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 theref
2、rom, 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 2008 SAE International All rights reserved. No part of this publication ma
3、y 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 AMS 2485K AEROSPACE MATERIAL SPECIFICATION Issued 1948-05 Revised 2008-01 Superseding AMS 2485J Coating, Black Oxide RATIONALE AMS 2485K results from a Five Year Review and update of this specification. 1. SCOPE 1.1 P
5、urpose This specification covers the requirements for black oxide coatings on parts. 1.2 Application This coating has been used typically to improve the anti-chafing and anti-friction properties of carbon and low-alloy steel parts, particularly for sliding or bearing surfaces, by providing a finish
6、coating that retains an oil film, but usage is not limited to such applications. 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 th
7、e hazards which may be involved in such use. It is 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 iss
8、ue 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 specific document issue is specified. When the referenced document has been cancelled and
9、 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: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org. AS2390 C
10、hemical Process Test Specimen Material Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE AMS 2485K - 2 - 2.2 ASTM Publications Available from ASTM International, 100 Barr Harbor Drive, P.O. Box C70
11、0, West Conshohocken, PA 19428-2959, Tel: 610-832-9585, www.astm.org. ASTM G 46 Examination and Evaluation of Pitting Corrosion 3. TECHNICAL REQUIREMENTS 3.1 Preparation 3.1.1 The coating shall be applied to part surfaces free from water-breaks. The cleaning procedure shall not produce pitting or in
12、tergranular attack of the basis metal and shall preserve dimensional requirements 3.1.2 Unless otherwise specified, steel parts 36 HRC or higher and which have been ground or cold worked after heat treatment shall be stress relieved. Temperatures to which parts are heated shall be such that maximum
13、stress relief is obtained without reducing the hardness of the parts below engineering drawing limits, but unless otherwise specified, not less than 275 F (135 C) for not less than four hours for parts with a hardness of 55 HRC or over, or not less than 375 F (191 C) for not less than four hours for
14、 all other parts. Black oxide is commonly used on steel parts carburized, carbonitrided or induction hardened. These surface or case hardened parts shall be stress relieved at a temperature of 275 F (135 C) or as specified by the cognizant engineering activity. 3.2 Procedure 3.2.1 The cleaned parts,
15、 while still wet, shall be immersed in one or more boiling aqueous alkali oxidizing baths for times and at temperatures which will produce coatings meeting the requirements of 3.3 and 3.4. See 8.3. 3.2.2 Coated parts shall be washed thoroughly in running tap water to remove all traces of processing
16、solution and salts. Parts shall not be allowed to dry during the entire sequence of operations until completion of this rinse. 3.2.3 Parts shall be thoroughly dried unless a water-displacing oil is used in 3.2.4, in which case complete drying may be omitted. 3.2.4 Parts shall be dipped in a suitable
17、 corrosion-preventative oil. 3.3 Properties Coated parts shall conform to the following requirements: 3.3.1 Smut Test Coatings on parts before oiling as in 3.2.4, or on oiled parts after degreasing, shall show no indications of reddish-brown or green smut when wiped with a clean, white cloth. 3.3.2
18、Dimensional Change When determined using a micrometer accurate to 0.0001 inch (2.5 mm), no dimensional change shall result from processing. Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE AMS 248
19、5K - 3 - 3.3.3 Oxalic Acid Spot Test The coating, prior to application of corrosion preventative oil, shall be tested as follows. Clean, dry coated parts or specimens of the same composition and heat treat condition as the parts and processed with the parts represented shall be handled with clean gl
20、oves. Each sample shall have deposited three drops of a 5% (approximately) solution of oxalic acid on a flat surface. Permit the accompanying reaction to continue for not less than eight minutes, followed by rinsing in cool water and drying. When examined, the area which was directly under the acid
21、test solution drops shall exhibit a black or dark brown center with a light border. Areas under the drop, which exhibit a gray center and lighter border are marginal coatings and are not acceptable. 3.3.4 Surface and Intergranular Attack The cleaning and coating process shall not result in any surfa
22、ce pitting, as determined by ASTM G 46 and intergranular attack, determined on metallographically-prepared cross-sections examined unetched at 400X to 500X magnification. 3.4 Quality Except as otherwise specified herein, the coating on polished surfaces shall be a uniformly lustrous black. Coating o
23、n other surfaces shall be black or dark gray in color, uniform on areas of equivalent surface roughness. Coating on all types of surfaces shall be free of spots of red oxide or an overall reddish-brown color but an overall reddish-brown cast on a basically black color is permissible. Coating shall b
24、e continuous, smooth, dense, and adherent and shall not rub off under any conditions incident to normal handling or storage. 4. QUALITY ASSURANCE PROVISIONS 4.1 Responsibility for Inspection The processor of coated parts shall supply all samples for processors tests and shall be responsible for the
25、performance of all required tests. Parts if required for tests shall be supplied by purchaser. Purchaser reserves the right to sample and to perform any confirmatory testing deemed necessary to ensure that processing conforms to specified requirements. 4.2 Classification of Tests 4.2.1 Acceptance Te
26、sts Smut test (3.3.1), oxalic acid spot test (3.3.3), and quality (3.4) are acceptance tests and shall be performed on parts, or samples representing parts when permitted by cognizant engineering organization, from each lot. 4.2.2 Periodic Tests Surface and intergranular attack (3.3.4) when parts 36
27、 HRC or higher are processed are periodic tests and shall be performed monthly unless frequency of testing is specified by the cognizant engineering organization. Tests of cleaning and coating baths are periodic tests and shall be performed at a frequency established by the processor unless frequenc
28、y of testing is specified by the cognizant engineering organization. See 4.4.3 and 8.2. 4.2.3 All property verification tests (section 3.3) are preproduction tests and shall be performed prior to production or on the initial shipment of coated parts to a purchaser, and when the cognizant engineering
29、 organization requires confirmatory testing. 4.3 Sampling and testing shall be not less than the following; a lot shall be all parts made of the same material, heat treated to the same hardness or tensile strength level, processed in the same solution(s) in not longer than eight consecutive hours, a
30、nd presented for processors inspection at one time. Parts for tests shall be selected randomly from all parts in the lot. 4.3.1 Acceptance tests shall be as shown in Table 1. Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted witho
31、ut license from IHS-,-,-SAE AMS 2485K - 4 - TABLE 1 - SAMPLING FOR ACCEPTANCE TESTS Lot Size Quality Smut Test Oxalic Acid Spot Test Up to 7 All All or 3* 1 7 to 15 7 4 1 16 to 40 10 4 1 41 to 110 15 5 2 111 to 300 25 6 3 301 to 500 35 7 4 Over 500 50 8 5 *Whichever is less 4.3.1.1 Periodic Tests Sa
32、mple quantity shall be selected at the discretion of the processor unless otherwise specified by the cognizant engineering organization. As a minimum, one sample shall be tested for all periodic tests. 4.3.2 When coated parts are of such configuration or size as to not be readily adaptable to specif
33、ied tests or when nondestructive testing is not practical on actual parts, or when it is not economically acceptable to perform destructive tests on actual parts, separate specimens of the same class of alloy and heat treat condition as the parts represented, cleaned and coated with the parts repres
34、ents may be used. 4.4 Approval 4.4.1 The process and control factors, a preproduction part, or both, whichever is specified, shall be approved by the cognizant engineering organization before production parts are supplied. 4.4.2 If the processor makes a significant change to any material, process or
35、 control factor from that which was used for process approval, all preproduction tests shall be performed and the results submitted to the cognizant engineering organization for process reapproval unless the change is approved by the cognizant engineering organization. A significant change is one wh
36、ich in the judgment of the cognizant engineering organization could affect the properties or performance of the parts. 4.4.3 Controls factors shall include, but not be limited to the following: Cleaning method Material designation and supplier Corrosion preventive oil used Periodic test plan for cle
37、aning and processing solutions. See 8.2. 4.5 Reports The processor of coated parts shall furnish with each shipment a report stating that the parts have been processed and tested in accordance with the specified requirements and that they conform to the acceptance test requirements. This report shal
38、l include the purchase order number, lot number, AMS 2485K, part number, and quantity. 4.6 Resampling and Retesting 4.6.1 If any acceptance test fails to meet specified test requirements, the parts in that lot may be stripped, recoated and retested. Alternatively, all parts in the lot may be inspect
39、ed for the nonconforming attribute, and the nonconforming parts may be stripped, recoated, and retested. 4.6.1.1 When stripping is performed, the method shall be acceptable to the cognizant engineering organization and shall not roughen, pit, or embrittle the basis metal or adversely affect part dim
40、ensions. When parts have been stripped and recoated, the purchaser shall be informed. Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE AMS 2485K - 5 - 4.6.2 If any periodic test fails to meet spec
41、ified test requirements, the process is nonconforming. No additional parts shall be coated until the process is corrected and new specimens are coated and tested. Results of all tests shall be recorded and, when requested, reported. Purchaser shall be notified of all parts coated since the last acce
42、ptable periodic test. 5. PREPARATION FOR DELIVERY 5.1 Coated parts shall be handled and packaged to ensure that the required properties of the coating are preserved. 5.2 Packages of coated parts shall be prepared for shipment in accordance with commercial practice and in compliance with applicable r
43、ules and regulations pertaining to the handling, packaging, and transportation of the parts to ensure carrier acceptance and safe delivery. 6. ACKNOWLEDGMENT Processor shall mention AMS 2485K in all quotations and when acknowledging purchase orders. 7. REJECTIONS Coated parts on which the coating do
44、es not conform to this specification, or to modifications authorized by purchaser, will be subject to rejection. 8. NOTES 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 previ
45、ous issue of a specification. An (R) symbol to the left of the document title indicates a complete revision of the specification. Change bars and (R) are not used in original publications, nor in specifications that contain editorial changes only. 8.2 ARP4992, Periodic Test Plan for Process Solution
46、s, is recommended to satisfy requirements for control of processing solutions. 8.3 No specific composition is given for the black oxide processing bath. The intensity of the black color is dependent on the time of immersion, the temperature of the bath, and the concentrations of the bath ingredients
47、. Typical black oxide baths consist of sodium hydroxide with additions of oxidizers and inhibitors, the composition being adjusted to maintain a selected boiling temperature in the range of 250 to 310 F (121 to 154 C). Immersion times range from 5 to 60 minutes. Composition is generally adjusted to
48、maintain the selected boiling temperature. In some cases, a two tank treatment is used, each with different processing conditions, but each essentially as described above. 8.4 The appearance of the coating is affected by the composition, condition, and surface finish of the basis material. 8.5 Preca
49、ution Assemblies containing parts made of metals other than steel or iron alloys should not be processed unless surfaces of such parts are masked or unless solutions contain agents which prevent deterioration of the solution(s) and allowance is made, where necessary, for removal of attacked areas. 8.5.1 By its nature, black oxide is an aggressive chemical process. Stress corrosion cracking can occur on parts with high residual tensile surface stre
