3.2), hardenability (3.3.3), 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. If grain refining elements (3.3.2.2) are not present, the AST
32、M 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 conducted on a periodic basis and shall be performed at a frequency selected by the producer (not to exceed one yea
33、r) unless frequency of testing is specified by purchaser. Grain flow 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 S
34、tock 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 producer identity, country where the metal was melted (e.g., final melt in the case of metal processed by multiple
35、 melting operations) and the results of tests for composition, macrostructure, hardenability and frequency-severity cleanliness rating of each heat and for condition and, if measured, average grain size of each lot, and stating that the product conforms to the other technical requirements. This repo
36、rt shall include the purchase order number, heat and lot numbers, AMS6250M, 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. If the grain size requirement of 3.3.2.2
37、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 be included. 4.4.2 Report the nominal metallurgically worked cross sectional size and the cut siz
38、e, if different (see 3.2.1). SAE INTERNATIONAL AMS6250M Page 6 of 7 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) and the res
39、ults of tests for composition, macrostructure, hardenability and frequency-severity cleanliness rating and the results of additional property requirements imposed by the purchase order (see 8.7). This report shall include the purchase order number, heat number and lot numbers, AMS6250M, size, and qu
40、antity. 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 of exact lengths are ordered, straight bars and tubing will be acc
41、eptable in mill lengths of 6 to 20 feet (1.8 to 6.1 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. 5.2.2 Forgings In accordance with AMS2808. 5.2.3 Forging Stock As agr
42、eed 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 to shipment. 5.4 Packaging The product shall be prepared for shipment in accordance with commercial practice an
43、d 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. ACKNOWLEDGMENT A producer shall include this specification number and its revision letter in all quotations and when ackno
44、wledging purchase orders. 7. REJECTIONS Product not conforming to this specification, or to modifications authorized by purchaser, will be subject to rejection. SAE INTERNATIONAL AMS6250M Page 7 of 7 8. NOTES 8.1 Revision Indicator A change bar (l) located in the left margin is for the convenience o
45、f 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 indicates a complete revision of the document, including technical revisions. Change bars and (R) are not used in orig
46、inal publications, nor in documents that contain editorial changes only. 8.2 Hardness conversion tables for metals are presented in ASTM E140. 8.3 Tensile strength to hardness conversions are presented in ASTM A370. 8.4 Terms used in AMS are clarified in ARP1917. 8.5 Dimensions and properties in inc
47、h/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 and are presented only for information. 8.6 Grain size The average grain size resulting from using the appropria
48、te test procedures per ASTM E112 will always 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 verification of fine grain steel based on chemistry alone. Included are ASTM International (Documents
49、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: AMS6250M Product form and size (and/or part number, if applicable) of product desired Quantity of product desired If forgi
