ASTM D6549-06(2021)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D6549 − 06 (Reapproved 2021)
Standard Test Method for
Determination of Cooling Characteristics of Quenchants by
Cooling Curve Analysis with Agitation (Drayton Unit)
This standard is issued under the fixed designation D6549; 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 2.3 Other Standards:
Wolfson Engineering Group Specification Laboratory Tests
1.1 This test method covers the equipment and the proce-
forAssessing the Cooling Curve Characteristics of Indus-
dure for evaluation of quenching characteristics of a quenching
trial Quenching Media
fluid by cooling rate determination.
2.4 ASTM Adjuncts:
1.2 This test method is designed to evaluate quenching
ADJD6300 D2PP, Determination of Precision and Bias
fluids with agitation, using the Drayton Agitation Unit.
Data for Use in Test Methods for Petroleum Products and
1.3 The values stated in SI units are to be regarded as Lubricants
standard. The values given in parentheses are for information
3. Terminology
only.
3.1 Definitions of Terms Specific to This Standard:
1.4 This standard does not purport to address all of the
3.1.1 aqueous polymer quenchant, n—an aqueous polymer
safety concerns, if any, associated with its use. It is the
quenchant is an aqueous solution containing a water soluble
responsibility of the user of this standard to establish appro-
polymer, typically including poly(alkylene glycol), poly(ethyl
priate safety, health, and environmental practices and deter-
oxazoline), poly(sodium acrylate), and poly(vinyl pyrrolidone)
mine the applicability of regulatory limitations prior to use.
(1, 2, 3). The quenchant solution also typically contains
1.5 This international standard was developed in accor-
additives for corrosion and foam control, if needed. Quench
dance with internationally recognized principles on standard-
severity of aqueous polymer quenchants is dependent on
ization established in the Decision on Principles for the
concentration and molecular weight of the specific polymer
Development of International Standards, Guides and Recom-
being evaluated, quenchant temperature, and agitation rate as
mendations issued by the World Trade Organization Technical
shown in Fig. 1, Fig. 2, and Fig. 3, respectively.
Barriers to Trade (TBT) Committee.
3.1.2 cooling curve, n—the cooling curve is a graphical
2. Referenced Documents
representation of the cooling time (t) versus temperature (T)
2.1 ASTM Standards: response of the probe (see 7.3). An example is illustrated in
Fig. 4.
E220 Test Method for Calibration of Thermocouples By
Comparison Techniques
3.1.3 cooling curve analysis, n—the process of quantifying
E230 Specification for Temperature-Electromotive Force
the cooling characteristics of a quenchant based on the tem-
(emf) Tables for Standardized Thermocouples
perature versus time profile obtained by cooling a preheated
2.2 SAE Standards:
metal probe assembly (see Fig. 4) under standard conditions
AMS 5665 NickelAlloy Corrosion and Heat Resistant Bars,
(1-7).
Forgings and Rings
3.1.4 cooling rate curve, n—the cooling rate curve is a
graphicalrepresentationoffirstderivativeofthecoolingcurve,
the rate of temperature change (dT/dt) versus temperature. An
This test method is under the jurisdiction of ASTM Committee D02 on
example is illustrated in Fig. 4.
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
Subcommittee D02.L0.06 on Non-Lubricating Process Fluids.
3.1.5 quenchant, n—a quenching medium may be either a
Current edition approved June 15, 2021. Published June 2021. Originally
liquid or a gas. Gasses that are used as quenchants include air,
approved in 2000. Last previous edition approved in 2015 as D6549 – 06 (2015).
DOI: 10.1520/D6549-06R21.
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 Available from Wolfson Heat Treatment Centre, Federation House, Vyse St.,
Standards volume information, refer to the standard’s Document Summary page on Birmingham, B18 6LT, UK. http://www.sea.org.uk/whtc.
the ASTM website. No longer available from ASTM International Headquarters.
3 6
Available from SAE International (SAE), 400 Commonwealth Dr.,Warrendale, The boldface numbers in parentheses refer to the list of references at the end of
PA 15096-0001, http://www.sae.org. this standard.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6549 − 06 (2021)
FIG. 1 Effect of Quenchant Concentration on Cooling Curve Performance for a Poly(Alkylene Glycol) Quenchant at 30 °C and 0.5 m/s
FIG. 2 Effect of Bath Temperature Variation on Cooling Curve Performance for 15 % Aqueous Solution of Poly(Alkylene Glycol) Quen-
chant at 0.5 m/s
FIG. 3 Effect of Agitation Rate Variation on Cooling Curve Performance for a 15 % Aqueous Poly(Alkylene Glycol) Quenchant Solution
at 30 °C
nitrogen, argon, and hydrogen and, with the exception of air, Liquid quenchants include water, brine (most commonly dilute
which is used at atmospheric pressure, are used under pressure. aqueous solutions of sodium chloride or sodium hydroxide),
D6549 − 06 (2021)
NOTE 1—a) Cooling Curve; b) Cooling Rate Curve
FIG. 4 Typical Temperature/Time and Temperature/Cooling Rate Plots for Test Probe Cooled in a Quenching Oil
oil, molten salt, molten metal, and aqueous solutions of water tioned in the center of the heating chamber. The furnace shall
soluble polymers. Water, brine, oil, and aqueous polymer be capable of maintaining the probe’s temperature within
quenchants are generally used with agitation. 62.5 °C (4.5 °F) over the specimen length. The furnace, that
is, the radiant tube heating media, shall be used with ambient
3.1.6 quench severity, n—theabilityofaquenchingmedium
atmosphere.
to extract heat from a hot metal (8).
7.2 Measurement System—The temperature-time measure-
4. Summary of Test Method
ment system shall be a computer based data acquisition system
4.1 This test method determines the cooling time versus
capable of providing a permanent record of the cooling
temperature of a standard nickel alloy probe assembly after it
characteristics of each sample tested, producing a record of
has been heated in a furnace to 850 °C (1562 °F) and then
variationinthetestprobeassemblyoftemperaturewithrespect
quenched in an aqueous polymer quenchant solution. The
to time and cooling rate with respect to temperature.
temperature inside the probe assembly and the cooling times
7.3 Probe—The probe shall be cylindrical, having a diam-
are recorded at selected time intervals to establish a cooling
eter of 12.5 mm 6 0.01 mm (0.492 in. 6 0.0004 in.) and a
temperature versus time curve. The resulting cooling curve
length of 60 mm 6 0.25 mm (2.362 in. 6 0.01 in.) with a
(profile) may be used to evaluate quench severity (see Note 1).
1.45 mm to 1.65 mm (0.057 in. to 0.065 in.) sheathed Type K
NOTE 1—Where appropriate for production testing, a furnace tempera-
thermocouple in its geometric center. The probe shall be made
ture from 815 °C to 857 °C (1500 °F to 1575 °F) may be used.
of a nickelAlloy 600 (UNS N06600), purchased in accordance
with AMS 5665, which has a nominal composition of 76.0 %
5. Significance and Use
Ni, 15.5 % Cr, 8.0 % Fe, 0.08 % C, and 0.25 % maximum Cu.
5.1 This test method provides a cooling time versus tem-
The probe shall be attached to a support tube with a minimum
perature curve (profile) that can be related to physical
length of 200 mm (7.874 in.). The thermocouple sheathing and
properties, such as the hardness obtainable upon quenching of
the support tube shall be the same material as the probe (see
a metal. The results obtained by this test method may be used
Note 2). See Fig. 5 for other manufacturing requirements.
as a guide in quenchant selection or as a comparison of quench
NOTE 2—Care shall be taken that the probe specimen is not damaged as
severities of different quenchants, new or used.
surface irregularities will influence results of the test.
6. Interferences
7.4 Drayton Agitation Unit:
6.1 The presence of contaminants, such as oil, salt, metal-
7.4.1 Construction—The sample container, a 2000 mL
working fluids, forging lubricants, and polymer degradation, stainless steel beaker that is the same as the standard container
may affect cooling curve results obtained by this test method
used in nonagitated cooling curve test, is modified to provide
for aqueous polymer quenchants. upwardoraxialflowofthequenchantpasttheprobe.Thisflow
occurs through a vertical flow tube located in the geometric
7. Apparatus
center of the container.As shown in Fig. 6, the unit includes a
7.1 Furnace—Use a horizontal or vertical electrical resis- variable speed dc drive centrifugal pump and large diameter
tance tube-type furnace capable of maintaining a constant flowmeter for direct measurement of flow velocity. It is noted
minimum temperature of 850 °C (1562 °F) over a heated that the flow tube is removable, which will provide a more
length of not less than 120 mm (4.72 in.) and a probe posi- turbulent flow pattern.
D6549 − 06 (2021)
NOTE 1—Dimensions above are nominal.
FIG. 5 Probe Details and General Probe Assembly
FIG. 6 Drayton Agitation Unit
7.4.2 Cleaning—The agitation assembly shall be cleaned assembly shall be rinsed with water at least three times to
prior to use with a detergent solution. After cleaning, the ensure that no quenchant residue or detergent solution remains.
D6549 − 06 (2021)
7.4.3 Flow Velocity—The variable speed pump and flow 8.1.1 If results do not comply with the specified ranges, the
meter allow reproducible setting of quenchant flow through the probe shall be replaced or reconditioned (see 9.3) or system
tube. The flowmeter is calibrated for water at 25 °C. Flow
adjustments made. Compliance to the specified limits of the
velocity for other fluids will vary with fluid viscosity and
primaryreferencefluidiscriticalforestablishingthevalidityof
temperature.
subsequent test results. It has been shown that the test method
7.4.4 Fluid Volume—The resulting cooling curve is influ-
has an excellent level of repeatability and reproducibility when
enced by the temperature rise during the quench, which is
the probe and system are shown to be in calibration (9, 10).
dependent on the total fluid volume. Therefore, the cooling
8.1.2 A secondary reference fluid may be used, provided
curve test shall be performed with a fixed volume of fluid.
that sufficient statistical cooling curve testing has been con-
7.5 Temperature Measurement—Any temperature detection ducted so that the results are (1) traceable to the primary
device may be used that is capable of measuring quenching
referencefluidand(2)comparedonthebasisofthesixprimary
fluid temperature to within 61 °C (1.8 °F).
cooling characteristics.
7.6 Transfer Mechanism—One of the following shall be 8.1.3 Reference fluids shall be stored in a sealed container
used to transfer the heated probe from the furnace to the test when not in use and shall be replaced after 200 quenches or
fluid. two years, whichever is sooner.
7.6.1 Mechanical Transfer—The agitation unit is positioned
8.2 Polishing Paper, 600 grit emery.
with the center of the test chamber coincident with the probe
centerline.Thetransfermechanismissettodelivertheprobeto
8.3 Cotton Cloth or Paper, lintless and absorbent.
the vertical center of the sample.
7.6.2 Manual Transfer—The probe is transferred to the
9. Cleaning and Conditioning
agitation unit through a probe guide, which is set (1) to the test
9.1 Cleaning Used Probes—Wipe the probe with a clean,
chamber centerline and (2) with a preset stop that causes the
wet, lintless cotton cloth or absorbent paper after removal from
probe to rest in the vertical center of the sample. The unit is
thequenchantandpriortoreturningtothefurnace.Unmounted
illustrated further in the sketch and photograph of Fig. 6 and
probes may be cleaned in the same manner or, alternatively,
Fig.7,respectively.Atimershallbeusedtoensureamaximum
washed under a stream of water, and then wiped dry.
transfer time of 3.0 s.
(Warning—The probe shall always be considered hot as a
7.7 Timer, graduated in seconds and minutes, and may be
temperature below visual hot temperatures can still cause
part of a computer clock.
injury to the skin or ignition of the cloth or paper used in
8. Reagents and Materials cleaning.)
8.1 Reference Quenching Fluid, used for initial calibration
9.2 Conditioning New Probes—Condition the probe prior to
and for periodic calibration verification. Data collected from
its initial use by carrying out a minimum of six trial quenches,
quench tests with the reference fluid shall be evaluated for
or a grater number if required to achieve consistency, using a
compliance to the specified values for the six primary charac-
clean, neutral, general purpose hydrocarbon oil. Clean the
teristics.These characteristics, as defined inWolfson Engineer-
probe assembly between quenches, as specified in 9.1. Quench
ing Group Specification, are as follows:
the probe in the reference quenching fluid and check in
Time to cool to 600 °C (1112 °F) 12 s–14 s
accordance with 12.3. If the probe does not meet the require-
Time to cool to 400 °C (752 °F) 19 s–21 s
ments of 12.3, recondition in accordance with 9.3 and then
Time to cool to 200 °C (392 °F) 50 s–55 s
Maximum cooling rate 47 °C ⁄s–53 °C ⁄s recalibrate again in accordance with 12.3. Do not use probes
(85 °F ⁄s–95 °F ⁄s)
that do not meet these requirements.
Temperature of the maximum cooling rate 490 °C–530 °C
(914 °F–986 °F)
9.3 Probe Reconditioning—The probe shall be recondi-
Cooling rate at 300 °C (572 °F) 6 °C ⁄s–8 °C ⁄s
tioned when the probe calibration, as described in 12.3, does
(10.8 °F ⁄s–14.4 °F ⁄s)
not meet the calibration limits of the six cooling characteristics
specified for the reference fluid. Recondition the probe by
polishing with emery paper. Although coarser 320-grit paper
may be used for initial polishing, the final finish shall be
provided by use of 600-grit emery paper. Following this
procedure, the probe shall be quenched until satisfactory
cooling curve results are obtained from the reference fluid.
10. Sampling
10.1 T
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