1、Designation: D 2512 95 (Reapproved 2002)e1Standard Test Method forCompatibility of Materials with Liquid Oxygen (ImpactSensitivity Threshold and Pass-Fail Techniques)1This standard is issued under the fixed designation D 2512; the number immediately following the designation indicates the year ofori
2、ginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of
3、Defense.e1NOTEAdjunct references were corrected editorially in June 2006.1. Scope1.1 This method2,3,4covers the determination of compatibil-ity and relative sensitivity of materials with liquid oxygenunder impact energy using the Army Ballistic Missile Agency(ABMA)-type impact tester. Materials that
4、 are impact-sensitivewith liquid oxygen are generally also sensitive to reaction byother forms of energy in the presence of oxygen.1.2 This standard should be used to measure and describethe properties of materials, products, or assemblies in responseto heat and flame under controlled laboratory con
5、ditions andshould not be used to describe or appraise the fire hazard orfire risk of materials, products, or assemblies under actual fireconditions. However, results of this test may be used aselements of a fire risk assessment which takes into account allof the factors which are pertinent to an ass
6、essment of the firehazard of a particular end use.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of r
7、egulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:C 145 Specification for Solid Load-Bearing Concrete Ma-sonry Units5D 1193 Specification for Reagent Water62.2 Military Standards:MIL-D-16791G Detergent, General Purpose (Liquid, Non-ionic)7MIL-P-27401C Propellant Pressurizi
8、ng Agent, Nitrogen7MIL-PRF-25508F Propellant, Oxygen7MIL-T-27602B Trichloroethylene, Oxygen PropellantCompatible8MIL-C-81302D Cleaning Compound, Solvent, Trichlorotri-fluorocarbon72.3 ASTM Adjuncts:Type Impact Tester and Anvil Region Assembly, 38 Draw-ings93. Summary of Test Method3.1 A sample of th
9、e test material is placed in a specimencup, precooled and covered with liquid oxygen, and placed inthe cup holder located in the anvil region assembly of theimpact tester. A precooled striker pin is then centered in thecup. The plummet is dropped from selected heights onto thepin, which transmits th
10、e energy to the test specimen. Observa-tion for any reaction is made and the liquid oxygen impactsensitivity of the test material is noted. Drop tests are continuedusing a fresh specimen cup and striker pin for each drop, until1This test method is under the jurisdiction of ASTM Committee G04 onCompa
11、tibility and Sensitivity of Materials in Oxygen Enriched Atmospheres and isthe direct responsibility of Subcommittee G04.01 on Test Methods.Current edition approved Feb. 15, 1995. Published April 1995. Originallypublished as D 2512 66. Last previous edition D 2512 82 (1994)e1.2“NASA Handbook 8060. 1
12、B, Ambient LOX Mechanical Impact ScreeningTest,” September 1981, pp. 4-53 through 4-71. “Oxygen Systems.” George C.Marshall Space Flight Center, National Aeronautics and Space Administration.Specification MSFC 106B. September 1981.3“Lubrication and Related Research and Test Method Development for Av
13、iationPropulsion Systems.” Technical Report No. 59-726. Wright Air DevelopmentDivision, January 1960.4“General Safety Precautions for Missile Liquid Propellants.”5Annual Book of ASTM Standards, Vol 04.05.6Annual Book of ASTM Standards, Vol 11.01.7Available from Standardization Documents Order Desk,
14、Bldg. 4 Section D, 700Robbins Ave., Philadelphia, PA 19111-5098, Attn: NPODS.8Cancelled in 1983. Previously available from Standardization DocumentsOrder Desk, Bldg. 4 Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098,Attn: NPODS.9Detailed drawings for the ABMA-Type Impact Tester and Anvil Re
15、gionAssembly are available from ASTM International Headquarters. Order AdjunctADJD2512.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.the threshold valve is achieved. A series of drop tests areconducted at an energy level of 98 J (7
16、2 ftlbf) or as specifiedfor the pass-fail tests.4. Significance and Use4.1 When this test method is used to measure the thresholdimpact sensitivity of a material, a relative sensitivity assess-ment is obtained which permits the ranking of materials.4.2 This test method may also be used for acceptanc
17、e-testing materials for use in liquid oxygen systems. Twentyseparate samples of the material submerged in liquid oxygenare subjected to 98 J (72 ftlbf) or as specified. Impact energydelivered through a 12.7-mm (12-in.) diameter contact. Morethan one indication of sensitivity is cause for immediatere
18、jection. A single explosion, flash, or other indication ofsensitivity during the initial series of 20 tests requires that anadditional 40 samples be tested without incident to ensureacceptability of the material.4.3 The threshold values are determined by this test methodat ambient pressure. The sens
19、itivity of materials to mechanicalimpact is known to increase with increasing pressure. Sincemost liquid oxygen systems operate at pressures above ambientcondition, some consideration should be given to increasedsensitivity and reactivity of materials at higher pressure whenselecting materials for u
20、se in pressurized system.5. Apparatus5.1 ABMA-Type Impact Tester9(Fig. 1 , See ADJD2512),for determining the sensitivity of materials to liquid oxygenwith impact energy. Fig. 2 shows the schematic diagram of thetypical power supply. The tester consists of the following parts:5.1.1 Three Guide Tracks
21、, capable of maintaining accuratevertical alignment under repeated shock conditions.5.1.2 Plummet, with a weight of 9.072 6 0.023 kg (20 60.05 lbs).5.1.3 Safety Catch, operated by a solenoid, and designed tohold the plummet near the base of the magnet. It is used tosupport the plummet in the event o
22、f a power failure.5.1.4 Electromagnet, for supporting or releasing the plum-met. The electromagnet is designed to hold 9.072 kg (20 lbs) ofweight with a minimum amount of electrical energy.5.1.5 BaseThe base of the tester is composed of thefollowing: a rigid 0.61- by 0.61- by 0.61-m (2- by 2- by 2-f
23、t)(min) reinforced concrete block (concrete conforming to Speci-fication C 145), a 3.2-mm (18-in.) stainless steel sheet, and a25-mm (1-in.) thick stainless steel base plate. Four stainlesssteel foundation bolts protruding from the concrete block areused to fasten the plate and sheet to the smooth s
24、urface of theconcrete block with stainless steel nuts.NOTE 1Where not otherwise indicated, stainless steel shall be of theAISI 300 series.5.1.6 Anvil Plate (Fig. 3), made from a 51-mm (2-in.) thickType 440B heat-treated steel plate, (56 to 58 HRC) that iscentered and rests on the base plate. It in t
25、urn centers thespecimen cup holder.5.1.7 Striker PinThe striker pins shall be machined fromAMS 5643D stainless steel, heat condition H-900 (Fig. 4).5.1.8 Striker Pin Guide.5.1.9 Specimen CupsOne- and two-piece specimen cupsshall be used. The one-piece specimen cup (Fig. 5) shall beused for liquid an
26、d solid test materials. When testing hardsamples that are sometimes capable of initiating reactions withthe aluminum cup, expendable Type 347 stainless steel disks17.5 mm (1116 in.) in diameter by 1.6 mm (116 in.) thick shallbe placed in the bottom of the cup. The two-piece cup (Fig. 6)shall be used
27、 for testing semisolid materials; a one-piece insertFIG. 1 ABMA-Type Impact TesterFIG. 2 Schematic Diagram of Power SupplyD 2512 95 (2002)e12cup (Fig. 7) may also be used. The recess of either of thesepermits use of a 1.27-mm (0.050-in.) thick sample.5.1.10 Specimen Cup Holder, consisting of a 25-mm
28、 (1-in.)thick stainless steel block centered on the anvil plate. Thisholder has two protruding spacers which align the striker pinguide, and in turn the striker pin, with the nose of the plummet,thus ensuring a direct hit by the nose of the plummet on thestriker pin in the specimen cup.5.2 Test Cell
29、The impact tester shall be housed in a testcell containing a concrete floor. Walls shall be constructed ofreinforced concrete or metal to provide protection from explo-sion or fire hazards. The cell shall be provided with ashatterproof observation window, and shall be darkened suffi-ciently to permi
30、t observation of flashes. The operator shall belocated in a darkened area. Continuous ventilation shall pro-vide fresh air to the test cell. Construction of the cell shall bedirected at providing a facility that can be maintained economi-cally at a high level of good housekeeping. The test cell shal
31、lbe cleaned periodically to ensure cleanliness of sample andequipment.5.3 Freezing Box, as illustrated in Fig. 8.5.4 Auxiliary EquipmentThe auxiliary equipment shallconsist of forceps for handling the specimen cups and strikerpins, stainless steel spatulas, liquid oxygen handling equipmentsuch as st
32、ainless steel Dewar flasks, liquid oxygen protectivegloves, lintless laboratory coat, eye protection equipment, andliquid oxygen storage containers. Special handling equipmentshall include striker pin holders (Fig. 9), specimen cup trays,covered storage container for specimen cups and striker pins,a
33、nd a vapor-phase degreaser. The following items are alsorecommended: microburet, control panel with switches toactivate the safety catch and electromagnet, stereomicroscope,micrometer depth gage with leveling blocks, press punch cutterfor preparation of plastic specimens, oven, and refrigerator. For
34、checking surface roughness of striker pins and specimen cups,a set of visual roughness comparison standards10or a surfaceroughness measuring instrument shall be required. Timinginstrumentation shall be required to measure the drop time ofthe plummet. A suitable free-fall timing circuit is illustrate
35、d inFig. 10.6. Reagents and Materials6.1 Alkaline Cleaner, for striker pins and stainless steelinserts, consisting of a solution of 15 g of sodium hydroxide(NaOH), 15 g of trisodium phosphate (Na3PO4), and 1 L ofdistilled or deionized water.6.2 Alkaline Cleaner, for cups; a nonetch-type solution suc
36、has Enthone NE11or equivalent shall be used.6.3 Aqua RegiaMix 18 parts of concentrated HNO3(sp gr1.42) with 82 parts of concentrated hydrochloric acid (HCl, spgr 1.19) by volume.6.4 Deionized Water, conforming to Specification D 1193.6.5 Detergent, General-Purpose (Liquid, Nonionic), con-forming to
37、MIL-D-16791G.6.6 Hydrofluoric Acid (48.0 to 51.0 %)Reagent gradeconcentrated hydrofluoric acid (HF).6.7 Liquid Nitrogen, conforming to MIL-P-27401C.(WarningContact with the skin can cause frostbites resem-bling burns.)6.8 Gaseous Nitrogen, conforming to MIL-P-27401C.(WarningCompressed gas under high
38、 pressure. Always usea pressure regulator. Release regulator tension before openingcylinder.)6.9 Liquid Oxygen, conforming to MIL-PRF-25508F.(WarningOxygen vigorously accelerates combustion. Con-tact with skin can cause frostbite resembling burns.)6.10 Nitric Acid (relative density 1.42)Reagent grad
39、enitric acid (HNO3).10American National Standard B 46.1-1962. Surface Texture standards may beused.11Available from Enthone, Inc., a division of American Smelting and RefiningCo., Box 1900, New Haven, CT 06508.FIG. 3 Anvil Region AssemblyNOTE 1Break sharp edges approximately 0.015.NOTE 2Machine all
40、surfaces 32 rums except as noted.NOTE 3Material: stainless steel AMS 5643 D.NOTE 4Heat treatment: H-900 to obtain Rc 43 to 44.NOTE 5Finish: electropolish after heat treatment.NOTE 6Surfaces A and B should be parallel and perpendicular to thecenter line within 0.001TIR and 16-32 rms along a radius.Al
41、l dimensions in inches.FIG. 4 Striker PinD 2512 95 (2002)e136.11 Trichloroethylene, conforming to MIL-T-27602.(WarningHarmful if inhaled. High concentrations maycause unconsciousness or death. Contact may cause skinirritation and dermatitis.)NOTE 2The use of trichloroethylene is banned in California
42、 by theCalifornia Air Pollution Board.6.12 Trichlorotrifluoroethane, conforming to MIL-C-81302D Type I. (WarningHarmful if inhaled.)7. Safety Precautions7.1 The hazards involved with liquid oxygen are veryserious. Contact with the skin can cause frostbites resemblingburns. Contact with hydrocarbons
43、or other fuels causes anexplosion hazard, as such mixtures are usually shock, impact,and vibration-sensitive.7.2 The first-aid procedure for liquid oxygen contact is toflush the affected area with water. This treatment should befollowed by medical attention. A safety shower must beavailable in the i
44、mmediate area.7.3 The following safety rules must be observed: personnelworking with liquid oxygen must be familiar with its natureand characteristics. Approved goggles or face shields, protec-tive clothing, gloves, and boots must be worn during handlingor transfer. Such operations shall be performe
45、d by not less thantwo persons as a group. Extreme caution shall be exercised inpreventing contact with oils or other combustible materials.Alltools must be degreased before use. Precautions shall be takento prevent accumulation of moisture in lines, valves, traps, andso forth to avert freezing and p
46、lugging with subsequentpressure ruptures. Care shall also be taken to prevent entrap-ment of liquid oxygen in unvented sections of any system.7.4 Safety shower and other protective equipment shall beinspected periodically and before each handling of liquidoxygen. Personnel leaving the working or sto
47、rage area shalltake steps to make sure that no oxygen remains absorbed inclothing before smoking or approaching any source of ignition.7.5 The threshold limit value, that is, the time-weighedaverage concentration of trichloroethylene believed safe forcontinuous exposure during a normal 8-h workday,
48、has beenestablished by the American Conference of GovernmentalIndustrial Hygienists at 100 ppm. Operations using trichloro-ethylene should always be conducted in a well-ventilated area.The comparable figure for trichlorotrifluorethane is 1000 ppm,and normal ventilation is usually adequate. When a ve
49、ntilationsystem is used, an effort should be made to have the natural aircurrents in the vicinity assist rather than oppose the mechanicalventilation. For cleaning by vapor degreasing, the vapor levelshall be controlled by heat input and cooling coils, whichNOTE 1Break sharp edges 0.015.NOTE 2The cup is formed by deep drawing.NOTE 3The thickness and parallelness of the cup bottom shall be controllled to 0.0610 to 0.0630 by coining.NOTE 4Materal: aluminum alloy QQ-A-318 (5052) temper H32.All dimensions in inches.FIG. 5 One-Piece Specimen CupD 2512 9
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