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 ther
2、efrom, 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
3、publication 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: +1 724-776-49
4、70 (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/AMS6328N AEROSPACE MATERIAL SPECIFICATION AMS6328 REV. N Issued 1945-08 Revised 2017-10 Supers
5、eding AMS6328M Steel, Bars, Forgings, and Tubing 0.50Cr - 0.55Ni - 0.25Mo (0.48 to 0.53C) (8750) (Composition similar to UNS K13550) RATIONALE AMS6328N results from a Five-Year Review and update of this specification that revises grain size determination (3.1.1 and 3.3.2), decarburization determinat
6、ion (3.3.4), surface quality (3.4.2), testing frequency (4.2), reporting (4.4), and identification (5.2). 1. SCOPE 1.1 Form This specification covers an aircraft-quality, low-alloy steel in the form of bars, forgings, mechanical tubing, and forging stock. 1.2 Application These products have been use
7、d typically for parts 0.80 inch (20.3 mm) and under in nominal section thickness at time of heat treatment requiring a through-hardening steel capable of developing hardness as high as 50 HRC when properly hardened and tempered and for parts of greater thickness but requiring proportionally lower ha
8、rdness, 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 spe
9、cific 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
10、-606-7323 (inside USA and Canada) or +1 724-776-4970 (outside USA), www.sae.org. AMS2251 Tolerances Low-Alloy Steel Bars AMS2253 Tolerances Carbon and Alloy Steel Tubing AMS2259 Chemical Check Analysis Limits Wrought Low-Alloy and Carbon Steels SAE INTERNATIONAL AMS6328N Page 2 of 9 AMS2301 Steel Cl
11、eanliness, Aircraft Quality Magnetic Particle Inspection Procedure AMS2370 Quality Assurance Sampling and Testing Carbon and Low-Alloy Steel Wrought Products and Forging Stock AMS2372 Quality Assurance Sampling and Testing Carbon and Low-Alloy Steel Forgings AMS2806 Identification Bars, Wire, Mechan
12、ical Tubing, and Extrusions Carbon and Alloy Steels and Corrosion and Heat-Resistant Steels and Alloys AMS2808 Identification Forgings ARP1917 Clarification of Terms Used in Aerospace Metals Specifications AS1182 Standard Stock Removal Allowance Aircraft-Quality and Premium Aircraft-Quality Steel Ba
13、rs 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, www.astm.org. ASTM A255 Determining the Hardenability of Steel ASTM A370 Mechanical Testing of Steel Products ASTM E112 Determi
14、ning 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 Hardness ASTM E350 Chemical Analysis of Carbon Steel, Low-Alloy Steel, Silicon Electr
15、ical Steel, Ingot Iron, and Wrought Iron ASTM E381 Macroetch Testing, Steel Bars, Billets, Blooms, and Forgings 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 chemical methods i
16、n 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 0.75 1.00 Silicon 0.15 0.35 Phosphorus - 0.025 Sulfur - 0.025 Chromium 0.40 0.60 Nickel 0.40 0.70 Molybdenum 0.20 0.30 Cop
17、per - 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. SAE INTERNATIONAL AMS6328N Page 3 of 9 3.1.2 Check Analysis Composition variations shall meet the appli
18、cable requirements of AMS2259. 3.2 Condition The product shall be supplied in the following condition; hardness and tensile strength shall be determined in accordance with ASTM A370: 3.2.1 Bars Bar shall not be cut from plate. (Also see 4.4.2.) 3.2.1.1 Bars 0.500 Inch (12.70 mm) and Under in Nominal
19、 Diameter or Least Distance Between Parallel Sides Cold finished having tensile strength not higher than 125 ksi (862 MPa) or equivalent hardness (see 8.2). 3.2.1.2 Bars Over 0.500 Inch (12.70 mm) in Nominal Diameter or Least Distance Between Parallel Sides Hot finished and annealed unless otherwise
20、 ordered, having hardness not higher than 229 HB, or equivalent (see 8.3). Bars ordered cold finished may have hardness as high as 248 HB, or equivalent (see 8.3). 3.2.2 Forgings Annealed, having hardness not higher than 21 HRC, or equivalent (see 8.3). 3.2.3 Mechanical Tubing Cold finished unless o
21、therwise ordered, having hardness not higher than 25 HRC, or equivalent (see 8.3). Tubing ordered hot finished and annealed shall have hardness not higher than 99 HRB, or equivalent (see 8.3). 3.2.4 Forging Stock As ordered by the forging manufacturer. 3.3 Properties The product shall conform to the
22、 following requirements; hardness testing shall be performed in accordance with ASTM A370: 3.3.1 Macrostructure Visual 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 E381, s
23、hall 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 limits Cross-Sectional Area Square Inches Cross-Sectional Area Square Centimeters Macrographs Up to 36, incl Up to 23
24、2, incl S2 - R1 - C2 Over 36 to 133, incl Over 232 to 858. incl S2 - R2 - C3 Over 133 Over 858 Note 1 Note 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. SAE INTERNATIO
25、NAL AMS6328N Page 4 of 9 3.3.1.1 If tubes are produced directly from ingots or large blooms, transverse sections may be taken from the tubes rather than tube rounds. Macroetch standards for such tubes shall be agreed upon by purchaser and producer. 3.3.2 Average Grain Size of Bars, Forgings and Tubi
26、ng Average grain size shall be determined by either 3.3.2.1 or 3.3.2.2. 3.3.2.1 Shall be ASTM No. 5 or finer, determined in accordance with ASTM E112. 3.3.2.2 The product of a heat shall be considered to have an ASTM No. 5 or finer austenitic grain size if one or more of the following are determined
27、 by heat analysis (see 8.7): 3.3.2.2.1 A total aluminum content of 0.020 to 0.050%. 3.3.2.2.2 An acid soluble aluminum content of 0.015 to 0.050%. 3.3.2.2.3 A vanadium content of 0.02 to 0.08%. 3.3.2.2.4 A columbium content of 0.02 to 0.05%. 3.3.3 Hardenability of Each Heat Shall be J 9/16 inch (14.
28、3 mm) = 51 HRC minimum and J 12/16 inch (19 mm) = 45 HRC minimum, determined on the standard end-quench test specimen in accordance with ASTM A255 except that the steel shall be normalized at 1700 F 10 F (927 C 6 C) and test specimen austenitized at 1500 F 10 F (816 C 6 C). 3.3.4 Decarburization 3.3
29、.4.1 Bars and tubing ordered ground, turned, or polished shall be free from decarburization on the ground, turned, or polished surfaces. Decarburization on tubing ID shall not exceed the maximum depth specified in Table 4. 3.3.4.2 Allowable decarburization of bars, billets, and tube rounds ordered f
30、or redrawing or forging or to specified microstructural requirements shall be as agreed upon by purchaser and producer. 3.3.4.3 Decarburization of bars that 3.3.4.1 or 3.3.4.2 is not applicable shall be not greater than shown in Table 3. Table 3 Table 3A - Maximum depth of decarburization limits, in
31、ch/pound units Nominal Diameter or Distance Between Parallel Sides Inches Total Depth of Decarburization Inch Up to 0.375, incl 0.010 Over 0.375 to 0.500, incl 0.012 Over 0.500 to 0.625, incl 0.014 Over 0.625 to 1.000, incl 0.017 Over 1.000 to 1.500, incl 0.020 Over 1.500 to 2.000, incl 0.025 Over 2
32、.000 to 2.500, incl 0.030 Over 2.500 to 3.000, incl 0.035 Over 3.000 to 4.000, incl 0.045 SAE INTERNATIONAL AMS6328N Page 5 of 9 Table 3B - Maximum depth of decarburization limits, SI units Nominal Diameter or Distance Between Parallel Sides Millimeters Total Depth of Decarburization Millimeters Up
33、to 9.52, incl 0.25 Over 9.52 to 12.70, incl 0.30 Over 12.70 to 15.88, incl 0.36 Over 15.88 to 25.40, incl 0.43 Over 25.40 to 38.10, incl 0.51 Over 38.10 to 50.80, incl 0.64 Over 50.80 to 63.50, incl 0.76 Over 63.50 to 76.20, incl 0.89 Over 76.20 to 101.60, incl 1.14 3.3.4.4 Decarburization of tubing
34、 that 3.3.4.1 or 3.3.4.2 is not applicable shall be not greater than shown in Table 4. Table 4 Table 4A - 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
35、0.109 to 0.203, incl 0.010 0.020 Over 0.203 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 Table 4B - Maximum depth of decarburization, SI units Nominal Wall Thickness Millimeters Total Depth of Decarburization Millimeter
36、 ID 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 3.3.4.5 Decarburization shall be evaluated by one of the two
37、methods of 3.3.4.5.1 or 3.3.4.5.2. 3.3.4.5.1 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. Optical indications of decarburiztion shall not show a layer of complete (f
38、errite) or partial decarburization exceeding the limits of Tables 3 and 4. SAE INTERNATIONAL AMS6328N Page 6 of 9 3.3.4.5.2 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
39、magnification not exceeding 100X, conducted on a hardened but untempered specimen 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 furthe
40、r increase in hardness. Such measurements shall be far enough away from any adjacent surface to be uninfluenced by any decarburization on the adjacent surface. Acceptance shall be as listed in Tables 3 and 4. 3.3.4.5.3 When determining the depth of decarburization, it is permissible to disregard loc
41、al areas provided the decarburization of such areas does not exceed the above limits by more than 0.005 inch (0.13 mm) and the width is 0.065 inch (1.65 mm) or less. 3.3.4.5.4 In case of dispute, the total depth of decarburization determined using the microindentation hardness traverse method shall
42、govern. 3.4 Quality The 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. 3.4.1 Steel shall be aircraft quality conforming to AMS2301. 3.4.2 Bars shall be free from seams, l
43、aps, tears, and cracks after removal of the standard stock removal allowance in accordance with AS1182. 3.4.3 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. 3.5 Tolerances 3.
44、5.1 Bars In accordance with AMS2251. 3.5.2 Mechanical Tubing In accordance with AMS2253. 4. QUALITY ASSURANCE PROVISIONS 4.1 Responsibility for Inspection The producer of the product shall supply all samples for producers tests and shall be responsible for the performance of all required tests. Purc
45、haser reserves the right to sample 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 Tests Composition (3.1), condition (3.2), macrostructure (3.3.1), average grain size (3.3.2), harden
46、ability (3.3.3), decarburization (3.3.4), and frequency-severity cleanliness (3.4.1) and tolerances (3.5) are acceptance tests and shall be performed on each heat or lot as applicable. If grain refining elements (3.3.2.2) are not present, the ASTM E112 grain size test (3.3.2.1) shall be conducted on
47、 each lot. SAE INTERNATIONAL AMS6328N Page 7 of 9 4.2.2 Periodic Tests Grain flow of die forgings (3.4.3) is a periodic test and shall be performed at a frequency selected by the producer unless a frequency of testing is specified by purchaser. If grain refining elements (3.3.2.2) are present, the A
48、STM E112 grain size test (3.3.2.1) 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. 4.3 Sampling and Testing 4.3.1 Bars, Mechanical Tubing, and Forging Stock In accord
49、ance with AMS2370. 4.3.2 Forgings In accordance with AMS2372. 4.4 Reports 4.4.1 The producer of the product 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), results of composition, macrostructure, hardenability and frequency-severity cleanliness rating for each heat an
