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 theref
2、rom, 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 InternationalAll rights reserved. No part of this publi
3、cation 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: +1 724-776-4970 (out
4、side USA)Fax: 724-776-0790Email: CustomerServicesae.orgSAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedbackon this Technical Report, please visithttp:/www.sae.org/technical/standards/AMS6373HAEROSPACEMATERIAL SPECIFICATIONAMS6373 REV. HIssued 1969-11Reaffirmed 2010-10Revised
5、2016-01Superseding AMS6373GSteel, Welded Tubing0.95Cr - 0.20Mo (0.28 - 0.33C) (SAE 4130)(Composition similar to UNS G41300)RATIONALEAMS6373H is a Five Year Review and update of this specification that revises grain size requirements, decarburization testing and reporting.1. SCOPE1.1 Form This specif
6、ication covers an aircraft-quality, low-alloy steel in the form of welded tubing.1.2 Application This tubing has been used typically for general use where welding and moderate tensile properties are required and especially when a minimum tensile strength of 160 ksi (1103 MPa) is required after heat
7、treatment, but usage is not limited to such applications.2. APPLICABLE DOCUMENTSThe 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 sp
8、ecific 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, PA 15096-0001, Tel: 877
9、-606-7323 (inside USA and Canada) or +1 724-776-4970 (outside USA), www.sae.org.AMS2253 Tolerances, Carbon and Alloy Steel TubingAMS2259 Chemical Check Analysis Limits, Wrought Low-Alloy and Carbon SteelsAMS2301 Steel Cleanliness, Aircraft-Quality Magnetic Particle Inspection ProcedureSAE INTERNATIO
10、NAL AMS6373H Page 2 of 7AMS2370 Quality Assurance Sampling and Testing, Carbon and Low-Alloy Steel Wrought Products and Forging StockAMS2807 Identification, Carbon and Low-Alloy Steels, Corrosion and Heat-Resistant Steels and Alloys, Sheet, Strip, Plate and Aircraft Tubing2.2 ASTM Publications Avail
11、able from ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959, Tel: 610-832-9585, www.astm.org.ASTM A370 Mechanical Testing of Steel ProductsASTM E112 Determining Average Grain SizeASTM E350 Chemical Analysis of Carbon Steel, Low-Alloy Steel, Silicon Electrical
12、 Steel, Ingot Iron, and Wrought IronASTM E384 Knoop and Vickers Hardness of MaterialsASTM E1444 Magnetic Particle Examination3. 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 spec
13、trochemical methods, or by other analytical methods acceptable to purchaser.Table 1 - CompositionElement min maxCarbon 0.28 0.33Manganese 0.40 0.60Silicon 0.15 0.35Phosphorus - 0.025Sulfur - 0.025Chromium 0.80 1.10Molybdenum 0.15 0.25Nickel - 0.25Copper - 0.353.1.1 Aluminum, vanadium and columbium a
14、re optional grain refining elements and need not be determined or reported unless used to satisfy the average grain size requirements of 3.4.3.2.3.1.2 Check AnalysisComposition variations shall meet the applicable requirements of AMS2259.3.2 Condition Cold finished and either normalized and tempered
15、, stress relieved, or otherwise heat treated.3.3 Fabrication Tubing shall be produced by a welded and drawn process. The external finishes may be produced by any method which will provide the required surface condition and not affect the limits of wall thickness, with the exception that centerless g
16、rinding is not acceptable. A light polish to improve surface appearance may be employed.SAE INTERNATIONAL AMS6373H Page 3 of 73.3.1 Tubing shall be processed to completely remove the weld reinforcement and any dimensional indication of the presence of welds.3.4 Properties Tubing shall conform to the
17、 following requirements; hardness and tensile testing shall be performed in accordance with ASTM A370:3.4.1 Tensile PropertiesShall be as shown in Table 2.Table 2A - Minimum tensile properties, inch/pound unitsNominal ODInchesNominal WallThicknessInchTensileStrengthksiYield Strengthat 0.2% Offsetksi
18、Elongation in2 Inches%Full TubeElongation in2 Inches%StripUp to 0.500, excl Up to 0.188, incl 95 75 10 -Up to 0.500, excl Over 0.188 90 70 12 -0.500 and over Up to 0.188, incl 95 75 12 70.500 and over Over 0.188 90 70 15 10Table 2B - Minimum tensile properties, SI unitsNominal ODMillimetersNominal W
19、allThicknessMillimetersTensileStrengthMPaYield Strengthat 0.2% OffsetMPaElongation in50.8 mm%Full TubeElongation in50.8 mm%StripUp to 12.70, excl Up to 4.78, incl 655 517 10 -Up to 12.70, excl Over 4.78 621 483 12 -12.70 and over Up to 4.78, incl 655 517 12 712.70 and over Over 4.78 621 483 15 103.4
20、.2 CrushingSpecimens as in 4.3.1.1 shall withstand, without failure of the weld, crushing axially under a gradually applied load until thecross-sectional dimension is increased in one zone by 20% or until one complete fold is formed, or until the specimen is reduced in length to two-thirds of the or
21、iginal length.3.4.3 Average Grain SizeAverage grain size shall be determined by either 3.4.3.1 or 3.4.3.2.3.4.3.1 Shall be ASTM No. 5 or finer, determined in accordance with ASTM E112. 3.4.3.2 The product of a heat shall be considered to have an ASTM No. 5 or finer austenitic grain size if one or mo
22、re of the following are determined by heat analysis (see 8.4):3.4.3.2.1 A total aluminum content of 0.020 to 0.050%.3.4.3.2.2 An acid soluble aluminum content of 0.015 to 0.050%.3.4.3.2.3 A vanadium content of 0.02 to 0.08%.3.4.3.2.4 A columbium content of 0.02 to 0.05%.SAE INTERNATIONAL AMS6373H Pa
23、ge 4 of 73.4.4 Decarburization 3.4.4.1 Tubing ordered ground, turned, or polished shall be free from decarburization on the ground, turned, or polished surfaces. 3.4.4.2 Tubing that 3.4.4.1 is not applicable shall be free from complete decarburization. Partial decarburization shall not exceed the li
24、mits specified in Table 3.Table 3A - Maximum total depth of decarburization, inch/pound unitsNominal Wall Thickness (T)InchDepth of Partial DecarburizationInchIDDepth of Partial DecarburizationInchODDepth of Partial DecarburizationInchID+ODUp to 0.040, incl 0.25T 0.25T 0.30TOver 0.040 to 0.050, incl
25、 0.009 0.009 0.012Over 0.050 to 0.070, incl 0.010 0.010 0.014Over 0.070 to 0.080, incl 0.012 0.012 0.016Over 0.080 to 0.090, incl 0.014 0.014 0.018Over 0.090 to 0.100, incl 0.015 0.015 0.020Over 0.100 to 0.150, incl 0.017 0.017 0.022Over 0.150 to 0.200, incl 0.020 0.020 0.026Table 3B - Maximum total
26、 depth of decarburization, SI unitsNominal Wall Thickness (T)MillimetersDepth of PartialDecarburization MillimetersIDDepth of PartialDecarburizationMillimetersODDepth of PartialDecarburizationMillimetersID+ODUp to 1.02, incl 0.25T 0.25T 0.30TOver 1.02 to 1.27, incl 0.23 0.23 0.30Over 1.27 to 1.78, i
27、ncl 0.25 0.25 0.36Over 1.78 to 2.03, incl 0.30 0.30 0.41Over 2.03 to 2.29, incl 0.36 0.36 0.46Over 2.29 to 2.54, incl 0.38 0.38 0.51Over 2.54 to 3.81, incl 0.43 0.43 0.56Over 3.81 to 5.08, incl 0.51 0.51 0.663.4.4.3 Decarburization shall be evaluated by one of the two methods of 3.4.4.3.1 or 3.4.4.3
28、.2.3.4.4.3.1 Metallographic MethodA cross section taken perpendicular to the surface shall be prepared, etched, and visually examined metallographically at a magnification not to exceed 100X. Optical indications of decarburization (including complete decarburization ferrite plus partial decarburizat
29、ion shall not exceed the limits of Table 3.3.4.4.3.2 Hardness Traverse MethodThe total depth of decarburization shall be determined by a traverse method using microhardness testing in accordance with ASTM E384, at a magnification not exceeding 100X, conducted on a hardened but untempered specimen pr
30、otected 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 any adjacent
31、 surface to be uninfluenced by any decarburization on the adjacent surface. Acceptance shall be as listed in Table 3.3.4.4.4 When determining the depth of decarburization, it is permissible to disregard local areas provided the decarburization of such areas does not exceed the limits of Table 3 by m
32、ore than 0.005 inch (0.13 mm) and the width is 0.065 inches (1.65 mm) or less.SAE INTERNATIONAL AMS6373H Page 5 of 73.4.4.5 In case of dispute, the total depth of decarburization determined using the microhardness traverse method shall govern.3.4.5 FlarabilityTubing shall withstand flaring at room t
33、emperature, without formation of cracks or other visible defects, by being forced axially with steady pressure over a hardened and polished tapered steel pin having a 74 degree included angle to produce a flare having not less than the permanent percentage OD increase shown in Table 4. After flaring
34、, the inside surface of the tubing shall be smooth and shall show no evidence of a bead that might prevent the assembly of pressure tight joints.Table 4 - Minimum OD increaseNominal Wall Thickness% of ODOD Increase%Up to 7, incl 35Over 7 453.5 Quality Tubing, as received by purchaser, shall be unifo
35、rm in quality and condition and shall have a finish conforming to the best practice for high-quality aircraft tubing. It shall be smooth and free from heavy scale or oxide, burrs, seams, tears, grooves, laminations, slivers, pits, and other imperfections detrimental to usage of the tubing. Surface i
36、mperfections, such as handling marks, straightening marks, light mandrel and die marks, shallow pits, and scale pattern, will not be considered injurious if the imperfections are removable within the tolerances specified for wall thickness but removal of such imperfections is not required.3.5.1 Stee
37、l shall be aircraft-quality conforming to AMS2301.3.5.2 When specified, the tubing, either with or without machining of the surface, shall pass magnetic particle inspection in accordance with ASTM E1444. Standards for acceptance shall be as agreed upon by purchaser and producer (see 8.5).3.6 Toleran
38、ces 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 tests. Purchaser reserves the right to sample
39、 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 TestsComposition (3.1), tensile properties (3.4.1), crushing (3.4.2), grain size (3.4.3), decarburization (3.4.4), frequency-severity
40、cleanliness rating (3.5.1), magnetic particle inspection when specified (3.5.2), and tolerances (3.6) are acceptance tests and shall be performed on each heat or lot as applicable. If grain refining elements (3.4.3.2) are not present, the ASTM E112 grain size test (3.4.2.1) shall be conducted on eac
41、h lot.4.2.2 Periodic TestsIf grain refining elements (3.4.3.2) are present, the ASTM E112 grain size test (3.4.3.1) 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. Fl
42、arability (3.4.5) is a periodic test and shall be performed at a frequency selected by the producer unless frequency of testing is specified by purchaser. SAE INTERNATIONAL AMS6373H Page 6 of 74.3 Sampling and Testing 4.3.1 For Acceptance TestsShall be in accordance with AMS2370 and the following:4.
43、3.1.1 At least one sample for the crushing test of 3.4.2 shall be selected from each 1000 feet (305 m) or less of tubing from each lot. Specimens shall have length equal to 1.5 times the nominal OD of the tube.4.3.2 Specimens for flarability test shall be full tubes or sections cut from a tube. The
44、end of the specimen to be flared shall be cut square, with the cut end smooth and free from burrs, but not rounded.4.4 Reports The producer 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 mult
45、iple melting operations) and the results of tests for composition and frequency-severity cleanliness rating of each heat, and for tensile properties and, if measured, average grain size of each lot, and stating that the product conforms to the other technical requirements. This report shall include
46、the purchase order number, heat and lot numbers, AMS6373H, size, and quantity. If the grain size requirement of 3.4.3.2 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 grain
47、size requirement shall be included.4.5 Resampling and Retesting Shall be in accordance with AMS2370.5. PREPARATION FOR DELIVERY 5.1 Sizes Except when exact lengths or multiples of exact lengths are ordered, straight tubing will be acceptable in mill lengths of 6 to 20 feet (1.8 to 6.1 m) but not mor
48、e than 10% of any shipment shall be supplied in lengths shorter than 10 feet (3 m).5.2 Identification Shall be in accordance with AMS2807.5.3 Protective Treatment Tubing shall be protected from corrosion prior to shipment.5.4 Packaging Tubing shall be prepared for shipment in accordance with commerc
49、ial practice and in compliance with applicable rules and regulations pertaining to the handling, packaging, and transportation of the tubing to ensure carrier acceptance and safe delivery.6. ACKNOWLEDGMENT A producer shall mention this specification 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
