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 there
2、from, 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 p
3、ublication 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: +1 724-776-497
4、0 (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:/www.sae.org/technical/standards/AMS6423H AEROSPACE MATERIAL SPECIFICATION AMS6423 REV. H Issued 1958-08 Reaffirme
5、d 2000-10 Revised 2016-04Superseding AMS6423G Steel Bars, Forgings, and Tubing 0.92Cr 0.75Ni 0.52Mo 0.003B 0.04V (Modified 98BV40) (Composition similar to UNS K24336)RATIONALE AMS6423H results from a review and update of this specification that revises decarburization testing. 1. SCOPE 1.1 Form This
6、 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 used typically for parts, 3.5 inches (89 mm) and under in nominal thickness at time of heat treatment, requiring a through-hardenin
7、g steel capable of developing minimum hardness of 30 HRC when properly hardened and tempered and also for parts of greater thickness but requiring proportionately lower hardness, but usage is not limited to such applications. 2. APPLICABLE DOCUMENTS The issue of the following documents in effect on
8、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 the referenced document has been cancelled and no superseding document has been specified
9、, 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: 877-606-7323 (inside USA and Canada) or +1 724-776-4970 (outside USA), www.sae.org. AMS2251 Tolerances, Low-Alloy Steel Bars AMS2253
10、 Tolerances, Carbon and Alloy Steel Tubing AMS2259 Chemical Check Analysis Limits, Wrought Low-Alloy and Carbon Steels SAE INTERNATIONAL AMS6423H Page 2 of 8 AMS2301 Steel Cleanliness, Aircraft Quality Magnetic Particle Inspection Procedure AMS2310 Qualification Sampling and Testing of Steels for Tr
11、ansverse Tensile Properties 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, Mechanical Tubing, and Extrusions, Carbon an
12、d Alloy Steels and Corrosion and Heat-Resistant Steels and Alloys AMS2808 Identification Forgings 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
13、. Box C700, West Conshohocken, PA 19428-2959, Tel: 610-832-9585, www.astm.org. ASTM A255 Determining Hardenability of Steel ASTM A370 Mechanical Testing of Steel Products ASTM E112 Determining Average Grain Size ASTM E350 Chemical Analysis of Carbon Steel, Low-Alloy Steel, Silicon Electrical Steel,
14、Ingot Iron, and Wrought Iron ASTM E381 Macroetch Testing Steel Bars, Billets, Blooms, and Forgings ASTM E384 Knoop and Vickers 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
15、 with ASTM E350, by spectrochemical methods, or by other analytical methods acceptable to purchaser. Table 1 - Composition Element min max Carbon 0.40 0.46 Manganese 0.75 1.00 Silicon 0.50 0.80 Phosphorus - 0.025 Sulfur - 0.025 Chromium 0.80 1.05 Nickel 0.60 0.90 Molybdenum 0.45 0.60 Boron 0.0005 0.
16、005 Vanadium 0.01 0.06 Copper - 0.35 SAE INTERNATIONAL AMS6423H Page 3 of 8 3.1.1 Check Analysis Composition variations shall meet the applicable requirements of AMS2259. 3.2 Condition The product shall be supplied in the following condition; hardness and tensile strength shall be determined in acco
17、rdance 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 or Least Distance Between Parallel Sides Annealed and cold finished having tensile strength not higher than 135 ksi (931 MPa). 3.2.1.2 Bars Over 0.500
18、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 241 HB, or equivalent (see 8.2). Bars ordered cold finished may have hardness as high as 269 HB, or equivalent (see 8.2). 3.2.2 Forgings No
19、rmalized and tempered having hardness not higher than 302 HB, or equivalent (see 8.2). 3.2.3 Mechanical Tubing Annealed and cold finished unless otherwise ordered, having hardness not higher than 30 HRC, or equivalent (see 8.2). Tubing ordered hot finished and annealed shall have hardness not higher
20、 than 25 HRC, or equivalent (see 8.2). 3.2.4 Forging Stock As ordered by the forging manufacturer. 3.3 Properties The product shall conform to the following requirements; tensile and hardness testing shall be performed in accordance with ASTM A370: 3.3.1 Macrostructure Visual examination of transver
21、se full cross-sections from bars, billets, tube rounds, 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. Tabl
22、e 2 - Macrostructure limits Cross-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 purc
23、haser and producer. The purchaser shall have written approval of the agreement from the cognizant engineering organization. SAE INTERNATIONAL AMS6423H Page 4 of 8 3.3.2 Average Grain Size of Bars, Forgings, and Mechanical Tubing Shall be ASTM No. 5 or finer, determined in accordance with ASTM E112.
24、3.3.3 Hardenability of Each Heat Shall be J20/16 inch (32 mm) = 55 HRC minimum and J32/16 inch (51 mm) = 53 HRC minimum, determined on the standard end-quench test specimen in accordance with ASTM A255 except that the steel shall be normalized at 1600 F 10 F (871 C 6 C) and the test specimen austeni
25、tized at 1550 F 10 F (843 C 6 C). 3.3.4 Decarburization 3.3.4.1 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
26、decarburization of bars, billets, and tube rounds ordered for 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. Tab
27、le 3A - Maximum total depth of decarburization, bars, inch/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
28、1.500, incl 0.020 Over 1.500 to 2.000, incl 0.025 Over 2.000 to 2.500, incl 0.030 Over 2.500 to 3.000, incl 0.035 Over 3.000 to 4.000, incl 0.045 Table 3B - Maximum total depth of decarburization, bars, SI units Nominal Diameter or Distance Between Parallel Sides Millimeters Total Depth of Decarburi
29、zation Millimeters Up 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 SAE INTERNA
30、TIONAL AMS6423H Page 5 of 8 3.3.4.4 Decarburization of tubing that 3.3.4.1 or 3.3.4.2 is not applicable shall be not greater than shown in Table 4. Table 4A - Maximum total depth of decarburization, tubes, inch/pound units Nominal Wall Thickness Inches Total Depth of Decarburization, Inch ID OD Up t
31、o 0.109, incl 0.008 0.015 Over 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 total depth of decarburization, tubes, SI units Nominal Wall Thickness Millimete
32、rs Total Depth of Decarburization, Millimeters ID 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 t
33、wo 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
34、 (ferrite) or partial decarburization exceeding the limits of Tables 3 and 4. 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 magnification not exceeding 100X, co
35、nducted 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 further increase in hardness. Such measure
36、ments 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. 3.3.4.6 When determining the depth of decarburization, it is permissible to disregard local areas provided the decarburization
37、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. 3.3.4.7 In case of dispute, the total depth of decarburization determined using the microindentation hardness traverse method shall govern. 3.3.5 Transverse Tensile Propert
38、ies Specimens, selected and tested in accordance with AMS2310, shall have tensile strength not lower than 280 ksi (1931 MPa) and reduction of area not lower than 5% after being normalized by heating to 1600 F 10 F (871 C 6 C ), holding at heat for not less than 60 minutes, and cooling in air; harden
39、ed by heating to 1550 F 10 F (843 C 6 C), holding at heat for 60 minutes 10 minutes, and quenching in oil, and tempered by heating to a temperature within the range 450 to 550 F (232 to 288 C), holding at the selected temperature within 10 F (6 C) for 2 to 3 hours, and cooling in air. SAE INTERNATIO
40、NAL AMS6423H 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 AMS2301. 3.4.2 Bars and mechan
41、ical tubing 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 open to the machined, ground, turned, or polished surface. 3.4.3 Grain flow of die forgings,
42、 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 3.5.1 Bars Shall be in accordance with AMS2251. 3.5.2 Mechanical Tubing Shall be in accordance with AMS2253. 4. QUALITY ASSURANCE PROVISION
43、S 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. Purchaser reserves the right to sample and to perform any confirmatory testing deemed necessary to ensure that the product
44、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), hardenability (3.3.3), decarburization (3.3.4), transverse tensile properties (3.3.5), frequency-severity cleanliness (3.4.1)
45、, and tolerances (3.5) are acceptance tests and shall be performed on each heat or lot as applicable. 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. 4.3
46、 Sampling and Testing 4.3.1 Bars, Forging Stock, and Mechanical Tubing Shall be in accordance with AMS2370. 4.3.2 Forgings Shall be in accordance with AMS2372. SAE INTERNATIONAL AMS6423H Page 7 of 8 4.4 Reports 4.4.1 The producer of bars, forgings, and mechanical tubing shall furnish with each shipm
47、ent 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, hardenability, and frequency-severity cleanliness rating of each heat and for the average
48、 grain size and tensile properties 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, AMS6423H, product form and size or part number, and quantity. If forgings are supplied, the size and me
49、lt source of stock used to make the forgings shall also be included. 4.4.2 Report the nominal metallurgically worked cross sectional size if different from the shipped/cut size (also see 3.2.1). 4.4.3 The producer of forging stock 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 proce
