1、Designation: D6666 04 (Reapproved 2014)Standard Guide forEvaluation of Aqueous Polymer Quenchants1This standard is issued under the fixed designation D6666; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.
2、 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 guide provides information, without specific limits,for selecting standard test methods for testing aqueous polymerquenchants f
3、or initial qualification, determining quality, andthe effect of aging.1.2 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
4、 applica-bility of regulatory requirements prior to use.2. Referenced Documents2.1 ASTM Standards:2D95 Test Method for Water in Petroleum Products andBituminous Materials by DistillationD445 Test Method for Kinematic Viscosity of Transparentand Opaque Liquids (and Calculation of Dynamic Viscos-ity)D
5、892 Test Method for Foaming Characteristics of Lubricat-ing OilsD1744 Test Method for Determination of Water in LiquidPetroleum Products by Karl Fischer ReagentD1747 Test Method for Refractive Index of Viscous Mate-rialsD1796 Test Method for Water and Sediment in Fuel Oils bythe Centrifuge Method (L
6、aboratory Procedure)D2624 Test Methods for Electrical Conductivity of Aviationand Distillate FuelsD3519 Test Method for Foam in Aqueous Media (BlenderTest) (Withdrawn 2013)3D3601 Test Method for Foam In Aqueous Media (BottleTest) (Withdrawn 2013)3D3867 Test Methods for Nitrite-Nitrate in WaterD4327
7、Test Method for Anions in Water by Suppressed IonChromatographyD5296 Test Method for Molecular Weight Averages andMolecular Weight Distribution of Polystyrene by HighPerformance Size-Exclusion ChromatographyD6482 Test Method for Determination of Cooling Charac-teristics of Aqueous Polymer Quenchants
8、 by CoolingCurve Analysis with Agitation (Tensi Method)D6549 Test Method for Determination of Cooling Charac-teristics of Quenchants by Cooling Curve Analysis withAgitation (Drayton Unit)E70 Test Method for pH of Aqueous Solutions With theGlass ElectrodeE979 Practice for Evaluation of Antimicrobial
9、Agents asPreservatives for Invert Emulsion and Other Water Con-taining Hydraulic FluidsE2275 Practice for Evaluating Water-Miscible Metalwork-ing Fluid Bioresistance and Antimicrobial Pesticide Per-formance3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 austenite, nsolid solut
10、ion of one or more elements inface-centered cubic iron (gamma iron) and unless otherwisedesignated, the solute is generally assumed to be carbon (1).43.1.2 austenitizing, nforming austenite by heating a fer-rous alloy into the transformation range (partial austenitizing)or above the transformation r
11、ange (complete austenitizing).When used without qualification, the term implies completeaustenitizing (1).3.1.3 aqueous polymer quenchant, na solution containingwater, and one or more water-soluble polymers includingpoly(alkylene glycol), poly(vinyl pyrrolidone), poly(sodiumacrylate), and poly(ethyl
12、 oxazoline) (2, 3) and additives forcorrosion and foam control, if needed.3.1.4 biodegradation, nthe process by which a substrate isconverted by biological, usually microbiological, agents intosimple, environmentally acceptable derivatives. (4)1This guide is under the jurisdiction of ASTM Committee
13、D02 on PetroleumProducts, Liquid Fuels, and Lubricants and is the direct responsibility of Subcom-mittee D02.L0.06 on Non-Lubricating Process Fluids.Current edition approved May 1, 2014. Published July 2014. Originally approvedin 2001. Last previous edition approved in 2009 as D6666 04 (2009). DOI:1
14、0.1520/D6666-04R14.2For 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 last approved version of this histori
15、cal standard is referenced onwww.astm.org.4The 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 States13.1.5 biodeterioration, nloss of product quality
16、 and per-formance and could be regarded as the initial stages ofbiodegradation (see 3.1.4) , but in the wrong place at the wrongtime, that is when the product is stored or in use. (4)3.1.6 convective cooling, nafter continued cooling, andthe interfacial temperature between the cooling metal and thea
17、queous polymer quenchant is less than the boiling point of thewater in the quenchant solution at which point cooling occursby a convective cooling process. For convective cooling, fluidmotion is due to density differences and the action of gravityand includes both natural motion and forced circulati
18、on (1, 5).This process is illustrated in Fig. 1.3.1.7 cooling curve, na graphical representation of thecooling time (t)temperature (T) response of the probe such asthat shown in Fig. 1. (5)3.1.8 cooling curve analysis, nthe process of quantifyingthe cooling characteristics of a quenchant medium base
19、d on thetemperature versus time profile obtained by cooling a pre-heated metal probe assembly (see Fig. 2) under specifiedconditions which include: probe alloy and dimensions, probeand bath temperature, agitation rate, and aqueous polymerquenchant concentration.3.1.9 cooling rate curve, nobtained by
20、 calculating the firstderivative (dT/dt) of the cooling time-temperature curve asillustrated in Fig. 1. (5)3.1.10 dragout, nsolution carried out of a bath on themetal being quenched and associated handling equipment. (1)3.1.11 full-film boiling, nupon initial immersion of hotsteel into a quenchant s
21、olution, a vapor blanket surrounds themetal surface resulting in full-film boiling as shown in Fig. 1.(5)3.1.12 nucleate boiling, nwhen the vapor blanket sur-rounding the hot metal collapses and a nucleate boiling processoccurs as illustrated in Fig. 1. (5)3.1.13 quenchant medium, nany liquid or gas
22、, or mixture,used to control the cooling of a metal to facilitate the formationof the desired microstructure and properties. (1)3.1.14 quench severity, nthe ability of a quenchant me-dium to extract heat from hot metal. (6)3.1.15 transformation temperatures, ncharacteristic tem-peratures that are im
23、portant in the formation of martensiticmicrostructure of steel including: Ae1equilibrium austeniti-zation phase change temperature; MStemperature at whichtransformation of austenite to martensite starts during coolingand Mftemperature at which transformation of austenite tomartensite is completed du
24、ring cooling. (1)4. Significance and Use4.1 The significance and use of each test method willdepend on the system in use and the purpose of the test methodlisted under Section 7. Use the most recent editions of the testmethods.5. Quenching Process5.1 Aqueous Polymer Quenchant Cooling MechanismsUpon
25、initial immersion of a heated metal into a solution ofan aqueous polymer quenchant, an insulating polymer film,which controls the heat transfer rate from the hot metal into thecooler quenchant solution, forms around the hot metal which isseparated by a vapor film (Fig. 3) (7) for the quenching proce
26、ssin a poly(alkylene glycol) quenchant. The overall heat transfermediating properties of the film are dependent on both the filmthickness (a function of polymer concentration) and interfacialfilm viscosity (a function of polymer type and bath tempera-ture). The timing of film formation and subsequen
27、t film ruptureand removal is dependent on the film strength of the polymer,agitation (both direction and mass flow), and turbulence of thepolymer solution surrounding the cooling metal.FIG. 1 Cooling Mechanisms of the Quenching ProcessD6666 04 (2014)25.1.1 The cooling process that occurs upon initia
28、l immer-sion of the hot metal into the aqueous polymer quenchant isfull-film boiling. This is frequently referred to as the vaporblanket stage. Cooling is slowest in this region. When the metalhas cooled sufficiently, the polymer film encapsulating the hotmetal ruptures and a nucleate boiling proces
29、s results. Thetemperature at the transition from full-film boiling to nucleateboiling is called the Leidenfrost temperature. Cooling is fastestin this region. When the surface temperature of the coolingmetal is less than the boiling temperature of water, convectivecooling results. All three cooling
30、mechanisms are superim-posed on a cooling curve and illustrated in Fig. 3. (7)6. Sampling6.1 SamplingFlow is never uniform in agitated quenchtanks. There is always variation of flow rate and turbulenceNOTE 1From Wolfson Engineering Group Specification, available from Wolfson Heat Treatment Centre, A
31、ston University, Aston Triangle,Birmingham B4 7ET, England, 1980.FIG. 2 Schematic Illustration of the Probe Details and Probe AssemblyFIG. 3 Illustration of the Three Phases of CoolingD6666 04 (2014)3from top to bottom and across the tank. This means there maybe significant variations of particulate
32、 contamination includingcarbon from the heat treating process and metal scale. Foruniform sampling, a number of sampling recommendationshave been developed.6.1.1 Sampling Recommendations:6.1.1.1 Minimum Sampling TimeThe circulation pumpsshall be in operation for at least 1 h prior to taking a sample
33、from the quench system.6.1.1.2 Sampling PositionFor each system, the well-mixed sample shall be taken from the same position each timethat system is sampled. The position in the tank where thesample is taken shall be recorded.6.1.1.3 Sampling ValuesIf a sample is taken from asampling valve, then suf
34、ficient quenchant should be taken anddiscarded to ensure that the sampling valve and associatedpiping has been flushed before the sample is taken.6.1.1.4 Effect of Quenchant Addition as Make-Up due toDragoutIt is important to determine the quantity and fre-quency of new quenchant additions, as large
35、 additions of newquenchant solution will have an effect on the test results, inparticular, the cooling curve. If a sample was taken just after alarge addition of new quenchant, this shall be taken intoconsideration when interpreting the cooling curve for thissample.6.1.1.5 Sampling ContainersSamples
36、 shall be collected innew containers. Under no circumstances shall used beverage orfood containers be used because of the potential for fluidcontamination and leakage.7. Recommended Test Procedures7.1 Performance-Related Physical and Chemical Proper-ties:7.1.1 AppearanceContamination of aqueous poly
37、merquenchants by such fluids as hydraulic or quench oils mayresult in a non-uniform quench with thermal gradients suffi-cient to cause cracking or increased distortion, or possiblestaining, of the metal being quenched. The simplest test (and anexcellent test) is to examine the appearance of an aqueo
38、uspolymer quenchant in a clear glass container, such as a bottle.A sample of an oil-contaminated fluid is illustrated in Fig. 4.(7) However, if the oil readily separates from the aqueouspolymer quenchant solution (Fig. 4), it may be removed byskimming. On the other hand, oil may form a milky-whiteem
39、ulsion which is not readily reclaimed by heat treaters.7.1.1.1 Other problems that are easy to identify visuallyinclude carbon and sludge contamination which often results incracking problems. Metal scale contamination is often identi-fiable by its magnetic properties by placing a magnet on theoutsi
40、de of the bottle next to the scale and determining if thescale exhibits any attraction for the magnet. Carbon, sludge,and scale may be removed from the quenchant by filtration orcentrifugation. Alternatively, the quenchant mixture may beallowed to settle, the quenchant solution pumped off, and these
41、parated solids then removed by shoveling. The amount ofinsoluble suspended solids or tramp oils may be quantified bya modification of Test Method D1796 where the aqueousquenchant is centrifuged without further dilution as describedin the method. The amount of tramp oil in the quenchant isdetermined
42、from the insoluble liquid layer at the top of thecentrifuge tube and the volume of the insoluble sediment istaken from the bottom of the centrifuge tube.7.1.2 Refractive Index, (Test Method D1747)One of themost common methods of monitoring the concentration ofaqueous polymer quenchants formulated us
43、ing poly(alkyleneglycol) coploymers is refractive index. As Fig. 5 (7) shows,there is a linear relationship between quenchant concentrationand refractive index. The refractive index of the quenchantsolution is determined using an Abb refractometer (TestMethod D1747) equipped with a constant temperat
44、ure bath.Although the refractive index could potentially be used at anytemperature within the control limits of the constant tempera-ture bath, typically either 40C or 100F is selected.7.1.2.1 Although refractive index is a relatively simple anda rapid method for determination of polymer quenchantco
45、ncentration, it is not sensitive to low levels of polymerdegradation and it is often significantly affected by solutioncontamination.(A) New aqueous polymer quenchant solution.(B) Used quenchant solution with oil contamination (see separated upper layer).FIG. 4 Sample of Oil Contaminated Aqueous Pol
46、ymer QuenchantD6666 04 (2014)4NOTE 1Refractive index is typically unsuitable for aqueous polymerquenchants formulated with polymers with molecular weights greater than50 000 to 60 000 because the total concentration is relatively low. Smallchanges in polymer concentration may result even from normal
47、 use whichimpart significant process effects but the corresponding variation inrefractive index may not be detectable.NOTE 2Although it is most desirable to use an Abb refractometerbecause of its sensitivity, this is only practical in a laboratory environment.In the heat treating industry, for tanks
48、ide monitoring and control, atemperature-compensated handheld refractometer (similar to the oneillustrated in Fig. 6) is used. The hand-held refractometer is self-compensated for temperatures between 60 and 100F. Although there arevarious models available, the most common models provide arbitraryref
49、ractive index readings in Brix units overa0to30range. Typically, thesmallest scale that can be read directly is in divisions of 0.2 as shown inFig. 7. A concentration-refractive index curve obtained by a hand-heldrefractometer is shown in Fig. 8. (7) Hand-held refractometers areavailable whose scale readings correlate directly to the concentration ofthe polymer quenchant being used. This is particularly convenient forindustrial tank-side use. However, since refractive index varies withcontamination (such as dissolved salts) that may accumula
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