ASTM E1181-02(2008)e1

Standard Test Methods for Characterizing Duplex Grain Sizes

SIGNIFICANCE AND USE
5.1 Duplex grain size may occur in some metals and alloys as a result of their thermomechanical processing history. For comparison of mechanical properties with metallurgical features, or for specification purposes, it may be important to be able to characterize grain size in such materials. Assigning an average grain size value to a duplex grain size specimen does not adequately characterize the appearance of that specimen, and may even misrepresent its appearance. For example, averaging two distinctly different grain sizes may result in reporting a size that does not actually exist anywhere in the specimen.  
5.2 These test methods may be applied to specimens or products containing randomly intermingled grains of two or more significantly different sizes (henceforth referred to as random duplex grain size). Examples of random duplex grain sizes include: isolated coarse grains in a matrix of much finer grains, extremely wide distributions of grain sizes, and bimodal distributions of grain size.  
5.3 These test methods may also be applied to specimens or products containing grains of two or more significantly different sizes, but distributed in topologically varying patterns (henceforth referred to as topological duplex grain sizes). Examples of topological duplex grain sizes include: systematic variation of grain size across the section of a product, necklace structures, banded structures, and germinative grain growth in selected areas of critical strain.  
5.4 These test methods may be applied to specimens or products regardless of their state of recrystallization.  
5.5 Because these test methods describe deviations from a single, log-normal distribution of grain sizes, and characterize patterns of variation in grain size, the total specimen cross-section must be evaluated.  
5.6 These test methods are limited to duplex grain sizes as identifiable within a single polished and etched metallurgical specimen. If duplex grain size is suspected in a product too ...
SCOPE
1.1 These test methods provide simple guidelines for deciding whether a duplex grain size exists. The test methods separate duplex grain sizes into one of two distinct classes, then into specific types within those classes, and provide systems for grain size characterization of each type.  
1.2 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety concerns associated with its use. It is the responsibility of the user of this standard to consult appropriate safety and health practices and determine the applicability of regulatory limitations prior to its use.

General Information

• Status: Historical
• Publication Date: 31-May-2008
• ICS: 19.120 - Particle size analysis. Sieving
• Technical Committee: E04 - Metallography
• Drafting Committee: E04.08 - Grain Size

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
´1
Designation: E1181 − 02(Reapproved 2008)
Standard Test Methods for
Characterizing Duplex Grain Sizes
This standard is issued under the fixed designation E1181; 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.
ε NOTE—Footnote 1 was editorially corrected in February 2015.
INTRODUCTION
Test methods are well established for the determination of average grain size, and estimation of
largest grain size, in products assumed to contain a single log-normal distribution of grain sizes. The
test methods in this standard are set forth to characterize grain size in products with any other
distributions of grain size.
The term “duplex grain size” is chosen to describe any of these other distributions of grain size,
because of its common usage and familiarity. However, the use of that term does not imply that only
two grain size distributions exist.
These test methods are equally aimed at describing the nature of the deviation from a single
log-normal distribution of grain sizes, and at describing with reasonable accuracy the distributions of
sizes that actually exist.
1. Scope E7 Terminology Relating to Metallography
E112 Test Methods for Determining Average Grain Size
1.1 These test methods provide simple guidelines for decid-
E407 Practice for Microetching Metals and Alloys
ing whether a duplex grain size exists. The test methods
E562 Test Method for Determining Volume Fraction by
separate duplex grain sizes into one of two distinct classes,
Systematic Manual Point Count
then into specific types within those classes, and provide
E883 Guide for Reflected–Light Photomicrography
systems for grain size characterization of each type.
E930 Test Methods for Estimating the Largest Grain Ob-
1.2 Units—The values stated in SI units are to be regarded
served in a Metallographic Section (ALA Grain Size)
as standard. No other units of measurement are included in this
2.2 ASTM Adjuncts:
standard.
Comparison Chart for Estimation of Area Fractions
1.3 This standard may involve hazardous materials,
3. Terminology
operations, and equipment. This standard does not purport to
address all of the safety concerns associated with its use. It is
3.1 Definitions:
the responsibility of the user of this standard to consult
3.1.1 All terms used in these test methods are either defined
appropriate safety and health practices and determine the in Terminology E7, or are discussed in 3.2.
applicability of regulatory limitations prior to its use.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 bands or banding— in grain size, alternating areas of
2. Referenced Documents
significantly different grain sizes. These areas are usually
elongated in a direction parallel to the direction of working.
2.1 ASTM Standards:
E3 Guide for Preparation of Metallographic Specimens
3.2.2 grain size—equivalent in meaning to the average of a
distribution of grain sizes.
3.2.3 necklace or necklace structure—individual coarse
These test methods are under the jurisdiction of ASTM Committee E04 on
grains surrounded by rings of significantly finer grains.
Metallography and are the direct responsibility of Subcommittee E04.08 on Grain
Size.
3.2.4 topologically varying—varying nonrandomly, in some
Current edition approved June 1, 2008. Published October 2008. Originally
definablepattern;thatpatternmayberelatedtotheshapeofthe
approved in 1987. Last previous edition approved in 2002 as E1181–02. DOI:
10.1520/E1181-02R08E01.
specimen or product being examined.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on This comparison chart shows different area percentages of light grains among
the ASTM website. dark grains. Available from ASTM Headquarters. Order Adjunct: ADJE1181.
Copyright ©ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA19428-2959. United States
´1
E1181 − 02 (2008)
4. Summary of Test Method does not adequately characterize the appearance of that
specimen, and may even misrepresent its appearance. For
4.1 These test methods provide means for recognizing the
example, averaging two distinctly different grain sizes may
presenceofduplexgrainsize.Thetestmethodsseparateduplex
result in reporting a size that does not actually exist anywhere
grain sizes into two classes (randomly varying, and topologi-
in the specimen.
cally varying), and define specific types of duplex grain sizes
within these classes. The test methods provide means for
5.2 These test methods may be applied to specimens or
estimating area fractions occupied by distinct grain sizes, and
products containing randomly intermingled grains of two or
offer existing standard methods (Test Methods E112, Test
more significantly different sizes (henceforth referred to as
Methods E930) for determining grain size in specific identified
random duplex grain size). Examples of random duplex grain
areas. The test methods provide for reporting of specific,
sizes include: isolated coarse grains in a matrix of much finer
distinctive information for each type of duplex grain size.And,
grains,extremelywidedistributionsofgrainsizes,andbimodal
as an alternative, the test methods offer a procedure for
distributions of grain size.
statistically determining the distribution of all the grain sizes
5.3 These test methods may also be applied to specimens or
present in a duplex grain size specimen.
products containing grains of two or more significantly differ-
5. Significance and Use
ent sizes, but distributed in topologically varying patterns
(henceforth referred to as topological duplex grain sizes).
5.1 Duplex grain size may occur in some metals and alloys
Examples of topological duplex grain sizes include: systematic
as a result of their thermomechanical processing history. For
variation of grain size across the section of a product, necklace
comparison of mechanical properties with metallurgical
structures, banded structures, and germinative grain growth in
features, or for specification purposes, it may be important to
selected areas of critical strain.
be able to characterize grain size in such materials. Assigning
an average grain size value to a duplex grain size specimen
5.4 These test methods may be applied to specimens or
products regardless of their state of recrystallization.
5.5 Because these test methods describe deviations from a
single, log-normal distribution of grain sizes, and characterize
patterns of variation in grain size, the total specimen cross-
section must be evaluated.
5.6 These test methods are limited to duplex grain sizes as
identifiable within a single polished and etched metallurgical
specimen. If duplex grain size is suspected in a product too
large to be polished and etched as a single specimen, mac-
roetchingshouldbeconsideredasafirststepinevaluation.The
entire macroetched cross-section should be used as a basis for
estimating area fractions occupied by distinct grain sizes, if
possible. If microscopic examination is subsequently
necessary, individual specimens must be taken to allow esti-
mation of area fractions for the entire product cross-section,
and to allow determination of grain sizes representing the
entire cross-section as well.
5.7 These test methods are intended to be applied to duplex
grain sizes. Duplex grain structures (for example, multiphase
alloys) are not necessarily duplex in grain size, and as such are
not the subject of these methods. However, the test methods
described here for area fraction estimation may be of use in
describing duplex grain structures.
6. Apparatus
6.1 Certain items may be helpful or necessary in applying
the various procedures of these test methods. These items are
briefly described below, under the headings of the specific
procedures to which they apply.
6.1.1 Comparison Procedure for Estimation of Area
Fractions—This procedure requires the use of a comparison
chart to improve the accuracy of visual estimates of area
FIG. 1 Comparison Chart for Estimation of Area Fractions
(Showing area percentages of light grains among dark grains) fractions occupied by distinct grain sizes. This comparison
´1
E1181 − 02 (2008)
chart is shown in Fig. 1 . The chart shows different area 6.1.9 Statistical Determination of Grain Size Distribution:
percentages of light grains among dark grains. 6.1.9.1 This procedure requires the use of a test grid on a
6.1.2 Point Count Procedure for Estimation of Area transparent overlay that can be superimposed on the specimen
Fractions—This procedure requires the use of a test grid on a image. The test grid consists of a series of fine, parallel lines,
transparentoverlay,orinareticle,thatcanbesuperimposedon with an interline spacing of 5 mm. Use of the grid is described
the specimen image. The grid should consist of equally spaced in 8.7.
points formed by the intersection of fine lines. Practice E562 6.1.9.2 This procedure may be carried out using manual
gives examples of such grids, as well as details on recom- measuring and counting techniques, but as such, will be very
mended grid spacing, and use of the grid. laborious and time-consuming. This procedure can be carried
6.1.3 Planimetric Procedure for Estimation of Area out much more efficiently through the use of an automated
Fractions—This procedure requires the use of a planimeter, a image analysis system with an electronic pencil or cursor, or
device for measuring the areas of irregular polygons. The through the use of a semi-automated image analysis system
regions occupied by a distinct grain size are manually outlined withadigitizingtabletandelectronicpencilorcursor. Theuse
on a photomicrograph or transparent overlay. The area of each of this equipment is also described in 8.7.
ofthoseregionsisthenmeasuredbytracingitsoutlinewiththe
planimeter. 7. Sampling and Test Specimens
6.1.4 Test Methods E930, Comparison Procedure for Esti-
7.1 Sampling:
mation of Largest Grain Size Observed.
7.1.1 These test methods are intended to characterize pat-
6.1.4.1 This procedure requires the use of a visual aid for
terns of variation in grain size, when they occur in a given
estimation of the size of the largest grain found in a given
specimen or product. To characterize these patterns accurately,
metallographic section. That visual aid is shown in Test
the entire cross-section of the specimen or product must be
Methods E930, and is available as anASTMAdjunct (see Test
evaluated.
Methods E930 for details).
7.1.2 If variations in grain size occur in a product too large
6.1.5 Test Methods E930, Measuring Procedure for Estima-
to be polished and etched as a single specimen, individual
tion of Largest Grain Size Observed.
specimens must be taken to allow estimation of area fractions
6.1.5.1 This procedure may require the use of a measuring
for the entire product cross-section, and to allow determination
microscope eyepiece or measuring microscope reticle. These
of grain sizes representing the entire cross-section as well.
are available from microscope manufacturers.
7.2 Specimen Orientation:
6.1.6 Test Methods E930, Referee Procedure for Estimation
7.2.1 All of the types of duplex grain size described in this
of Largest Grain Size Observed.
test method (see 3.2 and 8.3) can be detected in a longitudinal
6.1.6.1 This procedure requires the use of a test grid on a
specimenorientation(thatis,inaplaneparalleltothedirection
transparent overlay that can be superimposed on the specimen
of maximum product deformation, during manufacture).
image. The test grid consists of a square network of grid lines,
Accordingly, the longitudinal orientation is recommended,
witharecommendedinterlinespacingof5mm.Useofthegrid
with one exception. If the specimen being examined is the full
is described in Test Methods E930.
cross-sectionofaroundbar,thelongitudinalsectionshouldnot
6.1.7 Test Methods E112, Comparison Procedure for Deter-
beusedtoestimatetheareafractionoccupiedbydifferentgrain
mination of Average Grain Size.
sizes. That estimate can be made most accurately only on a
6.1.7.1 This procedure requires the use of grain size com-
transverse section. For a tubular product, estimates of area
parison charts or overlay transparencies, or grain size compari-
fractionsmadeonlongitudinalsectionsarereasonableapproxi-
son reticles fitted into microscopes. Various comparison charts
mationsofthesameestimatesmadeontransversesections.For
and overlay transparencies are available as ASTM adjuncts
all other products, area fraction estimates should be equally
(see Test Methods E112 for details).
accurate with either specimen orientation.
6.1.7.2 Grain size comparison reticles are available from
7.2.2 Other specimen orientations may be used, provided
various manufacturers of microscopes.
that their limitations are recognized. For instance, banding
6.1.8 Test Methods E112, Intercept Procedures for Determi-
present in a given specimen may not be easily recognizable in
nation of Average Grain Size,
a transverse orientation.
6.1.8.1 The Intercept Procedures of Test Methods E112
7.2.3 The specimen orientation used should be reported
require the use of patterns of test lines, usually on transparent
along with the duplex grain size characterization.
overlays. The use of these is described in detail in Test
Methods E112.Atransparency of one such pattern is available
8. Procedure
as an ASTM adjunct (see Test Methods E112 for details).
8.1 Specimen Preparation—Prepare specimens according to
Methods E3, and etch specimens in accordance with Practice
Leidheiser, H., Jr. and Kim, D. K., “A Chemical Test for Identifying the
E407. Etch specimens so that all grain boundaries are distinct
Fraction of Grains in the Surface of Galvanized Steel Sheet That Have Orientations
Approximating (0001)—Importance to Paint Adherence,”Metallurgical Transac- and easily visible.
tions “B,”American Society for Metals, Metals Park, OH 44073, December, 1978,
p. 590.
A Keuffel & Esser Compensating Polar Planimeter available from drafting
equipment suppliers, or equivalent, has been found to be satisfactory for this AZeissVideoplanSystem,oritsequivalent,hasbeenfoundsatisfactoryforthis
purpose. purpose.
´1
E1181 − 02 (2008)
8.2 Preparation of Photomicrographs—If photomicro- procedures for estimating area fraction are described, the
graphs are required for characterizing duplex grain siz
...

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.
´1
Designation: E1181 − 02 (Reapproved 2008) E1181 − 02 (Reapproved 2008)
Standard Test Methods for
Characterizing Duplex Grain Sizes
This standard is issued under the fixed designation E1181; 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.
ε NOTE—Footnote 1 was editorially corrected in February 2015.
INTRODUCTION
Test methods are well established for the determination of average grain size, and estimation of
largest grain size, in products assumed to contain a single log-normal distribution of grain sizes. The
test methods in this standard are set forth to characterize grain size in products with any other
distributions of grain size.
The term “duplex grain size” is chosen to describe any of these other distributions of grain size,
because of its common usage and familiarity. However, the use of that term does not imply that only
two grain size distributions exist.
These test methods are equally aimed at describing the nature of the deviation from a single
log-normal distribution of grain sizes, and at describing with reasonable accuracy the distributions of
sizes that actually exist.
1. Scope
1.1 These test methods provide simple guidelines for deciding whether a duplex grain size exists. The test methods separate
duplex grain sizes into one of two distinct classes, then into specific types within those classes, and provide systems for grain size
characterization of each type.
1.2 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this
standard.
1.3 This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all
of the safety concerns associated with its use. It is the responsibility of the user of this standard to consult appropriate safety and
health practices and determine the applicability of regulatory limitations prior to its use.
2. Referenced Documents
2.1 ASTM Standards:
E3 Guide for Preparation of Metallographic Specimens
E7 Terminology Relating to Metallography
E112 Test Methods for Determining Average Grain Size
E407 Practice for Microetching Metals and Alloys
E562 Test Method for Determining Volume Fraction by Systematic Manual Point Count
E883 Guide for Reflected–Light Photomicrography
E930 Test Methods for Estimating the Largest Grain Observed in a Metallographic Section (ALA Grain Size)
2.2 ASTM Adjuncts:
Comparison Chart for Estimation of Area Fractions
These test methods are under the jurisdiction of ASTM Committee E04 on Metallography and are the direct responsibility of Subcommittee E04.08 on Grain Size.
Current edition approved June 1, 2008. Published October 2008. Originally approved in 1994.1987. Last previous edition approved in 2002 as E1181–02. DOI:
10.1520/E1181-02R08.10.1520/E1181-02R08E01.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
This comparison chart shows different area percentages of light grains among dark grains. Available from ASTM Headquarters. Order Adjunct: ADJE1181.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
´1
E1181 − 02 (2008)
3. Terminology
3.1 Definitions:
3.1.1 All terms used in these test methods are either defined in Terminology E7, or are discussed in 3.2.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 bands or banding— in grain size, alternating areas of significantly different grain sizes. These areas are usually elongated
in a direction parallel to the direction of working.
3.2.2 grain size—equivalent in meaning to the average of a distribution of grain sizes.
3.2.3 necklace or necklace structure—individual coarse grains surrounded by rings of significantly finer grains.
3.2.4 topologically varying—varying nonrandomly, in some definable pattern; that pattern may be related to the shape of the
specimen or product being examined.
4. Summary of Test Method
4.1 These test methods provide means for recognizing the presence of duplex grain size. The test methods separate duplex grain
sizes into two classes (randomly varying, and topologically varying), and define specific types of duplex grain sizes within these
classes. The test methods provide means for estimating area fractions occupied by distinct grain sizes, and offer existing standard
methods (Test Methods E112, Test Methods E930) for determining grain size in specific identified areas. The test methods provide
for reporting of specific, distinctive information for each type of duplex grain size. And, as an alternative, the test methods offer
a procedure for statistically determining the distribution of all the grain sizes present in a duplex grain size specimen.
5. Significance and Use
5.1 Duplex grain size may occur in some metals and alloys as a result of their thermomechanical processing history. For
comparison of mechanical properties with metallurgical features, or for specification purposes, it may be important to be able to
FIG. 1 Comparison Chart for Estimation of Area Fractions
(Showing area percentages of light grains among dark grains)
´1
E1181 − 02 (2008)
characterize grain size in such materials. Assigning an average grain size value to a duplex grain size specimen does not adequately
characterize the appearance of that specimen, and may even misrepresent its appearance. For example, averaging two distinctly
different grain sizes may result in reporting a size that does not actually exist anywhere in the specimen.
5.2 These test methods may be applied to specimens or products containing randomly intermingled grains of two or more
significantly different sizes (henceforth referred to as random duplex grain size). Examples of random duplex grain sizes include:
isolated coarse grains in a matrix of much finer grains, extremely wide distributions of grain sizes, and bimodal distributions of
grain size.
5.3 These test methods may also be applied to specimens or products containing grains of two or more significantly different
sizes, but distributed in topologically varying patterns (henceforth referred to as topological duplex grain sizes). Examples of
topological duplex grain sizes include: systematic variation of grain size across the section of a product, necklace structures,
banded structures, and germinative grain growth in selected areas of critical strain.
5.4 These test methods may be applied to specimens or products regardless of their state of recrystallization.
5.5 Because these test methods describe deviations from a single, log-normal distribution of grain sizes, and characterize
patterns of variation in grain size, the total specimen cross-section must be evaluated.
5.6 These test methods are limited to duplex grain sizes as identifiable within a single polished and etched metallurgical
specimen. If duplex grain size is suspected in a product too large to be polished and etched as a single specimen, macroetching
should be considered as a first step in evaluation. The entire macroetched cross-section should be used as a basis for estimating
area fractions occupied by distinct grain sizes, if possible. If microscopic examination is subsequently necessary, individual
specimens must be taken to allow estimation of area fractions for the entire product cross-section, and to allow determination of
grain sizes representing the entire cross-section as well.
5.7 These test methods are intended to be applied to duplex grain sizes. Duplex grain structures (for example, multiphase alloys)
are not necessarily duplex in grain size, and as such are not the subject of these methods. However, the test methods described here
for area fraction estimation may be of use in describing duplex grain structures.
6. Apparatus
6.1 Certain items may be helpful or necessary in applying the various procedures of these test methods. These items are briefly
described below, under the headings of the specific procedures to which they apply.
6.1.1 Comparison Procedure for Estimation of Area Fractions—This procedure requires the use of a comparison chart to
improve the accuracy of visual estimates of area fractions occupied by distinct grain sizes. This comparison chart is shown in Fig.
1 . The chart shows different area percentages of light grains among dark grains.
6.1.2 Point Count Procedure for Estimation of Area Fractions—This procedure requires the use of a test grid on a transparent
overlay, or in a reticle, that can be superimposed on the specimen image. The grid should consist of equally spaced points formed
by the intersection of fine lines. Practice E562 gives examples of such grids, as well as details on recommended grid spacing, and
use of the grid.
6.1.3 Planimetric Procedure for Estimation of Area Fractions—This procedure requires the use of a planimeter, a device for
measuring the areas of irregular polygons. The regions occupied by a distinct grain size are manually outlined on a
photomicrograph or transparent overlay. The area of each of those regions is then measured by tracing its outline with the
planimeter.
6.1.4 Test Methods E930, Comparison Procedure for Estimation of Largest Grain Size Observed.
6.1.4.1 This procedure requires the use of a visual aid for estimation of the size of the largest grain found in a given
metallographic section. That visual aid is shown in Test Methods E930, and is available as an ASTM Adjunct (see Test Methods
E930 for details).
6.1.5 Test Methods E930, Measuring Procedure for Estimation of Largest Grain Size Observed.
6.1.5.1 This procedure may require the use of a measuring microscope eyepiece or measuring microscope reticle. These are
available from microscope manufacturers.
6.1.6 Test Methods E930, Referee Procedure for Estimation of Largest Grain Size Observed.
6.1.6.1 This procedure requires the use of a test grid on a transparent overlay that can be superimposed on the specimen image.
The test grid consists of a square network of grid lines, with a recommended interline spacing of 5 mm. Use of the grid is described
in Test Methods E930.
6.1.7 Test Methods E112, Comparison Procedure for Determination of Average Grain Size.
6.1.7.1 This procedure requires the use of grain size comparison charts or overlay transparencies, or grain size comparison
reticles fitted into microscopes. Various comparison charts and overlay transparencies are available as ASTM adjuncts (see Test
Methods E112 for details).
Leidheiser, H., Jr. and Kim, D. K., “A Chemical Test for Identifying the Fraction of Grains in the Surface of Galvanized Steel Sheet That Have Orientations
Approximating (0001)—Importance to Paint Adherence,”Metallurgical Transactions “B,” American Society for Metals, Metals Park, OH 44073, December, 1978, p. 590.
A Keuffel & Esser Compensating Polar Planimeter available from drafting equipment suppliers, or equivalent, has been found to be satisfactory for this purpose.
´1
E1181 − 02 (2008)
6.1.7.2 Grain size comparison reticles are available from various manufacturers of microscopes.
6.1.8 Test Methods E112, Intercept Procedures for Determination of Average Grain Size,
6.1.8.1 The Intercept Procedures of Test Methods E112 require the use of patterns of test lines, usually on transparent overlays.
The use of these is described in detail in Test Methods E112. A transparency of one such pattern is available as an ASTM adjunct
(see Test Methods E112 for details).
6.1.9 Statistical Determination of Grain Size Distribution:
6.1.9.1 This procedure requires the use of a test grid on a transparent overlay that can be superimposed on the specimen image.
The test grid consists of a series of fine, parallel lines, with an interline spacing of 5 mm. Use of the grid is described in 8.7.
6.1.9.2 This procedure may be carried out using manual measuring and counting techniques, but as such, will be very laborious
and time-consuming. This procedure can be carried out much more efficiently through the use of an automated image analysis
system with an electronic pencil or cursor, or through the use of a semi-automated image analysis system with a digitizing tablet
and electronic pencil or cursor. The use of this equipment is also described in 8.7.
7. Sampling and Test Specimens
7.1 Sampling:
7.1.1 These test methods are intended to characterize patterns of variation in grain size, when they occur in a given specimen
or product. To characterize these patterns accurately, the entire cross-section of the specimen or product must be evaluated.
7.1.2 If variations in grain size occur in a product too large to be polished and etched as a single specimen, individual specimens
must be taken to allow estimation of area fractions for the entire product cross-section, and to allow determination of grain sizes
representing the entire cross-section as well.
7.2 Specimen Orientation:
7.2.1 All of the types of duplex grain size described in this test method (see 3.2 and 8.3) can be detected in a longitudinal
specimen orientation (that is, in a plane parallel to the direction of maximum product deformation, during manufacture).
Accordingly, the longitudinal orientation is recommended, with one exception. If the specimen being examined is the full
cross-section of a round bar, the longitudinal section should not be used to estimate the area fraction occupied by different grain
sizes. That estimate can be made most accurately only on a transverse section. For a tubular product, estimates of area fractions
made on longitudinal sections are reasonable approximations of the same estimates made on transverse sections. For all other
products, area fraction estimates should be equally accurate with either specimen orientation.
7.2.2 Other specimen orientations may be used, provided that their limitations are recognized. For instance, banding present in
a given specimen may not be easily recognizable in a transverse orientation.
7.2.3 The specimen orientation used should be reported along with the duplex grain size characterization.
8. Procedure
8.1 Specime
...