1、 - SOUNDNESS REQUIREMENTS FOR ALUMINUM AND MAGNESIM CASTINGS (FOR SMALL ARMS PARTS) Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-i - - - MIL-STD-339A ND 9994933 O059750 2 MIL-STD -1 39A DEPARTMENT OF DEFENSE VASHINCN, D. C. Standardization D ivis
2、ion Radiographic Inspection; Soundness Requirements for Aluminum ancl Magnesiun Castings (for Small Arms Parts). MIL-STD-139A 1. This Military Standard has been approved by the Department of Defense and is mandatory for use by all Departments and :gencies of the Department of Defense. 2, Iiecommende
3、d corrections, adi.ti.ons, or deletions should be addressed to the Commanding General, U. C. Army Weapons Command, APTE!: Rock Island, Illinois 61202. FiHC!E-BDT, ii Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-iii Provided by IHSNot for ResaleNo
4、reproduction or networking permitted without license from IHS-,-,-MIL-STD-L34A ND W 7449411 13054752 b W MicL-STD-139A LIST OF TABLES I. Acceptance standards for Aluminum and Magnesium Castings up to 2 inches *.*,. 6 II a Acceptance standards for Aluminum and Magnesium Castinzs Over 2 inches II. 7 i
5、v Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-1 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-2. REFERENCED DOCIMENTS 2.1 The issues of the following documents in effect on date of invi- tation
6、for bids form n part of this standard to the extent specified herein . SPECIFICATIONS Governmental HIL-STD-105 - Sampling Procedures and Tables for Inspection by Attributes . BKL-STD-453 Inspection, Radiographic (Copies of standards required by contractors in connection with specific procurement fun
7、ctions should be obtained from the procuring agency or as directed by the contracting officer.) PUDLICATLONS Navy - NAVAER-OO-15PC-504 - Reference Radiographs for Inspection of Aluminum and Magnesium Castings, 2.2 Other publications. The following documents form a part of this standard. tation for b
8、ids shall apply: Unless otherwise indicated, the issue in effect on date of invi- AIERICAN SOCIETY FOR TESTING AM) MATERIALS ASTM Designation E 155-60T and ASTM Designation E 98-532 - Tentative Reference Radiographs for Inspection of Aluminum and Magnesium Castings o (Copies of ASTM publications may
9、 be obtained from the American Society for Testing and l.ateriaLs, 1916 Race Street, Philadelphia, Pa,) 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-
10、,-,-NIL-STD-lI39A ND R 99994lIL 005975b 3 R I-1xL-CTD -139A 4. GENERAL REQUIREI4ENTS 4.l Castings shall be radiographed and inspected in the position and locations specified on the applicable radiographic position chart drawing, component drawins, specification or as specified in the contract and in
11、 accordance with MIL-STD -453 except that non-film radiographic techniques are not permitted. wedge type approved by the procuring activity may be used. panetrameters used shall be identified in the inspection records, 4.1,l Penctrameters shall be as specified in MIL-STD-453, or a step The type of 4
12、*1.2 Unless otherwise Specified, radlographe shall show the image of at least: two holes (quality level 2-2T) and the outer edge of the pene erainctm , 4.2 shall nieet the requirements of MIL-STD-453, Laboratories and personnel performing radiographic inspection 4.3 EARKXKGS AND IDENFICATION, Unless
13、 otherwise specified, marking When the size of the casting is such that marking of individ- of parts and identification of penetrameters shall be in accordance with MIL-ST-453. ual castings is impractical, a procedure for identification shall be as agreed upon by the procuring agency and the contrac
14、tor. 4.4 DESIGNATION OF CUSSXFICATXON, 4,4,1, The required quality of the casting or of specific areas thereof shall be designated as class 1, 2, or 3 on the applicable drawing or other contractual documents, 4.4.2 Ylien radiographic inspection is required but the quality of the casting is not speci
15、fied on the applicable drawings or other contractual documents, class 2 shall apply, class of castings are as specified in tables I and TI. columns of these tables are the identification numbers of the applicable reference radiograph standard film to be used as acceptance standards, 4.5 ACCEPTANCE S
16、TANDAPDS, The acceptance standards for the designated The numbers in the 4.6 DEFECTS, The defects which are apt to cause casting failure may be recognized on the radiographic negative by the following descriptions: spots, occurring individually, in clusters, or distributed throughout the cas tin8 .
17、4,6.3. Gas holes, Appear as round or elongated, cmooth-edged dark 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- MIL-STD-337A ND W 7777733 0057757 5 /- . MIL-STD -1 39A 4.6.2 Gas porosity. Represented by round or elongated dark spots correspondin
18、g to minute voids usually distributed throughout the entire cas ting . 4.6.3 Shrinkaze cavity. Appears as a dendritic, filsnentay, or jagged darkened arpa, 4.6.4 Shrinkage sponge. Shrinkage sponge or porosity is a localized lacy or honeycomed darkened area. 4.6.5 Microshrinkage (Magaesium onlg) Appe
19、s-rs as dark feathery streaks or dark irregular patches , indicative of cavities occurring in the grain boundaries. 4.6.6 Foreign materials. Appear as isolated, irregular, or elongated variation af film density, not corresponding to variations in thickness of material nor to cavities. 4.6.7 Segregat
20、ions, Appear as vaiiiations in film density which can be explained by segregation of elements of atomic numbers different from that of the matrix. 46.8 Hot cracks. Appear as ragged dark lines of variable width and They have no definite line of continuity and may exist numerous branches, in groups, T
21、hey ortginate internally or at the surface. 4.6.9 Cold cracks. Appear as a straight line usually continuous throughout its length and generally exist singly. These cracks start at the surface, 4.6.10 Cold shuts. Appear as a distinct darkened line or band of variable length and definite smooth outlin
22、e - separations where two streams of molten metal do not form a bond. 4.6.11 Misruns, Appear as prominent darkened areas of variable dimensions with a definite smooth outline - where metal did not fill the mold, 5 Provided by IHSNot for ResaleNo reproduction or networking permitted without license f
23、rom IHS-,-,-MIL-STD-134A ND m 9777931 0059758 7 m H H al rl P F s al . w O D I In m rl w E 2 c .rl al ri P a rl .I4 fd 3 crl v1 o E H N O U 3 u) o c .rl cv w lu_ . -. -. . a n a al U ntU WM U U CI ICI CI la 6 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from I
24、HS-,-,-(d a C (d u m a, o C m u a al o o 4 MIL-STD-137A ND W 7777711 0057757 I. 7 n T! a, u na 7 m K -. MIL-STD-139A Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-STD-139A ND U 9999911 00597b0 5 U 5. DETAILED REQUIREMENTS 5.1 INSPECTION. Radiog
25、raphic inspection shall be performed by the contractor in accordance with the provisions of this standard. Contractors not having suitable radiographic facilities may obtain the services of a comercial testing laboratory acceptable to the Government. The Government reserves the right to perform any
26、of the inspections set forth herein where such inspections are deemed necessary to assure supplies and services conform to prescribed requirements . which are submitted for approval at the same time and from the same melt. 5.3 SAMPLING. Unless otherwise epecified in procurement documents, sampling i
27、nspection shall be as specified herein. 5.2 LT SIZE, A lot shall consist of all castings of same design accordance with inspection level S4 of MILISTD-105 using an AQL of 0.65 5.3.2 Class 2 and class 3 castinizs. Sampling inspection shall be performed only after satisfactory results have been obtain
28、ed with 50 con- secutive castings. performed in accordance with inspection level S4 of MIL-STD-105 using an hQL of 1,5 percent, specified in 5,3.1 or 5.3.2, as applicable, in the event that any of the following conditions occur: (a) (b) (c) (d) After this requirement has been met, sampling shall be
29、5.3.3 Inspection shall revert to the number of consecutive castings Failure of samples from a lot to meet the sampling Any pattern, permanent mold or die change or modification. Any major change of foundry technique, such as risering, Start of a new foundry. inspection acceptance criteria. gating, c
30、hilling, sand mix, or pouring temperatures . 3 months or more.) (Includes lapse of production of 5.4 DETERMINATION OF ACCEPTABILITY. 5.4.1 Acceptability of the casting shall be determined by comparing the actual radiograph with the designated reference radiographic standard film using the same illum
31、inator. 8 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- MIL-STD-139A 5.4.1.1 The frequency and distribution of the defects in the casting or specified casting area shall not exceed that illustrated in the designated reference radiographic standard
32、 film for that type of defect . 5.4.1.2 Despite the fact that the designated acceptance standard requirements are met for internal, shrinkage , gas holes , or foreign mate- rials, castings shall be rejected when such defects occur closer than twice their maximum dimension to any edge or surface of t
33、he casting. 5.4.2 Single-type defect. When the radiograph shows but one type of defect which is equal to or better than the designated acceptance standard specified for that type of defect, the casting shall be acceptable. the radiograph shows the casting to be lower quality than the designated acce
34、ptance standard, the casting shall be rejected. If 5.4.3 Multiple defects. 5.4.3.1 extent equal to or not significantly better than the acceptance standards for respective defects, the casting shall be rejected. When the radiograph ShQws two or more types of defects to an 5.4.3.2 When the radiograph
35、 shows two or more types of defects significantly better than the acceptance standard for respective defects, the casting shall be considered acceptable provided no defects occur closer to each other than a distance equal to twice the maximum dimension of the largest defect . 5.4.3.3 When the radiog
36、raph shows one predominant type of defect to an extent equal to or not significantly better than the acceptance standard and all other types of defects to an extent significantly better than the acceptance standard for respective defects, the casting shall be considered acceptable provided the other
37、 defects do not occur closer to the predominant defect than a distance equal to twice the maximum dimension of the predominant defect. 5.4.4 Special attention shall be given to application of the proper acceptance standards to probable defective areas that are specified by special symbol or area out
38、line on the applicable drawing. 5.4.5 False indications of defects. At times, radiographic films may indicate defective castings when actually the film is defective. If doubt exists as to whether the film .Qr the casting itself is defective, the casting shall be radiographed again. 9 e Provided by I
39、HSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-STD-L39A ND 9497711 00597b2 9 MIL-STD-139A 5.5 REPORTS OF INSPECTTON, The contractor shall furnish inspection reports in accordance with MIL-STD-453. shall be made to the procuring agency at time of delivery of
40、production castings. shall be packed in flat envelopes, cartons, or boxes so as to prevent injury to the negatives, individual negatives from each other. shall be suitably stiffened by cardboard, fiberboard, or other material to prevent bending or rolling of Ehe package. Delivery of reports and radi
41、ographs 5,S.L Packing, When radiographs are to be mailed or shipped, they Single paper sheets shall be used to separate Radiographs packed in flat envelopes (Copies of specifications, standards, drawings, and publications re- quired by contractors in connection with specific procurement functions sh
42、ould be obtained from the procuring agency or as directed by the contracting officer ,) (Copies of this standard for military use may be obtained as indicated (Copies of this standard may be obtained for other than official use by individuals, firms, and contractors from the Superintendent of Docume
43、nts, U, S. Government Printing Office, Washington 25, D. C.) in the foreword to the Index of Military Specifications and Standards.) Custodians: Amy - WC Navy - Wep Ar Force - 84 Review activity: Air Force - 4 Preparing activity: Army - WC Project No. 1005-0256 User activity: Amy - WC 10 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
