1、Designation: D6549 06 (Reapproved 2015)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 Nickel Alloy Corrosion and Heat Resistant Bars,Fo
6、rgings 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 andLubri
7、cants3. 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 pyrrolidon
8、e)(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
9、Fig. 1, Fig. 2, and Fig. 3, respectively.3.1.2 cooling curvethe cooling curve is a graphical repre-sentation 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 characteris
10、tics 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 temperat
11、ure 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 unde
12、r 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 te
13、st method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.L0.06 on Non-Lubricating Process Fluids.Current edition approved July 1, 2015. Published July 2015. Originally approvedin 2000. Last previo
14、us edition approved in 2011 as D6549 06 (2011). DOI:10.1520/D6549-06R15.2For 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 AS
15、TM website.3Available from 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
16、.6The boldface numbers in parentheses refer to the list of references at the end ofthis standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.6 quench severitythe ability of a quenching medium toextract heat from a hot metal (8
17、).FIG. 1 Effect of Quenchant 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) Quen-chant at 0.5 m/sFIG. 3 Effect of Agitation
18、Rate Variation on Cooling Curve Performance for a 15 % Aqueous Poly(Alkylene Glycol) Quenchant Solutionat 30CD6549 06 (2015)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 8
19、50 C (1562 F) and thenquenched 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 seve
20、rity (see Note 1).NOTE 1Where appropriate for production testing, a furnace tempera-ture from 815 C to 857 C (1500 F to 1575 F) 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 physicalproperties, such as the h
21、ardness obtainable upon quenching ofa metal. The results obtained by this test method may be usedas a 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, fo
22、rging lubricants, and polymer 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 850 C (1562 F) ov
23、er a heatedlength of not less than 120 mm (4.72 in.) and a probe posi-tioned in the center of the heating chamber. The furnace shallbe capable of maintaining the probes temperature within62.5 C (4.5 F) over the specimen length. The furnace, thatis, the radiant tube heating media, shall be used with
24、ambientatmosphere.7.2 Measurement SystemThe 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
25、 respectto time and cooling rate with respect to temperature.7.3 ProbeThe probe shall be cylindrical, having a diam-eter of 12.5 mm 6 0.01 mm (0.492 in. 6 0.0004 in.) and alength of 60 mm 6 0.25 mm (2.362 in. 6 0.01 in.) with a1.45 mm to 1.65 mm (0.057 in. to 0.065 in.) sheathed Type Kthermocouple i
26、n its geometric center. The probe shall be madeof a nickel Alloy 600 (UNS N06600), purchased in accordancewith 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 shall be attached to a support tube with a minimumlength of 200 mm (7.8
27、74 in.). The thermocouple sheathing andthe support tube shall be the same material as the probe (seeNote 2). See Fig. 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 Agitat
28、ion Unit:7.4.1 ConstructionThe sample container, a 2000 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 g
29、eometriccenter of the container. As shown in Fig. 6, the 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 agitatio
30、n assembly shall be cleanedprior to use with a detergent solution. After cleaning, theassembly shall be rinsed with water at least three times toensure that no quenchant residue or detergent solution remains.NOTE 1a) Cooling Curve; b) Cooling Rate CurveFIG. 4 Typical Temperature/Time and Temperature
31、/Cooling Rate Plots for Test Probe Cooled in a Quenching OilD6549 06 (2015)3NOTE 1Dimensions above are nominal.FIG. 5 Probe Details and General Probe AssemblyFIG. 6 Drayton Agitation UnitD6549 06 (2015)47.4.3 Flow VelocityThe variable speed pump and flowmeter allow reproducible setting of quenchant
32、flow through thetube. The flowmeter is calibrated for water at 25 C. 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. Theref
33、ore, the coolingcurve test shall be performed with a fixed volume of fluid.7.5 Temperature MeasurementAny temperature detectiondevice may be used that is capable of measuring quenchingfluid temperature to within 61 C (1.8 F).7.6 Transfer MechanismOne of the following shall beused to transfer the hea
34、ted probe from the furnace to the testfluid.7.6.1 Mechanical TransferThe 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 trans
35、ferred to theagitation unit through a probe guide, which is set (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 b
36、e used to ensure a maximumtransfer time of 3.0 s.7.7 Timer, graduated 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 ref
37、erence fluid shall be evaluated forcompliance to the specified values for the six primary charac-teristics. These characteristics, as defined in Wolfson Engineer-ing Group Specification, are as follows:Time to cool to 600 C (1112 F) 12 s14 sTime to cool to 400 C (752 F) 19 s21 sTime to cool to 200 C
38、 (392 F) 50 s55 sMaximum cooling rate 47 C s53 C s(85 F s95 F s)Temperature of the maximum cooling rate 490 C530 C(914 F986 F)Cooling rate at 300 C (572 F) 6 C s8 C s(10.8 F s14.4 F s)8.1.1 If results do not comply with the specified ranges, theprobe shall be replaced or reconditioned (see 9.3) or s
39、ystemadjustments made. Compliance to the specified limits of theprimary reference fluid is 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 c
40、alibration (9, 10).8.1.2 A secondary reference fluid may be used, providedthat sufficient statistical 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
41、fluids shall be stored in a sealed containerwhen not in use and shall be replaced after 200 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,
42、wet, lintless cotton cloth or absorbent paper after removal fromthe quenchant and prior to 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 a temperatu
43、rebelow visual hot temperatures can still cause injury to the skinor ignition of the cloth or paper used in cleaning.)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 ac
44、lean, neutral, general purpose hydrocarbon oil. Clean theprobe assembly between quenches, as 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 thenrecalibra
45、te again in accordance with 12.3. Do not use probesthat do not meet these requirements.9.3 Probe 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.
46、Recondition the probe bypolishing with emery paper. Although coarser 320-grit papermay be used 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 r
47、eference fluid.10. Sampling10.1 Take care that the gross media, from which the sampleis taken 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 Appa
48、ratus11.1 Preheat furnace to 850 C 6 2 C (1562 F 6 4 F), oralternatively, to 815 C to 857 C (1500 F to 1575 F) forproduction testing.FIG. 7 Commercially Available Drayton Agitation UnitD6549 06 (2015)511.2 Connect a dry, conditioned, calibrated probe in accor-dance with the equipment manufacturers i
49、nstructions, andinsert in furnace.11.3 Heat or cool the aqueous polymer quenchant to thedesired temperature 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 C 6 2 C (104 F6 3.6 F), but do not agitate the fluid during the calibrationtest.12. Calibration and Standardization12.1 Probe:12.1.1 Check the accuracy of the pro
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