1、- Sampling Procedures and Tables for Inspection by Attrib.utec - Quality Assurance Terms and Definitions Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,
2、-3. REQUIREMENTS MIL-P-48446 (MU) 3.1 General,-The components shall be manufactured by the powder metallurgy process and shall comply with the requirements on the applicable drawings, the referenced specification and the following: 3.2 Chemical Properties. 3.2.1 =.-The following chemical composition
3、 requirements shall apply to each core powder batch after milling and to each core component. weight of tungsten carbide shall be 87.0% to 89.0%; the percent by weight of cobalt shall be 11.0% to 13.0%. shall not contain more than 0.7% iron. The percentby Samples selected from any batch of mixed pow
4、der 3.2.2 %,-The following chemical composition requirements shall apply to each nose powder blend lot and each nose component. The minimum percent by weight of tungsten shall be 89.0%. 7.52 Nickel, 2.5X Copper, and 1.0% other elements. The balance of the composition is advisory 3.3 Mechanical Prope
5、rties. 3.3.1 Ultimate Tensile Strength.-Nose components shall have a minimum ultimate tensile strength of 115,000 pounds per square inch (psi). 3.3.2 Elongation.-Nose components shall have a minimum elongation of 10.OZ. 3.3.3 Compression.-Nose component compression test specimens shall show no sign
6、of cracking when compressed to one-half of the orignial height. A compressive yield strength of 120,000 pounds per square inch (psi) at 1.0% offset is advisory. 3.3.4 Hardness, 3.3.4.1 =.-The core components shall have a hardness value within the range of 86-89 on the Rockwell “A” scale. 3.3.4.2 %.-
7、The nose components shall have a hardness value within the range of 28-32 on the Rockwell “Cl scale. 3.4 Physical Properties. 3.4.1 -.-The core components shall have a minimum density of 14.10 grams per cubic centimeter (gm/cc). 3.4.2 -.-The nose components shall have a minimum density of 16.90 gram
8、s per cubic centimeter (gm/cc). 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-P-48446 (Mu) 4.2.1.1 Examination and Test.-After inspection and
9、provisional acceptance at source, the sample shall be irispected for all the requirements of the drawings and specifications at a Government laboratory or such other facility specified in the contract. 4.2.1.2 Initial Production Sample Failure.-Failure of the sample to comply with the requirements o
10、f the drawings and specification shall result in sample disapproval. 4.3 Inspection Provisions. 4.3.1 =.-A lot of cores or noses shall consist of not more than one blended powder batch which has been processed under the same conditions. 4.3.2 Examination.-One hundred percent examination shall be per
11、formed for all critical defects. on a defect basis in accordance with the classification of defects contained here- in using the sampling plans contained in MIL-STD-105, Continuous sampling plans in accordance with MIL-STD-1235 may be used if approved by the procuring activity. An AQL of 0.40 percen
12、t for each major defect and an AQL of 0.65 percent for each minor defect shall be used except where otherwise specified. material shall be rejected. The roughness comparison specimens prescribed by ANSI-B46.1 shall be used as a basis for roughness determination. Examination for major and minor defec
13、ts shall be performed All nonconforming 4.3.2.1 Core Drawing C8595471. Defect Method of Inspection CRITICAL None defined 101. Weight Approved Scale 102, Hardness Hardness Tester 103. Runout of tip with body Gage 104, Runout of basic taper with body Gage 105. Perpendicularity of rear face with body G
14、age 106. Diameter of body 107. Length to small basic diameter Gage 108, Length to large basic diameter Gage 109. Straightness Gage 110. Angle of tip Gage 111, Basic Taper Gage 112. Netal Defective (see Sketch 1) Visual -E 5 Provided by IHSNot for ResaleNo reproduction or networking permitted without
15、 license from IHS-,-,-MIL-P-48446 13 W 9999906 0320494 1 W MIL-P-48446 (MU) 4.3.2.1 (Cont d) Defect MINOR 201. Diameter of chamfer 202, Angle of base 203. Maximum flat of nose (if applicable) 204. Depth of recess in rear face (if app 205. Surface finish, improper 207. Foreign matter - 206. Burr I ic
16、a Method of Inspection le 4.3.2.2 Nose (Pachined) , Drawing 8595472. CRITICAL None defined MAJOR 101. Hardness 102. Runout of tip with diameter forward of flange 103. Runout of cavity with diameter forward of flange 104, True position of flange with diameter forward of 105. Diameter forward of flang
17、e 106. Diameter of flange 107. Depth of cavity 108. Profile of cavity 109 Thickness of flange 110. Metal defective, flange MINOR 201. Length from base to small basic diameter 202. Length from base to large basic diameter 203. Length, total 204,. Radii or chamfer, missing or incorrect 205. Surface fi
18、nish, improper 206. Burr 207, Foreign matter Gage Visual (see 6.2) Visual (see 6.2) Visual (see 6.2) Visual (see 6.2) Visual Visual Hardness Tester Gage Gage Gage Gage Gage Gage Gage Gage Visual Gage Gage Gage Yisual (see 6,2) Visual Visual Visual 4.3.3 Inspection Testing Methods and Procedure2.-The
19、 following tests ahall be per-fomed .in accordance with the specified procedures. 6 f Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-P-48446 (MU) 4.3.3.1 Chemical Analysis.-The chemical analysis determination shall be Certification of compliance
20、 with the respective chemistry requirements by methods and procedures subject to the approval of the Procuring Contracting Officer, for the core and nose shall accompany each core and nose lot. 4.3.3.2 Mechanical Properties, 4.3.3.2.1 Ultimate Tensile Strength and Elongation.-Four nose blanks shall
21、be randomly selected from each nose lot and tested for compliance with the requirements of paragraphs 3.3.1 and 3.3.2. From each nose blank selected, one longitudinal and one transverse tension test specimen shall be prepared and test- ed. Failure of any test specimen shall be cause for rejection of
22、 the lot repres- ented by the failed test specimen. The location of the test specimens shall be in accordance with sketch #2. to the dimensions in sketch #3. test specimen in terms of surface finish, end parallelism, and blend radii in order to obtain reproducible test results. The specimen shall be
23、 tested in a tensile test machine with a constant cross head speed of 0.015 inch per minute. The total time of the test shall not exceed twelve (12) minutes. The ultimate tensile strength shall be determined by dividing the load at fracture by the original diameter of the gage length of the specimen
24、 measured to an accuracy of - + 0.001 inch. ing to an accuracy of 0.0005 inch. fitted back together and the total length again measured to 0.0005 inch accuracy, The percent elongation shall be determined by the following: The tension test specimen shall be in conformance Care must be exercised in pr
25、eparing the tension The total length of the specimen shall be measured prior to test- After testing the broken specimen shall be % Elongation = (Length after Fracture - Original Length) X 100 (Original Gage Lenpyh) 4.3.3.2.2 Compression Test.-From each nose blank selected for the tension test, one c
26、ompression test specimen shall be prepared and tested. Failure of any test specimen to complv with the requirements of paragraph 3.3,3 shall be cause for rejection of the lot represented bv the failed test specimen. The location of the test specimens shall be 0.357 + 0.005 inch in diameter by 0,500
27、+ 0.0005 inch in length. 0.001 inch. not to influence test results. A machined finish on the cylindrical surface of 64 micro inches or better is acceptable. The ends of- the specimen shall be ground to a finish of 16 micro inches or better. The specimen shall be placed on the bed of a tensile testin
28、g machine and a load applicd such that a reduction in height of the specimen of 50% shall be attained while under load. Positive stops or “jo“ blocks may be used, provide that the specimen is prepared with sufficient percisi.on to guarantee that contact with the stop represents 50% compression. A de
29、flectometer shall be connected with the moving memher of the machine such that a strain diagram may be recorded and the compressive yield strength of 1.0% offset, determined. Rate of strain durina test shall be from 0.05 to 0.10 inches per minute. be removed and examined visually for sips of crackin
30、g. The ends of the test shall be parallel within Care must be taken in the preparation of the test specimen so as Upon completion of pressing, the specimen shall 7 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-P-4844b 13 M 7777706 032047b 5 M M
31、IL-P-48446 (MU) 4.3.3.2.3 After l0,OOO onsecutive noses have been aceepted for compliance with the tensile, elongation and compressive requirements of paragraphs 3.3.1, 3.3.2 and 3.3.3, the sampling may be reduced to two noses per lot for tensile and compression tests, upon the approval of the procu
32、ring contracting officer. If a lot of noses is rejected under 4.3.3.2.1 or 4.3.3.2.2, sampling shall revert to that originally specified until the requirements for reduced sampling are again met, 4.3.3.2.4 Retest.-If only one nose fails to coinply with tensile, elongation and cmpression requirements
33、 of paragraphs 3.3.1, 3.3.2 and 3.3.3, four additional noses shall be selected from the failed lot and tested for the characteristic which failed. If all the retest pieces pass this test, the lot shall be accepted. If one or more fail this test, the lot represented by the failed samples will be reje
34、cted 4.3.3.2.5 Hardness-.-Samples of cores and noses selected in accordance with paragraphs 4.3.2.1 and 4.3.2.2 shall be subjected to this test. flardness values on these components shall be determined utilizing the equipment and procedures established in ASTM specification E18, using the “A“ scale
35、for cores and the “C“ scale for noses. Failure of any one hardness reading to meet the requirements of paragraph 3.3.4 will result in rejection of the component with no retest allowed. Failure of a sample group to comply witli the acceptance criteria of NIL-STD-105 . will result in rejection of the
36、lot represneted by the sample. 4.3.3.2.5.1 &s-g.-Tvo hardness tests shall be taken on the rear face of 4.3.3.2.5.2 Calibrat&oi.-I!ardness test equipment shall be calibrated every four hours during continuous production and at the start of production following a s hutdovm in excess of four hours. 4.3
37、.3.3.1 Oet_core_anL_nose.-nensity detennination shall be made by a test method approved by the responsible technical agency. The procedure shall incorporate a balance with an accuracy of at least 0.010 grams. any dispute, the procedure established by ASTPI specification 15311 shall be used as a refe
38、rence. Four cones and four noses shallbe rondonlv selected from each lot of cores and noses and subjected to the approved test method. Failures of any rejection of the lot represented by the component, In the event of component to comply with the requirements of paragraph 3.3.4 will result in 8 f Pr
39、ovided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-P-48446 13 9999906 0320 I MIL-P-48446 (MU) 5. PREPARATION FOR DELIVERY 5.1 Preservation , packaging, packing, and marking. 5.1.3 Level C, - Minimum military package - Preservation, packaging, packing,
40、 and marking shall comply with the applicable drawing, specifications , Military Specification MIL-STD-1169 and this specification. “ physical damage during shipment from the supply source to the first receiving activity for immediate use. Shipping containers or method of packing shall conform to th
41、e Uniform Freight Classification Rules and Regulations or other carrier regulations as applicable to the mode of transportation. or order, interior packages and exterior shipping containers shall be marked in accordance with MIL-STD-129. 5.4 Shipping.-When components from more than one lot are shipp
42、ed as a carload, each lot must be kept separate and the division between lots clearly indicated to prevent mixing of lots in transit. 6, NOTES maintained, starting with the powder blend lot, through to and including final machining. The component marking should include manufactures symbols, and powd
43、er blend lot. requfrements is in doubt as a result of visual examination, this characteristic may be measured or gaged to determine acceptability. Custodian: Army - t- 9 Preparing activity: Army - F Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL
44、-P-48446 (MU) r 1.11. VISUAL STANDARDS FOR CORE, M392A1 METAL DEFECTS Corner chips up to 1/32“ dia. (showing no raised metal) acceptable 1 A. . No holes, or evidence of porosity permissible. - 1 a. c I - -C. Depressions, or surface imperfections up to 1./32 dia. acceptable where bottom is rounded an
45、d can be clearly seen, D Same as C., except that both C and D are not allowid on a single core. Total ayea of imperfections not to exceed P /- 2 square inches. Same as.B. Ground Surfa e (32 finish) required edge to edge. Evidence of porosity or defects same as C & D. Acceptable, as long / as defect
46、occurs in no other location. -/ I 10 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-COMP RESSION / -TWO HARDNESS 1 MPRE SS I N 5, go* APART LOCATION OF HARDNESS TESTS, TENSION AND COMPEESSION TEST SPECIMENS FROM NOSE COMPONENT SKETCH #2 11 Provided
47、by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-P-48446 (MU) -VIA _ _._ ,284 . r .258 I I 1265 ,1260 DI A - . d-:-. . . . TENSION TEST SPECIMEN I SKETCH #3 * U. S. GOVERNMENT PRINTING OFFICE: 1974 -713-154/5789 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
