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 2011 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/AMS2700E AEROSPACE MATERIAL SPECIFICATION AMS2700 REV. E Issued 2000-03 Revised 2011-11 Super
5、seding AMS2700D AMS-QQ-P-35 QQ-P-35 Passivation of Corrosion Resistant Steels RATIONALE AMS2700E is issued to incorporate all changes approved by AMS Committee B by 28 day Limited Scope Ballot closed on 6/14/2011 and which were intended to be reflected in AMS2700D but some of which were inadvertentl
6、y omitted. A complete list of each of these changes is listed in 8.17. 1. SCOPE 1.1 Purpose This specification covers the requirements for a process to assure removal of free iron or other less noble contaminants from the surfaces of corrosion resistant steel parts. 1.2 Application The processes def
7、ined in this specification have been used typically to dissolve tramp metallic elements from the surfaces of corrosion resistant steels to improve their corrosion resistance, but usage is not limited to such applications. 1.3 Classification 1.3.1 Methods Passivation methods covered by this specifica
8、tion are as follows: Method 1 - Passivation in Nitric Acid Method 2 - Passivation in Citric Acid Method 1 shall be used unless Method 2 is authorized by the cognizant engineering organization. 1.3.2 Types The following types may be specified for Method 1: Type 1 Low Temperature Nitric Acid with Sodi
9、um Dichromate Type 2 Medium Temperature Nitric Acid with Sodium Dichromate Type 3 High Temperature Nitric Acid with Sodium Dichromate Type 4 40% Nitric Acid for Free Machining Steels SAE AMS2700E Page 2 of 17 Type 5 Anodic, for High Carbon Martensitic Steels Type 6 Low Temperature Nitric Acid Type 7
10、 Medium Temperature Nitric Acid Type 8 Medium Temperature, High Nitric Acid Concentration Where no type is specified, the processor may use any of the listed types that meet the requirements given herein. 1.3.3 Classes Passivation verification classes are as follows: 1.3.3.1 Class 1 The following ty
11、pes of parts shall be selected for testing in accordance with 4.3.1. 1.3.3.1.1 Fasteners, including nuts, bolts, washers, rivets and related hardware where a test frequency is not defined in the procurement documents. 1.3.3.1.2 Standard parts defined by drawings labeled AN, MS, NAS or similar where
12、frequency of test is not otherwise defined. 1.3.3.1.3 When specified by purchaser. 1.3.3.2 Class 2 Frequency of corrosion testing shall be one part per lot. 1.3.3.3 Class 3 Frequency of testing shall be on a periodic basis. 1.3.3.4 Class 4 Parts for which AMS-QQ-P-35 or QQ-P-35 is specified shall be
13、 acceptance tested in accordance with 4.3.4. 1.3.3.5 When no class is specified and neither 1.3.3.1 nor 1.3.3.4 apply, class 2 shall apply. 1.4 Safety - Hazardous Materials While the materials, methods, applications, and processes described or referenced in this specification may involve the use of
14、hazardous materials, this specification does not address the 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
15、 of all personnel involved. 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 specific document issue is spe
16、cified. When the referenced document has been cancelled and no superseding document has been specified, the last published issue of that document shall apply. SAE AMS2700E Page 3 of 17 2.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-
17、606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org. 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 Ope
18、rating Salt Spray (Fog) Testing Apparatus ASTM D 1193 Reagent Water 3. REQUIREMENTS 3.1 Procedure 3.1.1 Passivation shall be performed only on surfaces free from water breaks and visible rust or scale. See 8.8. 3.1.2 Method 1 - Passivation in Nitric Acid 3.1.2.1 Passivation shall be accomplished by
19、immersion in a bath in accordance with Table 1. When permitted by the cognizant engineering organization, other nitric acid solutions may be used. See 8.13. 3.1.2.2 When a specific passivation type is not specified, Table 4 may be consulted for recommended types. SAE AMS2700E Page 4 of 17 TABLE 1 -
20、METHOD 1 PASSIVATION TYPES Type Feature Value 1 Bath Composition 20 to 25% by volume of HNO32 to 3% by weight Na2Cr2O72H2O Bath temperature 70 to 90 F (21 to 32 C) Immersion time 30 minutes minimum 2 Bath Composition 20 to 25% by volume of HNO32 to 3% by weight Na2Cr2O72H2O Bath temperature 120 to 1
21、30 F (49 to 54 C) Immersion time 20 minutes minimum 3 Bath Composition 20 to 25% by volume of HNO32 to 3% by weight Na2Cr2O72H2O Bath temperature 145 to 155 F (63 to 68 C) Immersion time 10 minutes minimum 4 Bath Composition 38 to 42% by volume of HNO32 to 3% by weight Na2Cr2O72H2O Bath temperature
22、70 to 120 F (21 to 49 C) Immersion time 30 minutes minimum 5 Bath Composition 20 to 25% by volume of HNO32 to 3% by weight Na2Cr2O72H2O Bath temperature 70 to 90 F (21 to 32 C) Immersion time 2 minutes minimum Voltage Part anodic at 3 to 5 volts 6 Bath Composition 25 to 45% by volume HNO3Bath temper
23、ature 70 to 90 F (21 to 32 C) Immersion time 30 minutes minimum 7 Bath Composition 20 to 25% by volume HNO3Bath temperature 120 to 140 F (49 to 60 C) Immersion time 20 minutes minimum 8 Bath Composition 45 to 55% by volume HNO3Bath temperature 120 to 130 F (49 to 54 C) Immersion time 30 minutes mini
24、mum NOTE: Nitric acid concentration shown is by volume of 42 Baume (sp. gr. 1.4) nitric acid. See 8.12. 3.1.3 Method 2 - Passivation in Citric Acid 3.1.3.1 Bath Composition Parts shall be immersed in an aqueous solution of 4 to 10 weight percent citric acid, with additional wetting agents and inhibi
25、tors as applicable. 3.1.3.2 Operating Conditions 3.1.3.2.1 Temperature Bath temperature shall be 70 to 160 F (21 to 71 C) with an immersion time of not less than 4 minutes for baths operating over 140 F (60 C), not less than 10 minutes for baths operating in the 120 to 140 F (49 to 60 C) range, not
26、less than 20 minutes for baths operating in the range of 100 to 119 F (38 to 48 C) or not less than 30 minutes for baths operating below 100 F (38 C). 3.1.4 Final Rinse Immediately after removal from the passivating solution the parts shall be thoroughly rinsed. Final rinse shall be carried out in c
27、lean water. See 8.14. SAE AMS2700E Page 5 of 17 3.1.5 Post Treatment When a post treatment is specified, after rinsing, parts made from ferritic, martensitic and precipitation hardening steels shall be immersed in a solution containing 4 to 6% by weight of sodium dichromate dihydrate (Na2Cr2O72H2O)
28、at 140 to 160 F (60 to 71 C) for 1 hour, rinsed, and dried. See 8.2. 3.2 Properties 3.2.1 Corrosion Resistance Except for parts containing 0.85% carbon or more (such as AISI 440C), parts shall meet one of the following conditions, or, when specified, a test method in Appendix A. 3.2.1.1 Humidity Par
29、ts shall be free from visible red rust after exposure to 95% minimum relative humidity at 100 to 115 F (38 to 46 C) for not less than 24 hours. 3.2.1.2 Water Immersion Parts shall be free from visible red rust after alternately immersing in reagent water (ASTM D 1193 Type IV) for 1 hour and allowing
30、 to dry in room temperature air for 1 hour, until 24 hours (12 cycles) have elapsed. See 8.15. 3.2.1.3 When specified or when permitted by the cognizant engineering organization, (1) for austenitic steels of the AISI 200 or AISI 300 series and (2) for precipitation hardened steels and ferritic steel
31、s containing more than 16% chromium, one of the following requirements shall be met in lieu of humidity or immersion testing: 3.2.1.3.1 Copper Sulfate Test Parts shall be swabbed with or immersed in a test solution containing 8 grams of copper sulfate (CuSO45H2O) and 2 to 3 milliliters of sulfuric a
32、cid (H2SO4, sp. gr. 1.84) in 500 milliliters of reagent water in accordance with ASTM D 1193 Type IV, keeping the surface wet for not less than 6 minutes. Rinse and dry the surface without disturbing any deposits. A copper colored deposit indicates the presence of unacceptable free iron. The effecti
33、veness of copper sulfate solutions shall be validated by one of the following methods: a. Periodic chemical analysis in accordance with 4.2.2.1 b. Verification before use. Test specimens of any convenient size, made from materials in accordance with AS2390 representing transformation hardening steel
34、s and properly cleaned, shall exhibit a copper-colored deposit when subjected to the test above. 3.2.1.3.2 Salt Spray Parts shall withstand exposure to 2 hours minimum in a salt spray environment operated in accordance with ASTM B 117. Parts shall not show evidence of red rust following completion o
35、f the test. 3.2.2 Surface Appearance After completion of processing, there shall be no evidence of etching, pitting, smutting, frosting, dimensional changes, or other chemical attack on the parts. However, loss of temper color when Method 2 is used is acceptable. SAE AMS2700E Page 6 of 17 3.3 Writte
36、n Procedure All processing and testing shall be done in accordance with a written procedure acceptable to the cognizant engineering organization. See 4.4.3. 4. QUALITY ASSURANCE PROVISIONS 4.1 Responsibility for Inspection The processor shall supply all test specimens for processors tests and shall
37、be responsible for the performance of all required tests. When parts are to be tested, such parts shall be supplied by purchaser, and, if acceptable after testing, may be included with the lot of processed parts. The cognizant engineering organization reserves the right to perform any confirmatory t
38、esting deemed necessary to ensure that processing conforms to specified requirements. 4.2 Classification of Tests 4.2.1 Acceptance Tests 4.2.1.1 Classes 1, 2 and 4 Corrosion resistance (3.2.1) and surface appearance (3.2.2) are acceptance tests and shall be performed on each lot. 4.2.1.2 Class 3 Sur
39、face appearance (3.2.2) is an acceptance test and shall be performed on each lot. 4.2.2 Periodic Tests 4.2.2.1 Compositions of passivating and post treatment solutions are periodic tests, and shall be performed at a frequency selected by the processor unless frequency of testing is specified by the
40、cognizant engineering organization. See 8.9 4.2.2.2 Class 3 Parts Corrosion resistance is a periodic test and shall be performed at a frequency selected by the processor unless frequency of testing is specified by the cognizant engineering organization. 4.2.3 Preproduction Tests All technical requir
41、ements (3.2 and 3.3) of this specification are preproduction tests, and shall be performed prior to production and when the cognizant engineering organization deems confirmatory testing is required. 4.3 Sampling for testing shall not be less than the following: A lot shall be all parts of the same p
42、art number, processed in the same set of solutions within a 24 hour period, and presented for processors inspection at the same time. Tested parts shall be selected randomly from all parts in each lot. 4.3.1 Class 1 Parts Unless the cognizant engineering organization specifies a different sampling p
43、lan, the minimum number of samples selected for test shall be as shown in Table 2. SAE AMS2700E Page 7 of 17 TABLE 2 - NUMBER OF PARTS TO BE TESTED Number of Parts in Lot Surface Appearance Corrosion Test 1 to 6 All 2 7 to 15 7 2 16 to 40 10 3 41 to 50 15 3 51 to 110 15 5 111 to 150 25 8 151 to 500
44、35 8 501 to 700 50 13 701 to 1200 75 13 Over 1200 125 13 4.3.2 Class 2 parts or samples shall be corrosion tested at a frequency of one part per lot, and visually examined at the frequency given in Table 2. 4.3.3 Where parts are not available for test, as in the case of large parts or parts that mig
45、ht be damaged by such testing, identically processed specimens fabricated from the same alloy as the parts represented may be used. See 8.10. 4.3.4 Class 4 parts or samples shall be tested as shown in Table 3. TABLE 3 - NUMBER OF PARTS TO BE TESTED FOR CLASS 4 Number of Parts in Lot (1)Surface Appea
46、rance Corrosion Test (2)1 to 13 All All 14 to 1200 13 13 1201 to 35 000 50 13 35 001 to 500 000 80 50 (1)For Class 4, a lot shall consist of one of the following: a) Parts of similar alloy and manufacturing methods that are pretreated and passivated in one days production or within a timeframe which
47、 will ensure consistent passivation results. b) The same product of one size from one heat in one shipment. c) When the quantity of passivated parts in one days production does not warrant daily testing, the lot size shall be as agreed upon by the cognizant engineering organization and the processor
48、. (2) Identically processed specimens, made from the same alloys used to fabricate the parts, may be used for test purposes. The test specimens shall be randomly distributed throughout the lot during processing. When multiple tests are to be performed, separate samples are required for each test. 4.
49、4 Approval 4.4.1 The process and control procedures, or a preproduction processed 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 control factor which was used for process approval, all preproduction tests sha
