ASTM A1033-04

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Designation:A1033–04
Standard Practice for
Quantitative Measurement and Reporting of Hypoeutectoid
Carbon and Low-Alloy Steel Phase Transformations
This standard is issued under the fixed designation A1033; 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.
e 5Dd/d 5 ~d 2 d !/d
1. Scope
D 0 1 0 0
3.1.2 hypoeutectoid steel—a term used to describe a group
1.1 This practice covers the determination of hypoeutectoid
steel phase transformation behavior by using high-speed of carbon steels with a carbon content less than the eutectoid
dilatometry techniques for measuring linear dimensional composition (0.8 % by weight).
changeasafunctionoftimeandtemperature,andreportingthe 3.1.3 longitudinal linear engineering strain—the strain, ei-
resultsaslinearstrainineitheranumericalorgraphicalformat. ther thermal or resulting from phase transformation, that is
1.2 The practice is applicable to high-speed dilatometry determined from a change in length as a result of a change in
equipment capable of programmable thermal profiles and with temperature, or over a period of time, and which is expressed
digital data storage and output capability. as follows:
1.3 This practice is applicable to the determination of steel
e 5Dl/L 5 l 2 l !/l
~
L 0 1 0 0
phase transformation behavior under both isothermal and
3.1.4 steel phase transformation—during heating, the crys-
continuous cooling conditions.
tallographic transformation from ferrite, pearlite, bainite, mar-
1.4 This practice includes requirements for obtaining met-
tensite or combinations of these constituents to austenite.
allographic information to be used as a supplement to the
During cooling, the crystallographic transformation from aus-
dilatometry measurements.
tenitetoferrite,pearlite,bainite,ormartensiteoracombination
1.5 This standard does not purport to address all of the
thereof.
safety concerns, if any, associated with its use. It is the
3.1.5 volumetric engineering strain—the strain, either ther-
responsibility of the user of this standard to establish appro-
mal or resulting from phase transformation, that is determined
priate safety and health practices and determine the applica-
fromachangeinvolumeasaresultofachangeintemperature,
bility of regulatory limitations prior to use.
or over a period of time, and which is expressed as follows:
2. Referenced Documents
e 5Dv/v 5 v 2 v /v
~ !
V 0 1 0 0
2.1 ASTM Standards:
e ' 3e ' 3e
V L D
E3 Guide for Preparation of Metallographic Specimens
3.2 Symbols:
E112 Test Methods for Determining Average Grain Size
e = longitudinal linear engineering strain
L
E407 Practice for Microetching Metals and Alloys
e = diametrical linear engineering strain
D
e = volumetric engineering strain
V
3. Terminology
Dl = change in test specimen length
3.1 Definitions of Terms Specific to This Standard:
l = test specimen length at specific temperature or time, or
3.1.1 diametrical linear engineering strain—the strain, ei-
both
ther thermal or resulting from phase transformation, that is
l = initial test specimen length
determined from a change in diameter as a result of a change
Dd = change in test specimen diameter
intemperature,oroveraperiodoftime,andwhichisexpressed
d = test specimen diameter at specific temperature or time,
as follows:
or both
d = initial test specimen diameter
This practice is under the jurisdiction of ASTM Committee A01 on Steel,
Dv = change in test specimen volume
Stainless Steel and RelatedAlloys and is the direct responsibility of Subcommittee
v = test specimen volume at a specific temperature or time,
A01.13 on Mechanical and Chemical Testing and Processing Methods of Steel
or both
Products and Processes.
Current edition approved March 1, 2004. Published March 2004. DOI: 10.1520/ v = initial test specimen volume
A1033-04.
Ac = the temperature at which austenite begins to form on
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
heating
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.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
A1033–04
Ac = the temperature at which the transformation of ferrite calcompositioncanresultinvariabilityinstrain,andcanaffect
to austenite is complete on heating the results of strain determinations, especially determination of
M = the temperature at which the transformation of auste- volumetric strain. Strains determined during cooling are sen-
s
nite to martensite starts during cooling sitive to the grain size of austenite, which is determined by the
heating cycle. The most consistent results are obtained when
4. Summary of Practice
austenitegrainsizeismaintainedbetweenASTMgrainsizesof
4.1 This practice is based upon the principle that, during
5 to 8. Finally, the eutectoid carbon content is defined as 0.8 %
heating and cooling of steels, dimensional changes occur as a
for carbon steels. Additions of alloying elements can change
result of both thermal expansion associated with temperature
this value, along with Ac and Ac temperatures. Heating
1 3
change and phase transformation. In this practice, sensitive
cycles need to be employed, as described below, to ensure
high-speed dilatometer equipment is used to detect and mea-
completeformationofausteniteprecedingstrainmeasurements
sure the changes in dimension that occur as functions of both
during cooling.
time and temperature during defined thermal cycles. The
6. Ordering Information
resulting data are converted to discrete values of strain for
specific values of time and temperature during the thermal
6.1 When this practice is to be applied to an inquiry,
cycle. Strain as a function of time or temperature, or both, can
contract, or order, the purchaser shall so state and should
then be used to determine the beginning and completion of one
furnish the following information:
or more phase transformations.
6.1.1 The steel grades to be evaluated,
6.1.2 The test apparatus to be used,
5. Significance and Use
6.1.3 The specimen configuration and dimensions to be
5.1 This practice is used to provide steel phase transforma-
used,
tion data required for use in numerical models for the predic-
6.1.4 The thermal cycles to be used, and
tion of microstructures, properties, and distortion during steel
6.1.5 The supplementary requirements desired.
manufacturing, forging, casting, heat treatment, and welding.
7. Apparatus
Alternatively, the practice provides end users of steel and
fabricatedsteelproductsthephasetransformationdatarequired
7.1 This practice is applicable to several types of commer-
for selecting steel grades for a given application by determin-
cially available high-speed dilatometer apparatus, which have
ing the microstructure resulting from a prescribed thermal
certain common features. These include the capabilities for:
cycle.
heating and cooling a steel specimen in vacuum or other
5.1.1 There are available several computer models designed
controlledatmosphere;programmablethermalcycles;inertgas
to predict the microstructures, mechanical properties, and
or liquid injection for rapid cooling; continuous measurement
distortion of steels as a function of thermal processing cycle.
of specimen dimension and temperature; and digital data
Their use is predicated on the availability of accurate and
storage and output. The apparatus differ in terms of method of
consistent thermal and transformation strain data. Strain, both
specimen heating and test specimen design.
thermal and transformation, developed during thermal cycling
7.1.1 Dilatometer Apparatus Using Induction Heating—
is the parameter used in predicting both microstructure and
The test specimen is heated by suspending it inside an
properties,andforestimatingdistortion.Itshouldbenotedthat
induction-heatingcoilbetweentwoplatensasshownschemati-
these models are undergoing continued development. This
cally in Fig. 1. Cooling is accomplished by a combination of
process is aimed, among other things, at establishing a direct
controlled reduction in heating current along with injection of
link between discrete values of strain and specific microstruc-
inert gas onto the test specimen. Dimensional change is
ture constituents in steels. This practice describes a standard-
measured by a mechanical apparatus along the longitudinal
ized method for measuring strain during a defined thermal
axis of the test specimen, and temperature is measured by a
cycle.
thermocouple welded to the surface of the specimen at the
5.1.2 This practice is suitable for providing data for com-
center of the specimen length. For this apparatus, only Type R
puter models used in the control of steel manufacturing,
or S thermocouples should be used.
forging, casting, heat-treating, and welding processes. It is also
7.1.2 Dilatometer Apparatus Using Resistance Heating —
useful in providing data for the prediction of microstructures
The test specimen is supported between two grips as shown
and properties to assist in steel alloy selection for end-use
schematicallyinFig.2,andheatedbydirectresistanceheating.
applications.
Cooling is accomplished by a combination of controlled
5.1.3 This practice is suitable for providing the data needed
reduction in heating current along with injection of inert gas
for the construction of transformation diagrams that depict the
onto the test specimen or internal liquid quenching. Dimen-
microstructures developed during the thermal processing of
sional change is measured along a diameter at the center of the
steels as functions of time and temperature. Such diagrams
test specimen length, and temperature is measured by a
provide a qualitative assessment of the effects of changes in
thermal cycle on steel microstructure. Appendix X2 describes
The sole source of supply of the apparatus known to the committee at this time
construction of these diagrams.
is Dynamic Systems Incorporated, Postenkill, NY. If you are aware of alternative
5.2 It should be recognized that thermal and transformation
suppliers, please provide this information to ASTM International Headquarters.
strains, which develop in steels during thermal cycling, are
Your comments will receive careful consideration at a meeting of the responsible
sensitive to chemical composition. Thus, anisotropy in chemi- technical committee , which you may attend.
A1033–04
FIG. 1 Schematic of Transformation Testing Using Induction Heating
FIG. 2 Schematic of Transformation Testing Using Resistance Heating
thermocouple welded to the surface of the specimen at the used for all thermal cycling conditions. The hollow specimen
center of the specimen length. Dimensional change can be shown in Fig. 5 may also be used for all thermal cycling
measured by either mechanical or non-contact (laser) dimen- conditions. The hollow specimens will achieve the highest
sion measuring apparatus. Temperature measurement can be cooling rates when quenching is employed.
made using Type K, Type R, or Type S thermocouples. 8.2 Sampling—Test specimens may be obtained from any
steel product form, including steel bar, plate, and sheet and
8. Test Specimens and Sampling of Test Specimens
strip products. Care should be exercised to avoid the effects of
8.1 Test Specimens—The test specimens to be used with metallurgical variables, such as chemical segregation, in deter-
each type of test equipment shall be selected from those shown miningwheretestspecimensareobtainedfromaproductform.
in Figs. 3-5. Procedures have been designed that offer the advantage of
8.1.1 Dilatometers Apparatus Using Induction Heating— equivalencyofstraindeterminationusingspecimensfromboth
Thespecimenstobeusedwiththistypeofapparatusareshown types of apparatus described in 7.1.1 and 7.1.2. For equiva-
in Fig. 3. The solid specimens may be used for all thermal lency of strain, the orientation of the longitudinal axis of test
cyclingconditions.Thehollowspecimensmayalsobeusedfor specimens for induction heating apparatus should be at 90
all thermal cycling conditions. The hollow specimens will degrees to the longitudinal axis of specimens for resistance
achieve the highest cooling rates when gas quenching is heating.
employed. 8.2.1 Example Sampling for Steel Bar Product Forms—
8.1.2 Dilatometer Apparatus Using Resistance Heating — Where material thickness permits, a selected test specimen
The specimens for use with this type of apparatus are shown in should be machined from the mid-radius position. Where
Figs. 4 and 5. The specimen with the reduced center section materialthicknessisinsufficienttopermitmachiningaselected
(Fig. 4) allows for internal cooling of the specimen ends by test specimen from the mid-radius position but sufficient to
eitherliquidorgas.ThesolidspecimenshowninFig.5maybe permit machining the test specimen from the mid-diameter
A1033–04
NOTE—All machining surface finishes being 0.8 µm RMS
FIG. 3 Test Specimens for Induction Heating Apparatus
NOTE—All machining surface finishes being 0.8 µm RMS
Test Specimen Dimension Guide Table
Specimen Length, Specimen Half Length, Reduced Section Length, Reduced Section Diameter, OD at Grip End, ID at Grip End, Grip End Drill Depth,
L1 6 0.10 (mm) L2 6 0.05 (mm) L3 6 0.025 (mm) D3 6 0.025 (mm) D1 6 0.025 (mm) D2 6 0.025 (mm) L4 6 0.05 (mm)
90 45 6 6 10 6.3 40
84 42 6 6 10 6.3 37
84 42 5 5 10 6.3 37
FIG. 4 Test Specimens with Reduced Center Section for Resistance Heating Apparatus
position, the test specimen may be obtained from the mid- axis of the test specimen perpendicular to the rolling direction
diameter position. In all cases, material thickness must be of the bar. Fig. 6 shows example orientations.
sufficient to permit machining a fully dimensioned test speci- 8.2.1.2 Dilatometer Apparatus Using Resistance Heating—
men. The test specimens are to be machined with the longitudinal
8.2.1.1 Dilatometer Apparatus Using Induction Heating— axis of the test specimen parallel to the rolling direction of the
The test specimens are to be machined with the longitudinal bar. Fig. 6 shows example orientations.
A1033–04
NOTE—All machining surface finishes being 0.8 µm RMS.
Test Specimen Dimension Guide Table
Specimen Length, Specimen Half Length, Reduced Section Length, Reduced Section Diameter, OD at Grip End, ID
...