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 reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions.Copyright 2012 SAE InternationalAll rights reserved. No part of this publication may b
3、e 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 (outside USA)Fax
4、: 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/AMS6551AEROSPACEMATERIALSPECIFICATIONAMS6551Issued 2013-02Steel Bars, Forgings and Tubing1.75 Cr 4.0 Ni 0
5、.5 Mo (0.35-0.40 C)Premium Aircraft QualityConsumable Electrode Vacuum Remelted(Composition Similar to UNS K57034)RATIONALEAMS6551 is a new specification to cover premium aircraft-quality UNS K57034.1. SCOPE1.1 FormThis specification covers a premium aircraft-quality, low-alloy steel in the form of
6、bars, forgings, mechanical tubing, and forging stock.1.2 ApplicationThese products have been used typically for carburized parts requiring high minimum core hardness with a narrow range, reduced distortion and subject to stringent magnetic particle inspection standards, but usage is not limited to s
7、uch 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 specific document issue is specified. When
8、 the referenced document has been cancelled and no superseding document has been specified, the last published issue of that document shall apply.SAE AMS6551 Page 2 of 72.1 SAE PublicationsAvailable from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside
9、USA and Canada) or 724-776-4970 (outside USA), www.sae.org.AMS2251 Tolerances, Low-Alloy Steel BarsAMS2253 Tolerances, Carbon and Alloy Steel TubingAMS2259 Chemical Check Analysis Limits, Wrought Low-Alloy and Carbon SteelsAMS2300 Steel Cleanliness, Premium Aircraft-Quality, Magnetic Particle Inspec
10、tion ProcedureAMS2370 Quality Assurance Sampling and Testing, Carbon and Low-Alloy Steel, Wrought Products and ForgingStockAMS2372 Quality Assurance Sampling and Testing, Carbon and Low-Alloy Steel, Forgings AMS2806 Identification, Bars, Wire, Mechanical Tubing, and Extrusions, Carbon and Alloy Stee
11、ls and Corrosion and Heat-Resistant Steels and AlloysAMS2808 Identification, ForgingsAS1182 Standard Stock Removal Allowance, Aircraft-Quality and Premium Aircraft-Quality Steel Bars and Mechanical Tubing2.2 ASTM PublicationsAvailable from ASTM International, 100 Barr Harbor Drive, P. O. Box C700, W
12、est Conshohocken, PA 19428-2959, Tel: 610-832-9585, www.astm.org.ASTM A 255 Determining Hardenability of SteelASTM A 370 Mechanical Testing of Steel ProductsASTM A 604 Macroetch Testing of Consumable Electrode Remelted Steel Bars and BilletsASTM E 112 Determining Average Grain SizeASTM E 350 Chemica
13、l Analysis of Carbon Steel, Low-Alloy Steel, Silicon Electrical Steel,Ingot Iron, and Wrought IronASTM E 384 Knoop and Vickers Hardness of Materials3. TECHNICAL REQUIREMENTS3.1 CompositionShall conform to the following percentages by weight shown in Table 1, determined by wet chemical methods in acc
14、ordance with ASTM E 350, by spectrochemical methods, or by other analytical methods acceptable to purchaser.SAE AMS6551 Page 3 of 7TABLE 1 COMPOSITIONElement min maxCarbon 0.34 0.40Manganese 0.15 0.60Silicon 0.15 0.40Phosphorus - 0.015Sulfur - 0.005Chromium 1.60 2.00Nickel 3.80 4.30Molybdenum 0.30 0
15、.60Copper - 0.20Vanadium - 0.203.1.1 Check AnalysisComposition variations shall meet the applicable requirements of AMS2259.3.2 Melting PracticeSteel shall be multiple melted using vacuum arc consumable electrode practice (VAR) in the remelt cycle.3.3 ConditionThe product shall be supplied in the fo
16、llowing condition; hardness and tensile strength shall be determined in accordance with ASTM A 370:3.3.1 BarsBar shall not be cut from plate. (Also see 4.4.2)3.3.1.1 Bars 0.500 inch (12.70 mm) and Under in Nominal Diameter or Least Distance Between Parallel Sides Cold finished having tensile strengt
17、h not higher than 142 ksi (980 MPa) or hardness not higher than 302 HB or equivalent (See 8.2).3.3.1.2 Bars over 0.500 inch (12.70 mm) in Nominal Diameter or Least Distance between Parallel Sides Hot finished and annealed, unless otherwise ordered, having hardness not higher than 302 HB or equivalen
18、t (See 8.2). Bars ordered cold finished may have hardness as high as 310 HB or equivalent (See 8.2).3.3.2 ForgingsAs ordered.3.3.3 Mechanical TubingCold finished, unless otherwise ordered, having hardness not higher than 302 HB, or equivalent (See 8.2). Tubing ordered hot finished and annealed or te
19、mpered shall have hardness not higher than 302 HB or equivalent (See 8.2).3.3.4 Forging Stock As ordered by the forging manufacturer.SAE AMS6551 Page 4 of 73.4 PropertiesThe product shall conform to the following requirements; hardness, tensile, and impact testing shall be performed in accordance wi
20、th ASTM A 370:3.4.1 MacrostructureVisual examination of transverse full cross-sections from bars, billets tube rounds (solid, not hollow), and forging stock, etched in hot hydrochloric acid in accordance with ASTM A 604, shall show no pipe or cracks. Porosity, segregation, inclusions, and other impe
21、rfections shall be no worse than the macrographs of ASTM A 604 shown in Table 2.TABLE 2 MACROSTRUCTURE LIMITSClass Condition Severity1FrecklsA2 White Spots A3 Radial Segregation A4 Ring Pattern C3.4.1.1 Macrostructure examination is not required for hollow tubes that are produced directly from ingot
22、s or blooms unless specified by purchaser, in which case the purchaser shall specify standards to be used.3.4.2 Average Grain Size of Bars, Forgings, and TubingShall be ASTM No. 5 or finer determined in accordance with ASTM E 112.3.4.3 Response to Heat Treatment of Bars, Forgings, Tubing and Forging
23、 StockSpecimens extracted from product shall have the properties shown in Table 3 after being austenitized by heating to 1607 F 25 (875 C 14), holding at heat for a time commensurate with section thickness, heating equipment, and procedure used, air quenched to below 90 F (32 C), cooling to -100 F (
24、-73 C) or colder, holding at that temperature for not less than two hours, and warming in air to room temperature followed by tempering for 2 hours minimum at 419 F 10 (215 C 6).TABLE 3 MINIMUM LONGITUDINAL MECHANICAL PROPERTIESPROPERTY VALUETensile Strength 254 ksi (1750 MPa)Yield Strength 0.2% 203
25、 ksi (1400 MPa)Elongation in 4D 8%Charpy Vnotch 11 ft-lb (15 J)3.5 QualityThe product, 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 product.3.5.1 Steel shall be premium aircraft-quality
26、conforming to AMS2300.3.5.2 Product ordered hot finished or cold finished or ground, turned, or polished shall, after removal of the standard stock removal allowance in accordance with AS1182, be free from seams, laps, tears, and cracks open to the ground, turned, or polished surface. 3.5.3 Grain fl
27、ow of die forgings, except in areas that contain flash-line end grain, shall follow the general contour of the forgings showing no evidence of reentrant grain flow.SAE AMS6551 Page 5 of 73.6 Tolerances3.6.1 BarsIn accordance with AMS2251.3.6.2 Mechanical Tubing In accordance with AMS2253.4. QUALITY
28、ASSURANCE PROVISIONS4.1 Responsibility for inspectionThe vendor of the product shall supply all samples for vendors 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
29、 the product conforms to specified requirements.4.2 Classification of Tests4.2.1 Acceptance Tests Composition (3.1), condition (3.3), macrostructure (3.4.1), average grain size (3.4.2), response to heat treatment (3.4.3), and tolerances (3.6) are acceptance tests and shall be performed on each heat
30、or lot as applicable.4.2.2 Periodic TestsFrequency-severity cleanliness rating (3.5.1) and grain flow of die forgings (3.5.3) are periodic tests and shall be performed at a frequency selected by the vendor unless frequency of testing is specified by purchaser.4.3 Sampling and Testing4.3.1 Bars, Mech
31、anical Tubing, and Forging Stock In accordance with AMS2370.4.3.2 ForgingsIn accordance with AMS2372.4.4 Reports4.4.1 The vendor of bars, forgings and tubing shall furnish with each shipment a report showing the results of tests for composition, macrostructure and response to heat treatment of each
32、heat, and for condition, average grain size of each lot, and stating that the product conforms to the other technical requirements. This report shall include the purchase order number, heat and lot numbers, AMS6551, product form and size (and/or part number, if applicable) and quantity. If forgings
33、are supplied, the size and melt source of stock used to make the forgings shall also be included.4.4.2 If the ship size/shape is cut from a larger cross section, report the nominal metallurgically worked size (See 3.3.1).4.4.3 The vendor of forging stock shall furnish with each shipment a report sho
34、wing the results of tests for composition, macrostructure and response to heat treatment of each heat. This report shall include the purchase order number, heat number, AMS6551, size and quantity.SAE AMS6551 Page 6 of 74.5 Resampling and Retesting4.5.1 Bars, Mechanical Tubing, and Forging StockIn ac
35、cordance with AMS2370.4.5.2 ForgingsIn accordance with AMS2372.5. PREPARATION FOR DELIVERY5.1 SizesExcept when exact lengths or multiples of exact lengths are ordered, straight bars and 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 sha
36、ll be supplied in lengths shorter than 10 feet (3 m).5.2 Identification5.2.1 Bars and Mechanical Tubing In accordance with AMS2806.5.2.2 ForgingsIn accordance with AMS2808.5.2.3 Forging StockAs agreed upon by purchaser and vendor.5.3 Protective TreatmentBars and mechanical tubing ordered cold drawn,
37、 cold rolled, ground, turned, or polished shall be protected from corrosion prior to shipment.5.4 PackagingThe product shall be prepared for shipment in accordance with commercial practice and in compliance with applicable rules and regulations pertaining to the handling, packaging, and transportati
38、on of the product to ensure carrier acceptance and safe delivery.6. ACKNOWLEDGMENTA vendor shall include this specification number in all quotations and when acknowledging purchase orders.7. REJECTIONSProduct not conforming to this specification, or to modifications authorized by purchaser, will be
39、subject to rejection.SAE AMS6551 Page 7 of 78. NOTES8.1 A change bar (|) 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 specification. An (R) symbol to the left of the docu
40、ment title indicates a complete revision of the specification, including technical revisions. Change bars and (R) are not used in original publications, nor in specifications that contain editorial changes only.8.2 Hardness conversion tables for metals are presented in ASTM E 140.8.3 Terms used in A
41、MS are clarified in ARP1917.8.4 Dimensions and properties in inch/pound units and the Fahrenheit temperatures are primary; dimensions and properties in SI units and the Celsius temperatures are shown as the approximate equivalents for the primary units and are presented only for information.8.5 Purchase documents should specify not less than the following:AMS6551Product form and size (and/or part number, if applicable) of product desiredQuantity of product desired.PREPARED BY AMS COMMITTEE “E”
