1、Designation: D 2319 98 (Reapproved 2003)An American National StandardStandard Test Method forSoftening Point of Pitch (Cube-in-Air Method)1This standard is issued under the fixed designation D 2319; the number immediately following the designation indicates the year oforiginal adoption or, in the ca
2、se 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.1. Scope1.1 This test method covers the determination of the soft-ening point above 176F (80C) of pit
3、ch. Test Method D 3104gives comparable results.1.2 The values stated in SI units are to be regarded as thestandard.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
4、safety and health 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)D 3104 Test Method for Softening Point of Pitches (MettlerSoftening Point Method)D 4296
5、Practice for Sampling PitchE1 Specification for ASTM 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.
6、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 contr
7、olled 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
8、 in.)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 supp
9、ortthe hooks with attached specimens. The ring shall be made of6mm(14-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 t
10、he oven, an inner pan 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-gage (BWG)copper
11、sheet, and the bottom of 0.8 mm (0.032 in.) thick or21-gage 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 mm(8 in.) in height.5.3 Shield for Oven:5.3.1 For Use wit
12、h 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.)diameter mica windows on opposite sides, positioned tocoincide with the windows of the oven when both are placed onthe electric heater. It shall
13、 be made of 0.7 mm (0.028 in.) thickor 22-gage sheet metal, painted inside and out with aluminumpaint.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.05 on Properties of Fuels, Petroleum Coke an
14、d Carbon Material.Current edition approved Nov. 1, 2003. Published November 2003. Originallyapproved in 1964. Last previous edition approved in 1998 as D 231998.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book o
15、f 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 HumboldtManufacturing Co., 7302 W. Agatite Ave., Chicago
16、, 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 apparatus itemsdescribed may be obtained from
17、any regular laboratory equipment supply house.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.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 mm(15 in.) in height a
18、nd 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 mm(12-in.) cubes of pitch, having cylindric
19、al core pins 12 gage(2.05 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 D61for details.5.5 HooksTwo L-shaped hooks made of 2.06 mm or12-gage copper wire. The foot of the hook shall be 25 mm (1in
20、.) 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 proper length, approximately 50 mm(2 in.), to position the foot on an imaginary line
21、 runninghorizontally through the center of the windows.5.6 ThermometerASTM High-Softening Point Thermom-eter, having a range from 30 to 200C (80 to 400F), andconforming to the requirements for Thermometer 16C asdescribed in Specification E1.5.7 Heat Source:5.7.1 Electric HeaterA hot plate provided w
22、ith 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 be
23、taken in accordancewith Practice D 4296 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 ove
24、n at 50C.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 p
25、itch. 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 50C (90F). Any foam that may form must beskimmed off the surface.8.2 Coat the inner
26、 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 smallbubb
27、les 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 i
28、nto 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 50C (90F)below the expected softening point before the specimens arepoured.8.3
29、 Place two cubes of pitch on hooks, as shown in Fig. 1 ofTest Method D61, warming the hooks slightly if necessary.The foot 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 to 0.
30、2in.) 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 clean th
31、e 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 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 spac
32、e 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 60C (108F) below the expected softenin
33、gpoint.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 imaginary
34、horizontal line throughthe center of the windows.10.2 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 bulb.10.3 Center the oven on
35、 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 5C/min (10F/min). The maximum permissible variationfrom this rate shall be 61.0C/min (62F/min)
36、 for the final50C (90F) below the softening point.10.5 Maintain a written record of the temperature to 0.25C(0.5F ) 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
37、 test in which the rate for any minute inD 2319 98 (2003)2this interval is outside the range from 4 to 6C (7 to 11F), orthe average 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 twoc
38、ubes 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 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.
39、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 1.0C (2F).12.1.2 Re
40、producibilityThe values reported by each of twolaboratories, representing the arithmetic average of duplicatedeterminations, shall not 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 thi
41、s test method.13. Keywords13.1 cube-in-air; pitch; softening pointASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any s
42、uch 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 be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invi
43、ted either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received
44、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, 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).D 2319 98 (2003)3
