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 reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions. Copyright 2009 SAE International All rights reserved. No part of this publication m
3、ay 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: 724-776-4970 (outside USA)
4、 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/AMS2759/9D AEROSPACE MATERIAL SPECIFICATION AMS2759/9D Issued 1996-11 Revised 2009-05Superseding
5、 AMS2759/9C Hydrogen Embrittlement Relief (Baking) of Steel Parts RATIONALE AMS2759/9D was issued to correct a publishing error in 3.3.3.6: “four” is returned to “24” hours. 1. SCOPE 1.1 Purpose This specification covers the requirements for embrittlement relief (baking) of heat treated steel parts
6、to remove hydrogen infused during plating and certain other chemical processing such as stripping, chemical milling, pickling, and etching. 1.2 Application This specification is applicable to parts made from carbon, low-alloy, and martensitic stainless steel heat treated to a minimum strength of 180
7、 ksi (1241 MPa) or heat treated to a minimum hardness of 40 HRC or equivalent. It is also applicable to threaded fasteners made from carbon, low-alloy, or martensitic stainless steels heat treated to a minimum strength of 150 ksi (1034 MPa) or 34 HRC or equivalent, parts made from high strength prec
8、ipitation hardening stainless steels other than A-286, and steel parts which have been case hardened (carburized, nitrided, nitrocarburized, or carbonitrided). See 8.2. 2. APPLICABLE DOCUMENTS The issue of the following documents in effect on the date of the purchase order forms a part of this speci
9、fication 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 been cancelled and no superseding document has been specified, the last published issue of that document shall apply.
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 724-776-4970 (outside USA), www.sae.org. AMS2649 Etch Inspection of High Strength Steel Parts AMS2750 Pyrometry AMS2759 Heat Treatment of Steel Parts
11、 SAE AMS2759/9D Page 2 of 5 3. TECHNICAL REQUIREMENTS In the event of a conflict between this specification and the document citing this specification, that document shall prevail. 3.1 Pyrometry shall conform to AMS2750 furnace class 5, instrumentation type D, as a minimum. 3.2 Heat treatment equipm
12、ent shall conform to AMS2759 and requirements specified herein. Furnaces shall be circulating-air type. 3.3 Procedure 3.3.1 Cleaning Parts shall be clean prior to baking. 3.3.2 Racking and Spacing Parts shall be placed in racks or trays, made of mesh or expanded metal, or supported or suspended so a
13、s to allow free circulation of the heating medium, except small parts may be randomly arranged in trays providing that layers of parts are not thicker than 2 inches (51 mm) and the distance between the layers is not less than 2 inches (51 mm). 3.3.2.1 Thickness of layers of small parts randomly arra
14、nged in trays may be greater than 2 inches (51 mm), provided tests have been made with load thermocouples to confirm that the center of the coldest load will reach the set temperature minus 25 F (14 C) within one hour of loading. 3.3.3 Parts shall be baked after the completion of the chemical proces
15、sing or plating designated in Table 1 or 2. (See 8.2.) 3.3.3.1 Delay Time Limits The elapsed time between completion of plating or other chemical processing operations and start of heating parts in the baking furnace shall not exceed 4 hours except, when baking is required after etch inspection (ref
16、er to footnote 4 of Tables 1 and 2) to detect abusive grinding or machining, the elapsed time shall not exceed 24 hours. 3.3.3.2 Bake Set Temperature 3.3.3.2.1 Standard bake set temperature shall be 375 F (191 C) in accordance with Table 1, nonstandard baking set temperatures listed in Table 2 shall
17、 be used for parts made from the following materials/processes: Carburize or carbonitride case hardening heat treatment AISI 52100 steel Type 440C corrosion and heat resisting steel Music wire Other alloys tempered below 400 F (204 C). 3.3.3.3 Bake Soak Time Bake soak time shall be as designated in
18、Table 1 or 2, as applicable. 3.3.3.4 Start of Soak Time Soaking time shall commence when parts are placed in the furnace, the furnace door(s) are closed, and the temperature indicated by the furnace control instrument is within 25 F (14 C) of the set temperature. SAE AMS2759/9D Page 3 of 5 3.3.3.5 S
19、oaking Interruptions 3.3.3.5.1 If the delay time (3.3.3.1) is less than 2 hours, soaking may be interrupted for the purpose of adding or removing parts. If the delay time (3.3.3.1) is 2 hours or more, parts shall be soaked for at least one hour before any such interruption. 3.3.3.5.2 If the temperat
20、ure indicated by the control instrument drops more than 25 F (14 C) below the set temperature, the time during which the indicated temperature was below that temperature shall not be considered part of the soaking time of any parts in the furnace. TABLE 1 - MINIMUM BAKE SOAK TIME (HOURS) AT 375 F (1
21、91 C) Steel/Part Description (9)Specified Temper, Minimum Strength or Minimum Hardness (1)Platings (8)Chemical TreatmentsCd dimensions and properties in SI units and the Celsius temperatures are shown as the approximate equivalents of the primary units and are presented only for information. PREPARED BY “AMEC” AND AMS COMMITTEE “B”
