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 2017 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:/standards.sae.org/AMS6512H AEROSPACE MATERIAL SPECIFICATION AMS6512 REV. H Issued 1970-05 Revised 2017-06 Superse
5、ding AMS6512G Steel, Maraging, Bars, Forgings, Tubing, and Rings 18Ni - 7.8Co - 4.9Mo - 0.40Ti - 0.10Al Consumable Electrode Vacuum Melted, Annealed (Composition similar to UNS K92890) RATIONALE AMS6512H results from a revision of the heat treatment parameters (3.4), quality (3.6.2) and reporting (4
6、.4). 1. SCOPE 1.1 Form This specification covers a premium aircraft-quality, maraging alloy steel in the form of bars, forgings, mechanical tubing, flash welded rings up through 10.000 inches (254.00 mm) inclusive in diameter or least distance between parallel sides and stock for forging or flash we
7、lded rings. 1.2 Application These products have been used typically for parts requiring through hardening, without quenching, to a minimum yield strength of 240 ksi (1655 MPa) and where such parts may require welding during fabrication, but usage is not limited to such applications. 2. APPLICABLE DO
8、CUMENTS 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 specific document issue is specified. When the referenced document has bee
9、n 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: 877-606-7323 (inside USA and Canada) or +1 724-776-4970 (outside USA), www
10、.sae.org. AMS2248 Chemical Check Analysis Limits, Corrosion and Heat-Resistant Steels and Alloys, Maraging and Other Highly-Alloyed Steels, and Iron Alloys AMS2251 Tolerances, Low-Alloy Steel Bars AMS2253 Tolerances, Carbon and Alloy Steel Tubing SAE INTERNATIONAL AMS6512H Page 2 of 9 AMS2300 Steel
11、Cleanliness, Premium 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 AMS2750 Pyrometry AMS2806 Ide
12、ntification Bars, Wire, Mechanical Tubing, and Extrusions, Carbon and Alloy Steels and Corrosion and Heat-Resistant Steels and Alloys AMS2808 Identification Forgings AMS7496 Rings, Flash Welded, Carbon and Low-Alloy Steels ARP1917 Clarification of Terms Used in Aerospace Metals Specifications AS1182
13、 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.org. ASTM A370 Mechanical Test
14、ing of Steel Products ASTM A604 Macroetch Testing of Consumable Electrode Remelted Steel Bars and Billets ASTM E45 Determining the Inclusion Content of Steel ASTM E112 Determining Average Grain Size ASTM E140 Hardness Conversion Tables for Metals ASTM E353 Chemical Analysis of Stainless, Heat-Resist
15、ing, Maraging, and Other Similar Chromium-Nickel-Iron Alloys ASTM E399 Plane-Strain Fracture Toughness of Metallic 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 E353, by spec
16、trochemical methods, or by other analytical methods acceptable to purchaser. SAE INTERNATIONAL AMS6512H Page 3 of 9 Table 1 - Composition Element min max Carbon - 0.03 Manganese - 0.10 Silicon - 0.10 Phosphorus - 0.010 Sulfur - 0.010 Nickel 17.00 19.00 Cobalt 7.00 8.50 Molybdenum 4.60 5.20 Titanium
17、0.30 0.50 Aluminum 0.05 0.15 Chromium - 0.50 Copper - 0.50 3.1.1 Additives Any additions of calcium, zirconium, and boron shall be made prior to pouring the first melt into electrodes; these elements shall not exceed 0.05% calcium, 0.02% zirconium, and 0.004% boron and shall be analyzed and reported
18、 in the final heat analysis. 3.1.2 Check Analysis Composition variations shall meet the applicable requirements of AMS2248. 3.2 Melting Practice Steel shall be produced by multiple melting using consumable electrode vacuum remelt (VAR) practice in the remelt cycle. 3.3 Condition 3.3.1 Bars Annealed
19、and descaled. Bar shall not be cut from plate (also see 4.4.2). 3.3.2 Forgings, Mechanical Tubing, and Flash Welded Rings Annealed and descaled. 3.3.2.1 Flash welded rings shall not be supplied unless specified or permitted on purchasers part drawing. When supplied, rings shall be manufactured in ac
20、cordance with AMS7496. 3.3.3 Stock for Forging or Flash Welded Rings As ordered by the forging or flash welded ring manufacturer. 3.4 Annealing Bars, forgings, mechanical tubing, and flash-welded rings shall be annealed by heating to a temperature within the range 1500 to 1700 F (816 to 927 C), hold
21、ing at the selected temperature within 25 F (14 C) for a minimum of 1 hour and air cooling or faster to room temperature. Pyrometry shall be in accordance with AMS2750. 3.5 Properties The product shall conform to the following requirements; hardness and tensile testing shall be performed in accordan
22、ce with ASTM A370: SAE INTERNATIONAL AMS6512H Page 4 of 9 3.5.1 Macrostructure Visual examination of transverse full cross-sections from bars, billets, tube rounds (solid, not hollow), and stock for forgings or flash welded rings, etched in hot hydrochloric acid in accordance with ASTM A604, shall s
23、how no pipe or cracks. Porosity, segregation, inclusions, and other imperfections shall be no worse than the macrographs of ASTM A604 shown in Table 2. Table 2 - Macrostructure limits Class Condition Severity 1 Freckles A 2 White Spots A 3 Radial Segregation B 4 Ring Pattern B 3.5.1.1 Macrostructure
24、 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. 3.5.2 Micro-Inclusion Rating of Each Heat No specimen shall exceed the limits shown in Table 3, determined in
25、accordance with ASTM E45, Method D. Table 3 - Micro-inclusion rating Type A B C D E Thin 1.5 1.5 1.5 2.0 3.0 Heavy 1.0 1.0 1.0 1.5 1.5 3.5.2.1 Type E is titanium nitride and shall be rated in the same manner as Type B. 3.5.3 Hardness of Bars, Forgings, Tubing, and Rings Bars over 0.500 inch (12.70 m
26、m) in nominal diameter or least distance between parallel sides, forgings, tubing, and flash welded rings shall have hardness not higher than 34 HRC, or equivalent (see 8.2). 3.5.3.1 Bars 0.500 inch (12.70 mm) and under in nominal diameter or least distance between parallel sides shall have tensile
27、strength not higher than 160 ksi (1103 MPa) or hardness not higher than 34 HRC, or equivalent (see 8.2). 3.5.4 Average Grain Size of Bars, Forgings, Tubing, and Rings Shall be as follows, determined in accordance with ASTM E112. 3.5.4.1 Product Under 2.50 Inches (63.5 mm) in Nominal Section Thicknes
28、s ASTM No. 6 or finer. 3.5.4.2 Product 2.50 to 10.00 Inches (63.5 to 254.0 mm), incl, in Nominal Section Thickness ASTM No. 4 or finer. SAE INTERNATIONAL AMS6512H Page 5 of 9 3.5.5 After Maraging Heat Treatment Specimens shall have the following properties after being maraged by heating to 900 10 F
29、(482 6 C), holding at heat for 6 0.5 hours, and cooling in air to room temperature: 3.5.5.1 Tensile Properties Shall be as shown in Table 4. Table 4 Table 4A - Minimum tensile properties, inch/pound units Nominal Section Thickness Inches Specimen Orientation Tensile Strength ksi Yield Strength at 0.
30、2% Offset ksi Elongation in 4D % Reduction of Area % Up to 4.000, excl Longitudinal 255 250 6 45 Transverse 255 250 4 35 4.000 to 10.000, incl Longitudinal 245 240 5 30 Transverse 245 240 3 20 Table 4B - Minimum tensile properties, SI units Nominal Section Thickness Millimeters Specimen Orientation
31、Tensile Strength MPa Yield Strength at 0.2% Offset MPa Elongation in 4D % Reduction of Area % Up to 101.60, excl Longitudinal 1758 1724 6 45 Transverse 1758 1724 4 35 101.60 to 254.00, incl Longitudinal 1689 1655 5 30 Transverse 1689 1655 3 20 3.5.5.1.1 Longitudinal requirements apply to specimens t
32、aken with axis of specimens approximately parallel to the grain flow and to specimens taken in the radial direction and in the tangential direction at the rim of disc forgings. All other specimens shall be considered to be in the transverse direction. 3.5.5.1.2 Transverse test requirements apply onl
33、y to product that tensile specimens not less than 2.50 inches (63.5 mm) in length can be taken. 3.5.5.1.3 Tensile properties in the longitudinal direction need not be determined on product tested in the transverse direction. 3.5.5.1.4 Mechanical property requirements for product outside the range co
34、vered by 1.1 shall be agreed upon between purchaser and producer. 3.5.5.2 Hardness Should be not lower than 48 HRC, or equivalent (see 8.2), but the product shall not be rejected on the basis of hardness if the tensile property requirements are acceptable, determined on specimens taken from the same
35、 sample as with the nonconforming hardness or from another sample with similar nonconforming hardness. 3.5.5.3 Fracture Toughness When specified, product shall be subjected to fracture toughness testing in accordance with ASTM E399. Acceptance standards shall be as agreed upon between purchaser and
36、producer (see 8.5). SAE INTERNATIONAL AMS6512H Page 6 of 9 3.5.6 Forging Stock Specimens extracted from a forged down test coupon heat treated as in 3.4 and 3.5.5 shall conform to the requirements of 3.5.5.1, 3.5.5.2, and, when specified, 3.5.5.3. If specimens taken from the stock after heat treatme
37、nt as in 3.4 and 3.5.5 conform to the requirements of 3.5.5.1, 3.5.5.2 and, when specified, 3.5.5.3, the tests shall be accepted as equivalent to tests of a forged coupon. 3.5.6.1 Forging stock from a heat meeting the requirements of 3.5.6 in one size need not be retested for qualification of a smal
38、ler size. 3.5.7 Stock for Flash Welded Rings Specimens taken from the stock after heat treatment as in 3.4 and 3.5.5 shall conform to the requirements of 3.5.5.1, 3.5.5.2, and, when specified, 3.5.5.3. 3.6 Quality The product, as received by purchaser, shall be uniform in quality and condition, soun
39、d, and free from foreign materials and from imperfections detrimental to usage of the product. 3.6.1 Steel shall be premium aircraft-quality conforming to AMS2300. 3.6.2 Bars and mechanical tubing shall be free from seams, laps, tears, and cracks after removal of the standard stock removal allowance
40、 in accordance with AS1182 3.6.3 Flash welded rings ordered ground, turned, or polished shall be free from seams, laps, tears, and cracks open to the ground, turned, or polished surfaces. 3.6.4 Grain flow of die forgings, except in areas that contain flash-line end grain, shall follow the general co
41、ntour of the forgings showing no evidence of reentrant grain flow. 3.7 Tolerances 3.7.1 Bars In accordance with AMS2251. 3.7.2 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 vend
42、ors 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. SAE INTERNATIONAL AMS6512H Page 7 of 9 4.2 Classification of Te
43、sts 4.2.1 Acceptance Tests The following requirements are acceptance tests and shall be performed on each heat or lot as applicable: 4.2.1.1 Composition (3.1), macrostructure (3.5.1), and micro-inclusion rating (3.5.2) of each heat. 4.2.1.2 Hardness (3.5.3) of each lot of bars, forgings, tubing, and
44、 flash welded rings as annealed and tensile strength (3.5.3.1) of each lot of bars as annealed. 4.2.1.3 Average grain size (3.5.4) of each lot of bars, forgings, tubing, and flash welded rings as annealed. 4.2.1.4 Tensile properties (3.5.5.1), hardness (3.5.5.2), and, when specified, fracture toughn
45、ess (3.5.5.3) of each lot of bars, forgings, tubing, and flash welded rings after maraging heat treatment. 4.2.1.5 Tolerances of bars (3.7.1) and mechanical tubing (3.7.2). 4.2.1.6 If stock for forgings or flash welded rings, tests to demonstrate ability to develop required properties (3.5.6 and 3.5
46、.7). 4.2.2 Periodic Tests Tests for frequency-severity rating (3.6.1), and grain flow of die forgings (3.6.4), 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 Tubi
47、ng, Flash Welded Rings, and Stock for Forgings and Flash Welded Rings In accordance with AMS2370. 4.3.2 Forgings In accordance with AMS2372. 4.4 Reports 4.4.1 The producer of bars, forgings, tubing, and flash welded rings shall furnish with each shipment a report showing the producer identity, count
48、ry where the metal was melted (e. g., final melt in the case of metal processed by multiple melting operations), results of tests for composition, macrostructure, and micro-inclusion rating, of each heat, and for average grain size and annealed hardness tensile properties, hardness, and, when specif
49、ied, fracture toughness of each lot after maraging heat treatment, and stating that the product conforms to the other technical requirements. This report shall include the purchase order number, heat and lot numbers, AMS6512H, product form and 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 I
