1、Designation: D2319/D2319M 141Standard 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 r
2、evision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1NOTEEditorial changes were made throughout the test method in September 2014.1. Scope*1.1 This test method covers the determination of
3、the soft-ening point above 80 C 176 F of pitch. Test Method D3104gives comparable 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 independe
4、ntly of the other. Combiningvalues from the two systems may result in non-conformancewith 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 h
5、ealth practices and determine the applica-bility of regulatory limitations prior 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 S
6、ampling PitchE1 Specification for ASTM Liquid-in-Glass Thermometers3. Summary of 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
7、.4 in.4. Significance and Use4.1 Pitch does not go through a solid-liquid phase changewhen 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 contro
8、lled method that must becarefully followed if test results are to be reproducible.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 i
9、n.in inside diameter by 155 mm 6.2 in. in height. It shall havetwo 75 mm 3 in. diameter 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 ho
10、oks with attached specimens. The ring shall be made of6mm14 in. brass, shall be 54 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 p
11、an 140 mm 5.6 in. in diametershall rest on three brass legs 5 mm 0.2 in. in height 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
12、 0.8 mm 0.032 in. thick or21 gauge copper.5.2 Tripod for Use with Gas BurnerThe tripod 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.1This test method is under the jurisdiction of ASTM Committee D02
13、onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.05 on Properties of Fuels, Petroleum Coke and Carbon Material.Current edition approved May 1, 2014. Published May 2014. Originallyapproved in 1964. Last previous edition approved in 2013 as D2319/D
14、2319M 98 (2013). DOI: 10.1520/D2319_D2319M-14E01.2For 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 ASTM website.3The sole so
15、urce of supply of the softening point apparatus items, obtainable asa unit on special order, known to the committee at this time is HumboldtManufacturing Co., 7302 W. Agatite Ave., Chicago, IL 60656. If you are aware ofalternative suppliers, please provide this information to ASTM InternationalHeadq
16、uarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee,1which you may attend. All other apparatus itemsdescribed may be obtained from any regular laboratory equipment supply house.*A Summary of Changes section appears at the end of this standardC
17、opyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15.3 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 height. It shall have two 76 mm or 3 in.
18、diameter mica windows on opposite sides, positioned tocoincide with the windows of the 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-t
19、ical with that described in 5.3.1 except that it shall be 375 mm15 in. in height and the windows shall coincide when theshield is standing on the bench and the oven on the tripoddescribed in 5.2.Adoor 115 mm by 115 mm 412 in. by 412 in.shall be provided at the bottom to give access to the burner.5.4
20、 MoldA mold suitable for forming two 12.7 mm12 in. cubes of pitch, having cylindrical core pins 12 gauge2.05 mm to 2.07 mm in diameter located in the base plate ofthe assembly to produce accurately centered suspension holesin the cubes. See Fig. 1 of Test Method D61 for details.5.5 HooksTwo L-shaped
21、 hooks made of 2.06 mm or12 gauge copper wire. The foot of the hook shall be 25 mm1 in. in length 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
22、 proper length, approximately 50 mm2 in., to position the foot on an imaginary line runninghorizontally through the center of the windows.5.6 ThermometerASTM High-Softening PointThermometer, having a range from 30 C to 200 C 80 F to400 F, and conforming to the requirements for Thermometer16C as desc
23、ribed in Specification E1. Temperature measuringdevices such as precision thermocouples, resistance tempera-ture detectors (RTDs), and liquid-in-glass thermometers withequal or better accuracies in the appropriate temperature rangemay be used.5.7 Heat Source:5.7.1 Electric HeaterA hot plate provided
24、 with a variabletransformer or other device for regulating the temperature ofthe heating element. 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 b
25、e taken in accordancewith Practice D4296 and shall be free of foreign substances.Thoroughly mix the 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 ov
26、en at 50 C.8. Test Specimens8.1 To melt a solid pitch sample, add the material to acontainer having 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
27、 pitch. After melting is complete, stirthoroughly but gently with the thermometer or glass rod,avoiding the incorporation of air bubbles. The maximumtemperature shall not exceed the expected softening point bymore than 50 C 90 F. Any foam that may form must beskimmed off the surface.8.2 Coat the inn
28、er surfaces and core pins of the mold lightlywith silicone oil or silicone grease. Pour molten pitch 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 smallbu
29、bbles markedly effect the weight of the cube and theobserved softening point. Use an excess of pitch 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
30、 into the cavities. Open the mold and remove the cubescarefully. Inspect each specimen for possible cracks or bubblesand reject any which are imperfect. To reduce the risk ofcracking, the mold may be heated to a temperature 50 C90 F below the expected softening point before the speci-mens are poured
31、.8.3 Place two cubes of pitch on hooks, as shown in Fig. 1 ofTest Method D61, warming the hooks slightly 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 mm to 5 mm0.1
32、in. to 0.2 in. from the specimen.9. Preparation of Apparatus9.1 Assemble the apparatus in an area free of drafts.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
33、 clean the hooks with a solvent for pitch. Avoidscraping or other mechanical methods that may alter thediameter of the wire, which shall be checked frequently forconformance with the specified 2.05 mm to 2.07 mm0.082 in. diameter.9.3 Set the pan on its legs on the bottom of the oven. Centerit so tha
34、t the space for air circulation is approximately equal allaround the circumference. Place a single 110 mm 4.4 in. filterpaper 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 60 C 108 F below the expected
35、 softeningpoint.10. Procedure10.1 Suspend the hooks with the test specimens in placefrom the supporting ring on the oven 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 i
36、maginary horizontal line throughthe center of the windows.D2319/D2319M 141210.2 Insert the thermometer through a cork in the centralhole 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 bu
37、lb.10.3 Center the oven on the heat source and place the shieldaround it so that the two are concentric.10.4 Preheat the oven if necessary and, when equilibrium isestablished, adjust the heating rate so that the temperature risesat 5 C min 10 F min. The maximum permissible variationfrom this rate sh
38、all be 61.0 C min 62 F min for the final50 C 90 F below the softening point.10.5 Maintain a written record of the temperature to 0.25 C0.5 F for each minute over the last 50 C 90 F. Averagethese readings algebraically. The average shall not deviatemore than 60.5 C 61 F from the 5 C min 10 F minover
39、this interval. Reject any test in which the rate for anyminute in this interval is outside the range from 4 C to 6 C7 F to 11 F, or the average is outside the range from 4.5 Cto 5.5 C 8 F to 10 F.10.6 The softening point is the average of the thermometerreadings (with no correction for emergent stem
40、) when the twocubes touch the pan. Estimate the readings to 0.25 C 0.5 F.If the individual values differ by more than 1.5 C 2.7 F,reject the result and repeat the test.11. Report11.1 Report the average as the softening point to the nearest1 F. If the result is required in degrees Celsius, report to
41、thenearest 0.5 C.12. Precision and Bias12.1 The following criteria shall be used to judge theacceptability of results (95 % confidence level) for softeningpoint (cube-in-air):12.1.1 RepeatabilityDuplicate results by the same opera-tor shall not be considered suspect unless they differ by morethan 1.
42、0 C 2 F.12.1.2 ReproducibilityThe values reported by each of twolaboratories, representing the arithmetic average of duplicatedeterminations, shall not be considered suspect unless theydiffer by more than 7.2 F 4.0 C.12.1.3 BiasThis procedure has no bias because the valueof softening point is define
43、d in terms of this test method.13. Keywords13.1 cube-in-air; pitch; softening pointSUMMARY OF CHANGESSubcommittee D02.05 has identified the location of selected 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) R
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45、nt of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or
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