1、Designation: G 86 98a (Reapproved 2005)Standard Test Method forDetermining Ignition Sensitivity of Materials to MechanicalImpact in Ambient Liquid Oxygen and Pressurized Liquidand Gaseous Oxygen Environments1This standard is issued under the fixed designation G 86; the number immediately following t
2、he designation indicates the year of originaladoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscriptepsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method2descr
3、ibes test equipment and tech-niques to determine the impact sensitivity of materials inoxygen under two different conditions: (1) in ambient pressureliquid oxygen (LOX) or (2) under pressure-controlled condi-tions in LOX or gaseous oxygen (GOX). It is applicable tomaterials for use in LOX or GOX sys
4、tems at pressures fromambient to 68.9 MPa (0 to 10 000 psig). The test methoddescribed herein addresses testing with pure oxygen environ-ments; however, other oxygen-enriched fluids may be substi-tuted throughout this document.1.2 This test method provides a means for ranking nonme-tallic materials
5、as defined in Guide G63for use in liquid andgaseous oxygen systems and may not be directly applicable tothe determination of the sensitivity of the materials in anend-use configuration. This test method may be used to providebatch-to batch acceptance data. This test method may providea means for eva
6、luating metallic materials in oxygen-enrichedatmospheres also; however, Guide G94should be consultedfor preferred testing methods.1.3 Values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.4 This standard does not purport to address all
7、 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 regulatory limitations prior to use. See also Section 9.2. Referenced Documents2.1 ASTM Standards:3D
8、 1193 Specification for Reagent WaterD 4080 Specification for Trichloroethylene, Technical andVapor DegreasingG63 Guide for Evaluating Nonmetallic Materials for Oxy-gen ServiceG88 Guide for Designing Systems for Oxygen ServiceG93 Practice for Cleaning Methods for Materials andEquipment Used in Oxyge
9、n-Enriched EnvironmentsG94 Guide for Evaluating Metals for Oxygen Service2.2 Military Document:4MIL-D-16791 Detergent, General Purpose (Liquid, Non-ionic), Type One2.3 American Chemical Society:5Trichloroethylene, Reagent Grade52.4 Compressed Gas Association:6G-4 OxygenG-4.1 Cleaning Equipment for O
10、xygen ServiceG-4.3 Oxygen, Gaseous, Type I BG-4.3 Oxygen, Liquid, Type II BG-10.1 Nitrogen, Gaseous, Type I BG-10.1 Nitrogen, Liquid, Type II B2.5 NASA Standard:7NSS 1740.15 Safety Standard for Oxygen and OxygenSystems1This test method is under the jurisdiction of ASTM Committee G04 onCompatibility
11、and Sensitivity of Materials in Oxygen Enriched Atmospheres and isthe direct responsibility of G04.01 on Test Methods.Current edition approved Sept. 1, 2005. Published December 2005. Originallyapproved in 1984. Last previous edition approved in 1998 as G 86 - 98a.2NASA Handbook 8060.1B, Pressurized
12、Liquid and Gaseous Oxygen Mechani-cal Impact Test, Sept. 1981, pp. 4-72.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe AS
13、TM website.4Available from Naval Publications and Forms Center (NPFA), 5801 TaborAve.,Philadelphia, PA 19120.5Available from American Chemical Society (ACS), 1155 Sixteenth Street, NWWashington, DC 200366Available from Compressed Gas Association (CGA), 1725 Jefferson DavisHwy., Suite 1004, Arlington
14、, VA 22202-4102.7Available from NationalAeronautics and SpaceAdminstration (NASA), NASAHeadquarters, Suite 1M32, Washington, DC 20546.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3. Terminology3.1 Definitions of Terms Specific to
15、This Standard:3.1.1 GOX, ngaseous oxygen.3.1.2 LOX, nliquid oxygen.3.1.3 mechanical impact, na blow delivered by a plum-met that has been dropped from a preestablished height onto astriker pin in contact with a sample.3.1.4 reaction, na chemical change or transformation inthe sample initiated by a m
16、echanical impact.3.1.4.1 DiscussionA reaction from ambient pressure,LOX mechanical impact may be determined by an audiblereport, an electronically or visually detected flash, obviouscharring of the sample, cup, or striker pin.3.1.4.2 DiscussionReactions in pressurized LOX or GOXare typically indicat
17、ed by an abrupt increase in test sampletemperature, chamber pressure, and light levels and may besupplemented by obvious changes in odor, color, or materialappearance as a result of thermal decompositions observedduring examination after the test.3.1.5 pressure threshold, nthe highest pressure at a
18、givenimpact energy level for which the passing criteria have beenmet.3.1.6 energy threshold, nthe highest impact energy levelat a given pressure for which the passing criteria have beenmet.4. Summary of Test Method4.1 The mechanical impact test system is designed toexpose material samples to mechani
19、cal impact in the presenceof liquid or gaseous oxygen at pressures from ambient to 68.9MPa (0 to 10 000 psig). The basic drop tower configurationconsists of: an electromagnet, a plummet, plummet guidetracks, plummet hold/release mechanism, base plate, anvilplate, a specimen cup holder, sample cup, a
20、nd striker pin (seeFig. 1). For tests conducted under pressure-controlled condi-tions, the anvil plate and specimen cup holder are replaced witha test chamber equipped with a striker pin or striker pincounterloader (see Fig. 2), test chamber purge, pressurizationand vent systems (see Fig. 3), and a
21、plummet catcher (see Fig.4). The general procedure is to prepare the test sample andrecord significant pretest data.4.2 Ambient LOX Impact TestThe test conditions (pres-sure and temperature) are the ambient pressure of the testfacility and the boiling point of LOX at that pressure. Eachsample is pla
22、ced into a specimen cup (see Fig. 5), precooled ina sample freezing box (Fig. 6), covered with LOX, and placedin the cup holder seater in the anvil assembly of the impacttester. The plummet is dropped from a selected height onto thestriker pin, which transmits the energy to the test sample.Observati
23、on for any reaction is made and noted. Drop tests arecontinued using a fresh sample, sample cup, and striker pin foreach drop until the threshold level is determined or the testseries is completed.4.3 For materials tested in pressurized LOX or GOX, eachsample is placed in the test chamber. The test
24、chamber is filledwith liquid or gaseous oxygen, pressurized to the required testpressure, and the striker pin or striker pin counterloader ispressed down against the top of the test sample. The plummetis dropped from a selected height onto the striker pin or strikerpin counterloader. Instrumentation
25、 devices that monitor the testchamber interior for pressure, temperature, and light emissionprovide evidence of test sample reaction. The sample isremoved from the chamber, and the sample is inspected forother evidence of reaction such as odor or charring. Drop testsare continued using a fresh sampl
26、e, sample holder, and strikerpin or striker pin counterloader for each drop, until thethreshold level is determined or the test series is completed.Additional modifications to the above procedure are requiredwhen testing is performed at temperatures above ambient.4.4 This test method may be used to
27、determine the impactsensitivity of a material, batch-to-batch acceptance, or tosatisfy other prescribed pass-fail criteria.5. Significance and Use5.1 This test method evaluates the relative sensitivity ofmaterials to mechanical impact in ambient pressure liquidoxygen, pressurized liquid oxygen, and
28、pressurized gaseousoxygen.5.2 Any change or variation in test sample configuration,thickness, preparation, or cleanliness may cause a significantchange in impact sensitivity/reaction threshold.5.3 Suggested criteria for discontinuing the tests are: (1)occurrence of two reactions in a maximum of 60 s
29、amples orless tested at the maximum energy level of 98 J (72 ftlbf) orone reaction in a maximum of 20 samples tested at any otherFIG. 1 Oxygen Impact Test FrameG 86 98a (2005)2energy level for a material that fails; (2) no reactions for 20samples tested at the 98-J (72-ftlbf) energy level; or (3) am
30、aximum of one reaction in 60 samples tested at the maximumenergy level.6. Criteria for Acceptance for Ambient LOX andPressurized LOX and GOX Mechanical Impact Test6.1 To meet the requirements for acceptability, the materialshall show no reaction when being subjected to 20 successiveimpact tests test
31、ed at 98 J (72 ftlbf) using the equipmentdescribed in Section 10.6.2 The test may be discontinued and the materials consid-ered to have failed if there is one reaction in 20 drops at anyenergy level less than 98 J (72 ftlbf).6.3 A material is acceptable after 60 successive impact testswith not more
32、than one reaction at 98 J (72 ftlbf). The test maybe terminated and the material considered to have failed ifthere are two reactions in 60 tests or less at 98 J (72 ftlbf).6.4 The material shall show none of the following reactionsduring any of the tests.6.4.1 Audible explosion.6.4.2 Flash (electron
33、ically or visually detected).1 Pneumatic Amplifier Chamber 9 High-Pressure Chamber2 Equalizer Pin Anvil 10 Sample Cup3 Equalizer Pin 11 Anvil Nut4 Pneumatic Amplifier Diaphragm 12 High-Pressure Seal5 Pneumatic Amplifier Chamber GN213 Pressurization PortCavity 14 Vent Port6 and 8 Striker Pin 15 Sight
34、glass for Photocell7 High-Pressure SealFIG. 2 Two Types of High-Pressure Test ChambersG 86 98a (2005)36.4.3 Evidence of burning (obvious charring, see Note 1).6.4.4 Major discoloration (as a result of ignition only ratherthan other phenomena).6.4.5 A temperature or pressure spike in elevated tempera
35、-ture tests.NOTE 1A burnt odor alone is not considered sufficient proof that areaction has occurred. If a reaction occurs (including those during bounceof plummet), it shall be reported as evidence of sensitivity. Inclusion ofbounce reactions applies to ambient LOX mechanical impact tests only.6.5 A
36、ll materials that fail 6.1 criteria and remain candidatesfor use must be subjected to LOX or GOX mechanical impactenergy threshold determinations in the thickness of use.FIG. 3 Typical Pressurization Piping system for a LOX/GOX Pressurized Test SystemFIG. 4 Typical Plummet Rebound Limiter AssemblyNO
37、TE 1Break sharp edges 0.4 mm.NOTE 2The cup is formed by deep drawing.NOTE 3The thickness and parallelness of the cup bottom shall becontrolled to 2.0 mm by coining.NOTE 4Material: any 3000 or 5000 series aluminum alloy.FIG. 5 LOX Impact Tester One-Piece Sample CupG 86 98a (2005)46.6 The material to
38、be tested must be traceable back to theoriginal manufacturer and to a specific batch or lot numbers, orboth.6.7 The thickness of the sample shall be the worst-casethickness. While the worst-case thickness has been found tovary from material to material, the general trend has been thatthinner samples
39、 of materials are generally more reactive.6.8 For the ambient LOX impact test, test conditions (pres-sure and temperature) are the ambient pressure of the testfacility and the boiling point of LOX at that pressure. For thepressurized test, test conditions (pressure and temperature)shall be determine
40、d for each test according to the requirementsspecified by the requester.6.9 Preparation of the samples for testing involve thefollowing tasks.6.9.1 Receiving the visually inspecting the material.6.9.2 Preparing the sample to the specified dimensions.6.9.3 Cleaning the samples.6.9.4 Inspecting the sa
41、mples.7. Sample Preparation7.1 The material to be tested must be traceable back to theoriginal manufacturer and to specific batch or lot numbers, orto both. When received, the test material must be accompaniedby proper identification, for example, product data sheets,batch or lot numbers identifying
42、 the sample, material manu-facturer, and appropriate material safety data sheets. Thematerial must be inspected to ensure that it is at the worst-caseuse thickness and any flaws shall be noted. Preparation ofsamples for testing involve the following tasks: (1) receivingand visually inspecting the ma
43、terial, (2) preparing samples tothe proper dimensions, (3) cleaning the samples, and (4)inspecting the samples.7.1.1 Sufficient material shall be available to permit prepa-ration and testing of 140 separate 17.5-mm (1116-in.) diameterdisk samples. Sheet materials up to 6.3-mm (14-in.) in thick-ness
44、shall be tested as 17.5 mm (1116-in.) diameter disks in thethickness intended for use (see Table 1).7.1.2 Materials normally used in thicknesses greater than6.35 mm (14 in.) shall be sized and tested as 17.5-mm diameterdisks of 6.35- 6 0.13-mm (0.250- 6 0.006-in.) thickness.Failure of samples to mee
45、t the requirements of this test methodshall be cause for the rejection of the material. Greases, fluids,and other materials, whose thicknesses are directed by condi-tions of use, shall be tested as 1.27- 6 0.13-mm (0.050- 60.005-in.) layers in special test cups. Materials not readilyavailable in she
46、et form shall be tested in the available configu-ration. Specimens shall be free of ragged edges, fins, or otherirregularities.7.2 Liquid SamplesPrepare a homogeneous sample. Amicroburette may be used to transfer the sample into specialsample cups 1.27 6 0.13 mm (0.050 6 0.005 in.) deep (seeFig. 7).
47、 For highly viscous materials, a microsyringe may beused. Determine the volume of the sample required to obtain asample thickness of 1.27 6 0.13 mm (0.050 6 0.005 in.) in thesample cup. This determination is required due to variations insuch physical properties as density, surface tension, andvolati
48、lity from liquid to liquid. A micrometre depth gauge withleveling blocks is suggested for measurement. The work tablemust be level. Test material should be loaded into the samplecup just before loading the cup into the test chamber (orfreezing box, if testing in liquid oxygen).7.3 Leak Check Compoun
49、ds, Dye, Dye Penetrant, andEmulsifier, Method 1Clean, unsealed, sulfuric acid-anodizedFIG. 6 Typical Sample Freezing BoxTABLE 1 Recommended Minimum Quantities of MaterialRequired for TestingMaterial FormAMinimum QuantitiesSheets 2000-cm2(319-in.2) total area by 3.5-mm (18-in.)maximum thicknessCoatings, inks, andadhesives120 cm3(4 fluid oz.)Foams 2000-cm2(310-in.2) total area by 3.5-mm (18-in.)maximum thicknessInsulated wires 50 cm (20 in.) in lengthAActual test configurations and material quantities for material forms other thanthose listed (for example,
