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/AMS6450K AEROSPACE MATERIAL SPECIFICATION AMS6450 REV. K Issued 1941-11 Revised 2017-09 Superse
5、ding AMS6450J Steel, Spring Wire 0.95Cr - 0.22V (0.48 - 0.53C) (SAE 6150) Annealed and Cold Drawn (Composition similar to UNS G61500) RATIONALE AMS6450K results from a Five-Year Review and update of this specification that adds tensile testing rates (3.3.4.1.1), reporting (4.4) and identification (5
6、.1). 1. SCOPE 1.1 Form This specification covers a low-alloy steel in the form of wire supplied as coils, spools, and straight lengths. 1.2 Application This wire has been used typically for valve springs and other springs requiring high-fatigue properties when used at moderately elevated temperature
7、s, but usage is not limited to such applications. 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
8、 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: 877-606-
9、7323 (inside USA and Canada) or +1 724-776-4970 (outside USA), www.sae.org. AMS2259 Chemical Check Analysis Limits, Wrought Low-Alloy and Carbon Steels AMS2301 Steel Cleanliness, Aircraft Quality, Magnetic Particle Inspection Procedure AMS2370 Quality Assurance Sampling and Testing, Carbon and Low-A
10、lloy Steel Wrought Products and Forging Stock SAE INTERNATIONAL AMS6450K Page 2 of 6 AMS2430 Shot Peening, Automatic ARP1917 Clarification of Terms Used in Aerospace Metals Specifications 2.2 ASTM Publications Available from ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken
11、, PA 19428-2959, Tel: 610-832-9585, www.astm.org. 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, Sc
12、leroscope Hardness, and Leeb Hardness ASTM E290 Bend Testing Material for Ductility ASTM E350 Chemical Analysis of Carbon Steel, Low-Alloy Steel, Silicon Electrical Steel, Ingot Iron, and Wrought Iron 3. TECHNICAL REQUIREMENTS 3.1 Composition Shall conform to the percentages by weight shown in Table
13、 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 0.48 0.53 Manganese 0.70 0.90 Silicon 0.15 0.35 Phosphorus - 0.025 Sulfur - 0.025 Chromium 0.80 1.10 V
14、anadium 0.15 0.30 Nickel - 0.25 Molybdenum - 0.06 Copper - 0.35 3.1.1 Check Analysis Composition variations shall meet the applicable requirements of AMS2259. 3.2 Condition Wire shall be uniformly annealed and cold drawn. Carbides shall be finely spheroidized and uniformly distributed. 3.3 Propertie
15、s Product shall conform to the following requirements: 3.3.1 Average Grain Size Shall be ASTM No. 5 or finer, determined in accordance with ASTM E112. SAE INTERNATIONAL AMS6450K Page 3 of 6 3.3.2 Carburization and Decarburization Wire shall not be carburized or decarburized to such an extent as will
16、 prevent finished springs from having a microstructure free from ferrite or massive carbide adjacent to the surface when metallographically examined at 500X after heat treatment in accordance with 3.3.4. 3.3.3 Bending Wire shall withstand, without cracking, bending in accordance with ASTM E290 throu
17、gh an angle of 180 around a diameter equal to the nominal diameter or thickness of the wire. 3.3.4 Response to Heat Treatment Wire shall have the following properties after being hardened by quenching in oil from 1575 F 25 F (857 C 14 C) and tempering at not lower than 700 F (371 C) for approximatel
18、y 2 hours at heat; hardness and tensile testing shall be performed in accordance with ASTM A370: 3.3.4.1 Tensile Properties Shall be as shown in Table 2. Table 2 - Minimum tensile properties Property Value Tensile Strength 220 ksi (1517 MPa) Reduction of Area 40% 3.3.4.1.1 Unless otherwise specified
19、, the strain rate shall be set at 0.005 inch/inch/minute (0.005 mm/mm/minute) and maintained within a tolerance of 0.002 inch/inch/minute (0.002 mm/mm/minute) through 0.2% offset yield strain. After the yield strain, the speed of the testing machine shall be set between 0.05 and 0.5 inch/inch (mm/mm
20、) of the length of the reduced section (or distance between the grips for specimens not having a reduced section) per minute. Alternatively, an extensometer and strain rate indicator may be used to set the strain rate between 0.05 and 0.5 inch/inch/min (mm/mm/minute). 3.3.4.2 Hardness Shall be not l
21、ower than 46 HRC, or equivalent (see 8.2). 3.3.4.3 Twisting (Round Wire) A straight specimen of suitable length shall be held between two clamps, one of which can be rotated, separated by a distance equal to 100 times the nominal wire diameter and twisted forward two complete 360 turns, reversed fou
22、r turns, and then reversed repeatedly after each succeeding four turns until failure. Twisting shall be done at a uniform rate and slowly enough so that the temperature of the wire while twisting shall not exceed 212 F (100 C). If it is impracticable to twist a specimen as long as 100 times the wire
23、 diameter because of limitations of the twisting machine, a specimen 50 times the diameter may be used, but the initial forward twist shall be just one turn and each succeeding reversal two turns. Specimens 100 times the diameter shall withstand not less than 24 turns, and specimens 50 times the dia
24、meter shall withstand not less than 12 turns. 3.3.4.4 Etching Examination, at 7 to 10X magnification, of surfaces of sections of wire, etched in hot hydrochloric acid (1:1) at 160 to 180 F (71 to 82 C) for sufficient time to remove approximately 1% of the diameter or thickness of the wire, shall sho
25、w no evidence of pits, cracks, laps, die marks, torn surfaces, or other imperfections detrimental to usage for springs. Coils, spools, and original coils of cut lengths from which defective samples are taken shall be subject to rejection; if 25% or more of the coils, spools, or original coils of cut
26、 lengths from a lot are rejected, the entire lot shall be rejected. SAE INTERNATIONAL AMS6450K Page 4 of 6 3.4 Quality Wire, 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 wire for springs
27、. 3.4.1 Steel shall be aircraft-quality conforming to AMS2301. 3.4.2 All welds shall be clearly and permanently marked, and the method of marking shall be included on the label or tag. 3.5 Tolerances Wire shall conform to the following: 3.5.1 Diameter or Thickness Shall be as specified in Table 3. T
28、able 3 Table 3A - Diameter or thickness tolerances, inch/pound units Nominal Diameter or Thickness Inch Tolerance, Inch Plus and Minus Up to 0.075, incl 0.00075 Over 0.075 to 0.148, incl 0.001 Over 0.148 to 0.375, incl 0.0015 Over 0.375 to 0.500, incl 0.002 Table 3B - Diameter or thickness tolerance
29、s, SI units Nominal Diameter or Thickness Millimeters Tolerance, Millimeter Plus and Minus Up to 1.90, incl 0.0190 Over 1.90 to 3.76, incl 0.025 Over 3.76 to 9.52, incl 0.038 Over 9.52 to 12.70, incl 0.05 3.5.2 Roundness Round wire shall not be out-of-round more than one-half the total tolerance spe
30、cified in Table 3. 4. QUALITY ASSURANCE PROVISIONS 4.1 Responsibility for Inspection The purchaser of the product shall supply all samples for purchasers tests and shall be responsible for the performance of all required tests. Purchaser reserves the right to sample and to perform any confirmatory t
31、esting deemed necessary to ensure that the product conforms to specified requirements. 4.2 Classification of Tests All technical requirements are acceptance tests and preproduction tests and shall be performed on each heat or lot prior to or on the initial shipment of product to a purchaser, as appl
32、icable. SAE INTERNATIONAL AMS6450K Page 5 of 6 4.3 Sampling and Testing Wire shall be in accordance with AMS2370 and as follows: A lot shall be all wire from the same heat of steel and drawn through the same sets of dies with the same processing schedule and without break in the set-up to the same n
33、ominal diameters and presented for purchasers inspection at the same time. 4.3.1 Bending and Twisting One specimen from each coil or spool (or original coil of cut length). 4.3.2 Etching One specimen from each end of each coil or spool (or original coil of cut length). 4.4 Reports 4.4.1 The purchase
34、r of wire 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), the results of tests for composition frequency-severity cleanliness rating of each heat, average grain s
35、ize and tensile properties of each lot and stating that the wire conforms to the other technical requirements. This report shall include the purchase order number, heat and lot numbers, AMS6450K, size, and quantity. 4.4.2 When material produced to this specification is beyond the sizes allowed in th
36、e scope or tables, or other exceptions are taken to the technical requirements listed in Section 3, (see 5.1.1) the report shall contain a statement “This material is certified as AMS6450J(EXC) because of the following exceptions:“ and the specific exceptions shall be listed. 4.5 Resampling and Rete
37、sting Shall be in accordance with AMS2370. 5. PREPARATION FOR DELIVERY 5.1 Identification Coiled, spooled or cut length wire shall be securely bundled or boxed. Each bundle shall be identified by a durable tag marked with not less than the purchase order number, AMS6450K, heat and lot numbers, nomin
38、al size, quantity, and manufacturers identification. Each box shall be marked with the same information. 5.1.1 When technical exceptions are taken (see 4.4.2), the material shall be marked with AMS6450J(EXC). 5.2 Protective Treatment Wire shall be protected from corrosion prior to shipment. 5.3 Pack
39、aging Wire shall be prepared for shipment in accordance with commercial practice and in compliance with applicable rules and regulations pertaining to the handling, packaging, and transportation of the product to ensure carrier acceptance and safe delivery (see 8.7). 6. ACKNOWLEDGMENT A purchaser sh
40、all mention this specification number and its revision letter in all quotations and when acknowledging purchase orders. 7. REJECTIONS Wire not conforming to this specification, or to modifications authorized by purchaser, will be subject to rejection. SAE INTERNATIONAL AMS6450K Page 6 of 6 8. NOTES
41、8.1 Revision Indicator A change bar (l) located in the left 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 revisi
42、on of the document, including technical revisions. Change bars 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 Welded portions of wire, including heat affected zones, may no
43、t satisfy the property requirements of this specification. 8.4 Notes Applicable to Finished Springs Requirements pertaining to finished springs have been removed from this specification because it was determined that the specification is used for procurement of wire, but rarely if ever used for proc
44、urement of finished springs. Other specifications and/or drawings are normally used for that purpose. Those previous requirements pertaining to springs are presented below for information purposes. 8.4.1 Springs are hardened and tempered after forming using the heat treat cycle of 3.3.4. 8.4.2 Shot
45、peening, if required, should be in accordance with AMS2430 with parameters specified by the purchaser. 8.4.3 Magnetic particle inspection of finished springs should be accomplished in accordance with ASTM E1444 or equivalent with acceptance criteria as agreed upon by purchaser and spring purchaser.
46、8.4.4 Hardness of finished springs is typically 43 to 46 HRC (see 8.2). 8.4.5 Finished spring surfaces, as received by purchaser, should be uniform and free from pits, nicks, scratches, and marks due to grinding, drawing, or coiling, and from other imperfections detrimental to performance of the spr
47、ings. 8.4.6 Approval, sampling, and inspection of springs, prior to shipping of production springs, should be agreed upon by purchaser and spring purchaser. 8.4.7 Springs of different part numbers should be shipped in separate containers, each marked with the appropriate part number and shall be pac
48、kaged to ensure that the finished springs are protected against mechanical damage and exposure to moisture. 8.4.8 Finished springs should contain no welds. 8.5 Terms used in AMS are clarified in ARP1917. 8.6 Dimensions and properties in inch/pound units and the Fahrenheit temperatures are primary; d
49、imensions 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. 8.7 Purchase documents should specify not less than the following: AMS6450K Form (coils, spools, or cut lengths) and size of wire desired Quantity of wire Special packaging, if required PREPARED BY AMS COMMITTEE “E”
