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 2012 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: +1 724-776-4970 (outside U
4、SA) 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/AMS2402K AEROSPACE MATERIAL SPECIFICATION AMS2402 REV. K Issued 1942-12 Revised 2013-02 Super
5、seding AMS2402J Plating, Zinc RATIONALE AMS2402K results from a Five Year Review and update of this specification and is revised to be consistent with similar plating specifications. NOTICE ORDERING INFORMATION: The following information shall be provided to the plating processor by the purchaser. 1
6、) Purchase order shall specify not less than the following: AMS2402K Plating thickness desired. See 3.4.1. Basis metal to be plated Tensile strength or hardness of the basis metal (applies to steel alloys only). Pre-plate stress relief to be performed by plating processor (time and temperature) if d
7、ifferent from 3.1.2 Special features, geometry or processing present on parts that require special attention by the plating processor Hydrogen embrittlement relief to be performed by plating processor (parameters or reference document) if different from 3.3 Minimum thickness on internal surfaces, if
8、 required. See 3.4.1.4. Periodic testing frequency and sample quantity, if different from 4.2.2 and 4.3.2 Whether approval is based on approval of process/control factors or sample part or both. See 4.4.1. Quantity of pieces to be plated 2) Parts manufacturing operations such as heat treating, formi
9、ng, joining and media finishing can affect the condition of the substrate for plating, or if performed after plating, could adversely affect the plated part. The sequencing of these types of operations should be specified by the cognizant engineering organization or purchaser and is not controlled b
10、y this specification. Unless otherwise specified by the cognizant engineering organization, high strength steel parts having a hardness of 45 HRC or greater shall not be electroplated. SAE AMS2402K Page 2 of 10 1. SCOPE 1.1 Purpose This specification covers the requirements for electrodeposited zinc
11、 plating. 1.2 Application This process has been used typically to provide corrosion resistance to metal parts, but usage is not limited to such applications. 1.2.1 Unless otherwise stated on the engineering drawing, high strength steel parts having a hardness of 45 HRC or greater shall not be electr
12、oplated to this document (See 8.8) 1.3 Safety-Hazardous Materials While the materials, methods, applications, and processes described or referenced in this specification may involve the use of hazardous materials, this specification does not address the hazards that may be involved in such use. It i
13、s the sole responsibility of the user to ensure familiarity with the safe and proper use of any hazardous materials and to take necessary precautionary measures to ensure the health and safety of all personnel involved. 2. APPLICABLE DOCUMENTS The issue of the following documents in effect on the da
14、te 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 specific document issue is specified. When the referenced document has been cancelled and no superseding document has been specified, the
15、last published issue of that document shall apply. 2.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org. AMS2759/9 Hydrogen Embrittlement Relief (Baking) of Steel
16、 Parts AS2390 Chemical Process Test Specimen Material 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 B 117 Operating Salt Spray (Fog) Testing Apparatus ASTM B 253 Preparation of Al
17、uminum Alloys for Electroplating ASTM B 487 Measurement of Metal and Oxide Coating Thicknesses by Microscopical Examination of a Cross Section ASTM B 499 Measurement of Coating Thicknesses by the Magnetic Method; Nonmagnetic Coatings on Magnetic Basis Metals ASTM B 504 Measurement of Thickness of Me
18、tallic Coatings by the Coulometric Method ASTM B 555 Measurement of Electrodeposited Metallic Coating Thicknesses by the Dropping Test ASTM B 567 Measurement of Coating Thickness by the Beta Backscatter Method SAE AMS2402K Page 3 of 10 ASTM B 568 Measurement of Coating Thickness by X-Ray Spectrometr
19、y ASTM B 571 Adhesion of Metallic Coatings ASTM E 376 Measuring Coating Thickness by Magnetic-Field or Eddy-Current (Electromagnetic) Test Methods ASTM F 519 Mechanical Hydrogen Embrittlement Evaluation of Plating Processes and Service Environments 3. TECHNICAL REQUIREMENTS 3.1 Preparation 3.1.1 Par
20、ts shall be within drawing dimension limits before plating, except as specified in 3.1.1.1. 3.1.1.1 Parts having part numbers with the prefix MA, AN, MS, or AS or parts where the drawing specifies dimensions apply after plating shall be made to such dimensions that parts will be within drawing limit
21、s after plating. Undercutting before plating shall not be permitted unless specifically authorized by specifications referenced or the applicable drawing. 3.1.2 Stress Relief Treatment All steel parts having a hardness of 36 HRC and above (and less than 45 HRC) and that are machined, ground, cold fo
22、rmed or cold straightened after heat treatment shall be cleaned to remove surface contamination and thermally stress relieved before plating for relief of residual tensile stresses. (Residual tensile stresses have been found to be damaging during electrofinishing.) Temperatures to which parts are he
23、ated shall be such that maximum stress relief is obtained while still maintaining hardness of parts within drawing limits. Unless otherwise specified, the following treatment temperatures and times shall be used: 3.1.2.1 For parts, excluding nitrided parts, having a hardness of 55 HRC and above, inc
24、luding carburized and induction hardened parts, stress relieve at 275 F 25 (135 C 14) for 5 to 10 hours. 3.1.2.2 For parts having a hardness less than 55 HRC, stress relieve at 375 F 25 (191 C 14) for a minimum of 4 hours. Nitrided parts fall into this category. Higher temperatures shall be used onl
25、y when specified or approved by the cognizant engineering organization. 3.1.2.3 For peened parts: If stress relief temperatures above 375 F (191 C) are elected, the stress relieve shall be performed prior to peening or the cognizant engineering organization shall be consulted and shall approve the s
26、tress relief temperature. 3.1.3 The plating shall be applied over a surface free from water breaks. The cleaning procedure shall not produce pitting or intergranular attack of the basis metal and shall preserve dimensional requirements. 3.1.4 Except for barrel plating, electrical contact points shal
27、l be as follows. For parts that are to be plated all over, location shall be acceptable to purchaser. For parts that are not to be plated all over, location shall be in areas on which plating is optional. 3.1.5 Aluminum alloys shall be zincate treated prior to plating in accordance with ASTM B 253 o
28、r other method permitted by the cognizant engineering organization. 3.2 Procedure 3.2.1 Except as noted, the zinc shall be deposited directly on the metal surface from a suitable zinc plating solution. 3.2.1.1 Nickel or cobalt alloys and corrosion resistant steels may be given a nickel or other suit
29、able metal strike prior to zinc plating. SAE AMS2402K Page 4 of 10 3.2.2 After rinsing in water and without allowing the parts to dry, unless otherwise specified, plated parts shall be chemically treated by a process that has been demonstrated to prevent the formation of white corrosion products. If
30、 trivalent chromium treatment is elected, it may be applied prior to hydrogen embrittlement thermal treatment (See 3.3) without subsequent reactivation retreatment, provided it has demonstrated acceptable corrosion resistance (See 3.4.3). When plated parts specifying a traditional type of supplement
31、ary treatment, such as hexavalent chromate, require post thermal treatment as in 3.3, surface reactivation and supplementary treatment shall follow hydrogen embrittlement relief. 3.2.3 Spotting-in and double plating are prohibited. 3.2.4 The use of metallic brighteners is prohibited. Organic brighte
32、ners may be used to the extent necessary to produce acceptable corrosion and appearance characteristics while at the same time minimizing embrittlement tendencies. 3.3 Hydrogen Embrittlement Relief Treatment of steel parts shall be in accordance with AMS2759/9. 3.4 Properties 3.4.1 Thickness shall b
33、e as specified on the drawing, determined in accordance with any of the following methods as applicable: ASTM B 487, ASTM B 499, ASTM B 504, ASTM B 567, ASTM B 568, or ASTM E 376, the drop test of ASTM B 555, or other method permitted by the cognizant engineering organization. When thickness is dete
34、rmined by the drop test method, plating shall not be perforated in less time than specified in Table 1D. 3.4.1.1 Plate thickness may be specified by AMS2402 and a suffix number normally designating the minimum thickness in ten-thousandths of an inch (m); except as indicated in Table 1, the maximum p
35、late thickness shall be 0.0002 inch (5 m) greater than the minimum. Thus AMS2402-2 designates a thickness of 0.0002 to 0.0004 inch (5 to 10 m) and AMS2402-6 designates a thickness of 0.0006 to 0.0008 inch (15 to 20 m). 3.4.1.1.1 Plate thickness, when specified by AMS2402 and a suffix number, shall b
36、e as specified in Table 1 for the specified suffix number and type of part or surface. 3.4.1.2 Where “zinc strike” is specified, plate thickness shall be approximately 0.0001 inch (2.5 m). SAE AMS2402K Page 5 of 10 TABLE 1A - PLATE THICKNESS, SALT SPRAY CORROSION RESISTANCE, AND PERFORATION TIME REQ
37、UIREMENTS, INCH/POUND UNITS AMS2402 Thickness Designation Specified External Threads Thickness Inch External Threads Salt Spray Resistance hours, min External Threads Perforation Time seconds, min Nuts, Washers, such parts shall withstand salt spray for not less than 250 hours and plating shall not
38、be perforated in less than 10X seconds in thickness determinations by drop test. NOTE 2: Perforation times specified above are for the drop test solution of 3.4.1 at 70 F; equivalent perforation times at other temperatures are as shown in Table 2B. TABLE 1B - EQUIVALENT PERFORATION TIME Perforation
39、Time Seconds at 70 F Seconds at Temperature Shown 75 F Seconds at Temperature Shown 80 F 10 10 10 20 20 19 30 30 29 41 39 37 51 49 47 SAE AMS2402K Page 6 of 10 TABLE 1C - PLATE THICKNESS, SALT SPRAY CORROSION RESISTANCE, AND PERFORATION TIME REQUIREMENTS, SI UNITS AMS2402 Thickness Designation Speci
40、fied External Threads Thickness m External Threads Salt Spray Resistance hours, min External Threads Perforation Time seconds, min Nuts, Washers, such parts shall withstand salt spray for not less than 250 hours and plating shall not be perforated in less than 10X seconds in thickness determinations
41、 by drop test. NOTE 2: Perforation times specified above are for the drop test solution of 3.4.1 at 70 F (21 C); equivalent perforation times at other temperatures are as shown in Table 1D. TABLE 1D - EQUIVALENT PERFORATION TIME Perforation Time, Seconds at 21 C Seconds at Temperature Shown 24 C Sec
42、onds at Temperature Shown 16 C 10 10 10 20 20 19 30 30 29 41 39 37 51 49 47 3.4.1.3 The plate shall be substantially uniform in thickness on significant surfaces except that slight build-up on exterior corners or edges will be permitted provided finished drawing dimensions are met. 3.4.1.4 All surfa
43、ces of the part, except those that cannot be touched by a sphere 0.75 inch (19 mm) in diameter, shall be plated to the specified thickness. Unless otherwise specified in Table 1 or on the drawing, surfaces such as holes, recesses, threads and other areas where a controlled deposit cannot be obtained
44、 under normal plating conditions, may be under the specified limit provided they show visual plating coverage. 3.4.2 Adhesion Plating shall be firmly adhered to the basis metal and shall be tested using one of the following methods: 3.4.2.1 The plating shall be scraped through to the basis metal wit
45、h a sharp knife or awl to expose the basis metal and examined at approximately 5X magnification for evidence of flaking off or separation. 3.4.2.2 The basis metal shall be plastically bent or deformed as required to cause it to crack and examined at approximately 5X magnification for evidence of fla
46、king or separation of the plating. SAE AMS2402K Page 7 of 10 3.4.2.3 Test adhesion using the burnishing test, draw test, or heat quench test of ASTM B 571. 3.4.2.4 Adhesion testing is not required for parts that are post treated by heating to at least 375 F (191 C), quenched, and examined for bliste
47、rs or other signs of lack of adhesion. 3.4.3 Corrosion Resistance Except as specified in 3.4.3.1, plated carbon and alloy steel parts or test panels (4.3.3.2) plated 0.0001 to 0.0003 inch (3 to 8 m) thick and that have received a supplementary chemical treatment as in 3.2.2 shall show no visual evid
48、ence of reddish corrosion product of the basis metal or whitish corrosion product of the plate after being subjected to 96 hours of continuous salt fog exposure in accordance with ASTM B 117. Intentionally unplated areas may be masked during testing. The cognizant engineering organization may specif
49、y an alternative plate thickness and/or salt fog exposure time. See Table 1. 3.4.3.1 Salt spray corrosion tests shall not apply to plated parts made of austenitic corrosion-resistant steels, to parts made of any corrosion-resistant steel or alloy when not plated all over, and to parts made of any steel when thickness is specified as “flash”. 3.4.4 Hydrogen Embrittlement The plating process
