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 ther
2、efrom, 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 2017 SAE International All rights reserved. No part of this
3、publication 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: +1 724-776-49
4、70 (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:/standards.sae.org/AMS6372N AEROSPACE MATERIAL SPECIFICATION AMS6372 REV. N Issued 1945-10 Reaffirmed 2009-03 Rev
5、ised 2017-10 Superseding AMS6372M Steel, Mechanical Tubing 0.95Cr 0.20Mo (0.33 0.38C) (SAE 4135) (Composition similar to UNS G41350) RATIONALE AMS6372N results from a Five-Year Review and update of this specification that revises grain size determination (3.1.1 and 3.3.2), decarburization determinat
6、ion (3.3.4.4), quality (3.4.2), testing frequency (4.2), reporting (4.4) and identification (5.2.1). 1. SCOPE 1.1 Form This specification covers an aircraft-quality, low-alloy steel in the form of mechanical tubing. 1.2 Application This tubing has been used typically for parts 0.75 inch (19 mm) and
7、under in nominal wall thickness at time of heat treatment requiring a through-hardening steel capable of developing hardness as high as 40 HRC when properly hardened and tempered and for parts of greater wall thickness but requiring proportionately lower hardness, but usage is not limited to such ap
8、plications. 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 document unless a specific document issue is specified. When the
9、 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 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or +1 724
10、-776-4970 (outside USA), www.sae.org. AMS2253 Tolerances, 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 AMS6372N Page 2 of 7 AMS2370 Quality
11、 Assurance Sampling and Testing, Carbon and Low-Alloy Steel Wrought Products and Forging Stock AMS2806 Identification Bars, Wire, Mechanical Tubing, and Extrusions Carbon and Alloy Steels and Corrosion and Heat-Resistant Steels and Alloys ARP1917 Clarification of Terms Used in Aerospace Metals Speci
12、fications 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. ASTM A255
13、 Determining Hardenability of Steel ASTM E18 Rockwell Hardness of Metallic Materials ASTM E140 Hardness Conversion Tables for Metals Relationship Among Brinell Hardness, Vickers Hardness, Rockwell Hardness, Superficial Hardness, Knoop Hardness, Scleroscope Hardness, and Leeb Hardness ASTM E112 Deter
14、mining Average Grain Size ASTM E350 Chemical Analysis of Carbon Steel, Low-Alloy Steel, Silicon Electrical Steel, Ingot Iron, and Wrought Iron ASTM E381 Macroetch Testing Steel Bars, Billets, Blooms, and Forgings ASTM E384 Microindentation Hardness of Materials 3. TECHNICAL REQUIREMENTS 3.1 Composit
15、ion 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 0.33 0.38 Manganese 0.70 0.90 Silicon 0.1
16、5 0.35 Phosphorus - 0.025 Sulfur - 0.025 Chromium 0.80 1.10 Molybdenum 0.15 0.25 Nickel - 0.25 Copper - 0.35 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
17、 Check Analysis Composition variations shall meet the applicable requirements of AMS2259. SAE INTERNATIONAL AMS6372N Page 3 of 7 3.2 Condition Cold finished, unless otherwise ordered, having hardness not higher than 25 HRC, or equivalent (see 8.2). Tubing ordered hot finished and annealed shall have
18、 hardness not higher than 99 HRB, or equivalent (see 8.2). Hardness shall be determined in accordance with ASTM E18. 3.3 Properties Tubing shall conform to the following requirements: 3.3.1 Macrostructure Visual examination of transverse full cross-sections from billets or tube rounds (not hollows),
19、 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 macrographs of ASTM E381 shown in Table 2. Table 2 - Macrostructure limits Section Size Square Inches Section Size Square Cen
20、timeters 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 shall be agreed upon by purchaser and producer. The purchaser shall have written approval of the agreement from the cogniz
21、ant engineering organization. 3.3.2 Average Grain Size 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 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
22、 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 0.015 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
23、Hardenability Shall be J 6/16 inch (9.5 mm) = 45 HRC minimum and J 8/16 inch (12.5 mm) = 40 HRC minimum, 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 6 C) and the test specimen austenitized at 1600 F
24、10 F (871 C 6 C). 3.3.4 Decarburization 3.3.4.1 Tubing ordered ground, turned, or polished shall be free from decarburization on the ground, turned, or polished surfaces. 3.3.4.2 Allowable decarburization of pierced billets, of tube rounds, and tubing for redrawing or forging, or of tubing ordered t
25、o specified microstructural requirements shall be as agreed upon by purchaser and producer. 3.3.4.3 Decarburization of tubing that 3.3.4.1 or 3.3.4.2 is not applicable shall be not greater than shown in Table 3. SAE INTERNATIONAL AMS6372N Page 4 of 7 Table 3 Table 3A - Maximum depth of decarburizati
26、on, inch/pound units Nominal Wall Thickness Inches Total Depth of Decarburization Inch ID Total Depth of Decarburization Inch OD Up to 0.109, incl 0.008 0.015 Over 0.109 to 0.203, incl 0.010 0.020 Over 0.203 to 0.400, incl 0.012 0.025 Over 0.400 to 0.600, incl 0.015 0.030 Over 0.600 to 1.000, incl 0
27、.017 0.035 Over 1.000 0.020 0.040 Table 3B - Maximum depth of decarburization, SI units Nominal Wall Thickness Millimeters Total Depth of Decarburization Millimeters ID Total Depth of Decarburization Millimeters OD Up to 2.77, incl 0.20 0.38 Over 2.77 to 5.16, incl 0.25 0.51 Over 5.16 to 10.16, incl
28、 0.30 0.64 Over 10.16 to 15.24, incl 0.38 0.76 Over 15.24 to 25.40, incl 0.43 0.89 Over 25.40 0.51 1.02 3.3.4.4 Decarburization shall be evaluated by one of the two methods of 3.3.4.4.1 or 3.3.4.4.2. 3.3.4.4.1 Metallographic Method A cross section taken perpendicular to the surface shall be prepared
29、, 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 3. 3.3.4.4.2 Hardness Traverse Method The total depth of decarburization shall be determined by
30、a traverse method using microindentation hardness 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. Depth of decarburization is defined as the perp
31、endicular 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 to be uninfluenced by any decarburization on the adjacent surface. Acceptance shall be as listed in Table 3. 3.3.4
32、.4.3 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 0.005 inch (0.13 mm) and the width is 0.065 inch (1.65 mm) or less. 3.3.4.4.4 In case of dispute, the total depth of
33、 decarburization determined using the microindentation hardness traverse method shall govern. 3.4 Quality Tubing, 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 tubing. SAE INTERNATIONAL A
34、MS6372N Page 5 of 7 3.4.1 Steel shall be aircraft quality conforming to AMS2301. 3.4.2 Mechanical tubing shall be free from seams, laps, tears, and cracks after removal of the standard stock removal allowance in accordance with AS1182. 3.5 Tolerances In accordance with AMS2253. 4. QUALITY ASSURANCE
35、PROVISIONS 4.1 Responsibility for Inspection The producer of the tubing 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
36、tubing conforms to specified requirements. 4.2 Classification of Tests 4.2.1 Acceptance Tests All technical requirements 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 ASTM E112 grain size test (3.3.2.1) shall
37、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 year) unless frequency of testing is speci
38、fied by purchaser. 4.3 Sampling and Testing In accordance with AMS2370. 4.4 Reports 4.4.1 The producer of 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 melting operations), t
39、he results of tests for composition, macrostructure, hardenability, and frequency-severity cleanliness rating of each heat and for hardness and average grain size (if measured) for each lot, and stating that the product conforms to the other technical requirements. This report shall include the purc
40、hase order number, heat and lot numbers, AMS6372N, product form, size, and quantity. If the grain size requirement of 3.3.2 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 gr
41、ain size requirement shall be included. 4.4.2 When material produced to this specification is beyond the sizes allowed in the scope or tables, or other exceptions are taken to the technical requirements listed in Section 3, (see 5.2.1) the report shall contain a statement “This material is certified
42、 as AMS6372N(EXC) because of the following exceptions:“ and the specific exceptions shall be listed. 4.5 Resampling and Retesting In accordance with AMS2370. SAE INTERNATIONAL AMS6372N Page 6 of 7 5. PREPARATION FOR DELIVERY 5.1 Sizes Except when exact lengths or multiples of exact lengths are order
43、ed, straight tubing will be acceptable 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 In accordance with AMS2806. 5.2.1 When technical exceptions are taken (see 4.4.2), the material sha
44、ll be marked with AMS6372N(EXC). 5.3 Protective Treatment: Tubing ordered cold drawn, cold rolled, ground, turned, or polished shall be protected from corrosion prior to shipment. 5.4 Packaging Tubing shall be prepared for shipment in accordance with commercial practice and in compliance with applic
45、able rules and regulations pertaining to the handling, packaging, and transportation of the tubing to ensure carrier acceptance and safe delivery. Packaging shall conform to carrier rules and regulations applicable to the mode of transportation. 6. ACKNOWLEDGMENT A producer shall include this specif
46、ication number and its revision letter in all quotations and when acknowledging purchase orders. 7. REJECTIONS Tubing not conforming to this specification, or to modifications authorized by purchaser, will be subject to rejection. 8. NOTES 8.1 Revision Indicator A change bar (I) located in the left
47、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 indicates a complete revision of the document, including technical revisions. Change ba
48、rs and (R) are not used in original publications, nor in documents that contain editorial changes only. 8.2 Hardness conversion tables for metals are presented in ASTM E140. 8.3 Terms used in AMS are clarified in ARP1917. 8.4 Dimensions and properties in inch/pound units and the Fahrenheit temperatu
49、res 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. 8.5 Purchase documents should specify not less than the following: AMS6372N Size of tubing desired Quantity of tubing desired SAE INTERNATIONAL AMS6372N Page 7 of 7 8.6 Grain size The average grain size resulting from using th
