1、Designation: D 6666 04An American National StandardStandard Guide forEvaluation of Aqueous Polymer Quenchants1This standard is issued under the fixed designation D 6666; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of l
2、ast 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 guide provides information, without specific limits,for selecting standard test methods for testing aqueous polym
3、erquenchants for 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
4、 determine the applica-bility of regulatory requirements prior to use.2. Referenced Documents2.1 ASTM Standards:2D 95 Test Method for Water in Petroleum Products andBituminous Materials by DistillationD 445 Test Method for Kinematic Viscosity of Transparentand Opaque Liquids (and the Calculation of
5、DynamicViscosity)D 892 Test Method for Foaming Characteristics of Lubri-cating OilsD 1744 Test Method for Determination of Water in LiquidPetroleum Products by Karl Fisher Reagent3D 1747 Test Method for Refractive Index of Viscous Mate-rialsD 1796 Test Method for Water and Sediment in Fuel Oils byth
6、e Centrifuge Method (Laboratory Procedure)D 2624 Test Method for Electrical Conductivity of Aviationand Distillate FuelsD 3519 Test Method for Foam in Aqueous Media (BlenderTest)D 3601 Test Method for Foam in Aqueous Media (BottleTest)D 3867 Test Methods for Nitrite-Nitrate in WaterD 4327 Test Metho
7、d for Anions in Water by ChemicallySuppressed Ion ChromatographyD 5296 Test Method for Molecular Weight Averages andMolecular Weight Distribution of Polystyrene by High-Performance Size-Exclusion ChromatographyD 6482 Test Method for Determination of Cooling Charac-teristics of Aqueous Polymer Quench
8、ants by CoolingCurve Analysis with Agitation (Tensi Method)D 6549 Test Method for Determination of Cooling Charac-teristics of Quenchants by Cooling Curve Analysis withAgitation (Drayton Unit)E 70 Test Method for pH of Aqueous Solutions With theGlass ElectrodeE 979 Test Method for Evaluation of Anti
9、microbial Agentsas Preservatives for Invert Emulsion and Other WaterContaining Hydraulic FluidsE 2275 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, nso
10、lid solution of one or more elementsin face-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 transfo
11、rmation range (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 p
12、oly(ethyl oxazoline) (2, 3) and additives forcorrosion and foam control, if needed.3.1.4 biodegradation, nthe process by which a substrateis converted by biological, usually microbiological, agents intosimple, environmentally acceptable derivatives. (4)1This guide is under the jurisdiction of ASTM C
13、ommittee D02 on PetroleumProducts and Lubricants and is the direct responsibility of Subcommittee D02.L0.06on Nonlubricating Process Fluids.Current edition approved Nov. 1, 2004. Published November 2004. Originallyapproved in 2001. Last previous edition approved in 2001 as D 6666 01a.2For referenced
14、 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.3Withdrawn.4The boldface numbers in parentheses refer to the list of referen
15、ces at the end ofthis standard.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.1.5 biodeterioration, nloss of product quality and per-formance and could be regarded as the initial stages ofbiodegradation (see 3.1.4) , but in the wr
16、ong 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 theaqueous polymer quenchant is less than the boiling point of thewater in the quenchant solution at which poi
17、nt 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 circulation (1, 5).This process is illustrated in Fig. 1.3.1.7 cooling curve, na graphical representation of thecoo
18、ling 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 based on thetemperature versus time profile obtained by cooling a pre-heated metal probe assembly (see Fig. 2)
19、 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 calculating the firstderivative (dT/dt) of the cooling time-temperature curve asillustrated in Fig. 1. (5
20、)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 solution, a vapor blanket surrounds themetal surface resulting in full-film boiling as shown in Fig. 1.(5)3
21、.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, or mixture,used to control the cooling of a metal to facilitate the formationof the desired microstructu
22、re 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 important in the formation of martensiticmicrostructure of steel including: Ae1equilibrium austeniti-zation
23、phase change temperature; MStemperature at whichtransformation of austenite to martensite starts during coolingand Mftemperature at which transformation of austenite tomartensite is completed during cooling. (1)4. Significance and Use4.1 The significance and use of each test method willdepend on the
24、 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 initial immersion of a heated metal into a solution of anaqueous polymer quenchant, an insulating polymer
25、film, whichcontrols the heat transfer rate from the hot metal into the coolerquenchant solution, forms around the hot metal which isseparated by a vapor film (Fig. 3) (7) for the quenching processin a poly(alkylene glycol) quenchant. The overall heat transfermediating properties of the film are depe
26、ndent 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 subsequent film ruptureand removal is dependent on the film strength of the polymer,agitation (both direction and m
27、ass flow), and turbulence of thepolymer solution surrounding the cooling metal.FIG. 1 Cooling Mechanisms of the Quenching ProcessD66660425.1.1 The cooling process that occurs upon initial immer-sion of the hot metal into the aqueous polymer quenchant isfull-film boiling. This is frequently referred
28、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 process results. Thetemperature at the transition from full-film boiling to nucleateboiling is called the Leidenfrost te
29、mperature. 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 mechanisms are superim-posed on a cooling curve and illustrated in Fig. 3. (7)6. Sampling6.1 SamplingFlow is never
30、 uniform in agitated quenchtanks. There is always variation of flow rate and turbulenceNOTEFrom Wolfson Engineering Group Specification, available from Wolfson Heat Treatment Centre,Aston University,Aston Triangle, BirminghamB4 7ET, England, 1980.FIG. 2 Schematic Illustration of the Probe Details an
31、d Probe AssemblyFIG. 3 Illustration of the Three Phases of CoolingD6666043from top to bottom and across the tank. This means there maybe significant variations of particulate contamination includingcarbon from the heat treating process and metal scale. Foruniform sampling, a number of sampling recom
32、mendationshave 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 samplefrom the quench system.6.1.1.2 Sampling PositionFor each system, the well-mixed sample shall be taken from the same position e
33、ach 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 sufficient quenchant should be taken anddiscarded to ensure that the sampling valve and associatedpiping has been flushed before
34、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 additions of newquenchant solution will have an effect on the test results, inparticular, the cooling curve. If a sample was
35、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 shall be collected innew containers. Under no circumstances shall used beverage orfood containers be used because of the pote
36、ntial for fluidcontamination and leakage.7. Recommended Test Procedures7.1 Performance-Related Physical and Chemical Proper-ties:7.1.1 AppearanceContamination of aqueous polymerquenchants by such fluids as hydraulic or quench oils mayresult in a non-uniform quench with thermal gradients suffi-cient
37、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 aqueouspolymer quenchant in a clear glass container, such as a bottle.A sample of an oil-contaminated fluid is illustrated in Fig.
38、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-whiteemulsion which is not readily reclaimed by heat treaters.7.1.1.1 Other problems that are easy to identify visuallyinclude carbon
39、 and sludge contamination which often results incracking problems. Metal scale contamination is often identi-fiable by its magnetic properties by placing a magnet on theoutside of the bottle next to the scale and determining if thescale exhibits any attraction for the magnet. Carbon, sludge,and scal
40、e may be removed from the quenchant by filtration orcentrifugation. Alternatively, the quenchant mixture may beallowed to settle, the quenchant solution pumped off, and theseparated solids then removed by shoveling. The amount ofinsoluble suspended solids or tramp oils may be quantified bya modifica
41、tion of Test Method D 1796 where the aqueousquenchant is centrifuged without further dilution as describedin the method. The amount of tramp oil in the quenchant isdetermined from the insoluble liquid layer at the top of thecentrifuge tube and the volume of the insoluble sediment istaken from the bo
42、ttom of the centrifuge tube.7.1.2 Refractive Index, (Test Method D 1747)One of themost common methods of monitoring the concentration ofaqueous polymer quenchants formulated using poly(alkyleneglycol) coploymers is refractive index. As Fig. 5 (7) shows,there is a linear relationship between quenchan
43、t concentrationand refractive index. The refractive index of the quenchantsolution is determined using an Abb refractometer (TestMethod D 1747) equipped with a constant temperature bath.Although the refractive index could potentially be used at anytemperature within the control limits of the constan
44、t 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 quenchant con-centration, it is not sensitive to low levels of polymer degra-dation and it is often significantly affected by solution
45、 con-tamination.(A) New aqueous polymer quenchant solution.(B) Used quenchant solution with oil contamination (see separated upper layer).FIG. 4 Sample of Oil Contaminated Aqueous Polymer QuenchantD6666044NOTE 1Refractive index is typically unsuitable for aqueous polymerquenchants formulated with po
46、lymers 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 use whichimpart significant process effects but the corresponding variation inrefractive index may not be detectable.NOTE 2A
47、lthough 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 tankside monitoring and control, atemperature-compensated handheld refractometer (similar to the oneillustrated in Fig. 6) is used
48、. The hand-held refractometer is self-compensated for temperatures between 60 and 100F. Although there arevarious models available, the most common models provide arbitraryrefractive index readings in Brix units overa0to30range. Typically, thesmallest scale that can be read directly is in divisions
49、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 accumulate fromevaporation of hard water, the actual quenchant concentration shall beverified periodically by other methods, and appropri
