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/AMS6526H AEROSPACE MATERIAL SPECIFICATION AMS6526 REV. H Issued 1968-05 Revised 2016-12Supersed
5、ing AMS6526G Steel, Bars, Forgings, Tubing, and Rings 1.0Cr - 7.5Ni - 4.5Co - 1.0Mo - 0.09V (0.29 - 0.34C) Consumable Electrode Vacuum Remelted, Annealed (Composition similar to UNS K91283) RATIONALE AMS6526H results from a Five-Year Review and update of this specification that revises the test proc
6、edure for micro-inclusion rating (3.5.2.1) and decarburization (3.5.4.5), quality (3.6), and reporting (4.4). 1. SCOPE 1.1 Form This specification covers a premium aircraft-quality, high-strength, low-alloy steel in the form of bars, forgings, mechanical tubing, flash welded rings, and stock for for
7、ging or flash welded rings. 1.2 Application These products have been used typically for 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 procedu
8、res and service 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
9、 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. SAE INTERNA
10、TIONAL AMS6526H Page 2 of 10 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 Tolerances Carbon and Alloy
11、Steel Tubing AMS2259 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 Qua
12、lity Assurance 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, Car
13、bon and Low-Alloy Steels ARP1110 Minimizing Stress Corrosion Cracking in Wrought Forms of Steels and Corrosion Resistant Steels and Alloys ARP1917 Clarification of Terms Used in Aerospace Metals Specifications AS1182 Standard Stock Removal Allowance, Aircraft-Quality and Premium Aircraft-Quality Ste
14、el 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 Products ASTM A604 Macroetch Testing of Consumable Electrode Remelted
15、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-Resisting, Maraging, and Other Similar Chromium-Nickel-Iron Alloys ASTM E384 Microindenta
16、tion Hardness of Materials ASTM E399 Plane-Strain Fracture Toughness of Metallic Materials SAE INTERNATIONAL AMS6526H Page 3 of 10 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, b
17、y spectrochemical methods, or by other analytical methods acceptable to purchaser. Table 1 - Composition Element Min. Max. Carbon 0.29 0.34 Manganese 0.10 0.35 Silicon - 0.20 Phosphorus - 0.010 Sulfur - 0.010 Chromium 0.90 1.10 Nickel 7.00 8.00 Cobalt 4.25 4.75 Molybdenum 0.90 1.10 Vanadium 0.06 0.1
18、2 Copper - 0.35 3.1.1 Check Analysis Composition variations shall meet the applicable requirements of AMS2259. 3.2 Melting Practice Steel 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; h
19、ardness and tensile strength shall be determined in accordance with ASTM A370: 3.3.1 Bars Bar shall not be cut from plate (also see 4.4.2). 3.3.1.1 Bars 0.500 Inch (12.70 mm) and Under in Nominal Diameter or Least Distance Between Parallel Sides Annealed and cold finished having tensile strength not
20、 higher than 165 ksi (1138 MPa) or equivalent hardness (see 8.2). 3.3.1.2 Bars Over 0.500 Inch (12.70 mm) in Nominal Diameter or Least Distance Between Parallel Sides and Forgings, Flash Welded Rings, and Mechanical Tubing Hot finished, annealed, and descaled having hardness not higher than 341 HBW,
21、 or equivalent (see 8.3). 3.3.2 Forgings and Flash Welded Rings Hot finished, annealed, and descaled having hardness not higher than 341 HBW, or equivalent (see 8.3). 3.3.2.1 Flash welded rings shall not be supplied unless specified or permitted on purchasers part drawing. When supplied, rings shall
22、 be manufactured in accordance with AMS7496. 3.3.3 Stock for Forging or Flash Welded Rings As ordered by the forging or flash welded ring manufacturer. SAE INTERNATIONAL AMS6526H Page 4 of 10 3.4 Heat Treatment Bars, forgings, mechanical tubing, and flash welded rings shall be duplex annealed by hea
23、ting to 1250 F 25 F (677 C 14 C), holding at heat for 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 atmospher
24、e at a rate equivalent to an air cool. Pyrometry shall be in accordance with AMS2750. 3.5 Properties The product shall conform to the following requirements; hardness, tensile, and impact testing shall be performed in accordance with ASTM A370: 3.5.1 Macrostructure Visual examination of transverse f
25、ull cross-sections from bars, billets, tube rounds (solid, not hollow), 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 macro
26、graphs 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 examination is not required for hollow tubes that are produced directly from ingots or blooms unless specified by
27、 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 accordance with ASTM E45, Method D. Table 3 - Micro-inclusion limits Type A Thin A Heavy B Thin B Heavy C Thin C H
28、eavy D Thin D Heavy 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
29、as one that has a 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, tubin
30、g, and flash welded 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. SAE INTERNATIONAL AMS6526H Page 5 of 10 3.5.4.2 Allowable decarburizatio
31、n of bars, billets, and tube rounds ordered for redrawing, 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 exce
32、ed the values shown in Table 4. Table 4A - 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 0.010 Over 0.375 to 0.500, incl 0.012 Over 0.500 to 0.625, incl 0.014 Over 0.625 to 1.0
33、00, incl 0.017 Over 1.000 to 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 5.000, incl 0.045 Table 4B - Maximum total depth of decarburization, SI units Nominal Diameter or Distance Between Parallel Sides Millimeters T
34、otal Depth of Decarburization 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
35、, incl 1.14 3.5.4.4 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.
36、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 SAE INTERNATIONAL AMS6526H Page 6 of 10 Table 5B - Maximum total depth of decarburization, SI units Nominal Wall Th
37、ickness Millimeters Total Depth ID Millimeter Total Depth 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 3.5.4.5 Decarburization shall be evalu
38、ated by one of the two methods of 3.5.4.5.1 or 3.5.4.5.2. 3.5.4.5.1 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
39、 a layer of complete (ferrite) or partial decarburization exceeding the limits of Tables 4 or 5. 3.5.4.5.2 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
40、 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 the depth under that surface where there is not further increase in h
41、ardness. 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 or 5. 3.5.4.6 When determining the depth of decarburization, it is permissible to disregard local areas provided
42、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. 3.5.4.7 In case of dispute, the total depth of decarburization determined using the microindentation hardness traverse method shall govern. 3.5.5 Respon
43、se to Heat Treatment Specimens taken from bars, forgings, mechanical tubing, and parent metal of flash welded rings, heat treated as in 3.5.5.1, shall conform to the requirements of 3.5.5.2 and, when specified, 3.5.5.3. Product need not be annealed as in 3.3 before heat treatment to determine confor
44、mance to these requirements. 3.5.5.1 Heat Treatment 3.5.5.1.1 Normalizing Heat to 1675 F 25 F (913 C 14 C), hold at heat for not less than 1 hour per inch (25 mm) of maximum section thickness, and cool at a rate equivalent to air cooling to room temperature. 3.5.5.1.2 Hardening Heat to 1550 F 25 F (
45、843 C 14 C), hold at heat for 1 hour per inch (25 mm) of maximum section thickness, but not less than 1 hour, quench sections 4.0 inches (102 mm) and under in nominal thickness into room temperature oil or water and sections over 4.0 inches (102 mm) in nominal thickness into room temperature oil. Co
46、ol to -100 F 10 F (-73 C 6 C), within 2 hours after quenching, hold at -100 F 10 F (-73 C 6 C) for not less than 2 hours, and warm in air to room temperature. SAE INTERNATIONAL AMS6526H Page 7 of 10 3.5.5.1.3 Tempering Heat to 1000 F 10 F (538 C 6 C), hold at heat for not less than 2 hours, cool to
47、below 125 F (52 C), reheat to 1000 F 10 F (538 C 6 C), hold at heat for not less than 2 hours, and cool in air to room temperature. 3.5.5.2 Tensile Properties Shall be as shown in Table 6. Table 6 - Minimum tensile properties Property Value Tensile Strength 220 ksi (1517 MPa) Yield Strength at 0.2%
48、Offset 190 ksi (1310 MPa) Elongation in 4D 10% Reduction of Area 40% 3.5.5.3 Fracture Toughness Fracture toughness, when specified, shall be not less than 90.0 ksi (99 MPa ) KIC, determined in accordance with ASTM E399 on any product form that a specimen of a standardized ASTM E399 orientation can b
49、e extracted having dimensions not less than 1.50 inches (38.1 mm) in section thickness and not less than 4.00 inches (101.6 mm) in width. 3.5.6 Forging Stock Specimens extracted from a forged down test coupon heat treated as in 3.5.5.1 shall conform to the requirements of 3.5.5.2, and, when specified, 3.5.5.3. If specimens taken from the stock after
