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 2017 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:/standards.sae.org/AMS6371L AEROSPACE MATERIAL SPECIFICATION AMS6371 REV. L Issued 1942-12 Revised 2017-11 Superse
5、ding AMS6371K Steel, Mechanical Tubing 0.95Cr - 0.20Mo (0.28 - 0.33C) (SAE 4130) (Composition similar to UNS G41300) RATIONALE AMS6371L results from a Five-Year Review and update of this document that revises grain size determination (3.1.1 and 3.3.1), decarburization determination (3.3.3.3), qualit
6、y (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, 0.375 inch (9.52 mm) and under in nominal
7、 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 applications. 2. A
8、PPLICABLE 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 supplied herein. The supplier may work to a subsequent revision of a document unless a specific document issue is specified. When the referenced docum
9、ent 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 +1 724-776-4970 (outsid
10、e 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 AMS6371L Page 2 of 6 AMS2370 Quality Assurance Samplin
11、g 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 Specifications AS1182 St
12、andard 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, or www.astm.org. ASTM A255 Determining Har
13、denability of Steel ASTM A370 Mechanical Testing of Steel Products ASTM E112 Determining Average Grain Size ASTM E140 Hardness Conversion Tables for Metals Relationship Among Brinell Hardness, Vickers Hardness, Rockwell Hardness, Superficial Hardness, Knoop Hardness, Scleroscope Hardness, and Leeb H
14、ardness ASTM E350 Chemical Analysis of Carbon Steel, Low-Alloy Steel, Silicon Electrical Steel, Ingot Iron, and Wrought Iron ASTM E384 Microindentation Hardness of Materials 3. TECHNICAL REQUIREMENTS 3.1 Composition Shall conform to the percentages by weight shown in Table 1, determined by wet chemi
15、cal methods in accordance with ASTM E350, by spectrochemical methods, or by other analytical methods acceptable to purchaser. Table 1 Composition Element Min Max Carbon 0.28 0.33 Manganese 0.40 0.60 Silicon 0.15 0.35 Phosphorus - 0.025 Sulfur - 0.025 Chromium 0.80 1.10 Molybdenum 0.15 0.25 Nickel -
16、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 Check Analysis Composition variations shall meet the applicable requirements of AMS2259.
17、SAE INTERNATIONAL AMS6371L Page 3 of 6 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 or tempered shall have hardness not higher than 99 HRB, or equivalent (see 8.2). Hardness shall be de
18、termined in accordance with ASTM A370. 3.3 Properties Tubing shall conform to the following requirements: 3.3.1 Grain Size Average grain size shall be determined by either 3.3.1.1 or 3.3.1.2. 3.3.1.1 Shall be ASTM No. 5 or finer, determined in accordance with ASTM E112. 3.3.1.2 The product of a heat
19、 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): 3.3.1.2.1 A total aluminum content of 0.020 to 0.050%. 3.3.1.2.2 An acid soluble aluminum content of 0.015 to 0.050%. 3.3.1.2.3 A vanadium content of 0
20、.02 to 0.08%. 3.3.1.2.4 A columbium content of 0.02 to 0.05%. 3.3.2 Hardenability Shall be J 5/16 inch (7.9 mm) = 35 HRC minimum and J 8/16 inch (13 mm) = 28 HRC minimum, determined on the standard end-quench test specimen in accordance with ASTM A255 except that the steel shall be normalized at 170
21、0 F 10 F (927 C 6 C) and the test specimen austenitized at 1600 F 10 F (871 C 6 C). 3.3.3 Decarburization 3.3.3.1 Tubing ordered ground, turned, or polished shall be free from decarburization on the ground, turned, or polished surfaces. 3.3.3.2 Decarburization of tubing that 3.3.3.1 is not applicabl
22、e shall be not greater than shown in Table 2. Table 2 Table 2A - Maximum depth of decarburization, 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 0.2
23、03 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 0.017 0.035 Over 1.000 0.020 0.040 SAE INTERNATIONAL AMS6371L Page 4 of 6 Table 2B - Maximum depth of decarburization, SI units Nominal Wall Thickness Millimeters Total Depth of Decarburization Millimeter I
24、D 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 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 3.3.3.3 Decarburization shall be evaluated by one of the two me
25、thods of 3.3.3.3.1 or 3.3.3.3.2. 3.3.3.3.1 Metallographic Method A cross section taken perpendicular to the surface shall be prepared, etched, and visually examined metallographically at a magnification not to exceed 100X. The product shall not show a layer of complete (ferrite) or partial decarburi
26、zation exceeding the limits of Table 2. 3.3.3.3.2 Hardness Traverse Method The total depth of decarburization shall be determined by a traverse method using microindentation hardness testing in accordance with ASTM E384, at a magnification not exceeding 100X, conducted on a hardened but untempered s
27、pecimen protected during heat treatment to prevent changes in surface carbon content. 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 an
28、y adjacent surface to be uninfluenced by any decarburization on the adjacent surface. Acceptance shall be as listed in Table 2. 3.3.3.3.3 When determining the depth of decarburization, it is permissible to disregard local areas provided the decarburization of such areas does not exceed the above lim
29、its by more than 0.005 inch (0.13 mm) and the width is 0.065 inch (1.65 mm) or less. 3.3.3.3.4 In case of dispute, the total depth of decarburization determined using the microindentation hardness traverse method shall govern. 3.4 Quality Tubing, as received by purchaser, shall be uniform in quality
30、 and condition, sound, and free from foreign materials and from imperfections detrimental to usage of the tubing. 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 allowan
31、ce in accordance with AS1182. 3.5 Tolerances Shall conform to all applicable requirements of AMS2253. 4. QUALITY ASSURANCE PROVISIONS 4.1 Responsibility for Inspection The producer of tubing shall supply all samples for producers tests and shall be responsible for the performance of all required tes
32、ts. Purchaser reserves the right to sample and to perform any confirmatory testing deemed necessary to ensure that the tubing conforms to specified requirements. SAE INTERNATIONAL AMS6371L Page 5 of 6 4.2 Classification of Tests 4.2.1 Acceptance Tests Tests for all technical requirements are accepta
33、nce tests and shall be performed on each heat or lot as applicable. If grain refining elements (3.3.1.2) are not present, the ASTM E112 grain size test (3.3.1.1) shall be conducted on each lot. 4.2.2 Periodic Tests If grain refining elements (3.3.1.2) are present, the ASTM E112 grain size test (3.3.
34、1.1) 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 specified by purchaser 4.3 Sampling and Testing In accordance with AMS2370. 4.4 Reports 4.4.1 The producer of tubing shall furnish with e
35、ach 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), the results of composition, hardenability, and frequency-severity rating for each heat and for hardness and average grain size for eac
36、h lot, and stating that the product conforms to the other technical requirements. This report shall include the purchase order number, heat and lot numbers, AMS6371L, size, and quantity. If the grain size requirement of 3.3.1 is met by the aluminum, vanadium and/or columbium content, the aluminum, v
37、anadium and/or columbium content shall be reported and a statement that the chemistry satisfies the grain size requirement shall be included. 4.4.2 When material produced to this specification has exceptions taken to the technical requirements listed in Section 3, (see 5.2.1) the report shall contai
38、n a statement “This material is certified as AMS6371L(EXC) because of the following exceptions:“ and the specific exceptions shall be listed. 4.5 Resampling and Retesting In accordance with AMS2370. 5. PREPARATION FOR DELIVERY 5.1 Sizes Except when exact lengths or multiples of exact lengths are ord
39、ered, 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 sh
40、all be marked with AMS6371L(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
41、able rules and regulations pertaining to the handling, packaging, and transportation of the tubing to ensure carrier acceptance and safe delivery. SAE INTERNATIONAL AMS6371L Page 6 of 6 6. ACKNOWLEDGMENT A producer shall include this specification number and its revision letter in all quotations and
42、 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 margin is for the convenience of the user in locating areas
43、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 original publications, nor in doc
44、uments 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 Purchase documents should specify not less than the following: AMS6371L Size of tubing desired Quantity of tubing desired 8.5 Grain si
45、ze 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 verification of fine grain steel based on chemist
46、ry 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. 8.6 Similar Specifications MIL-T-6736/AMST6736. PREPARED BY AMS COMMITTEE “E”
