1、NOTE: MIL-STD-340(AT) has been redesignated as a handbook, and is to be used for guidancepurposes only. This document is no longer to be cited as a requirement. For administrativeexpediency, the only physical change from MIL-STD-340(AT) is this cover page. However, thisdocument is no longer to be ci
2、ted as a requirement. If cited as a requirement, contractors maydisregard the requirements of this document and interpret its contents only as guidance.INCH-POUNDMIL-HDBK-506(AT)10 April 1998DEPARTMENT OF DEFENSEHANDBOOKPROCESS FOR COATING, PACK CEMENTATION,CHROME ALUMINIDEAMSC N/A FSC 8030DISTRIBUT
3、ION STATEMENT A . Approved for public release; distribution is unlimited.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-STD-340(AT)iiDEPARTMENT OF DEFENSEWashington, DC 20301Coating, Pack Cementation, Chrome Aluminide, Process for1. This Militar
4、y Standard is approved for use by U.S. Army Tank-Automotive Command,Department of the Army, and is available for use by all Departments and Agencies of theDepartment of Defense.2. Beneficial comments (recommendations, additions, deletions) and any pertinent datawhich may be of use in improving this
5、document should be addressed to: U.S. Army Tank-Automotive Command, ATTN: AMSTA-GDS, Warren, MI 48397 -5000, by using the self-addressed Standardization Document Improvement Proposal (DD Form 1426) appearing at theend of this document or by letter.Provided by IHSNot for ResaleNo reproduction or netw
6、orking permitted without license from IHS-,-,-MIL-STD-340(AT)iiiF O R E W O R DThis Military Standard covers the pack cementation coating processes, chrome aluminidefor high temperature parts used in gas turbine engines for ground vehicles.Provided by IHSNot for ResaleNo reproduction or networking p
7、ermitted without license from IHS-,-,-MIL-STD-340(AT)ivC O N T E N T SPARAGRAPH PAGE1. SCOPE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1 Purpo se . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8、 . 11.2 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12. APPLICABLE DOCUMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22.1 Government documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22.
9、1.1 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22.2 Other publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22.3 Order of precedence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10、. . . . 23. DEFINITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33.1 Cementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33.2 Diffusion coating . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
11、. . . . . . . . . . . . 33.3 Aluminizing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33.4 Aluminide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33.5 Chromizing . . . . . . . . . . . . . . . . . . . . . . .
12、. . . . . . . . . . . . . . . . . . . . . . 34. GENERAL REQUIREMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44.1 Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44.1.1 Furnaces . . . . . . . . . . . . . . . . . . . . . . .
13、. . . . . . . . . . . . . . . . . . . . . . . . 44.1.1.1 Temperatures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44.1.2 Retorts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44.2 Materials . . . . . . .
14、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44.2.1 Pack materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44.2.2 Test panels. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
15、.2.2.1 Uncoated weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44.2.2.2 Coated weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45. DETAILED REQUIREMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
16、. . . 55 .1 Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55.1.1 Chromizing process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55.1.2 Fabrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
17、. . . . . . . . . . . . . . 55.1.3 Aluminizing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55.2 Test methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55.2.1 Visual . . . . . . . . . . . . . . . . . . . . . .
18、 . . . . . . . . . . . . . . . . . . . . . . . . . . . 55.2.2 Test samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55.2.2.1 Chromizing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55.2.2.2 Aluminizing . .
19、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55.2.2.3 Reduced sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55.2.2.4 Resistance welding samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
20、.2.3 Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65.2.3.1 Chromized test panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65.2.3.2 Aluminized test panel . . . . . . . . . . . . . . . . . . . . . . . . .
21、. . . . . . . . . . . . . 6Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-STD-340(AT)vC O N T E N T SPARAGRAPH PAGE6. NOTES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76.1 Intended use .
22、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76.2 Subject term (key word) listing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76.3 Supersession data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7FIGURESFIG
23、URE PAGE1. Typical accept able chromized coating 82. Typical acceptable aluminized coating 9Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-STD-340(AT)11. SCOPE1.1 Purpose . This process is one of many used by industry to provide a coating(s) ont
24、horia dispersed (TD) nickel alloys to protect them against environmental oxidation, corrosion orerosion at high temperature operation.1.2 Scope . This military standard covers the procedure for the application and inspectionof a chrome aluminide pack cementation coating on TD nickel alloys.Provided
25、by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-STD-340(AT)22. APPLICABLE DOCUMENTS2.1 Government documents .2.1.1 Specifications . Unless otherwise specified, the following specifications of the issuelisted in that issue of the Department of Defense Inde
26、x of Specifications and Standards (DoDISS)specified in the solicitation form a part of this standard to the extent specified herein.SPECIFICATIONSDEPARTMENT OF DEFENSEMIL-H-6875 - Heat Treatment of Steel, Process for.(Copies of specifications required by contractors in connection with specific acqui
27、sitionfunctions should be obtained from the contracting activity or as directed by the contractingofficer.)2.2 Other publications . The following document(s) form a part of this standard to theextent specified herein. Unless otherwise specified, the issues of the documents which are DoDadopted are t
28、hose listed in the issue of the DoDISS specified in the solicitation. The issues ofdocuments which have not been adopted shall be those in effect on the date of the cited DoDISS.SOCIETY OF AUTOMOTIVE ENGINEERS, INC. (SAE)AMS 58 65 - Nickel Sheet and Strip, Corrosion and Heat ResistantThoria Dispersi
29、on Strengthened, 2.2THO 2 .(Application for copies should be addressed to the Society for Automotive Engineers,Inc., 400 Commonwealth Avenue, Warrendale, PA 15096.)(Nongovernment standards are generally available for reference from libraries. They arealso distributed among nongovernment standards bo
30、dies and using Federal agencies.)2.3 Order of precedence . In the event of a conflict between the text of this standard andthe references cited herein, the text of this standard and the references cited herein, the text of thisstandard shall take precedence.Provided by IHSNot for ResaleNo reproducti
31、on or networking permitted without license from IHS-,-,-MIL-STD-340(AT)33. DEFINITIONS3.1 Cementation . The introduction of one or more elements into the outer portion of ametal object by means of diffusion at high temperature.3.2 Diffusion coating . An alloy coating produced at high temperature by
32、the inwarddiffusion of the coating material into the base material.3.3 Aluminizing . A surface treatment at elevated temperature, generally carried out inpack, hot dipping or hot spraying, in which a protective surface alloy is formed by the inwarddiffusion of aluminum or aluminum alloy into the bas
33、e metal.3.4 Aluminide . Aluminide is the protective surface alloy formed as a result of aluminizingtreatment.3.5 Chromizing . A surface treatment at elevated temperature, generally carried out inpack, vapor or salt bath, in which a protective surface alloy is formed by the inward diffusion ofchromiu
34、m into the base metal.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-STD-340(AT)44. GENERAL REQUIREMENTS4.1 Equipment .4.1.1 Furnaces . Furnaces shall be of sufficient size and equipped with temperature andatmosphere controllers to perform its i
35、ntended function. In addition, furnaces shall meet theuniform temperature control requirements specified in MIL-H-6875.4.1.1.1 Temperatures . Temperatures of the diffusion furnace shall be maintained duringthe diffusion coating processes at up to 2350 + 25 degrees Fahrenheit ( F) 1288 + 14 degreesCe
36、lsius ( C) for chromizing process and up to 1850 + 25 F (1010 + 14 C) for aluminizingprocess.4.1.2 Retorts . Retorts shall be of sufficient size and shape to the parts to be coated,required number of test panels, and sufficient pack material to produce the desired coating.4.2 Materials .4.2.1 Pack m
37、aterials . Pack materials shall be chromalloy R-17 material for thechromizing process and chromalloy R-1700 material for the aluminizing process in accordancewith Chromalloy Research and Technology Division, Orangeburg, NY 10962, or equivalent.4.2.2 Test panels . Test panels shall be 0.75 x 4.0 inch
38、es (in.) 19.0 x 101.6 millimeter(mm) TD nickel metal panels in accordance with AMS 5865. Each panel shall be weighed to thenearest 0.1 milligram (mg) and shall be permanently marked with a serial number. Marking shallbe made in a manner that will be legible through the coating. Test panels shall be
39、identified bytheir thickness as follows:ThicknessIdentification in. mmMIL-STD-XXXX-01MIL-STD-XXXX-02MIL-STD-XXXX-03MIL-STD-XXXX-04MIL-STD-XXXX-05MIL-STD-XXXX-060.0250.0310.0370.0390.0400.0500.6350.7870.9400.9911.0161.2704.2.2.1 Uncoated weights . The weight of each uncoated test panel shall be recor
40、ded withthe corresponding serial number. The weight of any test panel given special treatment prior tocoating shall be verified and reported by the coating vendor.4.2.2.2 Coated weights . The chromized and the aluminized weights of each test panelshall be kept along with each other on records with t
41、heir corresponding serial number and coatingrun number.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-STD-340(AT)55. DETAILED REQUIREMENTS5.1 Procedure . All part preparation, coating processes, and post cleaning shall be inaccordance with Chrom
42、alloy Research and Technology Division.5.1.1 Chromizing process . The detail parts and test panels shall be prepared andchromized in such a manner to provide a chromized coating weight of 35 to 60 mg per 100 squaremillimeters.5.1.2 Fabrication . After chromizing, the parts shall be fabricated into a
43、ssemblies bymachining, brazing, or welding prior to aluminizing.5.1.3 Aluminizing . The chromized assemblies and test panels shall be prepared andaluminized in such a manner to provide an aluminized coating weight of 1.5 to 6.0 mg per100 square millimeters.5.2 Test methods .5.2.1 Visual . All parts
44、or assemblies and test panels shall be visually inspected afterchromizing and aluminizing. The surface shall be smooth in its entirety and without evidence ofcracking and spalling. There shall be no evidence of untreated areas of pack material adhering tothe surface. In addition, there shall be no s
45、ignificant difference in color indicative of unevencoating.5.2.2 Test samples .5.2.2.1 Chromizing . There shall be not less than two test panels placed in each retort ofparts to be chromized. The test panels shall be placed in the retort in a manner which willaccurately represent detail coating qual
46、ity. In some cases, it may be required to place several testpanels in the retort to provide a sufficient number of chromized test panels.5.2.2.2 Aluminizing . There shall be not less than one acceptable chromized test panel(see 5.2.2.1) placed in each retort of parts or assemblies to be aluminized.
47、The test panels shall beplaced in the retort in a manner which will accurately represent part coating quality.5.2.2.3 Reduced sampling . Once the chromizing and aluminizing cycles are fixed for aspecific part, the use of test panels may be reduced or discontinued. When any changes are madein either
48、the chromizing or aluminizing cycles, test panels shall again be processed with the parts.5.2.2.4 Resistance welding samples . When requested by manufacturing, test specimensfor resistance welding shall be processed through the chromizing cycle. The test specimens forProvided by IHSNot for ResaleNo
49、reproduction or networking permitted without license from IHS-,-,-MIL-STD-340(AT)6resistance welding shall be of the same thickness and material and chromized in the same manneras the parts represented by the test specimens.5.2.3 Testing .5.2.3.1 Chromized test panel . The chromized test panels shall be evaluated as follows:a. Coating weight: Each chromized test panel shall have
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