1、METRIC MIL-STD-870C(USAF) w/CHANGE 1 27 April 2009 SUPERSEDING MIL-STD-870C 01 March 2007 DEPARTMENT OF DEFENSE STANDARD PRACTICE CADMIUM PLATING, LOW EMBRITTLEMENT, ELECTRODEPOSITION This document is inactive for new design. AMSC: N/A AREA: MFFP Provided by IHSNot for ResaleNo reproduction or netwo
2、rking permitted without license from IHS-,-,-MIL-STD-870C w/CHANGE 1 FOREWORD 1. This military standard is approved for use by 309MXSG/MXR, Department of the Air Force and is available for use by all departments and agencies of the Department of Defense. 2. This standard provides guidance for the Ai
3、r Force repair process, acquisition, and manufacture of parts and/or spare parts on the landing gear of all military aircraft. 3. Beneficial comments, recommendations, additions, deletions, clarifications, etc. and any data that may improve this document should be sent to 309MXSG/MXRL, Hill AFB, UT
4、84056-2609 or e-mailed to: 309MXSG/MXRLfo!)hill.af.mil. Since contact information can change, verification of currency of this address information through ASSIST Online database at http:/assist.daps.dla.mil. II Provided by IHSNot for ResaleNo reproduction or networking permitted without license from
5、 IHS-,-,-MIL-STD-870C w/CHANGE 1 CONTENTS PARAGRAPHS FOREWORD 1. SCOPE 1.1 Scope 1.2 Documentation 1.3 Classification 1.3.1 Classes 2. APPLICABLE DOCUMENTS 2.1 2.2 2.2.1 2.2.2 2.3 2.4 3. 3.1 3.2 4. 4.1“ 4.2 4.2.1 4.2.2 4.3 4.4 4.5 4.6 5. 5.1 5.2 5.2.1 5.2.2 5.2.3 5.2.4 5.2.5 5.2.6 General Government
6、 documents Soecifications. standards, handbooks, and commercial item descriptions Other Government documents Non-Government publications Order of precedence DEFINITIONS High strength steel Material batch GENERAL REQUIREMENTS General Materials and Eauipment Materials Eauipment Specification SAE-AMS-Q
7、Q-P-416 Embrittlement Finish Reprocessing DETAILED REQUIREMENTS General Prior to platina Baking Platina seguence Storage of parts Handling of parts Masking Racking PAGE in Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-STD-870C w/CHANGE 1 CONTEN
8、TS PARAGRAPHS 5.3 5.3.1 5.3.2 5.3.3 5.3.4 5.3.5 5.3.6 5.3.7 5.4 5.4.1 5.4.2 5.4.3 5.5 5.6 5.7 5.8 5.9 5.9.1 5.9.2 5.10 6. 6.1 6.2 6.3 Platinq procedures Step Number 1 Step Number 2 Step Number 3 Step Number 4 Step Number 5 Step Number 6 Step Number 7 Post plating treatment Types of platina Type II T
9、ype III Inspection Process control Qualification embrittlement test Re-qualification Process control embrittlement acceptance test Method I. Hvdroaen detection instrument testing Method II. Notched tensile tests Safetv and health NOTES Intended use Subject term (kev word) listing Changes notations C
10、ONCLUDING MATERIAL PAGE 5 5 5 5 5 5 6 6 6 6 6 6 6 6 6 7 7 7 8 8 8 8 8 9 9 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-STD-870C w/CHANGE 1 SUMMARY OF CHANGE 1 MODIFICATIONS Delete the following reference document from paragraph 2.3, ASTM E 8,
11、Metallic Materials, Tension Testing of. There is no longer a need for this test method; no superseding document will be identified. The following detail requirement of MIL-STD-870C has been revised, paragraph 5.3.2, Step Number 2: New Requirement: All parts shall be cleaned by dry blasting using 80
12、- 320 grit aluminum oxide (Al203), silicon dioxide (Si02) or garnet per MIL-STD-1504. Elapsed time between completion of cleaning and Step Number 3 shall not exceed four (4) hours. Old Requirement: All parts shall be cleaned by dry blasting using 80 - 320 grit aluminum oxide (Al203), silicon dioxide
13、 (Si02) or garnet per MIL-STD-1504. Elapsed time between completion of cleaning and Step Number 3 shall not exceed 60 minutes. Deleted “Embrittlement“ from section 6.2 “Subject terms (key words) listing, no replacement added. v Provided by IHSNot for ResaleNo reproduction or networking permitted wit
14、hout license from IHS-,-,-MIL-STD-870C w/CHANGE 1 1. SCOPE 1.1 Scope. This standard covers the process and materials required for the electro-deposition of cadmium on high strength steel substrates. Subsequent heat treating techniques needed to insure low embrittlement of steel are also described. T
15、his process is not authorized for use on steel heat treated above 1.65 X 109 PASCALS (Pa) (240,000 pounds per square inch psi) without the approval of the applicable procuring activity. 1.2 Documentation. This standard meets the corrosion resistance requirements of SAE-AMS-QG-P-416. It may be used w
16、henever SAE-AMS-QQ-P-416 is specified provided any unique requirements in SAE-AMS-QQ-P-416 are compiled with. 1.3 Classification. 1.3.1 Classes. Cadmium plating covered by this standard identifies the following classes: a. Class 1 0.013mm (0.0005 inch) thick minimum b. Class 2 0.008mm (0.0003 inch)
17、thick minimum c. Class 3 0.005mm (0.0002 inch) thick minimum 2. APPLICABLE DOCUMENTS 2.1 General. The documents listed in this section are specified in sections 4 and 5 of this standard. This section does not include documents cited in other sections of this standard or recommended for additional in
18、formation or as examples. While every effort has been made to ensure the completeness of this list, document users are cautioned that they must meet all specified requirements or documents cited in sections 4 and 5 of this standard, whether or not they are listed. 2.2 Government documents. 2.2.1 Spe
19、cifications, standards, handbooks, and commercial item descriptions. The following specifications, standards, handbooks, and commercial item descriptions form a part of this document to the extent specified herein. Unless otherwise specified, the issues of these documents are those cited in the soli
20、citation or contract. DEPARTMENT OF DEFENSE SPECIFICATIONS MIL-S-5002 Surface Treatments and Inorganic Coatings for Metal Surfaces of Weapon System 1 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-STD-870C w/CHANGE 1 DEPARTMENT OF DEFENSE STANDA
21、RDS MIL-STD-871 Electro-chemical Stripping of Inorganic Finishes (Inactive) MIL-STD-1504 Abrasive Blasting of Aircraft Components (Inactive) COMMERCIAL ITEM DESCRIPTIONS A-A-50800 Cadmium Oxide A-A-51126 Anodes, Cadmium (Copies of these documents are available from the Standardization Document Order
22、 Desk, 700 Robbins Avenue, Building 4D, Philadelphia, PA 19111 -5094 or http:/assist.daps.dla.mil/online/start/.) 2.2.2 Other Government documents, drawings, and publications. The following other Government documents, drawings, and publications form a part of this document to the extent specified he
23、rein. Unless otherwise specified, the issues of these documents are those cited in the solicitation or contract. CODE OF FEDERAL REGULATIONS (CFR) 29 CFR 1910 Toxic and Hazardous Substances (Copies of this document are available online at www.access.gpo.gov/nara/cfr or from the Superintendent of Doc
24、uments, U.S. Printing Office, North Capitol however, supersedes applicable law and regulations unless a specific exemption has been obtained. 3. DEFINITIONS 3.1 High strength steel. For the purpose of this standard, high strength steel is defined as steel heat treated to 1.24 X 109Pa (1.26 X 102kgf/
25、mm) (1.8X105psi) and above. 3.2 Material batch. All items processed at one time through the plating bath. 4. GENERAL REQUIREMENTS 4.1 General. This section covers the materials and equipment required to accomplish the described process. 4.2 Materials and Eauipment. 4.2.1 Materials. The use of reclai
26、med materials shall be encouraged to the maximum extent possible. Materials used in cadmium plating are as follows: a. Sodium Hydroxide, flake or granulated. b. Sodium Cyanide, plating grade (96 - 98%NaCN). c. Cadmium Ball Anodes (A-A-51126) d. Cadmium Oxide (A-A-50800). 4.2.2 Eouipment. Equipment u
27、sed in cadmium plating is as follows: a. Either generated or rectified D.C. current may be used. Ripple value shall not exceed 10 percent as measured by dividing the Root Mean Square of the A.C. voltage component by the D.C. voltage. b. Tanks shall be resistant to the operating temperature and the c
28、hemical environment. Tanks, in which any electrolytic action is taking place, must be free of shorts. c. Processing tanks to be operated at temperatures other than room temperature shall be equipped with automatic temperature indicating and regulating devices. d. An ammeter shall be placed in series
29、 with the cadmium tank cathode. The ammeter shall have sufficient shunts and switches to provide a full-scale reading equal to the maximum capacity of the power source, and an accuracy of 10 percent of the current being measured. 3 Provided by IHSNot for ResaleNo reproduction or networking permitted
30、 without license from IHS-,-,-MIL-STD-870C w/CHANGE 1 e. A blast cabinet shall be located near the plating line. The size of the cabinet shall be adequate to enclose the parts to be plated. Air lines shall be suitably trapped and filtered to prevent in-process contamination of the parts to be cleane
31、d. f. An oven capable of baking parts at 190.5 13.9C (375 25F) shall be located near the plating line. The size of the oven shall be adequate to enclose parts to be plated. The oven shall be equipped with temperature indication, recording, and regulating devices. 4.3 Specification SAE-AMS-QQ-P-416.
32、The requirements of SAE-AMS-QQ-P-416 shall be compiled with on all parts, in conjunction with those specified in this standard. If there is a conflict between the two documents; however, the requirements of this standard shall be govern. 4.4 Embrittlement. Qualification test specimens and process co
33、ntrol test specimens shall be subjected to a sustained load test at 75 percent of the ultimate notched tensile strength. The specimens shall endure this sustained load for 200 hours minimum without failing or cracking. 4.5 Finish. The plated part will have a finish that is smooth, continuous, homoge
34、neous, adherent, and free from pits, blisters, nodules, and any other indications of harmful defects. The appearance of a properly applied plate may very from a dull grey to a frosty white. A bright, dense deposit indicates malfunction of the process, which may produce embrittled parts (See: MIL-S-5
35、002). 4.6 Re-processing. Parts rejected for defective plating, requiring stripping and re-plating, shall include all of the pre-plating steps of this standard. Parts shall be stripped in accordance with MIL-STD-871. 5. DETAILED REQUIREMENTS 5.1 General. This section provides the detailed requirement
36、s required to accomplish the plating process identified in this standard. 5.2 Prior to plating. Prior to plating, all machining, forming, welding, and shot peening shall be completed. 5.2.1 Baking. Parts shall be baked for stress relief before plating for four (4) hours minimum at 190.5 13.9C (375 2
37、5F) provided the part is baked for 23 hours minimum after completion of the cadmium plating. 5.2.2 Platina seguence. If chromium and cadmium are used in combination, the chromium shall be deposited first. When chrome plating is to be followed by cadmium plating, the 23 hours minimum bake period can
38、be replaced by a four (4) hour bake period at 190.5 13.9C (375 25F) provided the part is baked for 23 hours minimum after completion of the cadmium plating. 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-STD-870C w/CHANGE 1 5.2.3 Storage of pa
39、rts. Storage of parts between stress relief and cleaning shall be controlled to prevent contact with water or other corrosive materials. Parts shall be stored to permit free circulation of air around the parts. 5.2.4 Handling of parts. After the parts have been cleaned, they shall be handled in such
40、 a manner (white gloves, etc.) that will ensure a minimum of contamination. 5.2.5 Masking. Sections or areas of a part that are not to be plated shall be masked off. Plugging and masking materials, which do not contaminate the plating bath, shall be used. Masking shall be performed at the most conve
41、nient step prior to plating. 5.2.6 Racking. Sufficient contact area and pressure shall be provided to carry the current without overheating. Racking should be performed at the most convenient step prior to plating. 5.3 Plating procedures. The cadmium plating procedure shall be as described below: 5.
42、3.1 Step Number 1. Parts shall be degreased as necessary. No minimum elapsed time requirement shall apply between this operation and the cleaning operation of Step Number 2. 5.3.2 Step Number 2. All parts shall be cleaned by dry blasting using 80 - 320 grit aluminum oxide (Al203), silicon dioxide (S
43、i02) or garnet per MIL-STD-1504. Elapsed time between completion of cleaning and Step Number 3 shall not exceed four (4) hours. 5.3.3 Step Number 3. Rinse parts in cold water. A cyanide holding tank can be used to hold parts if the plating tank is full. 5.3.4 Step Number 4. Cadmium plate at 5.4 to 7
44、.5 amperes/sq decimeters (50 - 70 amperes/sq foot) in the following solution: Cadmium metal 21 - 30 g/l (2.8 - 4.0 oz/gal) Total cyanide 90-135 g/l (12-18 oz/gal) Sodium hydroxide 11.2 - 30 g/l (1.5-4 oz/gal) Sodium carbonate 0-60 g/l (0-8 oz/gal) Ratio NaCN/Cd 4/1 to 6/1 Temperature 15.5-26.6C (60-
45、80F) Total permissible iron 700 parts/million 5.3.5 Step Number 5. Rinse parts in cold water. 5 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-STD-870C w/CHANGE 1 5.3.6 Step Number 6. Rinse parts in hot water and blow dry with compressed air. El
46、apsed time between completion of plating and start of baking, Step Number 7, shall not exceed four (4) hours. 5.3.7 Step Number 7. Bake all parts heat treated above 1.24 X 109Pa (180,000 psi) for 23 hours minimum, at 190.5 13.9C (375 25F). NOTE: Refer to paragraphs 5.4.1, 5.4.2, and 5.4.3 if post pl
47、ating treatment is required. If post plating treatment is not required, refer paragraph 5.5. 5.4 Post plating treatment. 5.4.1 Types of Plating. Refer to applicable directives for type of plating. If the type of plating is not specified, the part shall be given the Type II treatment. Type I No post
48、plating treatment required (See: paragraph 5.5) Type II (See: paragraph 5.4.2) Type III (See paragraph 5.4.3) 5.4.2 Type II. a. Immerse in the Type II chromating solution (Iridite No. 8P or equivalent) for 15 to 30 seconds. b. Rinse thoroughly in clean water. An additional rinse in warm water (60C 140F maximum) may be used to facilitate drying. c. See paragraph 5.5 5.4.3 Type III. a. Immerse parts in Type III (reference SAE-AMS-QQ-P-416) phosphate solution for 15 to 20 seconds. b. Rinse thoroughly in clean water. An additional rinse in warm water (60C 140F maximum) may be used to facilitate d
