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 2014 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/AMS2759/4C AEROSPACE MATERIAL SPECIFICATION AMS2759/4 REV. C Issued 1984-10 Revis
5、ed 2008-03 Reaffirmed 2014-04 Superseding AMS2759/4B Heat Treatment Austenitic Corrosion-Resistant Steel Parts RATIONALE AMS2759/4C has been reaffirmed to comply with the SAE five-year review policy. 1. SCOPE This specification, in conjunction with the general requirements for steel heat treatment c
6、overed in AMS2759, establishes the requirements for annealing, stress relieving, and stabilizing heat treatment of austenitic corrosion-resistant steel parts. Parts are defined in AMS2759. 1.1 Application This specification is applicable to parts made from the following corrosion-resistant steels: 2
7、01, 202, 301, 302, 303, 304, 304L, 305, 309, 310, 314, 316, 316L, 321, 347, and 348 (See Table 1, Note 1). 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 specified herein. The supplier may work
8、 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 Available from SAE International, 400 Com
9、monwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org. AMS2759 Heat Treatment of Steel Parts, General Requirements ARP1820 Chord Method of Evaluating Surface Microstructural Characteristics SAE INTERNATIONAL AMS2759/4C Page 2
10、 of 7 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 A 262 Detecting Susceptibility to Intergranular Attack in Austenitic Stainless Steels ASTM A 380 Cleaning and Descaling Stainle
11、ss Steel Parts, Equipment, and Systems ASTM E 3 Preparation of Metallographic Specimens 3. TECHNICAL REQUIREMENTS 3.1 Heat Treatment Shall conform to AMS2759 and requirements specified herein. 3.2 Equipment Shall conform to AMS2759. Furnace temperature uniformity requirements for annealing, stress r
12、elieving, and stabilizing shall be 25 F (14 C). 3.3 Atmospheres Shall be controlled to not contaminate the parts being heat treated. Furnaces used to heat treat other classes of steel using atmospheres, which could contaminate austenitic corrosion-resistant steel parts, such as endothermic, exotherm
13、ic, carbon-containing nitrogen base, etc, shall have purge cycles (See 8.2) run and then shall be tested to ensure that the surfaces of parts are not contaminated beyond the limits specified in 3.5.1. Materials which could attack or contaminate metal shall not contact parts. Composition and maintena
14、nce of salt baths shall be such as to prevent contamination of the parts. Salt baths shall be tested in accordance with AMS2759. Heat treating performed in air shall be in the natural atmosphere of a muffle furnace. 3.3.1 Heating Environment Parts shall be heat treated in either air or protective at
15、mosphere. Acceptable protective atmospheres include argon, helium, hydrogen, neutral salt, vacuum, and exothermic. Nitrogen and nitrogen-hydrogen blends are permitted below 1425 F (774 C). Nitrogen and nitrogen-hydrogen blends are permitted at 1425 F (774 C) or over only if 0.020 inch (0.51 mm) is r
16、emoved from all surfaces after heat treatment. Nitrogen and nitrogen-hydrogen blends are permitted up to 1925 F (1052 C) as a backfill quench for vacuum furnaces. Use of nitrogen from dissociated ammonia is prohibited. For scale-free or discoloration-free parts, an air atmosphere and air cooling sho
17、uld be avoided. 3.3.2 Protective Coatings A supplemental coating is permitted, to minimize oxidation on finished machined surfaces, when approved by the cognizant engineering organization. 3.4 Procedure 3.4.1 Acid Cleaning Parts shall be acid cleaned in accordance with ASTM A 380 before thermal trea
18、tment following forming with dies made from lead, kirksite, or other low-melting-temperature materials. SAE INTERNATIONAL AMS2759/4C Page 3 of 7 3.4.2 Soaking Heating shall be controlled, as described in AMS2759, such that either the heating medium or the part temperature, as applicable, is maintain
19、ed at the set temperature shown in Table 1 for the soak time shown in Table 2. Soaking shall commence when all control, indicating, and recording thermocouples reach the specified set temperature minus the required temperature uniformity tolerance or, if load thermocouples as defined in AMS2759 are
20、used, when the part temperature reaches the minimum of the furnace uniformity at the set temperature. 3.4.3 Annealing, Stress Relief, and Dimensional Stabilization Shall be accomplished by heating, soaking, and cooling as shown in Tables 1 and 2. 3.4.4 Heating, stress relieving, or slow coaling of u
21、nstabilized grades, except 304L and 316L, between 875 and 1500 F (468 and 816 C) is prohibited. 3.4.5 Straightening When approved by the cognizant engineering organization, straightening shall be accomplished at ambient temperature with a post-straightening stress relief as shown in Table 1 or at th
22、e stress relieving temperature shown in Table 1 without a subsequent stress relief. For parts subject to excessive warpage, dimensional stabilization may be substituted for stress relief, when approved by the cognizant engineering organization. 3.5 Properties 3.5.1 Surface Contamination When any sur
23、face of a part is not machined after heat treatment, the protective atmosphere or backfill medium in furnaces, for heating parts above 1350 F (732 C), shall be controlled not to produce carburization or nitriding (See 3.5.1.1), and intergranular oxidation shall not exceed 0.0007 inch (0.018 mm). Par
24、ts heat treated in salt baths shall be free of residual salts. 3.5.1.1 Unless specifically informed that the parts will be machined all over, the heat treating processor shall process the parts as though some surfaces will not have subsequent metal removal and, therefore, shall heat treat parts usin
25、g controlled atmosphere which will conform to the surface contamination requirements. Unless specified, controlled atmosphere is not required for parts with only raw material surfaces, except those made from sheet or strip. 3.5.1.2 Furnaces used exclusively to heat treat parts which will have all co
26、ntamination removed shall not require testing. 3.5.2 Carbide Precipitation When using other means of cooling in accordance with Table 1, Note 2, carbide precipitation is not permitted. 3.6 Test Methods Shall be in accordance with AMS2759 and as follows: 3.6.1 Surface Contamination Testing shall be b
27、y metallurgical examination at approximately 500X magnification of etched specimens prepared in accordance with ASTM E 3. The chord method in ARP1820 may be used to enhance this examination. SAE INTERNATIONAL AMS2759/4C Page 4 of 7 3.6.2 Carbide Precipitation Shall be determined in accordance with A
28、STM A 262. 4. QUALITY ASSURANCE PROVISIONS The responsibility for inspection, classification of tests, sampling, approval, entries, records, and reports shall be in accordance with AMS2759 and as specified in 4.1 and 4.2. 4.1 Classification of Tests The classification of acceptance, periodic, and pr
29、eproduction tests shall be as specified in AMS2759 and as specified in 4.1.1 and 4.1.2. 4.1.1 Periodic Tests Surface contamination (3.5.1) is a periodic test and shall be performed for each piece of equipment after the purging of atmospheres whenever the equipment has been used previously to heat tr
30、eat using atmospheres, such as endothermic, exothermic, carbon-containing nitrogen base, etc, which could contaminate austenitic corrosion-resistant steel parts. 4.1.2 Preproduction Tests Surface contamination (3.5.1) is a preproduction test and shall be performed prior to any production heat treati
31、ng for each piece of equipment and type of atmosphere to be used in each furnace. Additionally, tests to determine conformance to the requirements for carbide precipitation shall be performed prior to any production heat treatment for each piece of equipment and each alternate means of cooling. 4.2
32、Sampling Shall be in accordance with AMS2759 and as follows: 4.2.1 Surface Contamination Testing One or more samples shall be processed. 5. PREPARATION FOR DELIVERY See AMS2759. 6. ACKNOWLEDGMENT See AMS2759. 7. REJECTIONS See AMS2759. 8. NOTES Shall be in accordance with 8.1, 8.2, and AMS2759. SAE
33、INTERNATIONAL AMS2759/4C Page 5 of 7 8.1 A change bar (|) located in the left margin is for the convenience of the user in locating areas where technical revisions, not editorial changes, have been made to the previous issue of this document. An (R) symbol to the left of the document title indicates
34、 a complete revision of the document, including technical revisions. Change bars and (R) are not used in original publications, nor in documents that contain editorial changes only. 8.2 Purge Cycles Effective purge cycles can be run to remove contamination from refractory furnace linings using inert
35、 gases with small amounts of reducing agents. 8.3 Terms used in AMS are clarified in ARP1917. 8.4 Dimensions and properties in inch/pound units and the Fahrenheit temperatures are primary; dimensions and properties in SI units and the Celsius temperatures are shown as the approximate equivalents of
36、the primary units and are presented only for information. PREPARED BY AMS COMMITTEE “F“ AND AMEC SAE INTERNATIONAL AMS2759/4C Page 6 of 7 TABLE 1 - ANNEALING, STRESS RELIEVING, AND DIMENSIONAL STABILIZING TREATMENTS FOR AUSTENITIC CORROSION-RESISTANT STEEL PARTS Treatment Alloy (1)Set Temperature F
37、Set Temperature C Soaking Time Minutes Quench or Cooling Method (2) Annealing (3) (4) 201, 202, 301, 302, 303, 304, 305, 309, 310 (6) 1950 1066 Table 2 Water (5) Annealing (3) (4) 314, 316 (6) 2000 1093 Table 2 Water (5) Annealing (3) 321 1800 982 Table 2 Air, Oil, Polymer, or Water (7) Annealing (3
38、) (4) 347, 348 1900 1038 Table 2 Air, Oil, Polymer, or Water (7) Stress Relieving (3) (9) 201, 202, 301, 302, 303, 304, 305 309, 310, 314, 316 (6) 1650 (8) 899 (8) Table 2 Water (5) Stress Relieving (3) (9) 321, 347, 348 (6) 1650 (8) 899 (8) Table 2 (9) Air, Polymer, or Water (7) Dimensional Stabili
39、zing (3) All (6) 800 (10) 427 (10) 60 (11) (12) Air NOTES: 1. Includes letter designations of the same alloy, unless otherwise indicated. Examples: 302B, 303S, 303Se, 304L, 309S, 310S, 316L, etc. 2. Other means of cooling are permitted provided tests substantiate that the rate is rapid enough to pre
40、vent carbide precipitation. 3. Parts fabricated from material in a strain-hardened condition 1/4 hard, 1/2 hard, etc shall not be annealed, stress relieved, or dimensionally stabilized without approval of the cognizant engineering organization. 4. When specified, lower temperatures down to 1800 F (9
41、82 C) may be used to maintain a fine grain size. 5. Sections under 0.10 inch (2.5 mm) thick may be air cooled or polymer quenched to minimize distortion. 6. Heat treating or slow cooling of unstabilized grades, except 304L and 316L, between 875 and 1500 F (468 and 816 C) is prohibited. 7. Sections o
42、ver 0.25 inch (6.4 mm) thick should be water quenched to minimize carbide precipitation. 8. Annealing treatment temperatures for these alloys are also permitted. 9. When stress relieving after welding is specified, hold for 30 minutes minimum at the annealing temperature followed by water quenching
43、or 2 hours minimum at the stress relieving temperature. 10. Set temperatures between 750 and 850 F (399 and 454 C) are permitted. 11. Per inch (25 mm) of section thickness or diameter or fraction thereof. 12. Minimum. SAE INTERNATIONAL AMS2759/4C Page 7 of 7 TABLE 2 - SOAKING TIME FOR AUSTENITIC COR
44、ROSION-RESISTANT STEEL PARTS Alloy (1) Diameter or Thickness of Maximum Section (2) Inches Diameter or Thickness of Maximum Section (2) Millimeters Minimum Soaking Time (3) (4) Atmosphere Furnace Minimum Soaking Time (3) (4) Salt Bath 201, 202, 301, 302, 303, 304, 305 309, 310, 314, 316 321, 347, 34
45、8 Up to 0.100, incl Over 0.100 to 0.250, incl Over 0.250 to 0.500, incl Over 0.500 to 1.00, incl Over 1.00 to 1.50, incl Over 1.50 to 2.00, incl Over 2.00 to 2.50, incl Over 2.50 to 3.00, incl Over 3.00 Up to 0.100, incl Over 0.100 to 0.250, incl Over 0.250 to 0.500, incl Over 0.500 to 1.00, incl Ov
46、er 1.00 to 1.50, incl Over 1.50 to 2.00, incl Over 2.00 to 2.50, incl Over 2.50 to 3.00, incl Over 3.00 Up to 2.54, incl Over 2.54 to 6.35, incl Over 6.35 to 12.70, incl Over 12.70 to 25.4, incl Over 25.4 to 38.1, incl Over 38.1 to 50.8, incl Over 50.8 to 63.5, incl Over 63.5 to 76.2, incl Over 76.2
47、 Up to 2.54, incl Over 2.54 to 6.35, incl Over 6.35 to 12.70, incl Over 12.70 to 25.4, incl Over 25.4 to 38.1, incl Over 38.1 to 50.8, incl Over 50.8 to 63.5, incl Over 63.5 to 76.2, incl Over 76.2 20 minutes 25 minutes45 minutes 1 hour, 1 hour, 15 minutes 1 hour, 30 minutes 1 hour, 45 minutes 2 hou
48、rs, (5) 40 minutes 45 minutes1 hour, 5 minutes 1 hour, 20 minutes 1 hour, 35 minutes 1 hour, 50 minutes 2 hours, 5 minutes 2 hours, 20 minutes (7) 17 minutes 18 minutes35 minutes 40 minutes45 minutes 50 minutes55 minutes 1 hour, (6) 37 minutes 38 minutes55 minutes 1 hour, 1 hour, 5 minutes 1 hour, 1
49、0 minutes 1 hour, 15 minutes 1 hour, 20 minutes (8) NOTES: 1. See Table 1, Note 1. 2. Thickness is the minimum dimension of the heaviest section of a part or nested load of parts. 3. Soaking shall commence as specified in 3.4.2. 4. In all cases, the parts shall be held for sufficient time to ensure that the center of the most massive section has reached temperature and the n
