ASTM A1033-18(2023)
(Practice)Standard Practice for Quantitative Measurement and Reporting of Hypoeutectoid Carbon and Low-Alloy Steel Phase Transformations
Standard Practice for Quantitative Measurement and Reporting of Hypoeutectoid Carbon and Low-Alloy Steel Phase Transformations
SIGNIFICANCE AND USE
5.1 This practice is used to provide steel phase transformation data required for use in numerical models for the prediction of microstructures, properties, and distortion during steel manufacturing, forging, casting, heat treatment, and welding. Alternatively, the practice provides end users of steel and fabricated steel products the phase transformation data required for selecting steel grades for a given application by determining the microstructure resulting from a prescribed thermal cycle.
5.1.1 There are available several computer models designed to predict the microstructures, mechanical properties, and distortion of steels as a function of thermal processing cycle. Their use is predicated on the availability of accurate and consistent thermal and transformation strain data. Strain, both thermal and transformation, developed during thermal cycling is the parameter used in predicting both microstructure and properties, and for estimating distortion. It should be noted that these models are undergoing continued development. This process is aimed, among other things, at establishing a direct link between discrete values of strain and specific microstructure constituents in steels. This practice describes a standardized method for measuring strain during a defined thermal cycle.
5.1.2 This practice is suitable for providing data for computer models used in the control of steel manufacturing, forging, casting, heat-treating, and welding processes. It is also useful in providing data for the prediction of microstructures and properties to assist in steel alloy selection for end-use applications.
5.1.3 This practice is suitable for providing the data needed for the construction of transformation diagrams that depict the microstructures developed during the thermal processing of steels as functions of time and temperature. Such diagrams provide a qualitative assessment of the effects of changes in thermal cycle on steel microstructure. Appendix X2 describes ...
SCOPE
1.1 This practice covers the determination of hypoeutectoid steel phase transformation behavior by using high-speed dilatometry techniques for measuring linear dimensional change as a function of time and temperature, and reporting the results as linear strain in either a numerical or graphical format.
1.2 The practice is applicable to high-speed dilatometry equipment capable of programmable thermal profiles and with digital data storage and output capability.
1.3 This practice is applicable to the determination of steel phase transformation behavior under both isothermal and continuous cooling conditions.
1.4 This practice includes requirements for obtaining metallographic information to be used as a supplement to the dilatometry measurements.
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.6 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.7 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.
General Information
Relations
Standards Content (Sample)
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: A1033 − 18 (Reapproved 2023)
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.
1. Scope 2. Referenced Documents
2.1 ASTM Standards:
1.1 This practice covers the determination of hypoeutectoid
steel phase transformation behavior by using high-speed E3 Guide for Preparation of Metallographic Specimens
E112 Test Methods for Determining Average Grain Size
dilatometry techniques for measuring linear dimensional
change as a function of time and temperature, and reporting the E407 Practice for Microetching Metals and Alloys
results as linear strain in either a numerical or graphical format.
3. Terminology
1.2 The practice is applicable to high-speed dilatometry
3.1 Definitions of Terms Specific to This Standard:
equipment capable of programmable thermal profiles and with
3.1.1 diametrical linear engineering strain—the strain, ei-
digital data storage and output capability.
ther thermal or resulting from phase transformation, that is
1.3 This practice is applicable to the determination of steel
determined from a change in diameter as a result of a change
phase transformation behavior under both isothermal and
in temperature, or over a period of time, and which is expressed
continuous cooling conditions.
as follows:
1.4 This practice includes requirements for obtaining met-
e 5 Δd/d 5 ~d 2 d !/d
D 0 1 0 0
allographic information to be used as a supplement to the
3.1.2 hypoeutectoid steel—a term used to describe a group
dilatometry measurements.
of carbon steels with a carbon content less than the eutectoid
composition (0.8 % by weight).
1.5 The values stated in SI units are to be regarded as
standard. No other units of measurement are included in this
3.1.3 longitudinal linear engineering strain—the strain, ei-
standard.
ther thermal or resulting from phase transformation, that is
determined from a change in length as a result of a change in
1.6 This standard does not purport to address all of the
temperature, or over a period of time, and which is expressed
safety concerns, if any, associated with its use. It is the
as follows:
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
e 5 Δl/L 5 l 2 l /l
~ !
L 0 1 0 0
mine the applicability of regulatory limitations prior to use.
3.1.4 steel phase transformation—during heating, the crys-
1.7 This international standard was developed in accor-
tallographic transformation from ferrite, pearlite, bainite, mar-
dance with internationally recognized principles on standard-
tensite or combinations of these constituents to austenite.
ization established in the Decision on Principles for the
During cooling, the crystallographic transformation from aus-
Development of International Standards, Guides and Recom-
tenite to ferrite, pearlite, bainite, or martensite or a combination
mendations issued by the World Trade Organization Technical
thereof.
Barriers to Trade (TBT) Committee.
3.1.5 volumetric engineering strain—the strain, either ther-
mal or resulting from phase transformation, that is determined
from a change in volume as a result of a change in temperature,
This practice is under the jurisdiction of ASTM Committee A01 on Steel,
or over a period of time, and which is expressed as follows:
Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee
A01.13 on Mechanical and Chemical Testing and Processing Methods of Steel
Products and Processes. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Sept. 1, 2023. Published September 2023. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 2004. Last previous edition approved in 2018 as A1033 – 18. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/A1033-18R23. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
A1033 − 18 (2023)
e 5 Δv/v 5 v 2 v /v link between discrete values of strain and specific microstruc-
~ !
V 0 1 0 0
e '3e '3e
ture constituents in steels. This practice describes a standard-
V L D
ized method for measuring strain during a defined thermal
3.2 Symbols: e = longitudinal linear engineering strain
L
cycle.
e = diametrical linear engineering strain
D
5.1.2 This practice is suitable for providing data for com-
e = volumetric engineering strain
V
puter models used in the control of steel manufacturing,
Δl = change in test specimen length
forging, casting, heat-treating, and welding processes. It is also
l = test specimen length at specific temperature or time, or
useful in providing data for the prediction of microstructures
both
and properties to assist in steel alloy selection for end-use
l = initial test specimen length
applications.
Δd = change in test specimen diameter
5.1.3 This practice is suitable for providing the data needed
d = test specimen diameter at specific temperature or time,
for the construction of transformation diagrams that depict the
or both
microstructures developed during the thermal processing of
d = initial test specimen diameter
steels as functions of time and temperature. Such diagrams
Δv = change in test specimen volume
provide a qualitative assessment of the effects of changes in
v = test specimen volume at a specific temperature or time,
thermal cycle on steel microstructure. Appendix X2 describes
or both
construction of these diagrams.
v = initial test specimen volume
Ac = the temperature at which austenite begins to form on
5.2 It should be recognized that thermal and transformation
heating
strains, which develop in steels during thermal cycling, are
Ac = the temperature at which the transformation of ferrite
sensitive to chemical composition. Thus, anisotropy in chemi-
to austenite is complete on heating
cal composition can result in variability in strain, and can affect
M = the temperature at which the transformation of austen-
the results of strain determinations, especially determination of
s
ite to martensite starts during cooling
volumetric strain. Strains determined during cooling are sen-
sitive to the grain size of austenite, which is determined by the
4. Summary of Practice
heating cycle. The most consistent results are obtained when
austenite grain size is maintained between ASTM grain sizes of
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
change and phase transformation. In this practice, sensitive 1 3
cycles need to be employed, as described below, to ensure
high-speed dilatometer equipment is used to detect and mea-
complete formation of austenite preceding strain measurements
sure the changes in dimension that occur as functions of both
during cooling.
time and temperature during defined thermal cycles. The
resulting data are converted to discrete values of strain for
6. Ordering Information
specific values of time and temperature during the thermal
cycle. Strain as a function of time or temperature, or both, can 6.1 When this practice is to be applied to an inquiry,
then be used to determine the beginning and completion of one
contract, or order, the purchaser shall so state and should
or more phase transformations. furnish the following information:
6.1.1 The steel grades to be evaluated,
5. Significance and Use
6.1.2 The test apparatus to be used,
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.
Alternatively, the practice provides end users of steel and
7. Apparatus
fabricated steel products the phase transformation data required
for selecting steel grades for a given application by determin- 7.1 This practice is applicable to several types of commer-
ing the microstructure resulting from a prescribed thermal cially available high-speed dilatometer apparatus, which have
cycle. certain common features. These include the capabilities for:
5.1.1 There are available several computer models designed heating and cooling a steel specimen in vacuum or other
to predict the microstructures, mechanical properties, and controlled atmosphere; programmable thermal cycles; inert gas
distortion of steels as a function of thermal processing cycle. or liquid injection for rapid cooling; continuous measurement
Their use is predicated on the availability of accurate and of specimen dimension and temperature; and digital data
consistent thermal and transformation strain data. Strain, both storage and output. The apparatus differ in terms of method of
thermal and transformation, developed during thermal cycling specimen heating and test specimen design.
is the parameter used in predicting both microstructure and 7.1.1 Dilatometer Apparatus Using Induction Heating—The
properties, and for estimating distortion. It should be noted that test specimen is heated by suspending it inside an induction-
these models are undergoing continued development. This heating coil between two platens as shown schematically in
process is aimed, among other things, at establishing a direct Fig. 1. Cooling is accomplished by a combination of controlled
A1033 − 18 (2023)
FIG. 1 Schematic of Transformation Testing Using Induction Heating
reduction in heating current along with injection of inert gas sion measuring apparatus. Temperature measurement can be
onto the test specimen. Dimensional change is measured by a made using Type K, Type R, or Type S thermocouples.
mechanical apparatus along the longitudinal axis of the test
specimen, and temperature is measured by a thermocouple
8. Test Specimens and Sampling of Test Specimens
welded to the surface of the specimen at the center of the
8.1 Test Specimens—The test specimens to be used with
specimen length. For this apparatus, only Type R or S
each type of test equipment shall be selected from those shown
thermocouples should be used.
in Figs. 3-5.
7.1.2 Dilatometer Apparatus Using Resistance Heating —
8.1.1 Dilatometers Apparatus Using Induction Heating—
The test specimen is supported between two grips as shown
The specimens to be used with this type of apparatus are shown
schematically in Fig. 2, and heated by direct resistance heating.
in Fig. 3. The solid specimens may be used for all thermal
Cooling is accomplished by a combination of controlled
cycling conditions. The hollow specimens may also be used for
reduction in heating current along with injection of inert gas
all thermal cycling conditions. The hollow specimens will
onto the test specimen or internal liquid quenching. Dimen-
achieve the highest cooling rates when gas quenching is
sional change is measured along a diameter at the center of the
employed.
test specimen length, and temperature is measured by a
8.1.2 Dilatometer Apparatus Using Resistance Heating —
thermocouple welded to the surface of the specimen at the
The specimens for use with this type of apparatus are shown in
center of the specimen length. Dimensional change can be
Figs. 4 and 5. The specimen with the reduced center section
measured by either mechanical or non-contact (laser) dimen-
(Fig. 4) allows for internal cooling of the specimen ends by
either liquid or gas. The solid specimen shown in Fig. 5 may be
used for all thermal cycling conditions. The hollow specimen
The sole source of supply of the apparatus known to the committee at this time
is Dynamic Systems Incorporated, Postenkill, NY. If you are aware of alternative
shown in Fig. 5 may also be used for all thermal cycling
suppliers, please provide this information to ASTM International Headquarters.
conditions. The hollow specimens will achieve the highest
Your comments will receive careful consideration at a meeting of the responsible
cooling rates when quenching is employed.
technical committee , which you may attend.
FIG. 2 Schematic of Transformation Testing Using Resistance Heating
A1033 − 18 (2023)
NOTE 1—All machining surface finishes being 0.8 μm RMS.
FIG. 3 Test Specimens for Induction Heating Apparatus
NOTE 1—All machining surface finishes being 0.8 μm RMS.
Test Specimen Dimension Guide Table
Reduced Section
Specimen Length, Specimen Half Length, Reduced Section Diameter, OD at Grip End, ID at Grip End, Grip End Drill Depth,
Length,
L1 ± 0.10 (mm) L2 ± 0.05 (mm) D3 ± 0.025 (mm) D1 ± 0.025 (mm) D2 ± 0.025 (mm) L4 ± 0.05 (mm)
L3 ± 0.025 (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
8.2 Sampling—Test specimens may be obtained from any types of apparatus described in 7.1.1 and 7.1.2. For equiva-
steel product form, including steel bar, plate, and sheet and lency of strain, the orientation of the longitudinal axis of test
strip products. Care should be exercised to avoid the effects of specimens for induction heating apparatus should be at 90
metallurgical variables, such as chemical segregation, in deter- degrees to the longitudinal axis of specimens for resistance
mining where test specimens are obtained from a product form. heating.
Procedures have been designed that offer the advantage of 8.2.1 Example Sampling for Steel Bar Product Forms—
equivalency of strain determination using specimens from both Where material thickness permits, a selected test specimen
A1033 − 18 (2023)
NOTE 1—All machining surface finishes being 0.8 μm RMS.
Test Specimen Dimension Guide Table
Reduced Section
Specimen Lengt
...
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