ASTM D6666-04(2014)
(Guide)Standard Guide for Evaluation of Aqueous Polymer Quenchants
Standard Guide for Evaluation of Aqueous Polymer Quenchants
SIGNIFICANCE AND USE
4.1 The significance and use of each test method will depend on the system in use and the purpose of the test method listed under Section 7. Use the most recent editions of the test methods.
SCOPE
1.1 This guide provides information, without specific limits, for selecting standard test methods for testing aqueous polymer quenchants for initial qualification, determining quality, and the effect of aging.
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory requirements prior to use.
General Information
Relations
Buy Standard
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D6666 − 04 (Reapproved 2014)
Standard Guide for
Evaluation of Aqueous Polymer Quenchants
This standard is issued under the fixed designation D6666; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope D3867 Test Methods for Nitrite-Nitrate in Water
D4327 Test Method for Anions in Water by Suppressed Ion
1.1 This guide provides information, without specific limits,
Chromatography
forselectingstandardtestmethodsfortestingaqueouspolymer
D5296 Test Method for Molecular Weight Averages and
quenchants for initial qualification, determining quality, and
Molecular Weight Distribution of Polystyrene by High
the effect of aging.
Performance Size-Exclusion Chromatography
1.2 This standard does not purport to address all of the
D6482 Test Method for Determination of Cooling Charac-
safety concerns, if any, associated with its use. It is the
teristics of Aqueous Polymer Quenchants by Cooling
responsibility of the user of this standard to establish appro-
Curve Analysis with Agitation (Tensi Method)
priate safety and health practices and determine the applica-
D6549 Test Method for Determination of Cooling Charac-
bility of regulatory requirements prior to use.
teristics of Quenchants by Cooling Curve Analysis with
Agitation (Drayton Unit)
2. Referenced Documents
E70 Test Method for pH of Aqueous Solutions With the
2.1 ASTM Standards:
Glass Electrode
D95 Test Method for Water in Petroleum Products and
E979 Practice for Evaluation of Antimicrobial Agents as
Bituminous Materials by Distillation
Preservatives for Invert Emulsion and Other Water Con-
D445 Test Method for Kinematic Viscosity of Transparent
taining Hydraulic Fluids
and Opaque Liquids (and Calculation of Dynamic Viscos-
E2275 Practice for Evaluating Water-Miscible Metalwork-
ity)
ing Fluid Bioresistance and Antimicrobial Pesticide Per-
D892 Test Method for Foaming Characteristics of Lubricat-
formance
ing Oils
D1744 Test Method for Determination of Water in Liquid
3. Terminology
Petroleum Products by Karl Fischer Reagent
3.1 Definitions of Terms Specific to This Standard:
D1747 Test Method for Refractive Index of Viscous Mate-
3.1.1 austenite, n—solidsolutionofoneormoreelementsin
rials
face-centered cubic iron (gamma iron) and unless otherwise
D1796 Test Method for Water and Sediment in Fuel Oils by
designated, the solute is generally assumed to be carbon (1).
the Centrifuge Method (Laboratory Procedure)
3.1.2 austenitizing, n—forming austenite by heating a fer-
D2624 Test Methods for Electrical Conductivity ofAviation
rous alloy into the transformation range (partial austenitizing)
and Distillate Fuels
or above the transformation range (complete austenitizing).
D3519 Test Method for Foam in Aqueous Media (Blender
When used without qualification, the term implies complete
Test) (Withdrawn 2013)
austenitizing (1).
D3601 Test Method for Foam In Aqueous Media (Bottle
Test) (Withdrawn 2013)
3.1.3 aqueous polymer quenchant, n—a solution containing
water, and one or more water-soluble polymers including
poly(alkylene glycol), poly(vinyl pyrrolidone), poly(sodium
This guide is under the jurisdiction of ASTM Committee D02 on Petroleum
acrylate), and poly(ethyl oxazoline) (2, 3) and additives for
Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcom-
corrosion and foam control, if needed.
mittee D02.L0.06 on Non-Lubricating Process Fluids.
CurrenteditionapprovedMay1,2014.PublishedJuly2014.Originallyapproved
3.1.4 biodegradation, n—theprocessbywhichasubstrateis
in 2001. Last previous edition approved in 2009 as D6666 – 04 (2009). DOI:
converted by biological, usually microbiological, agents into
10.1520/D6666-04R14.
simple, environmentally acceptable derivatives. (4)
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
3 4
The last approved version of this historical standard is referenced on The boldface numbers in parentheses refer to the list of references at the end of
www.astm.org. this standard.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6666 − 04 (2014)
FIG. 1 Cooling Mechanisms of the Quenching Process
3.1.5 biodeterioration, n—loss of product quality and per- 3.1.13 quenchant medium, n—any liquid or gas, or mixture,
formance and could be regarded as the initial stages of usedtocontrolthecoolingofametaltofacilitatetheformation
biodegradation(see3.1.4),butinthewrongplaceatthewrong of the desired microstructure and properties. (1)
time, that is when the product is stored or in use. (4)
3.1.14 quench severity, n—the ability of a quenchant me-
3.1.6 convective cooling, n—after continued cooling, and
dium to extract heat from hot metal. (6)
the interfacial temperature between the cooling metal and the
3.1.15 transformation temperatures, n—characteristic tem-
aqueous polymer quenchant is less than the boiling point of the
peratures that are important in the formation of martensitic
water in the quenchant solution at which point cooling occurs
microstructure of steel including: A —equilibrium austeniti-
e1
by a convective cooling process. For convective cooling, fluid
zation phase change temperature; M —temperature at which
S
motion is due to density differences and the action of gravity
transformation of austenite to martensite starts during cooling
and includes both natural motion and forced circulation (1, 5).
and M—temperature at which transformation of austenite to
f
This process is illustrated in Fig. 1.
martensite is completed during cooling. (1)
3.1.7 cooling curve, n—a graphical representation of the
coolingtime(t)—temperature(T)responseoftheprobesuchas
4. Significance and Use
that shown in Fig. 1. (5)
4.1 The significance and use of each test method will
3.1.8 cooling curve analysis, n—the process of quantifying
depend on the system in use and the purpose of the test method
thecoolingcharacteristicsofaquenchantmediumbasedonthe
listed under Section 7. Use the most recent editions of the test
temperature versus time profile obtained by cooling a pre-
methods.
heated metal probe assembly (see Fig. 2) under specified
conditions which include: probe alloy and dimensions, probe
5. Quenching Process
and bath temperature, agitation rate, and aqueous polymer
quenchant concentration.
5.1 Aqueous Polymer Quenchant Cooling Mechanisms
—Upon initial immersion of a heated metal into a solution of
3.1.9 cooling rate curve, n—obtained by calculating the first
an aqueous polymer quenchant, an insulating polymer film,
derivative (dT/dt) of the cooling time-temperature curve as
which controls the heat transfer rate from the hot metal into the
illustrated in Fig. 1. (5)
cooler quenchant solution, forms around the hot metal which is
3.1.10 dragout, n—solution carried out of a bath on the
separatedbyavaporfilm(Fig.3) (7)forthequenchingprocess
metal being quenched and associated handling equipment. (1)
in a poly(alkylene glycol) quenchant. The overall heat transfer
3.1.11 full-film boiling, n—upon initial immersion of hot
mediating properties of the film are dependent on both the film
steel into a quenchant solution, a vapor blanket surrounds the
thickness (a function of polymer concentration) and interfacial
metal surface resulting in full-film boiling as shown in Fig. 1.
film viscosity (a function of polymer type and bath tempera-
(5)
ture).Thetimingoffilmformationandsubsequentfilmrupture
3.1.12 nucleate boiling, n—when the vapor blanket sur- and removal is dependent on the film strength of the polymer,
rounding the hot metal collapses and a nucleate boiling process agitation (both direction and mass flow), and turbulence of the
occurs as illustrated in Fig. 1. (5) polymer solution surrounding the cooling metal.
D6666 − 04 (2014)
NOTE 1—From Wolfson Engineering Group Specification, available from Wolfson Heat Treatment Centre, Aston University, Aston Triangle,
Birmingham B4 7ET, England, 1980.
FIG. 2 Schematic Illustration of the Probe Details and Probe Assembly
FIG. 3 Illustration of the Three Phases of Cooling
5.1.1 The cooling process that occurs upon initial immer- cooling results. All three cooling mechanisms are superim-
sion of the hot metal into the aqueous polymer quenchant is posed on a cooling curve and illustrated in Fig. 3. (7)
full-film boiling. This is frequently referred to as the vapor
blanketstage.Coolingisslowestinthisregion.Whenthemetal
6. Sampling
has cooled sufficiently, the polymer film encapsulating the hot
6.1 Sampling—Flow is never uniform in agitated quench
metal ruptures and a nucleate boiling process results. The
tanks. There is always variation of flow rate and turbulence
temperature at the transition from full-film boiling to nucleate
from top to bottom and across the tank. This means there may
boiling is called the Leidenfrost temperature. Cooling is fastest
be significant variations of particulate contamination including
in this region. When the surface temperature of the cooling
metal is less than the boiling temperature of water, convective
D6666 − 04 (2014)
(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 Quenchant
carbon from the heat treating process and metal scale. For (7) However, if the oil readily separates from the aqueous
uniform sampling, a number of sampling recommendations polymer quenchant solution (Fig. 4), it may be removed by
have been developed. skimming. On the other hand, oil may form a milky-white
6.1.1 Sampling Recommendations: emulsion which is not readily reclaimed by heat treaters.
6.1.1.1 Minimum Sampling Time—The circulation pumps 7.1.1.1 Other problems that are easy to identify visually
shall be in operation for at least 1 h prior to taking a sample includecarbonandsludgecontaminationwhichoftenresultsin
from the quench system. cracking problems. Metal scale contamination is often identi-
6.1.1.2 Sampling Position—For each system, the well- fiable by its magnetic properties by placing a magnet on the
mixed sample shall be taken from the same position each time outside of the bottle next to the scale and determining if the
that system is sampled. The position in the tank where the scale exhibits any attraction for the magnet. Carbon, sludge,
sample is taken shall be recorded. and scale may be removed from the quenchant by filtration or
6.1.1.3 Sampling Values—If a sample is taken from a centrifugation. Alternatively, the quenchant mixture may be
sampling valve, then sufficient quenchant should be taken and allowed to settle, the quenchant solution pumped off, and the
discarded to ensure that the sampling valve and associated separated solids then removed by shoveling. The amount of
piping has been flushed before the sample is taken. insoluble suspended solids or tramp oils may be quantified by
6.1.1.4 Effect of Quenchant Addition as Make-Up due to a modification of Test Method D1796 where the aqueous
Dragout—It is important to determine the quantity and fre- quenchant is centrifuged without further dilution as described
quency of new quenchant additions, as large additions of new in the method. The amount of tramp oil in the quenchant is
quenchant solution will have an effect on the test results, in determined from the insoluble liquid layer at the top of the
particular, the cooling curve. If a sample was taken just after a centrifuge tube and the volume of the insoluble sediment is
large addition of new quenchant, this shall be taken into taken from the bottom of the centrifuge tube.
consideration when interpreting the cooling curve for this 7.1.2 Refractive Index, (Test Method D1747)—One of the
sample. most common methods of monitoring the concentration of
6.1.1.5 Sampling Containers—Samples shall be collected in aqueous polymer quenchants formulated using poly(alkylene
newcontainers.Undernocircumstancesshallusedbeverageor glycol) coploymers is refractive index. As Fig. 5 (7) shows,
food containers be used because of the potential for fluid there is a linear relationship between quenchant concentration
contamination and leakage. and refractive index. The refractive index of the quenchant
solution is determined using an Abbé refractometer (Test
7. Recommended Test Procedures
Method D1747) equipped with a constant temperature bath.
Although the refractive index could potentially be used at any
7.1 Performance-Related Physical and Chemical Proper-
temperature within the control limits of the constant tempera-
ties:
ture bath, typically either 40ºC or 100ºF is selected.
7.1.1 Appearance—Contamination of aqueous polymer
7.1.2.1 Although refractive index is a relatively simple and
quenchants by such fluids as hydraulic or quench oils may
a rapid method for determination of polymer quenchant
result in a non-uniform quench with thermal gradients suffi-
concentration, it is not sensitive to low levels of polymer
cient to cause cracking or increased distortion, or possible
degradation and it is often significantly affected by solution
staining,ofthemetalbeingquenched.Thesimplesttest(andan
contamination.
excellent test) is to examine the appearance of an aqueous
polymer quenchant in a clear glass container, such as a bottle.
NOTE 1—Refractive index is typically unsuitable for aqueous polymer
A sample of an oil-contaminated fluid is illustrated in Fig. 4. quenchantsformulatedwithpolymerswithmolecularweightsgreaterthan
D6666 − 04 (2014)
FIG. 5 Illustration of the Linear Relationship Between Refractive Index and Concentration
50 000 to 60 000 because the total concentration is relatively low. Small
7.1.5 Water Content (Test Methods D95 and D1744)—
changes in polymer concentration may result even from normal use which
Aqueous polymer quenchants are composed of water, a water
impart significant process effects but the corresponding variation in
soluble polymer and an additive package to provide corrosion
refractive index may not be detectable.
inhibition,foamcontrol,andsoforth.Therefore,determination
NOTE 2—Although it is most desirable to use an Abbé refractometer
becauseofitssensitivity,thisisonlypracticalinalaboratoryenvironment. of water content is necessary to establish the concentration
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D6666 − 04 (Reapproved 2009) D6666 − 04 (Reapproved 2014)
Standard Guide for
Evaluation of Aqueous Polymer Quenchants
This standard is issued under the fixed designation D6666; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This guide provides information, without specific limits, for selecting standard test methods for testing aqueous polymer
quenchants for initial qualification, determining quality, and the effect of aging.
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
requirements prior to use.
2. Referenced Documents
2.1 ASTM Standards:
D95 Test Method for Water in Petroleum Products and Bituminous Materials by Distillation
D445 Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity)
D892 Test Method for Foaming Characteristics of Lubricating Oils
D1744 Test Method for Determination of Water in Liquid Petroleum Products by Karl Fischer Reagent
D1747 Test Method for Refractive Index of Viscous Materials
D1796 Test Method for Water and Sediment in Fuel Oils by the Centrifuge Method (Laboratory Procedure)
D2624 Test Methods for Electrical Conductivity of Aviation and Distillate Fuels
D3519 Test Method for Foam in Aqueous Media (Blender Test) (Withdrawn 2013)
D3601 Test Method for Foam In Aqueous Media (Bottle Test) (Withdrawn 2013)
D3867 Test Methods for Nitrite-Nitrate in Water
D4327 Test Method for Anions in Water by Suppressed Ion Chromatography
D5296 Test Method for Molecular Weight Averages and Molecular Weight Distribution of Polystyrene by High Performance
Size-Exclusion Chromatography
D6482 Test Method for Determination of Cooling Characteristics of Aqueous Polymer Quenchants by Cooling Curve Analysis
with Agitation (Tensi Method)
D6549 Test Method for Determination of Cooling Characteristics of Quenchants by Cooling Curve Analysis with Agitation
(Drayton Unit)
E70 Test Method for pH of Aqueous Solutions With the Glass Electrode
E979 Practice for Evaluation of Antimicrobial Agents as Preservatives for Invert Emulsion and Other Water Containing
Hydraulic Fluids
E2275 Practice for Evaluating Water-Miscible Metalworking Fluid Bioresistance and Antimicrobial Pesticide Performance
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 austenite, n—solid solution of one or more elements in face-centered cubic iron (gamma iron) and unless otherwise
designated, the solute is generally assumed to be carbon (1).
This guide is under the jurisdiction of ASTM Committee D02 on Petroleum Products Products, Liquid Fuels, and Lubricants and is the direct responsibility of
Subcommittee D02.L0.06 on Non-Lubricating Process Fluids.
Current edition approved April 15, 2009May 1, 2014. Published July 2009July 2014. Originally approved in 2001. Last previous edition approved in 20042009 as
D6666 – 04.D6666 – 04 (2009). DOI: 10.1520/D6666-04R09.10.1520/D6666-04R14.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
The boldface numbers in parentheses refer to the list of references at the end of this standard.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6666 − 04 (2014)
FIG. 1 Cooling Mechanisms of the Quenching Process
3.1.2 austenitizing, n—forming austenite by heating a ferrous alloy into the transformation range (partial austenitizing) or above
the transformation range (complete austenitizing). When used without qualification, the term implies complete austenitizing (1).
3.1.3 aqueous polymer quenchant, n—a solution containing water, and one or more water-soluble polymers including
poly(alkylene glycol), poly(vinyl pyrrolidone), poly(sodium acrylate), and poly(ethyl oxazoline) (2, 3) and additives for corrosion
and foam control, if needed.
3.1.4 biodegradation, n—the process by which a substrate is converted by biological, usually microbiological, agents into
simple, environmentally acceptable derivatives. (4)
3.1.5 biodeterioration, n—loss of product quality and performance and could be regarded as the initial stages of biodegradation
(see 3.1.4) , but in the wrong place at the wrong time, that is when the product is stored or in use. (4)
3.1.6 convective cooling, n—after continued cooling, and the interfacial temperature between the cooling metal and the aqueous
polymer quenchant is less than the boiling point of the water in the quenchant solution at which point cooling occurs by a
convective cooling process. For convective cooling, fluid motion is due to density differences and the action of gravity and includes
both natural motion and forced circulation (1, 5). This process is illustrated in Fig. 1.
3.1.7 cooling curve, n—a graphical representation of the cooling time (t)—temperature (T) response of the probe such as that
shown in Fig. 1. (5)
3.1.8 cooling curve analysis, n—the process of quantifying the cooling characteristics of a quenchant medium based on the
temperature versus time profile obtained by cooling a preheated metal probe assembly (see Fig. 2) under specified conditions which
include: probe alloy and dimensions, probe and bath temperature, agitation rate, and aqueous polymer quenchant concentration.
3.1.9 cooling rate curve, n—obtained by calculating the first derivative (dT/dt) of the cooling time-temperature curve as
illustrated in Fig. 1. (5)
3.1.10 dragout, n—solution carried out of a bath on the metal being quenched and associated handling equipment. (1)
3.1.11 full-film boiling, n—upon initial immersion of hot steel into a quenchant solution, a vapor blanket surrounds the metal
surface resulting in full-film boiling as shown in Fig. 1. (5)
3.1.12 nucleate boiling, n—when the vapor blanket surrounding the hot metal collapses and a nucleate boiling process occurs
as illustrated in Fig. 1. (5)
3.1.13 quenchant medium, n—any liquid or gas, or mixture, used to control the cooling of a metal to facilitate the formation
of the desired microstructure and properties. (1)
3.1.14 quench severity, n—the ability of a quenchant medium to extract heat from hot metal. (6)
3.1.15 transformation temperatures, n—characteristic temperatures that are important in the formation of martensitic
microstructure of steel including: A —equilibrium austenitization phase change temperature; M —temperature at which
e1 S
transformation of austenite to martensite starts during cooling and M —temperature at which transformation of austenite to
f
martensite is completed during cooling. (1)
D6666 − 04 (2014)
NOTE 1—From Wolfson Engineering Group Specification, available from Wolfson Heat Treatment Centre, Aston University, Aston Triangle,
Birmingham B4 7ET, England, 1980.
FIG. 2 Schematic Illustration of the Probe Details and Probe Assembly
4. Significance and Use
4.1 The significance and use of each test method will depend on the system in use and the purpose of the test method listed under
Section 7. Use the most recent editions of the test methods.
5. Quenching Process
5.1 Aqueous Polymer Quenchant Cooling Mechanisms —Upon initial immersion of a heated metal into a solution of an aqueous
polymer quenchant, an insulating polymer film, which controls the heat transfer rate from the hot metal into the cooler quenchant
solution, forms around the hot metal which is separated by a vapor film (Fig. 3) (7) for the quenching process in a poly(alkylene
glycol) quenchant. The overall heat transfer mediating properties of the film are dependent on both the film thickness (a function
of polymer concentration) and interfacial film viscosity (a function of polymer type and bath temperature). The timing of film
formation and subsequent film rupture and removal is dependent on the film strength of the polymer, agitation (both direction and
mass flow), and turbulence of the polymer solution surrounding the cooling metal.
5.1.1 The cooling process that occurs upon initial immersion of the hot metal into the aqueous polymer quenchant is full-film
boiling. This is frequently referred to as the vapor blanket stage. Cooling is slowest in this region. When the metal has cooled
sufficiently, the polymer film encapsulating the hot metal ruptures and a nucleate boiling process results. The temperature at the
transition from full-film boiling to nucleate boiling is called the Leidenfrost temperature. Cooling is fastest in this region. When
the surface temperature of the cooling metal is less than the boiling temperature of water, convective cooling results. All three
cooling mechanisms are superimposed on a cooling curve and illustrated in Fig. 3. (7)
6. Sampling
6.1 Sampling—Flow is never uniform in agitated quench tanks. There is always variation of flow rate and turbulence from top
to bottom and across the tank. This means there may be significant variations of particulate contamination including carbon from
the heat treating process and metal scale. For uniform sampling, a number of sampling recommendations have been developed.
6.1.1 Sampling Recommendations:
6.1.1.1 Minimum Sampling Time—The circulation pumps shall be in operation for at least 1 h prior to taking a sample from the
quench system.
6.1.1.2 Sampling Position—For each system, the well-mixed sample shall be taken from the same position each time that system
is sampled. The position in the tank where the sample is taken shall be recorded.
6.1.1.3 Sampling Values—If a sample is taken from a sampling valve, then sufficient quenchant should be taken and discarded
to ensure that the sampling valve and associated piping has been flushed before the sample is taken.
6.1.1.4 Effect of Quenchant Addition as Make-Up due to Dragout—It is important to determine the quantity and frequency of
new quenchant additions, as large additions of new quenchant solution will have an effect on the test results, in particular, the
D6666 − 04 (2014)
FIG. 3 Illustration of the Three Phases of Cooling
cooling curve. If a sample was taken just after a large addition of new quenchant, this shall be taken into consideration when
interpreting the cooling curve for this sample.
6.1.1.5 Sampling Containers—Samples shall be collected in new containers. Under no circumstances shall used beverage or
food containers be used because of the potential for fluid contamination and leakage.
7. Recommended Test Procedures
7.1 Performance-Related Physical and Chemical Properties:
7.1.1 Appearance—Contamination of aqueous polymer quenchants by such fluids as hydraulic or quench oils may result in a
non-uniform quench with thermal gradients sufficient to cause cracking or increased distortion, or possible staining, of the metal
being quenched. The simplest test (and an excellent test) is to examine the appearance of an aqueous polymer 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 aqueous polymer quenchant solution (Fig. 4), it may be removed by skimming. On the other hand, oil may form
a milky-white emulsion which is not readily reclaimed by heat treaters.
7.1.1.1 Other problems that are easy to identify visually include carbon and sludge contamination which often results in
cracking problems. Metal scale contamination is often identifiable by its magnetic properties by placing a magnet on the outside
of the bottle next to the scale and determining if the scale exhibits any attraction for the magnet. Carbon, sludge, and scale may
be removed from the quenchant by filtration or centrifugation. Alternatively, the quenchant mixture may be allowed to settle, the
quenchant solution pumped off, and the separated solids then removed by shoveling. The amount of insoluble suspended solids
or tramp oils may be quantified by a modification of Test Method D1796 where the aqueous quenchant is centrifuged without
further dilution as described in the method. The amount of tramp oil in the quenchant is determined from the insoluble liquid layer
at the top of the centrifuge tube and the volume of the insoluble sediment is taken from the bottom of the centrifuge tube.
7.1.2 Refractive Index, (Test Method D1747)—One of the most common methods of monitoring the concentration of aqueous
polymer quenchants formulated using poly(alkylene glycol) coploymers is refractive index. As Fig. 5 (7) shows, there is a linear
relationship between quenchant concentration and refractive index. The refractive index of the quenchant solution is determined
using an Abbé refractometer (Test Method D1747) equipped with a constant temperature bath. Although the refractive index could
potentially be used at any temperature within the control limits of the constant temperature bath, typically either 40ºC or 100ºF
is selected.
7.1.2.1 Although refractive index is a relatively simple and a rapid method for determination of polymer quenchant
concentration, it is not sensitive to low levels of polymer degradation and it is often significantly affected by solution
contamination.
NOTE 1—Refractive index is typically unsuitable for aqueous polymer quenchants formulated with polymers with molecular weights greater than 50
000 to 60 000 because the total concentration is relatively low. Small changes in polymer concentration may result even from normal use which impart
significant process effects but the corresponding variation in refractive index may not be detectable.
NOTE 2—Although it is most desirable to use an Abbé refractometer because of its sensitivity, this is only practical in a laboratory environment. In
D6666 − 04 (2014)
(A) New aqueous polymer quenchant solution.
(B) Used quenchant solution with oil contamin
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.