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:/standards.sae.org/AMS6525E AEROSPACE MATERIAL SPECIFICATION AMS6525 REV. E Issued 1976-01 Revised 2016-12Supersed
5、ing AMS6525D Steel, Bars, Forgings, Tubing, and Rings 0.75Cr - 9.0Ni - 4.5Co - 1.0Mo - 0.09V (0.17 - 0.23C) Consumable Electrode Vacuum Melted (Composition similar to UNS K91472)RATIONALE AMS6525E results from a Five-Year Review and update of this specification that revises the test procedure for mi
6、cro-inclusion rating (3.5.2.1) and decarburization (3.5.4.6), quality (3.6), and reporting (4.4). 1. SCOPE 1.1 Form This specification covers a premium aircraft-quality, low-alloy steel in the form of bars, forgings, mechanical tubing, flash welded rings, and stock for forging or flash welded rings.
7、 1.2 Application These products have been used typically for heat-treated parts requiring toughness and through-hardening to high strength levels and where such parts may require welding during fabrication, but usage is not limited to such applications. 1.2.1 Certain processing procedures and servic
8、e conditions may cause these products to become subject to stress-corrosion cracking; ARP1110 recommends practices to minimize such conditions. 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 sp
9、ecified 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 SAE Publications Avai
10、lable 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 SAE INTERNATIONAL AMS6525E Page 2 of 11 A
11、MS2259 Chemical Check Analysis Limits Wrought Low-Alloy and Carbon Steels AMS2300 Steel 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
12、Sampling and Testing Carbon and Low-Alloy Steel Forgings AMS2750 Pyrometry AMS2806 Identification 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
13、Steels ARP1917 Clarification of Terms Used in Aerospace 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 Con
14、shohocken, PA 19428-2959, Tel: 610-832-9585, www.astm.org. ASTM A370 Mechanical Testing 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 Hardnes
15、s Conversion Tables for Metals ASTM E353 Chemical Analysis of Stainless, Heat-Resisting, Maraging, and Other Similar Chromium-Nickel-Iron Alloys ASTM E384 Microindentation Hardness of Materials ASTM E399 Plane-Strain Fracture Toughness of Metallic Materials SAE INTERNATIONAL AMS6525E Page 3 of 11 3.
16、 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 spectrochemical methods, or by other analytical methods acceptable to purchaser. Table 1 - Composition Element Min. Max. Carbon 0.1
17、7 0.23 Manganese 0.20 0.40 Silicon - 0.20 Phosphorus - 0.010 Sulfur - 0.010 Chromium 0.65 0.85 Nickel 8.50 9.50 Cobalt 4.25 4.75 Molybdenum 0.90 1.10 Vanadium 0.06 0.12 Copper - 0.35 3.1.1 Check Analysis Composition variations shall meet the applicable requirements of AMS2259. 3.2 Melting Practice S
18、teel shall be multiple melted using consumable electrode vacuum practice in the remelt cycle. 3.3 Condition The product shall be supplied in the following condition; hardness and tensile strength shall be determined in accordance with ASTM A370. 3.3.1 Bars Bar shall not be cut from plate (also see 4
19、.4.2). 3.3.1.1 Bars 0.500 Inch (12.70 mm) and Under in Nominal Diameter or Least Distance Between Parallel Sides Annealed, or normalized and tempered, and cold finished having tensile strength not higher than 180 ksi (1241 MPa) or equivalent hardness (see 8.2). 3.3.1.2 Bars Over 0.500 Inch (12.70 mm
20、) in Nominal Diameter or Least Distance Between Parallel Sides Hot finished, annealed, or normalized and tempered, and descaled, having hardness not higher than 341 HBW, or equivalent (see 8.3). Bars ordered annealed and cold finished may have hardness as high as 352 HBW, or equivalent. SAE INTERNAT
21、IONAL AMS6525E Page 4 of 11 3.3.2 Forgings and Flash Welded Rings Annealed, or normalized and tempered, in accordance with 3.4, and descaled having hardness not higher than 352 HBW, or equivalent (see 8.3). 3.3.2.1 Flash welded rings shall not be supplied unless specified or permitted on purchasers
22、part drawing. When supplied, rings shall be manufactured in accordance with AMS7496. 3.3.3 Mechanical Tubing Annealed, or normalized and tempered, and cold finished having hardness not higher than 38 HRC, or equivalent (see 8.3). Tubing ordered hot finished and annealed shall have hardness not highe
23、r than 36 HRC, or equivalent (see 8.3). 3.3.4 Stock for Forging or Flash Welded Rings As ordered by the forging or flash welded ring manufacturer. 3.4 Heat Treatment Bars, forgings, mechanical tubing, and flash welded rings shall be annealed by heating to 1250 F 25 F (677 C 14 C), holding at heat fo
24、r 4 hours 0.25 hour, cooling to room temperature in air or other atmosphere at a rate equivalent to an air cool, reheating to 1150 F 25 F (621 C 14 C), holding at heat for 4 hours 0.25 hour, and cooling to room temperature in air or other atmosphere at a rate equivalent to an air cool. Pyrometry sha
25、ll be in accordance with AMS2750. 3.4.1 When specified by purchaser, the product shall be normalized prior to annealing by heating to 1650 F 25 F (899 C 14 C), holding at heat for not less than 1 hour per inch (25 mm) of maximum thickness, but not less than 1 hour, and cooling to room temperature in
26、 air or other atmosphere at a rate equivalent to an air cool. 3.5 Properties The product shall conform to the following requirements; hardness and tensile testing shall be performed in accordance with ASTM A370: 3.5.1 Macrostructure Visual examination of transverse full cross-sections from bars, bil
27、lets, tube rounds, and stock for forging or flash welded rings, etched in hot hydrochloric acid in accordance with ASTM A604, shall show 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 - Macro
28、structure limits Class Condition Severity 1 Freckles A 2 White Spots A 3 Radial Segregation B 4 Ring Pattern B SAE INTERNATIONAL AMS6525E Page 5 of 11 3.5.1.1 Macrostructure examination is not required for hollow tubes that are produced directly from ingots or blooms unless specified by purchaser, i
29、n 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 accordance with ASTM E45, Method D. Table 3 - Micro-inclusion limits A Thin A Heavy B Thin B Heavy C Thin C Heavy D Thin D Heav
30、y Worst Field Severity 1.5 1.0 1.5 1.0 1.5 1.0 1.5 1.0 Worst Field Frequency, maximum a 1 a 1 a 1 3 1 Total Rateable Fields, Frequency, maximum b 1 b 1 b 1 8 1 a - Combined A+B+C, not more than 3 fields b - Combined A+B+C, not more than 8 fields 3.5.2.1 A rateable field is defined as one which has a
31、 type A, B, C, or D inclusion rating of at least 1.0 thin or heavy in accordance with ASTM E45. 3.5.3 Average Grain Size of Bars, Forgings, Tubing and Flash Welded Rings Shall be ASTM No. 5 or finer, determined in accordance with ASTM E112. 3.5.4 Decarburization 3.5.4.1 Bars, tubing, and flash welde
32、d rings 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 5. 3.5.4.2 Allowable decarburization of bars, billets, and tube rounds ordered for redrawing,
33、 forging, or flash welding or to specified microstructural requirements shall be as agreed upon by purchaser and producer. 3.5.4.3 Decarburization of bars and flash welded rings, for which 3.5.4.1 or 3.5.4.2 are not applicable, shall not exceed the values shown in Table 4. Table 4A - Maximum total d
34、epth of decarburization, 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 1.500, incl 0.020 Over 1.500
35、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 5.000, incl 0.045 SAE INTERNATIONAL AMS6525E Page 6 of 11 Table 4B - Maximum total depth of decarburization, SI units Nominal Diameter or Distance Between Parallel Sides Millimeters Total Depth of Deca
36、rburization 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 127.00, incl 1.14 3.5.4.
37、4 Decarburization of tubing, for which 3.5.4.1 or 3.5.4.2 are not applicable, shall not exceed the values shown in Table 5. Table 5A - Maximum total depth of decarburization, inch/pound units Nominal Wall Thickness Inches Total Depth ID Inch Total Depth OD Inch Up to 0.109, incl 0.008 0.015 Over 0.1
38、09 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 5B - Maximum total depth of decarburization, SI units Nominal Wall Thickness Millimeters Total Depth ID Millimeter Total Depth
39、OD Millimeters 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 SAE INTERNATIONAL AMS6525E Page 7 of 11 3.5.4.5 Depth of decarburization on forgings shall be no
40、t greater than 0.060 inch (1.52 mm); forgings shall show no carburization. 3.5.4.6 Decarburization shall be evaluated by one of the two methods of 3.5.4.6.1 or 3.5.4.6.2. 3.5.4.6.1 Metallographic Method A cross section taken perpendicular to the surface shall be prepared, etched, and visually examin
41、ed metallographically at a magnification not to exceed 100X. Optical indications of decarburization shall not show a layer of complete (ferrite) or partial decarburization exceeding the limits of Tables 4 or 5. 3.5.4.6.2 Hardness Traverse Method The total depth of decarburization shall be determined
42、 by a traverse method using microindentation hardness 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 th
43、e perpendicular 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 4
44、 or 5. 3.5.4.7 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. 3.5.4.8 In case of dispute, the total
45、depth of decarburization determined using the microindentation hardness traverse method shall govern. 3.5.5 Response to Heat Treatment Specimens, taken from product 100 in2(645 cm2) and under in cross-sectional area after heat treatment as in 3.5.5.1, shall meet the requirements of 3.5.5.2, 3.5.5.3,
46、 and, when specified, 3.5.5.4. 3.5.5.1 Heat Treatment 3.5.5.1.1 Normalizing Heat to 1650 F 25 F (899 C 14 C), hold at heat for 1 hour per inch (25.4 mm) of maximum cross-section, and cool to room temperature at a rate equivalent to air cooling. 3.5.5.1.1.1 Normalizing may be omitted if the product w
47、as supplied normalized and annealed. 3.5.5.1.2 Hardening Heat to 1525 F 25 F (829 C 14 C), hold at heat for 1 hour per inch (25 mm) of maximum section thickness, but not less than 1 hour, and quench in oil at 60 to 150 F (16 to 66 C), cool within 2 hours to -100 F 25 F (-73 C 14 C), hold at -100 F 2
48、5 F (-73 C 14 C) for not less than 1 hour, and warm to room temperature. 3.5.5.1.3 Tempering Heat to 1050 F 25 F (566 C 14 C), hold at heat for not less than 4 hours, and cool in air to room temperature. SAE INTERNATIONAL AMS6525E Page 8 of 11 3.5.5.2 Tensile Properties Shall be as shown in Table 6.
49、 Table 6 - Minimum tensile properties Property Value Tensile Strength 190 ksi (1310 MPa) Yield Strength at 0.2% Offset 180 ksi (1241 MPa) Elongation in 4D 12% Reduction of Area 45% 3.5.5.3 Hardness Shall be 41 to 45 HRC, or equivalent (see 8.3). 3.5.5.4 Fracture Toughness Fracture toughness, when specified, shall be not less than 110 ksi (121 MPa ) KIC or
