1、Designation: D2319/D2319M 14Standard Test Method forSoftening Point of Pitch (Cube-in-Air Method)1This standard is issued under the fixed designation D2319/D2319M; the number immediately following the designation indicates theyear of original adoption or, in the case of revision, the year of last re
2、vision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers the determination of the soft-ening point above 80C 176F of pitch. Test Method D3104gives comparable
3、 results.1.2 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conform
4、ancewith the standard.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 regulatory limitations prior
5、to use.2. Referenced Documents2.1 ASTM Standards:2D61 Test Method for Softening Point of Pitches (Cube-in-Water Method)D3104 Test Method for Softening Point of Pitches (MettlerSoftening Point Method)D4296 Practice for Sampling PitchE1 Specification for ASTM Liquid-in-Glass Thermometers3. Summary of
6、Test Method3.1 Two cubes of pitch, supported on wire hooks, are heatedin a standardized air oven at a linear rate. The softening pointis the mean of the temperatures at which the cubes sagdownwards a distance of 60 mm 2.4 in.4. Significance and Use4.1 Pitch does not go through a solid-liquid phase c
7、hangewhen heated and therefore does not have a true melting point.As the temperature is raised, pitch softens and becomes lessviscous. The softening point is arbitrarily defined and must bedetermined by a closely controlled method that must becarefully followed if test results are to be reproducible
8、.4.2 This test method is useful in determining the consis-tency of pitch as one element in establishing the uniformity ofshipments and sources of supply.5. Apparatus35.1 Air OvenThe oven shall be cylindrical, 150 mm 6 in.in inside diameter by 155 mm 6.2 in. in height. It shall havetwo 75 mm 3-in. di
9、ameter windows of mica, centeredvertically on opposite sides, and shall be fitted with a coverhaving a central opening 25 mm 1 in. in diameter to hold athermometer, and a concentric ring suspended below to supportthe hooks with attached specimens. The ring shall be made of6mm14-in. brass, shall be 5
10、4 mm 218 in. in outsidediameter, and shall be centrally suspended 30 mm 1.2 in.below the cover. The cover shall have two 3 mm 0.12-in.holes on a diagonal 50 mm 2 in. from the center. On thebottom of the oven, an inner pan 140 mm 5.6 in. in diametershall rest on three brass legs 5 mm 0.2 in. in heigh
11、t fastenedto the bottom of the pan to provide an air space between thepan and the bottom of the oven. The side wall, cover, and panshall be made of 0.7 mm 0.028 in. thick or 22-gauge (BWG)copper sheet, and the bottom of 0.8 mm 0.032 in. thick or21-gauge copper.5.2 Tripod for Use with Gas BurnerThe t
12、ripod ring shallbe approximately 125 mm 5 in. in inside diameter so that theoven is supported only on its outer edges. It shall be 200 mm8 in. in height.5.3 Shield for Oven:5.3.1 For Use with Electric HeaterThe shield shall becylindrical, 216 mm or 8.64 in. in inside diameter by 181 mmor 714 in. in
13、height. It shall have two 76 mm or 3-in.diameter mica windows on opposite sides, positioned to1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.05 on Properties of Fuels, Petroleum
14、Coke and Carbon Material.Current edition approved May 1, 2014. Published May 2014. Originallyapproved in 1964. Last previous edition approved in 2013 as D2319/D2319M 98 (2013). DOI: 10.1520/D2319_D2319M-14.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer
15、Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The sole source of supply of the softening point apparatus items, obtainable asa unit on special order, known to the committee at this time is HumboldtMan
16、ufacturing Co., 7302 W. Agatite Ave., Chicago, IL 60656. If you are aware ofalternative suppliers, please provide this information to ASTM InternationalHeadquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee,1which you may attend. All other a
17、pparatus itemsdescribed may be obtained from any regular laboratory equipment supply house.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1coincide with the windows of t
18、he oven when both are placed onthe electric heater. It shall be made of 0.7 mm 0.028 in. thickor 22-gauge sheet metal, painted inside and out with aluminumpaint.5.3.2 For Use with Gas BurnerThe shield shall be iden-tical with that described in 5.3.1 except that it shall be 375 mm15 in. in height and
19、 the windows shall coincide when theshield is standing on the bench and the oven on the tripoddescribed in 5.2. A door 115 by 115 mm 412 by 412 in. shallbe provided at the bottom to give access to the burner.5.4 MoldA mold suitable for forming two 12.7 mm12-in. cubes of pitch, having cylindrical cor
20、e pins 12 gauge2.05 to 2.07 mm in diameter located in the base plate of theassembly to produce accurately centered suspension holes inthe cubes. See Fig. 1 of Test Method D61 for details.5.5 HooksTwo L-shaped hooks made of 2.06 mm or12-gauge copper wire. The foot of the hook shall be 25 mm1 in. in l
21、ength and at a right angle to the upright portion forinsertion into the central hole of the pitch cube. The uprightportion shall have a partial loop at the top to fit over the supportring, and shall be of the proper length, approximately 50 mm2 in., to position the foot on an imaginary line runningh
22、orizontally through the center of the windows.5.6 ThermometerASTM High-Softening PointThermometer, having a range from 30 to 200C 80 to 400F,and conforming to the requirements for Thermometer 16C asdescribed in Specification E1. Temperature measuring devicessuch as precision thermocouples, resistanc
23、e temperature detec-tors (RTDs), and liquid-in-glass thermometers with equal orbetter accuracies in the appropriate temperature range may beused.5.7 Heat Source:5.7.1 Electric HeaterA hot plate provided with a variabletransformer or other device for regulating the temperature ofthe heating element.
24、It should be shielded from drafts on threesides.5.7.2 Gas Burner, bunsen-type, with a chimney and asensitive valve for regulating the size of the flame.6. Bulk Sampling6.1 Samples from shipments shall be taken in accordancewith Practice D4296 and shall be free of foreign substances.Thoroughly mix th
25、e sample before removing a representativeportion for the determination or for dehydration.7. Dehydration7.1 If the bulk sample contains free water, air-dry a repre-sentative portion in a forced draft oven at 50C.8. Test Specimens8.1 To melt a solid pitch sample, add the material to acontainer having
26、 a height equal to or exceeding its width, anda volume of not less than 50 mL, until it is about half full. Placethe container on a hot plate, or in an oven or bath. Do not usean open flame for melting pitch. After melting is complete, stirthoroughly but gently with the thermometer or glass rod,avoi
27、ding the incorporation of air bubbles. The maximumtemperature shall not exceed the expected softening point bymore than 50C 90F. Any foam that may form must beskimmed off the surface.8.2 Coat the inner surfaces and core pins of the mold lightlywith silicone oil or silicone grease. Pour molten pitch
28、into thecavities of the mold with the lip of the container close to thesurface to minimize entrainment of air bubbles. Underpouringpast the blade of a spatula is helpful in this respect. Even smallbubbles markedly effect the weight of the cube and theobserved softening point. Use an excess of pitch
29、to allow forshrinkage on cooling. Cool in the mold until firm, and removethe surplus by drawing the heated blade of a putty-knife orspatula across the surface of the mold so that the cubes arepressed into the cavities. Open the mold and remove the cubescarefully. Inspect each specimen for possible c
30、racks or bubblesand reject any which are imperfect. To reduce the risk ofcracking, the mold may be heated to a temperature 50C 90Fbelow the expected softening point before the specimens arepoured.8.3 Place two cubes of pitch on hooks, as shown in Fig. 1 ofTest Method D61, warming the hooks slightly
31、if necessary. Thefoot of the hook passes through the center of two oppositefaces, while the other four shall be at an angle of 45 to thehorizontal. The shaft of the hook shall be 3 to 5 mm 0.1 to0.2 in. from the specimen.9. Preparation of Apparatus9.1 Assemble the apparatus in an area free of drafts
32、.9.2 Ensure that the oven, cover, and pan are clean, bright,and free of dents, since tarnished or dirty apparatus maychange the apparent softening point. After each determination,carefully clean the hooks with a solvent for pitch. Avoidscraping or other mechanical methods that may alter thediameter
33、of the wire, which shall be checked frequently forconformance with the specified 2.05 to 2.07 mm 0.082 in.diameter.9.3 Set the pan on its legs on the bottom of the oven. Centerit so that the space for air circulation is approximately equal allaround the circumference. Place a single 110 mm 4.4 in. f
34、ilterpaper on the pan.9.4 Specimens and oven are normally at room temperature.For harder pitches, the oven may be preheated to a temperaturenot higher than 60C 108F below the expected softeningpoint.10. Procedure10.1 Suspend the hooks with the test specimens in placefrom the supporting ring on the o
35、ven cover with the tips of thehooks pointing toward each other from the left and right sidesof the thermometer as viewed through the windows. The feet ofthe hooks shall lie along an imaginary horizontal line throughthe center of the windows.10.2 Insert the thermometer through a cork in the centralho
36、le in the cover so that the bottom of the bulb is level with thebottom edges of the cubes, and the ends of the feet of the hooksare close to, but do not touch, the bulb.D2319/D2319M 14210.3 Center the oven on the heat source and place the shieldaround it so that the two are concentric.10.4 Preheat t
37、he oven if necessary and, when equilibrium isestablished, adjust the heating rate so that the temperature risesat 5C/min 10F/min. The maximum permissible variationfrom this rate shall be 61.0C/min 62F/min for the final50C 90F below the softening point.10.5 Maintain a written record of the temperatur
38、e to 0.25C0.5F for each minute over the last 50C 90F. Averagethese readings algebraically. The average shall not deviatemore than 60.5C 61F from the 5C/min 10F/min overthis interval. Reject any test in which the rate for any minute inthis interval is outside the range from 4 to 6C 7 to 11F, orthe av
39、erage is outside the range from 4.5 to 5.5C 8 to 10F.10.6 The softening point is the average of the thermometerreadings (with no correction for emergent stem) when the twocubes touch the pan. Estimate the readings to 0.25C 0.5F.If the individual values differ by more than 1.5C 2.7F,reject the result
40、 and repeat the test.11. Report11.1 Report the average as the softening point to the nearest1F. If the result is required in degrees Celsius, report to thenearest 0.5C.12. Precision and Bias12.1 The following criteria shall be used to judge theacceptability of results (95 % confidence level) for sof
41、teningpoint (cube-in-air):12.1.1 RepeatabilityDuplicate results by the same opera-tor shall not be considered suspect unless they differ by morethan 1.0C 2F.12.1.2 ReproducibilityThe values reported by each of twolaboratories, representing the arithmetic average of duplicatedeterminations, shall not
42、 be considered suspect unless theydiffer by more than 7.2F 4.0C.12.1.3 BiasThis procedure has no bias because the valueof softening point is defined in terms of this test method.13. Keywords13.1 cube-in-air; pitch; softening pointSUMMARY OF CHANGESSubcommittee D02.05 has identified the location of s
43、elected changes to this standard since the last issue(D2319/D2319M 98 (2013) that may impact the use of this standard. (Approved May 1, 2014.)(1) Revised subsection 5.6.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin
44、this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must
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46、esponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700,
47、 West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D2319/D2319M 143
