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 2015 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/AMS2759/3F AEROSPACE MATERIAL SPECIFICATION AMS2759/3 REV. F Issued 1984-10 Reaff
5、irmed 2014-04 Revised 2015-12 Superseding AMS2759/3E Heat Treatment Precipitation-Hardening Corrosion-Resistant and Maraging Steel Parts RATIONALE AMS2759/3F removes the requirement for cooling “within 1 hour” after solution heat treatment from Table 3 for 15-5 PH, 17-4 PH and PH 13-8 Mo, as this ha
6、s been found to be unnecessary. 1. SCOPE This specification, in conjunction with the general requirements for steel heat treatment covered in AMS2759, establishes the requirements for heat treatment of precipitation-hardening corrosion- resistant and maraging steel parts. Parts are defined in AMS275
7、9. 1.1 Application This specification is applicable to parts made from the steels listed in Table 1. Table 1 - List of steels 15-5 PH 17-4 PH 17-7 PH PH 13-8 Mo PH 14-8 Mo PH 15-7 Mo A-286 AM-350 AM-355 Custom 450 Custom 455 Maraging 250 Maraging 300 The above designations are trademark or commercia
8、l designations and are for alloy recognition only. 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 to a subsequent revision of a document unless a specifi
9、c 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 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606
10、-7323 (inside USA and Canada) or +1 724-776-4970 (outside USA), www.sae.org. AMS2759 Heat Treatment of Steel Parts, General Requirements SAE INTERNATIONAL AMS2759/3F Page 2 of 15 ARP1820 Chord Method of Evaluating Surface Microstructural Characteristics 2.2 ASTM Publications Available from ASTM Inte
11、rnational, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959, Tel: 610-832-9585, www.astm.org. ASTM A380 Cleaning and Descaling Stainless Steel Parts, Equipment, and Systems ASTM E3 Preparation of Metallographic Specimens ASTM E8 Tension Testing of Metallic Materials ASTM E8M Te
12、nsion Testing of Metallic Materials (Metric) 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 shall be as follows: 3.2.1 Furnaces used at temperatures of 1,400
13、F (760 C) and higher and for stress relieving: 25 F (14 C). 3.2.2 Furnaces used at temperatures from 1,300 to 1,375 F (704 to 746 C): 15 F (8 C). 3.2.3 Furnaces used at temperatures below 1,300 F (704 C): 10 F (6 C). 3.3 Atmospheres Shall be controlled so as not to contaminate the parts being heat t
14、reated. Furnaces used to heat treat other classes of steel using atmospheres, which could contaminate precipitation-hardening or maraging steel parts, such as endothermic, exothermic, carbon-containing nitrogen-base, etc, shall have purge cycles (see 8.2) run and then shall be tested to ensure that
15、the surfaces of parts are not contaminated beyond the limits specified in 3.5.3. Materials which could attack or contaminate metal shall not contact parts. Composition and maintenance of salt baths shall be such as to prevent contamination of the parts. Salt baths shall be tested in accordance with
16、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 air or protective atmosphere. Acceptable protective atmospheres include argon, helium, hydrogen, neutral salt, and vacuum. Nitrogen and nitrogen-hy
17、drogen blends are permitted below 1,425 F (774 C). Nitrogen and nitrogen-hydrogen blends are permitted at or above 1,425 F (774 C) only if 0.020 inch (0.51 mm) is removed from all surfaces after heat treatment. Nitrogen and nitrogen-hydrogen blends are permitted up to 1,925 F (1,052 C) as a backfill
18、 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 should be avoided. 3.3.2 Protective Coatings A supplemental coating is permitted to minimize oxidation of finished machined surfaces when
19、 approved by the cognizant engineering organization. SAE INTERNATIONAL AMS2759/3F Page 3 of 15 3.4 Procedure 3.4.1 Acid Cleaning Parts shall be acid cleaned in accordance with ASTM A380 before thermal treatment following forming with dies made from lead, kirksite, or other low-melting-temperature ma
20、terials. 3.4.2 Soaking 3.4.2.1 Solution Heat Treating and Austenite Conditioning Soaking shall be for the required time without interruption. Heating shall be controlled as described in AMS2759, such that either the temperature of the control thermocouple or the load thermocouple, as applicable, is
21、maintained within the set temperature uniformity range for the soak time shown in Tables 2, 3, 4, or 6. Soaking time shall commence when the furnace control thermocouple reaches within 5 F (3 C) of the specified set temperature and all other thermocouples reach the minimum of the temperature uniform
22、ity range. Alternatively, if a load thermocouple, as defined in AMS2759, is used, soaking time shall commence when its temperature reaches the minimum of the furnace uniformity range. 3.4.2.2 Aging The control instrument set temperature and the soaking time shall conform to Table 3 except as specifi
23、ed in 3.4.2.2.1. Start of soaking time shall be based on either the furnace control thermocouple (3.4.2.2.1) or a load thermocouple (1) in contact with a part or (2) in contact with a sample representing a part or (3) buried in the load (3.4.2.2.2). Soaking time shall end when parts are removed from
24、 the furnace or when parts cool to the minimum of the furnace uniformity range. 3.4.2.2.1 Furnace Control Thermocouple Soaking time shall start when the temperature indicated by the furnace control instrument (not recorder) recovers to within 5 F (3 C) of the set temperature and all other thermocoup
25、les reach the minimum of the temperature uniformity range. It is permissible to increase the soaking time by up to 50% of the time specified in Table 3 to compensate for the lag in part temperature due to specific characteristics of the parts or the load, for example part thickness, load weight, shi
26、elding or interference with circulation due to part configuration. 3.4.2.2.2 Load Thermocouple Soaking time shall start when the load thermocouple temperature reaches the minimum of the temperature uniformity range. 3.4.3 Solution Heat Treating (Solution Annealing, Annealing), Austenite Conditioning
27、, and Aging (Precipitation Heat Treating) Shall be accomplished by heating to the temperature specified in Tables 3 or 6, soaking for the time specified in Tables 3, 4, or 6, and cooling continuously without interruption as specified in Tables 3, 4, and 6. 3.4.3.1 Re-solution Heat Treating Only one
28、re-solution heat treatment is permitted. 3.4.4 Stress Relieving When required by the cognizant engineering organization, heat treated parts shall be stress relieved by heating to 100 F (56 C) below the aging temperature and soaking for at least 1 hour plus 1 hour additional for each inch (25 mm) of
29、thickness or fraction thereof greater than 1 inch (25 mm). When load thermocouples are used, the soaking time shall be at least 1 hour. Stress relieving is prohibited on parts which have been peened or thread-rolled after aging. SAE INTERNATIONAL AMS2759/3F Page 4 of 15 3.4.5 Carbide Solutioning Tre
30、atment (For AM-355) When required, carbide solutioning shall be accomplished by heating to 1,900 F (1,038 C), soaking for the times shown in Table 2 for the respective section thickness, water quenching to room temperature, cooling to -90 F (-68 C) or below, holding for 1 to 3 hours, and warming in
31、air to room temperature. Table 2 - Time for carbide solution treatment Section Thickness Inches Section Thickness Millimeters Soaking Time Hours, minimum Up to1, excl 1 to 3, incl Over 3 Up to 25, excl 25 to 76, incl Over 76 1 2 3 3.4.6 Straightening When approved by the cognizant engineering organi
32、zation, straightening shall be accomplished at either ambient temperature, during aging, or by heating to not higher than 50 F (28 C) below the aging temperature. Ambient temperature straightening and hot or warm straightening after aging shall be followed by stress relieving. It is permissible to s
33、tress relieve after straightening during aging. 3.5 Properties Testing shall be as required by AMS2759 and as specified herein. 3.5.1 Hardness Precipitation-hardening corrosion-resistant and maraging steel parts shall conform to the hardness shown in Table 5 for the required condition. 3.5.2 Tensile
34、 Properties When tensile tests are required, results shall conform to the specified values. When tensile properties are not specified, they shall conform to those specified by the applicable material specification. 3.5.3 Surface Contamination When any surface of a part is not to be machined after he
35、at treatment, the protective atmosphere or backfill medium in furnaces for heating parts above 1,350 F (732 C) shall be controlled to not produce carburization or nitriding (see 3.5.3.1) and intergranular oxidation shall not exceed 0.0007 inch (0.018 mm). Parts heat treated in salt baths shall be fr
36、ee of residual salts. 3.5.3.1 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 above 1,350 F (732 C) with controlled atmosphere wh
37、ich 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. 3.5.3.2 Furnaces used exclusively to heat treat parts which will have all contamination removed shall
38、not require testing. SAE INTERNATIONAL AMS2759/3F Page 5 of 15 3.6 Test Methods Shall be in accordance with AMS2759 and as follows: 3.6.1 Surface Contamination Testing shall be by metallurgical examination at approximately 500X magnification of etched specimens prepared in accordance with ASTM E3. T
39、he chord method in ARP1820 may be used to enhance this examination. 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
40、 Tests The classification of acceptance, periodic, and preproduction tests shall be as specified in AMS2759 and as specified in 4.1.1 thru 4.1.3. 4.1.1 Acceptance Tests Tensile property requirements (3.5.2) for the following are acceptance tests and shall be performed on each lot: AM-350 and AM-355
41、parts; 17-7PH and PH15-7Mo parts heat treated to the RH Condition; 15-5PH and 17-4PH parts aged from 1,100 F (593 C) to 1,150 F (621 C); when specified, for re-solution heat treated parts. 4.1.2 Periodic Tests Surface contamination (3.5.3) is a periodic test and shall be performed for each piece of
42、equipment after the purging of atmospheres whenever the equipment has been used previously to heat treat using atmospheres, such as endothermic, exothermic, carbon-containing nitrogen-base, etc., which could contaminate precipitation-hardening or maraging steel parts. 4.1.3 Preproduction Tests Surfa
43、ce contamination (3.5.3) is a preproduction test and shall be performed prior to any production heat treating for each piece of equipment and for each type of atmosphere to be used in each furnace. 4.2 Sampling and Testing Shall be in accordance with AMS2759 and as follows: 4.2.1 Tensile Testing 4.2
44、.1.1 For AM-350 and AM-355 One or more tensile specimens conforming to ASTM E8 or ASTM E8M shall be processed with each austenite-conditioning load. It shall be of the same alloy designation as the parts and shall continue with the parts through final aging. 4.2.1.2 For 17-4PH and 15-5PH aged from 1
45、,100 F (593 C) to 1,150 F (621 C) One or more tensile specimens conforming to ASTM E8 or ASTM E8M shall be processed with each aging load. It shall be of the same alloy designation as the parts. SAE INTERNATIONAL AMS2759/3F Page 6 of 15 4.2.1.3 For 17-7PH and PH15-7Mo to the RH Condition One or more
46、 tensile specimen conforming to ASTM E8 or ASTM E8M shall be processed with each austenite-conditioning load. It shall be of the same alloy designation as the parts and shall continue with the parts through final aging. 4.2.1.4 For Re-solution Heat Treated Parts When specified, one or more tensile s
47、pecimens conforming to ASTM E8 or ASTM E8M shall be processed with each load. It shall be of the same alloy designation as the parts and shall continue with the parts through final aging. 4.2.2 Surface Contamination Testing One or more samples shall be processed. 5. PREPARATION FOR DELIVERY In accor
48、dance with AMS2759. 6. ACKNOWLEDGMENT In accordance with AMS2759. 7. REJECTIONS In accordance with AMS2759. 8. NOTES Shall be in accordance with 8.1, 8.2, 8.3, and AMS2759. 8.1 Revision Indicator A change bar (l) located in the left margin is for the convenience of the user in locating areas where t
49、echnical 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 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 rem
