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/AMS6302K AEROSPACE MATERIAL SPECIFICATION AMS6302 REV. K Issued 1953-06 Revised 2017-11 Supers
5、eding AMS6302J Low-Alloy Steel, Heat-Resistant, Bars, Forgings, and Tubing 0.65Si - 1.25Cr - 0.50Mo - 0.25V (0.28 - 0.33C) (Composition similar to UNS K23015) RATIONALE AMS6302K results from a Five-Year Review and update of this specification that revises composition determination (3.1), decarburiza
6、tion testing (3.3.5), quality (3.4.2), testing frequency for grain size (4.2), reporting (4.4) and identification (5.2). 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 Applicati
7、on These products have been used typically for parts such as shafts and fasteners, in service up to 1000 F (538 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 specificati
8、on to the extent 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 SA
9、E Publications Available 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 Bars AMS2253 Tolerances, Carbon and Alloy Steel Tubing AMS2259 Chemical Che
10、ck Analysis Limits, Wrought Low-Alloy and Carbon Steels AMS2301 Steel Cleanliness, Aircraft Quality, Magnetic Particle Inspection Procedure SAE INTERNATIONAL AMS6302K Page 2 of 8 AMS2370 Quality Assurance Sampling and Testing, Carbon and Low-Alloy Steel Wrought Products and Forging Stock AMS2372 Qua
11、lity Assurance Sampling and Testing, Carbon and 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
12、 Metals Specifications AS1182 Standard Stock Removal 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.
13、org. ASTM A370 Mechanical Testing of Steel Products ASTM A751 Standard Test Methods, Practices, and Terminology for Chemical Analysis of Steel Products ASTM E112 Determining Average Grain Size ASTM E140 Hardness Conversion Tables for Metals Relationship Among Brinell Hardness, Vickers Hardness, Rock
14、well Hardness, Superficial Hardness, Knoop Hardness, Scleroscope Hardness, and Leeb Hardness 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 sho
15、wn in Table 1, determined in accordance with ASTM A751 or by other analytical methods acceptable to purchaser. Table 1 - Composition Element Min Max Carbon 0.28 0.33 Manganese 0.45 0.65 Silicon 0.55 0.75 Phosphorus - 0.025 Sulfur - 0.025 Chromium 1.00 1.50 Molybdenum 0.40 0.60 Vanadium 0.20 0.30 Nic
16、kel - 0.25 Copper - 0.35 3.1.1 Check Analysis Composition variations shall meet the applicable requirements of AMS2259. SAE INTERNATIONAL AMS6302K Page 3 of 8 3.2 Condition The product shall be supplied in the following condition; hardness and tensile strength shall be determined in accordance with
17、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 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 Ove
18、r 0.500 Inch (12.70 mm) in Nominal Diameter or Least Distance Between Parallel Sides Hot finished, unless otherwise specified, having hardness not higher than 241 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 Anne
19、aled having hardness not higher than 241 HB, or equivalent (see 8.3). 3.2.3 Mechanical Tubing Cold finished unless otherwise specified, having hardness not higher than 25 HRC, or equivalent (see 8.3). Tubing ordered hot finished shall have hardness not higher than 99 HRB, or equivalent (see 8.3). 3.
20、2.4 Forging Stock As ordered by the forging manufacturer. 3.3 Properties The product shall conform to the 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 round
21、s (solid, not hollow), and forging stock, etched in hot hydrochloric acid in accordance with ASTM E381, shall 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
22、-Sectional Area Square Inches Cross-Sectional Area Square Centimeters Macrographs Up to 36, incl Up to 232, 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 s
23、hall have written approval of the agreement from the cognizant engineering organization. 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.
24、 SAE INTERNATIONAL AMS6302K Page 4 of 8 3.3.2 Average Grain Size of Bars, Forgings, and Tubing Shall be ASTM No. 5 or finer, determined 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, tu
25、rned, or polished surfaces. Decarburization on tubing ID shall not exceed the maximum depth specified in Table 4. 3.3.3.2 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 purcha
26、ser and producer. 3.3.3.3 Where 3.3.3.1 or 3.3.3.2 are not applicable, decarburization of bars shall be not greater than shown in Table 3. Table 3 Table 3A - Maximum depth of decarburization, inch/pound units Nominal Diameter or Distance Between Parallel Sides Inches Total Depth of Decarburization I
27、nch 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, incl 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 - Maxim
28、um depth of decarburization, SI units Nominal Diameter or Distance Between Parallel Sides Millimeters Total Depth 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
29、 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 1.14 3.3.3.4 Where 3.3.3.1 or 3.3.3.2 are not applicable, decarburization of tubing shall be not greater than shown in Table 4. SAE INTERNATIONAL AMS6302K Page 5 of 8 Table 4 Table 4A - Maxi
30、mum 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 0.020 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 O
31、ver 0.600 to 1.000, incl 0.017 0.040 Over 1.000 0.020 0.045 Table 4B - Maximum depth of decarburization, 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
32、 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 0.43 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
33、surface shall 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 Tables 3 and 4. 3.3.3.5.2 Hardness Traverse Method The total depth of decarbu
34、rization shall be determined by a traverse method using microindentation hardness testing in accordance with ASTM E384, 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 perpendicul
35、ar 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 adjacent surface to be uninfluenced by any decarburization on the adjacent surface. Acceptance shall be as listed in Tables 3 and 4. 3.3.3
36、.5.3 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 more than 0.005 inch (0.13 mm) and the width is 0.065 inch (1.65 mm) or less. 3.3.3.5.4 In case of dispute, the total depth of
37、 decarburization determined using the microindentation hardness traverse method shall govern. 3.3.4 Response to Heat Treatment of Each Heat. Specimens as in 4.3.3 heated to 1750 F 25 F (954 C 14 C), held at heat for 60 to 90 minutes, and cooled at a rate equivalent to still air cooling, and reheated
38、 to 1100 F 15 F (593 C 8 C), held at heat for 6 hours 0.25 hour, and cooled in air, shall have hardness at the center of the test specimen not lower than 331 HB or equivalent (see 8.3) for sections 2 inches (51 mm) and under, and not lower than 302 HB or equivalent (see 8.3) for up to 4 inch (102 mm
39、) sections. SAE INTERNATIONAL AMS6302K Page 6 of 8 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 AMS2
40、301. 3.4.2 Bars and mechanical tubing shall, be free 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 for
41、gings showing no evidence of reentrant grain flow. 3.5 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
42、 product shall supply all samples for producers 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 the product conforms to specified requirements. 4.2 Classification
43、of Tests 4.2.1 Acceptance Tests Composition (3.1), condition (3.2), macrostructure (3.3.1), decarburization (3.3.3), response to heat treatment (3.3.4), frequency-severity cleanliness (3.4.1), and tolerances (3.5) are acceptance tests and shall be performed on each heat or lot as applicable. 4.2.2 P
44、eriodic Tests Average grain size (3.3.2) and grain flow of die forgings (3.4.3) 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 accord
45、ance with AMS2370. 4.3.2 Forgings In accordance with AMS2372. 4.3.3 Samples 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 tha
46、t they were cut, except that sections over 2 to 4 inches (over 51 to 102 mm), inclusive, in nominal diameter or least distance between parallel sides shall be reduced to 2.00 inches 0.01 inch (51 mm 0.3 mm) and sections over 4 inches (102 mm) shall be reduced to 4.00 inches 0.01 inch (101.6 mm 0.3 m
47、m). SAE INTERNATIONAL AMS6302K Page 7 of 8 4.4 Reports 4.4.1 The producer of bars, forgings and tubing 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
48、tests for composition, macrostructure, response to heat treatment and frequency-severity cleanliness rating of each heat, and for hardness 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
49、, AMS6302K, product form, size (and/or part number, if applicable), and quantity. If forgings 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 3.2.1). 4.4.3 The producer of forging stock shall furnish with each shipment a r
