1、Designation: D6549 06 (Reapproved 2011)Standard Test Method forDetermination of Cooling Characteristics of Quenchants byCooling Curve Analysis with Agitation (Drayton Unit)1This standard is issued under the fixed designation D6549; the number immediately following the designation indicates the year
2、oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the equipment and the proce-dure
3、for evaluation of quenching characteristics of a quenchingfluid by cooling rate determination.1.2 This test method is designed to evaluate quenchingfluids with agitation, using the Drayton Agitation Unit.1.3 The values stated in SI units are to be regarded asstandard. The values given in parentheses
4、 are for informationonly.1.4 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 pri
5、or to use.2. Referenced Documents2.1 ASTM Standards:2E220 Test Method for Calibration of Thermocouples ByComparison TechniquesE230 Specification and Temperature-Electromotive Force(EMF) Tables for Standardized Thermocouples2.2 SAE Standards:3AMS 5665 NickelAlloy Corrosion and Heat Resistant Bars,For
6、gings and Rings2.3 Other Standards:4Wolfson Engineering Group Specification Laboratory Testsfor Assessing the Cooling Curve Characteristics of Indus-trial Quenching Media2.4 ASTM Adjuncts:5ADJD6300 D2PP, Determination of Precision and BiasData for Use in Test Methods for Petroleum Products andLubric
7、ants3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 aqueous polymer quenchantan aqueous polymerquenchant is an aqueous solution containing a water solublepolymer, typically including poly(alkylene glycol), poly(ethyloxazoline), poly(sodium acrylate), and poly(vinyl pyrrolidone
8、)(1, 2, 3).6The quenchant solution also typically containsadditives for corrosion and foam control, if needed. Quenchseverity of aqueous polymer quenchants is dependent onconcentration and molecular weight of the specific polymerbeing evaluated, quenchant temperature, and agitation rate asshown in F
9、ig. 1, Fig. 2, and Fig. 3, respectively.3.1.2 cooling curvethe cooling curve is a graphical rep-resentation of the cooling time (t) versus temperature (T)response of the probe (see 7.3). An example is illustrated inFig. 4.3.1.3 cooling curve analysisthe process of quantifying thecooling characterist
10、ics of a quenchant based on the temperatureversus time profile obtained by cooling a preheated metal probeassembly (see Fig. 4) under standard conditions (1-7).3.1.4 cooling rate curvethe cooling rate curve is a graphi-cal representation of first derivative of the cooling curve, therate of temperatu
11、re change (dT/dt) versus temperature. Anexample is illustrated in Fig. 4.3.1.5 quenchanta quenching medium may be either aliquid or a gas. Gasses that are used as quenchants include air,nitrogen, argon, and hydrogen and, with the exception of air,which is used at atmospheric pressure, are used under
12、 pressure.Liquid quenchants include water, brine (most commonly diluteaqueous solutions of sodium chloride or sodium hydroxide),oil, molten salt, molten metal, and aqueous solutions of watersoluble polymers. Water, brine, oil, and aqueous polymerquenchants are generally used with agitation.1This tes
13、t method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.L0.06 on Non-Lubricating Process Fluids.Current edition approved May 1, 2011. Published August 2011. Originallyapproved in 2000. Last previous edition appr
14、oved in 2006 as D654906. DOI:10.1520/D6549-06R11.2For 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.3Available f
15、rom SAE International (SAE), 400 Commonwealth Dr., Warrendale,PA 15096-0001, http:/www.sae.org.4Available from Wolfson Heat Treatment Centre, Federation House, Vyse St.,Birmingham, B18 6LT, UK. http:/www.sea.org.uk/whtc.5No longer available from ASTM International Headquarters.6The boldface numbers
16、in parentheses refer to the list of references at the end ofthis standard.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.1.6 quench severitythe ability of a quenching mediumto extract heat from a hot metal (8).FIG. 1 Effect of Que
17、nchant Concentration on Cooling Curve Performance for a Poly(Alkylene Glycol) Quenchant at 30C and 0.5 m/sFIG. 2 Effect of Bath Temperature Variation on Cooling Curve Performance for 15 % Aqueous Solution of Poly(Alkylene Glycol)Quenchant at 0.5 m/sFIG. 3 Effect of Agitation Rate Variation on Coolin
18、g Curve Performance for a 15 % Aqueous Poly(Alkylene Glycol) Quenchant Solutionat 30CD6549 06 (2011)24. Summary of Test Method4.1 This test method determines the cooling time versustemperature of a standard nickel alloy probe assembly after ithas been heated in a furnace to 850C (1562F) and thenquen
19、ched in an aqueous polymer quenchant solution. Thetemperature inside the probe assembly and the cooling timesare recorded at selected time intervals to establish a coolingtemperature versus time curve. The resulting cooling curve(profile) may be used to evaluate quench severity (see Note 1).NOTE 1Wh
20、ere appropriate for production testing, a furnace tempera-ture from 815 to 857C (1500 to 1575F) may be used.5. Significance and Use5.1 This test method provides a cooling time versus tem-perature curve (profile) that can be related to physical proper-ties, such as the hardness obtainable upon quench
21、ing of ametal. The results obtained by this test method may be used asa guide in quenchant selection or as a comparison of quenchseverities of different quenchants, new or used.6. Interferences6.1 The presence of contaminants, such as oil, salt, metal-working fluids, forging lubricants, and polymer
22、degradation,may affect cooling curve results obtained by this test methodfor aqueous polymer quenchants.7. Apparatus7.1 FurnaceUse a horizontal or vertical electrical resis-tance tube-type furnace capable of maintaining a constantminimum temperature of 850C (1562F) over a heated lengthof not less th
23、an 120 mm (4.72 in.) and a probe positioned in thecenter of the heating chamber. The furnace shall be capable ofmaintaining the probes temperature within 62.5C (4.5F)over the specimen length. The furnace, that is, the radiant tubeheating media, shall be used with ambient atmosphere.7.2 Measurement S
24、ystemThe temperature-time measure-ment system shall be a computer based data acquisition systemcapable of providing a permanent record of the coolingcharacteristics of each sample tested, producing a record ofvariation in the test probe assembly of temperature with respectto time and cooling rate wi
25、th respect to temperature.7.3 ProbeThe probe shall be cylindrical, having a diam-eter of 12.5 6 0.01 mm (0.492 6 0.0004 in.) and a length of60 6 0.25 mm (2.362 6 0.01 in.) with a 1.45 to 1.65-mm(0.057 to 0.065-in.) sheathed Type K thermocouple in itsgeometric center. The probe shall be made of a nic
26、kel Alloy600 (UNS N06600), purchased in accordance with AMS 5665,which has a nominal composition of 76.0 % Ni, 15.5 % Cr,8.0 % Fe, 0.08 % C, and 0.25 % maximum Cu. The probe shallbe attached to a support tube with a minimum length of 200mm (7.874 in.). The thermocouple sheathing and the supporttube
27、shall be the same material as the probe (see Note 2). SeeFig. 5 for other manufacturing requirements.NOTE 2Care shall be taken that the probe specimen is not damaged assurface irregularities will influence results of the test.7.4 Drayton Agitation Unit:7.4.1 ConstructionThe sample container, a 2000-
28、mLstainless steel beaker that is the same as the standard containerused in nonagitated cooling curve test, is modified to provideupward or axial flow of the quenchant past the probe. This flowoccurs through a vertical flow tube located in the geometriccenter of the container. As shown in Fig. 6, the
29、 unit includes avariable speed dc drive centrifugal pump and large diameterflowmeter for direct measurement of flow velocity. It is notedthat the flow tube is removable, which will provide a moreturbulent flow pattern.7.4.2 CleaningThe agitation assembly shall be cleanedprior to use with a detergent
30、 solution. After cleaning, theassembly shall be rinsed with water at least three times toensure that no quenchant residue or detergent solution remains.NOTEa) Cooling Curve; b) Cooling Rate CurveFIG. 4 Typical Temperature/Time and Temperature/Cooling Rate Plots for Test Probe Cooled in a Quenching O
31、ilD6549 06 (2011)3NOTEDimensions above are nominal.FIG. 5 Probe Details and General Probe AssemblyFIG. 6 Drayton Agitation UnitD6549 06 (2011)47.4.3 Flow VelocityThe variable speed pump and flowmeter allow reproducible setting of quenchant flow through thetube. The flowmeter is calibrated for water
32、at 25C. Flowvelocity for other fluids will vary with fluid viscosity andtemperature.7.4.4 Fluid VolumeThe resulting cooling curve is influ-enced by the temperature rise during the quench, which isdependent on the total fluid volume. Therefore, the coolingcurve test shall be performed with a fixed vo
33、lume of fluid.7.5 Temperature MeasurementAny temperature detectiondevice may be used that is capable of measuring quenchingfluid temperature to within 61C (1.8F).7.6 Transfer MechanismOne of the following shall beused to transfer the heated probe from the furnace to the testfluid.7.6.1 Mechanical Tr
34、ansferThe agitation unit is positionedwith the center of the test chamber coincident with the probecenterline. The transfer mechanism is set to deliver the probe tothe vertical center of the sample.7.6.2 Manual TransferThe probe is transferred to theagitation unit through a probe guide, which is set
35、 (1) to the testchamber centerline and (2) with a preset stop that causes theprobe to rest in the vertical center of the sample. The unit isillustrated further in the sketch and photograph of Fig. 6 andFig. 7, respectively.Atimer shall be used to ensure a maximumtransfer time of 3.0 s.7.7 Timer, gra
36、duated in seconds and minutes, and may bepart of a computer clock.8. Reagents and Materials8.1 Reference Quenching Fluid, used for initial calibrationand for periodic calibration verification. Data collected fromquench tests with the reference fluid shall be evaluated forcompliance to the specified
37、values for the six primary charac-teristics. These characteristics, as defined in Wolfson Engineer-ing Group Specification, are as follows:Time to cool to 600C (1112F) 12-14 sTime to cool to 400C (752F) 19-21 sTime to cool to 200C (392F) 50-55 sMaximum cooling rate 47-53C/s (85-95F/s)Temperature of
38、the maximum cooling rate 490-530C (914-986F)Cooling rate at 300C (572F) 6-8C/s (10.8-14.4F/s)8.1.1 If results do not comply with the specified ranges, theprobe shall be replaced or reconditioned (see 9.3) or systemadjustments made. Compliance to the specified limits of theprimary reference fluid is
39、critical for establishing the validity ofsubsequent test results. It has been shown that the test methodhas an excellent level of repeatability and reproducibility whenthe probe and system are shown to be in calibration (9, 10).8.1.2 A secondary reference fluid may be used, providedthat sufficient s
40、tatistical cooling curve testing has been con-ducted so that the results are (1) traceable to the primaryreference fluid and (2) compared on the basis of the six primarycooling characteristics.8.1.3 Reference fluids shall be stored in a sealed containerwhen not in use and shall be replaced after 200
41、 quenches ortwo years, whichever is sooner.8.2 Polishing Paper, 600 grit emery.8.3 Cotton Cloth or Paper, lintless and absorbent.9. Cleaning and Conditioning9.1 Cleaning Used ProbesWipe the probe with a clean,wet, lintless cotton cloth or absorbent paper after removal fromthe quenchant and prior to
42、returning to the furnace. Unmountedprobes may be cleaned in the same manner or, alternatively,washed under a stream of water, and then wiped dry.(WarningThe probe shall always be considered hot as atemperature below visual hot temperatures can still causeinjury to the skin or ignition of the cloth o
43、r paper used incleaning.)9.2 Conditioning New ProbesCondition the probe prior toits initial use by carrying out a minimum of six trial quenches,or a grater number if required to achieve consistency, using aclean, neutral, general purpose hydrocarbon oil. Clean theprobe assembly between quenches, as
44、specified in 9.1. Quenchthe probe in the reference quenching fluid and check inaccordance with 12.3. If the probe does not meet the require-ments of 12.3, recondition in accordance with 9.3 and thenrecalibrate again in accordance with 12.3. Do not use probesthat do not meet these requirements.9.3 Pr
45、obe ReconditioningThe probe shall be recondi-tioned when the probe calibration, as described in 12.3, doesnot meet the calibration limits of the six cooling characteristicsspecified for the reference fluid. Recondition the probe bypolishing with emery paper. Although coarser 320-grit papermay be use
46、d for initial polishing, the final finish shall beprovided by use of 600-grit emery paper. Following thisprocedure, the probe shall be quenched until satisfactorycooling curve results are obtained from the reference fluid.10. Sampling10.1 Take care that the gross media, from which the sampleis taken
47、 to fill the agitation unit, is well mixed to ensure that thesample is representative of the media being tested. Anycontainers used to secure the quenchant sample must be cleanand dry.11. Preparation of Apparatus11.1 Preheat furnace to 850 6 2C (1562 6 4F), oralternatively, to 815 to 857C (1500 to 1
48、575F) for productiontesting.FIG. 7 Commercially Available Drayton Agitation UnitD6549 06 (2011)511.2 Connect a dry, conditioned, calibrated probe in accor-dance with the equipment manufacturers instructions, andinsert in furnace.11.3 Heat or cool the aqueous polymer quenchant to thedesired temperatu
49、re if production testing is being performed.Continuously agitate the quenchant sample at the desired flowrate while the sample is being heated. If the primary referencequenching fluid is being tested, heat it to 40 6 2C (104 63.6F), but do not agitate the fluid during the calibration test.12. Calibration and Standardization12.1 Probe:12.1.1 Check the accuracy of the probe thermocouple byattaching a previously calibrated thermocouple to the outersurface of the probe. Locate the tip of the calibrated thermo-couple 30 m
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