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 2016 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/AMS6304M AEROSPACE MATERIAL SPECIFICATION AMS6304 REV. M Issued 1955-08 Revised 2016-12Superse
5、ding AMS6304L Low-Alloy Steel, Heat-Resistant, Bars, Forgings, and Tubing 0.95Cr - 0.55Mo - 0.30V (0.40 - 0.50C) (Composition similar to UNS K14675) RATIONALE AMS6304M results from a Five Year Review and update of this specification revises macrostructure (3.3.1), the test procedure for decarburizat
6、ion (3.3.3.5), quality (3.4), classification of tests (4.2) and reporting (4.4). 1. SCOPE 1.1 Form This specification covers an aircraft-quality, low-alloy, heat-resistant steel in the form of bars, forgings, mechanical tubing, and forging stock. 1.2 Application These products have been used typical
7、ly for parts, such as shafts and fasteners, in service up to 1000 F (540 C), 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
8、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 Publications Available from SAE Inter
9、national, 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 Bars AMS2253 Tolerances Carbon and Alloy Steel Tubing AMS2259 Chemical Check Analysis Limits Wrought Low-Alloy and
10、Carbon Steels AMS2301 Steel Cleanliness, Aircraft Quality Magnetic Particle Inspection Procedure SAE INTERNATIONAL AMS6304M Page 2 of 8 AMS2370 Quality Assurance Sampling and Testing Carbon and Low-Alloy Steel Wrought Products and Forging Stock AMS2372 Quality Assurance Sampling and Testing Carbon a
11、nd Low-Alloy Steel Forgings AMS2806 Identification Bars, Wire, Mechanical 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 Rem
12、oval Allowance Aircraft-Quality and Premium Aircraft-Quality Steel Bars 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 A370 Mechanical Testing of Steel Produc
13、ts ASTM E112 Determining Average Grain Size ASTM E140 Hardness Conversion Tables for Metals ASTM E350 Chemical Analysis of Carbon Steel, Low-Alloy Steel, Silicon Electrical Steel, Ingot Iron, and Wrought Iron ASTM E381 Macroetch Testing Steel Bars, Billets, Blooms, and Forgings ASTM E384 Microindent
14、ation 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 in accordance with ASTM E350, by spectrochemical methods, or by other analytical methods acceptable to purchaser. Table 1 Composition
15、Element Min. Max. Carbon 0.40 0.50Manganese 0.40 0.70 Silicon 0.15 0.35Phosphorus - 0.025 Sulfur - 0.025Chromium 0.80 1.10 Molybdenum 0.45 0.65Vanadium 0.25 0.35 Nickel - 0.25Copper - 0.35 SAE INTERNATIONAL AMS6304M Page 3 of 8 3.1.1 Check Analysis Composition variations shall meet the applicable re
16、quirements 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 Diameter
17、 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 in Nominal Diameter or Least Distance Between Parallel Sides Hot finished and annealed unless otherwise ordered, having har
18、dness not higher than 229 HBW, or equivalent (see 8.3). Bars ordered cold finished may have hardness as high as 248 HBW, or equivalent (see 8.3). 3.2.2 Forgings Annealed having hardness not higher than 248 HBW, or equivalent (see 8.3). 3.2.3 Mechanical Tubing Cold finished unless otherwise ordered,
19、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 following require
20、ments; 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, shall show no pipe
21、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-Section Area Square Inches Cross-Section Area Square Centimeters Macrographs Up to 36, incl Up to 232, incl S2 - R1 - C2 Ove
22、r 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 INTERNATIONAL AMS6304M Page 4 of 8
23、 3.3.1.1 Macrostructure examination is not required for hollow tubes that are produced directly from ingots or blooms unless specified by purchaser, in which case the purchaser shall specify standards to be used. 3.3.2 Average Grain Size of Bars, Forgings and Tubing Shall be ASTM No. 5 or finer, det
24、ermined in accordance with ASTM E112. 3.3.3 Decarburization 3.3.3.1 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 total depth specified in Table 4. 3.3.3.2
25、Allowable decarburization of bars, billets, tube rounds, and tubing ordered for redrawing or forging or to specified microstructural requirements shall be as agreed upon by purchaser and producer. 3.3.3.3 Decarburization of bars, for which 3.3.3.1 or 3.3.3.2 are not applicable, shall not exceed the
26、values shown in Table 3. Table 3A - Maximum total depth of decarburization, inch/pound units Nominal Diameter or Distance Between Parallel Sides Inches Total Depth of Decarburization Inch Up to 0.375, incl 0.015 Over 0.375 to 0.500, incl 0.017 Over 0.500 to 0.625, incl 0.019 Over 0.625 to 1.000, inc
27、l 0.022 Over 1.000 to 1.500, incl 0.025 Over 1.500 to 2.000, incl 0.030 Over 2.000 to 2.500, incl 0.035 Over 2.500 to 3.000, incl 0.040 Over 3.000 to 4.000, incl 0.045 Table 3B - Maximum total depth of decarburization, SI units Nominal Diameter or Distance Between Parallel Sides Millimeters Total De
28、pth of Decarburization Millimeters Up to 9.52, incl 0.38 Over 9.52 to 12.70, incl 0.43 Over 12.70 to 15.88, incl 0.48 Over 15.88 to 25.40, incl 0.56 Over 25.40 to 38.10, incl 0.64 Over 38.10 to 50.80, incl 0.76 Over 50.80 to 63.50, incl 0.89 Over 63.50 to 76.20, incl 1.02 Over 76.20 to 101.60, incl
29、1.14 SAE INTERNATIONAL AMS6304M Page 5 of 8 3.3.3.4 Decarburization of tubing, for which 3.3.3.1 or 3.3.3.2 are not applicable, shall not exceed the values shown in Table 4. Table 4A - Maximum total depth of decarburization, inch/pound units Nominal Wall Thickness Inches Total Depth of Decarburizati
30、on Inch ID Total Depth of Decarburization Inch OD Up to 0.109, incl 0.008 0.020 Over 0.109 to 0.203, incl 0.010 0.025 Over 0.203 to 0.400, incl 0.012 0.030 Over 0.400 to 0.600, incl 0.015 0.035 Over 0.600 to 1.000, incl 0.017 0.040 Over 1.000 0.020 0.045 Table 4B - Maximum total depth of decarburiza
31、tion, SI units Nominal Wall Thickness Millimeters Total Depth of Decarburization Millimeter ID Total Depth of Decarburization Millimeters OD Up to 2.77, incl 0.20 0.51 Over 2.77 to 5.16, incl 0.25 0.64 Over 5.16 to 10.16, incl 0.30 0.76 Over 10.16 to 15.24, incl 0.38 0.89 Over 15.24 to 25.40, incl 0
32、.43 1.02 Over 25.40 0.51 1.14 3.3.3.5 Decarburization shall be evaluated by one of the two methods of 3.3.3.5.1 or 3.3.3.5.2. 3.3.3.5.1 Metallographic Method A cross section taken perpendicular to the surface shall be prepared, etched, and visually examined metallographically at a magnification not
33、to exceed 100X. Optical indications of decarburiztion shall not show a layer of complete (ferrite) or partial decarburization exceeding the limits of Tables 3 or 4. 3.3.3.5.2 Hardness Traverse Method The total depth of decarburization shall be determined by a traverse method using microindentation h
34、ardness 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. Depth of decarburization is defined as the perpendicular distance from the surface to t
35、he depth under that surface where there is not further 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 or 4. 3.3.3.6 When determining the depth of d
36、ecarburization, it is permissible to disregard local 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. 3.3.3.7 In case of dispute, the total depth of decarburization determined using the
37、microindentation hardness traverse method shall govern. 3.3.4 Response to Heat Treatment Specimens as in 4.3.3 shall have hardness at the center of the specimen not lower than 331 HBW, or equivalent (see 8.3), for cross-sections 2 inches (50.8 mm) and under and not lower than 302 HBW, or equivalent
38、(see 8.3), for larger cross-sections after being heated to 1750 F 25 F (954 C 14 C), held at heat for 60 to 90 minutes, cooled at a rate equivalent to still air cooling, reheated to 1100 F 15 F (593 C 8 C), held at heat for 6 hours 0.25 hour, and cooled in air. SAE INTERNATIONAL AMS6304M Page 6 of 8
39、 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 and mechanical tubing shall be fre
40、e from seams, laps, 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.
41、5 Tolerances 3.5.1 Bars Shall conform to all applicable requirements of AMS2251. 3.5.2 Mechanical Tubing Shall conform to all applicable requirements of AMS2253. 4. QUALITY ASSURANCE PROVISIONS 4.1 Responsibility for Inspection The producer of the product shall supply all samples for producers tests
42、 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 the product conforms to specified requirements. 4.2 Classification of Tests 4.2.1 Acceptance Tests Composition (3.1), co
43、ndition (3.2), macrostructure (3.3.1), decarburization (3.3.3), quality (3.4.1) and tolerances (3.5) are acceptance tests and shall be performed on each heat or lot as applicable. 4.2.2 Periodic Tests Average grain size (3.3.2), response to heat treatment (3.3.4) and grain flow of die forgings (3.4.
44、3) are periodic tests and shall be performed at a frequency selected by the producer unless frequency of testing is specified by purchaser. 4.3 Sampling and Testing 4.3.1 Bars, Mechanical Tubing, and Forging Stock In accordance with AMS2370. 4.3.2 Forgings In accordance with AMS2372. 4.3.3 Specimens
45、 for response to heat treatment (3.3.4) shall be not shorter than twice the nominal diameter or distance between parallel sides or 6 inches (152 mm), whichever is less, and shall have the full cross-section of the product that they were cut from except that sections over 2 to 4 inches (over 51 to 10
46、2 mm), inclusive, in nominal diameter or least distance between parallel sides shall be reduced to 2.00 inches 0.01 inch (51 mm 0.03 mm) and sections over 4 inches (102 mm) shall be reduced to 4.00 inches 0.01 inch (101.6 mm 0.03 mm). SAE INTERNATIONAL AMS6304M Page 7 of 8 4.4 Reports 4.4.1 The prod
47、ucer of bars, forgings, and tubing shall furnish with each shipment a report showing the 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-sever
48、ity cleanliness rating of each heat and stating that the product conforms to the other technical requirements. This report shall include the purchase order number, heat and lot numbers, AMS6304M, product form, and size (and/or part number, if applicable), and quantity. If forgings are supplied, the
49、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 (also see 3.2.1). 4.4.3 The producer of forging stock shall furnish with each shipment a report showing the producer identity, country where the metal was melted, (e. g., final melt in the ca
