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 2015 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/AMS6325KAEROSPACEMATERIAL SPECIFICATIONAMS6325 REV. KIssued 1942-08Reaffirmed 2000-08Revised
5、2015-12Superseding AMS6325JSteel, Bars, and Forgings0.50Cr - 0.55Ni - 0.25Mo (0.38 - 0.43C) (SAE 8740)Heat Treated, 105 ksi (724 MPa) Tensile Strength(Composition similar to UNS G87400)RATIONALEAMS6325K results from a Five Year Review and update of this specification that revises macrostructure, gra
6、in size testing, decarburization testing methods, and reporting.1. SCOPE1.1 FormThis specification covers an aircraft-quality, low-alloy steel in the form of heat treated bars and forgings.1.2 ApplicationThese products have been used typically for parts, such as nuts, bolts, and screws, 1.750 inches
7、 (44.45 mm) and under in section thickness requiring a minimum tensile strength of 105 ksi (724 MPa), 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
8、 specified herein. The supplier may work to a subsequent revision of a document unless a specific 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 PublicationsAva
9、ilable from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or +1 724-776-4970 (outside USA), www.sae.org.AMS2251 Tolerances, Low-Alloy Steel BarsAMS2259 Chemical Check Analysis Limits, Wrought Low-Alloy and Carbon SteelsAMS2301 Steel C
10、leanliness, Aircraft Quality, Magnetic Particle Inspection ProcedureAMS2370 Quality Assurance Sampling and Testing, Carbon and Low-Alloy Steel Wrought Products and Forging StockSAE INTERNATIONAL AMS6325K Page 2 of 7AMS2372 Quality Assurance Sampling and Testing, Carbon and Low-Alloy Steel ForgingsAM
11、S2750 PyrometryAMS2759/1 Heat Treatment of Carbon and Low-Alloy Steel Parts Minimum Tensile Strength Below 220 ksi (1517 MPa)AMS2806 Identification, Bars, Wire, Mechanical Tubing, and Extrusions, Carbon and Alloy Steels and Corrosion and Heat-Resistant Steels and AlloysAMS2808 Identification Forging
12、sAS1182 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, West Conshohocken, PA 19428-2959, Tel: 610-832-9585, www.astm.org.ASTM A370 Mechanical
13、 Testing of Steel ProductsASTM E112 Determining Average Grain SizeASTM E350 Chemical Analysis of Carbon Steel, Low-Alloy Steel, Silicon Electrical Steel, Ingot Iron, and Wrought IronASTM E381 Macroetch Testing Steel Bars, Billets, Blooms, and ForgingsASTM E384 Knoop and Vickers Hardness of Materials
14、3. TECHNICAL REQUIREMENTS3.1 CompositionShall 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 - CompositionElement min maxCarbon 0.38 0.4
15、3Manganese 0.75 1.00Silicon 0.15 0.35Phosphorus - 0.025Sulfur - 0.025Chromium 0.40 0.60Nickel 0.40 0.70Molybdenum 0.20 0.30Copper - 0.353.1.1 Aluminum, vanadium and columbium are optional grain refining elements and need not be determined or reported unless used to satisfy the average grain size req
16、uirements of 3.4.2.2.3.1.2 Check AnalysisComposition variations shall meet the applicable requirements of AMS2259.SAE INTERNATIONAL AMS6325K Page 3 of 73.2 ConditionThe product shall be supplied in the following condition:3.2.1 BarsBar shall not be cut from plate (also see 4.4.2).3.2.1.1 Bars 0.500
17、Inch (12.70 mm) and Under in Nominal Diameter or Least Distance Between Parallel SidesCold finished, hardened, and tempered.3.2.1.2 Bars Over 0.500 Inch (12.70 mm) in Nominal Diameter or Least Distance Between Parallel SidesHot finished, (or cold finished when so ordered), hardened, and tempered.3.2
18、.2 ForgingsHardened and tempered in accordance with AMS2759/1.3.3 Heat TreatmentThe product shall be austenitized and hardened by quenching from 1550 F 25 F (843 C 14 C) and tempered as required to meet the requirements of 3.4.4 and 3.4.5. Pyrometry shall be in accordance with AMS2750.3.4 Properties
19、The product shall conform to the following requirements; hardness and tensile testing shall be performed in accordance with ASTM A370:3.4.1 MacrostructureVisual examination of transverse full cross-sections from bars and forging stock etched in hot hydrochloric acid in accordance with ASTM E381, sha
20、ll show no pipe or cracks. Porosity, segregation, inclusions, and other imperfections shall be no worse than the macrographs of ASTM E381 shown in Table 2.Table 2 - Macrostructure limitsCross-Section AreaSquare InchesCross-Section AreaSquare Centimeters MacrographsUp to 36, incl Up to 232, incl S2 -
21、 R1 - C2Over 36 to 133, incl Over 232 to 858, incl S2 - R2 - C3Over 133 Over 858 Note 1Note 1: Limits for larger sizes shall be agreed upon by purchaser and producer. The purchaser shall have written approval of the agreement from the cognizant engineering organization.3.4.2 Average Grain SizeAverag
22、e grain size shall be determined by either 3.4.2.1 or 3.4.2.2.3.4.2.1 Shall be ASTM No. 5 or finer, determined in accordance with ASTM E112 on specimens following heat treatment per 3.3 and the specimen shall be without further heat treatment that involves re-austenitization.3.4.2.2 The product of a
23、 heat 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):3.4.2.2.1 A total aluminum content of 0.020 to 0.050%.SAE INTERNATIONAL AMS6325K Page 4 of 73.4.2.2.2 An acid soluble aluminum content of 0.015 to
24、0.050%.3.4.2.2.3 A vanadium content of 0.02 to 0.08%.3.4.2.2.4 A columbium content of 0.02 to 0.05%.3.4.3 Decarburization3.4.3.1 Bars ordered ground, turned, or polished shall be free from decarburization on the ground, turned, or polished surfaces.3.4.3.2 Decarburization of bars that 3.4.3.1 is not
25、 applicable shall be not greater than shown in Table 3.Table 3A - Maximum total depth of decarburization, inch/pound unitsNominal Diameter or DistanceBetween Parallel SidesInchesTotal Depth of DecarburizationInchUp to 0.375, incl 0.010Over 0.375 to 0.500, incl 0.012Over 0.500 to 0.625, incl 0.014Ove
26、r 0.625 to 1.000, incl 0.017Over 1.000 to 1.500, incl 0.020Over 1.500 to 1.750, incl 0.025Table 3B - Maximum total depth of decarburization, SI unitsNominal Diameter or DistanceBetween Parallel SidesMillimetersTotal Depth of DecarburizationMillimeterUp to 9.52, incl 0.25Over 9.52 to 12.70, incl 0.30
27、Over 12.70 to 15.88, incl 0.36Over 15.88 to 25.40, incl 0.43Over 25.40 to 38.10, incl 0.51Over 38.10 to 44.45, incl 0.643.4.3.3 Decarburization shall be evaluated by one of the two methods of 3.4.3.3.1 or 3.4.3.3.2.3.4.3.3.1 Metallographic MethodA cross section taken perpendicular to the surface sha
28、ll 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 decarburization exceeding the limits of Table 3.3.4.3.3.2 Hardness Traverse Method The total depth of decarburization shall be d
29、etermined 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 protected during heat treatment to prevent changes in surface carbon content. Tempering is generally not recommended, but if
30、 tempered, the tempering temperature shall be not higher than 300 F (149 C). 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 adjacen
31、t surface to be uninfluenced by any decarburization on the adjacent surface. Acceptance shall be as listed in Table 3.3.4.3.3.3 When determining the depth of decarburization, it is permissible to disregard local areas provided the decarburization of such areas does not exceed the above limits by mor
32、e than 0.005 inch (0.13 mm) and the width is 0.065 inch (1.65 mm) or less.SAE INTERNATIONAL AMS6325K Page 5 of 73.4.3.3.4 In case of dispute, the total depth of decarburization determined using the microhardness traverse method shall govern.3.4.4 Tensile PropertiesSpecimens, cut from bars 1.750 inch
33、es (44.45 mm) and under in nominal diameter or distance between parallel sides and from forgings 1.750 inches (44.45 mm) and under in nominal cross section, shall conform to the properties shown in Table 4.Table 4 - Minimum tensile propertiesProperty ValueTensile Strength 105 ksi (724 MPa)Yield Stre
34、ngth at 0.2% Offset 85 ksi (586 MPa)Elongation in 4D 17%Reduction of Area 55% 3.4.5 HardnessShall be 233 to 262 HB, or equivalent (see 8.2).3.5 QualityThe product, as received by purchaser, shall be uniform in quality and condition, sound, and free from foreign materials and from imperfections detri
35、mental to usage of the product.3.5.1 Steel shall be aircraft-quality conforming to AMS2301.3.5.2 Bars ordered hot rolled or cold drawn, 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 o
36、pen to the machined, ground, turned, or polished surface.3.5.3 Grain flow 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.3.6 TolerancesBars shall conform to all applicable requirements o
37、f AMS2251.4. QUALITY ASSURANCE PROVISIONS4.1 Responsibility for InspectionThe producer of the product shall supply all samples for producers tests and shall be responsible for the performance all required tests. Purchaser reserves the right to sample and to perform any confirmatory testing deemed ne
38、cessary to ensure that the product conforms to specified requirements.4.2 Classification of Tests4.2.1 Acceptance TestsComposition (3.1), macrostructure (3.4.1), average grain size (3.4.2), decarburization (3.4.3), tensile properties (3.4.4), hardness (3.4.5), frequency-severity cleanliness (3.5.1),
39、 and tolerances (3.6) are acceptance tests and shall be performed on each heat or lot as applicable. If grain refining elements (3.4.2.2) are not present, the ASTM E112 grain size test (3.4.2.1) shall be conducted on each lot.SAE INTERNATIONAL AMS6325K Page 6 of 74.2.2 Periodic TestsIf grain refinin
40、g elements (3.4.2.2) are present, the ASTM E112 grain size test (3.4.2.1) 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 specified by purchaser. Grain flow of die forgings (3.5.3) is a peri
41、odic test and shall be performed at a frequency selected by the producer unless a frequency of testing is specified by purchaser.4.3 Sampling and Testing4.3.1 BarsShall be in accordance with AMS2370.4.3.2 ForgingsShall be in accordance with AMS2372.4.4 Reports4.4.1 The producer of the product shall
42、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, macrostructure, and frequency-severity cleanliness rating of each heat, and for te
43、nsile properties, hardness and, if measured, 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, AMS6325K, product form and size or part number, and quantity. If forgings
44、 are supplied, the size and melt source of stock used to make the forgings shall also be included. If the grain size requirement of 3.4.2.2 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
45、satisfies the grain size requirement shall be included.4.4.2 Report the nominal metallurgically worked cross sectional size and the cut size, if different (see 3.2.1).4.5 Resampling and Retesting4.5.1 BarsShall be in accordance with AMS2370.4.5.2 ForgingsShall be in accordance with AMS2372.5. PREPAR
46、ATION FOR DELIVERY5.1 SizesExcept when exact lengths or multiples of exact lengths are ordered, straight bars will be acceptable in mill lengths of 6 to20 feet (1.8 to 6.1 mm), but not more than 10% of any shipment shall be supplied in lengths shorter than 10 feet (3 m).5.2 Identification5.2.1 BarsS
47、hall be in accordance with AMS2806.5.2.2 ForgingsShall be in accordance with AMS2808.SAE INTERNATIONAL AMS6325K Page 7 of 75.3 Protective TreatmentBars ordered ground, turned, or polished shall be protected from corrosion prior to shipment.5.4 PackagingThe product shall be prepared for shipment in a
48、ccordance 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.6. ACKNOWLEDGMENTA producer shall include this specification number and its revision numb
49、er in all quotations and when acknowledging purchase orders.7. REJECTIONSProduct not conforming to this specification, or to modifications authorized by purchaser, will be subject to rejection.8. NOTES8.1 Revision IndicatorA 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
