1、I INCH-POUND I MIL-PRF-l8950A(OS) 26 May 1999 SUPERSEDING MIL-PRF- 18950(NOrd) 23 January 1956 PERFORMANCE SPECIFICATION PROJECTILES, HIGH-CAPACITY, ANTI-AIRCRAFT, AND ILLUMINATING This specijcation is approved for use within the Naval Sea System Command Department of the Navy, and is available for
2、use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 Scope. This specification establishes the requirements for high-capacity, anti-aircraft and illuminating projectiles inert parts, and is augmented by drawings and specifications shown on the list of drawings and specifica
3、tions particular to the item of the contract. 2. APPLICABLE DOCUMENTS 2.1 General. The documents listed in this section are specified in sections 3 and 4 of this specification. This section does not include documents cited in other sections of this specification or recommended for additional informa
4、tion 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 documents cited in sections 3 and 4 of this specification, whether or not they are listed. 2.2 Government documents. 2.2.1 Specif
5、kations. The following specifications form a part of this document to the extent specified herein. Unless otherwise specified, the issues of these documents are those listed in the issue of the Department of Defense Index of Specifications and Standards (DODISS) and supplement thereto, cited in the
6、solicitation (see 6.2). Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of use in improving this document should be addressed to: Commander, Indian Head Division, Naval Surface Warfare Center, Standardization Team (Code 840M), Indian Head, MD 20640-503
7、5 by using the Standardization Document Improvement Proposal (DD Form 1426) appearing at the end of this document or sending a letter. AMSC NIA FSC 1320 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Provided by IHSNot for ResaleNo reproduction or networking permit
8、ted without license from IHS-,-,-MIL-PRF-l8950A(OS) SPECIFICATIONS DEPARTMENT OF DEFENSE MIL-PRF- 18907 Bands, Projectile Rotating MIL-P-18948 Projectiles, Painting, Marking, and Greasing of MIL-PRF- 18949 Projectiles, Illuminating, Localized Heat Treatment of (Unless otherwise indicated, copies of
9、DoD specifications are available from the Standardization Documents Order Desk, Building 4D, 700 Robbins Avenue, Philadelphia, PA 191 11-5094.) 2.2.2 Other Government documents, drawings, and publications. The following other Government documents, drawings, and publications form a part of this docum
10、ent to the extent specified herein. Unless otherwise specified, the issues are those cited in the solicitation (see 6.2). DRAWINGS NAVAL SEA SYSTEMS COMMAND (CAGE Code 53711) 2838457 Ultrasonic Test (UT) For 5 Inch Steel Projectile Bodies (Application for copies of drawings should be addressed to: C
11、ommander, Naval Surface Warfare Center, Dahlgren Division, Attn: Code G52, 17320 Dahlgren Road, Dahlgren, VA 22448-5 100.) 2.3 Non-Government publications. The following documents form a part of this document to the extent specified herein. Unless otherwise specified, the issues of the documents whi
12、ch are DoD adopted are those listed in the issue of the DoDISS cited in the solicitation. Unless otherwise specified, the issues of documents not listed in the DoDISS are the issues of the documents cited in the solicitation (see 6.2). AMERICAN SOCIETY FOR TESTING AND MATERIALS ASTM E 8 Metallic Mat
13、erials, Tension Testing of (DoD adopted) ASTM E 1742 Radiographic Examination (DoD adopted) (Application for copies should be addressed to the American Society for Testing and Materials, 100 Barr Harbor Dr., West Conshohocken, PA 19428-2959.) AMERICAN NATIONAL STANDARDS INSTITUTE (ANSI)/AMERICAN SOC
14、IETY FOR QUALITY CONTROL (ASQC) 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-l8950A(OS) ANSUASQC Z1.4 Sampling Procedures and Tables for Inspection by Attributes (DoD adopted) (DoD activities may obtain copies of ANSUASQC Z1.4 from the S
15、tandardization Documents Order Desk, 700 Robbins Avenue, Building 4D, Philadelphia, PA 19111-5094. The private sector and other Government agencies may purchase copies from the American Society for Quality Control, 61 1 East Wisconsin Avenue, Milwaukee, WI 53202-4606.) 2.4 Order of precedence. In th
16、e event of a conflict between the text of this document and the references cited herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained. 3. REQUIREMENTS 3.1 First article. When sp
17、ecified (see 6.2), a sample shall be subjected to first article inspection in accordance with 4.2. 3.2 Material. The material for the body and base plug shall be high grade homogeneous steel produced and fabricated by a forging process. The basic configuration is obtained by the steel being mechanic
18、ally worked while above its critical temperature, with final machining where necessary. Sufficient top and bottom discard shall be taken from the ingot to ensure that the blooms, billets, or bars from which the projectiles are made are free from piping, segregation, flake, rolling, or forging tears
19、or similar defects. When only one projectile body is made from a single ingot, the base shall be toward the bottom of the ingot. 3.2.1 Mechanical properties. Mechanical properties of the projectiles shall be as listed on the applicable drawings or as required in the appropriate specifications. 3.2.2
20、 Chemical composition. Chemical composition of the projectile assembly components shall be as specified on the applicable drawings. Prior to manufacture of projectiles, the contractor shall submit a statement of the composition of the material proposed for use in the manufacture of the bodies, plugs
21、, and bands to NAVSURFWARCEN, Crane for approval. This statement shall indicate the maximum and minimum percentages of alloying elements intentionally added or otherwise present in the steel. The chemical composition of all projectiles furnished under the contract shall be in accordance with this st
22、atement as approved by the contracting activity. Unless otherwise specified, the phosphorous and sulfur content shall each be limited to 0.05 percent maximum as determined by ladle analysis. 3.2.3 Heat treatment. All components shall be given uniform heat treatment to produce material conforming to
23、the requirements of this specification. Components produced by band welding, cold forming operations or subjected to any cold work after heat treatment shall be adequately stress relieved to assure freedom from susceptibility to cracking or subsequent distortion as a result of unrelieved stresses. H
24、ollow forgings shall not be quenched in water from above the critical 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-l8950A(OS) temperature. The requirements of MIL-PRF- 18949 shall govern the localized heat treatment required on illuminat
25、ing projectiles. 3.3 Surface finish. 3.3.1 Exterior. All exterior surfaces shall have a smooth finish and shall be free from burrs, nicks, sharp edges, sharp corners, rough spots, or areas which fail to clean up. Bourrelets and other surfaces which make contact with the gun shall have a superior fin
26、ish. Surface roughness shall not exceed the values specified on the applicable drawing. 3.3.2 Cavities. All cavities shall have smooth surfaces, free from burrs, nicks, sharp edges, sharp corners, rough spots or areas which fail to clean up. Cavities with surfaces as forged or cold formed are accept
27、able provided all requirements of finish, concentricities, dimensions, etc, are met. 3.4 Shape. The interior and exterior shape of the projectile shall be as shown on the applicable drawing. 3.5 Interchangeability. Components such as fuze hole plugs, adapters, and so forth which are not permanently
28、assembled by the contractor or which, because of the requirements of fit or other considerations, are not clearly intended to be used in selective assembly, shall be entirely interchangeable. 3.6 Band and band seat. The projectile rotating band shall conform to MIL-PRF-18907. The band seat shall be
29、machined before banding as shown on the applicable drawing. 3.7 Marking. 3.7.1 Process marking. The contractor shall mark projectile bodies and other components as required by the contract (see 6.2) to identify the component with its melt, ingot number, heat treatment, or other pertinent processes o
30、r stages of manufacture. 3.7.2 Identifkation marking. Finished projectiles shall be marked in accordance with the applicable drawing or MIL-P-18948 as specified in the contract (see 6.2). For projectiles assembled from bodies, base plugs or other components which are not entirely interchangeable, ea
31、ch component assembly shall be marked with the same serial numbedzone symbol. 3.8 Cleaning and preservation. All surfaces of finished projectiles shall be cleaned and coated in accordance with the requirements of MIL-P- 18948. 3.9 Base plugs. For projectiles with base plugs, the plugs and their mati
32、ng counter bores in the projectiles shall be such that a gas-tight fit is obtained when the plug is assembled with a gasket. Unless otherwise specified on the drawings, interference fits between plugs and projectiles designed to have such a fit shall be 0.004 f 0.001 inches. Base fuze hole plugs sha
33、ll be made in such a manner that the longitudinal axis of the plug is normal (90“) to the fiber or grain flow lines of the material of 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-l8950A(OS) which the plug is manufactured. When Acme thre
34、ads are specified for a projectile and its mating base plug, special care shall be exercised to ensure the interchangeability of the parts. All threaded plugs shall be hand tight when shipped to the loading plant with the projectile and shall be readily removable upon arrival. 3.10 Gaskets. When gas
35、kets are specified to be supplied under the contract (see 6.2), they shall be in accordance with the applicable drawing and specification. Unless otherwise specified, gaskets shall not be assembled with the projectiles but shall accompany each lot of projectiles; the number supplied shall be 10 perc
36、ent in excess of the number of projectiles. 3.11 Workmanship. The workmanship shall be as specified on the applicable drawings, specifications, and the best industrial practices governing the quality production of interchangeable parts for maintaining the dimensions, finishes, tolerances, and qualit
37、y specified herein. All components and assemblies shall be free from burrs, contamination, corrosion, sharp edges, or foreign material which could result in malfunction of the projectiles or be a safety hazard in handling. 4. VERIFICATION 4.1 Classifkation of inspections. The inspection requirements
38、 specified herein are classified as follows : a. First article inspection (see 4.2). b . Quality conformance inspection (see 4.3). 4.2 First article inspection. A first article sample of projectiles shall be inspected for conformance to the weight and dimension requirements of the applicable drawing
39、s. These projectiles shall be supplied in a bare metal condition with only a light coating of preservative oil or grease to prevent corrosion. A specified number of those projectiles shall also be tested in accordance with MIL- PRF-18907 and the applicable drawing, for conformance to 3.2.1. Addition
40、al first article projectiles shall be supplied in the phosphated and primed condition and subjected to the dry film thickness, adhesion, and salt spray tests of MIL-P-18948. The number of first article samples to be furnished in the different conditions and subjected to the various first article tes
41、ts shall be as specified in the contract or order (see 6.2). Failure of any projectile shall cause rejection of the first article sample. Production of projectiles prior to acceptance of the first article inspection shall be at the contractors risk. 4.3 Quality conformance inspection. The tests of 4
42、.4 are required on all production lots. Any lot sampling shall be conducted in accordance with ANSUASQC 21.4. For the first melt, a chemical analysis of the steel shall be forwarded to NAVSURFWARCEN Crane. For each additional melt, a chemical analysis shall be presented to the Government quality ass
43、urance representative. The analysis may be performed by the contractor or may be a certified analysis by the steel producer. The heat treatment of each lot, and the mechanical properties test results shall be recorded along with the result of dimensional inspections. 5 Provided by IHSNot for ResaleN
44、o reproduction or networking permitted without license from IHS-,-,-MIL-PRF-l8950A(OS) Caliber 4“ and smaller 4.3.1 Production lot. A production lot is a group of projectiles that are processed and heat treated as a group. No more than two mill heats of steel are allowed in one production lot and on
45、e mill heat of steel shall not be used in more than two production lots. The number of projectiles in the production lot shall be as specified in table 1. Lot Size Minimum Maximum 500/lot 5000/lot TABLE I. Lot size. 5“ 500/lot 2,50O/lot 4.3.2 Inspection lot. A grouping of one or more production lots
46、 submitted for inspection at the same time. All projectiles in an inspection lot shall be the same mill heat of steel. More than one heat treat may be combined in an inspection lot providing the heat treat process has been consistent over all these combined lots. 4.4 Inspection and tests methods. In
47、structions for inspection, tests, and manufacture of the projectile body are specified in the drawings and specifications and in 4.4.1 through 4.4.7. 4.4.1 Samples for chemical analysis. When specified in the contract (see 6.2), a chemical analysis of any bar or forging of any melt shall be made to
48、determine the conformity of the material to 3.2.2. 4.4.2 Fracture and macro-etch tests. Sufficient discard from each ingot to ensure freedom from piping and segregation shall be determined by either a fracture test or a macro-etch test which shall be conducted on the cold stock representing the uppe
49、rmost portion of each ingot. The fracture of macro-etched section shall show at least 10% of the cross-sectional area of the ingot, bloom, billet or bar; shall be at least 2“ in diameter; shall be centrally located to show the axis of the ingot and shall be free from indications of piping or segregation. Discard shall be continued until the fracture or macro-etched section discloses satisfactory material. A fracture may be ground flat and suitably etched to indicate the condition of the m
