ASTM E1181-02(2015)

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: 30-Sep-2015
• ICS: 77.040.99 - Other methods of testing of metals
• 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
Designation: E1181 − 02 (Reapproved 2015)
Standard Test Methods for
1
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.
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 E407 Practice for Microetching Metals and Alloys
E562 Test Method for Determining Volume Fraction by
1.1 These test methods provide simple guidelines for decid-
Systematic Manual Point Count
ing whether a duplex grain size exists. The test methods
E883 Guide for Reflected–Light Photomicrography
separate duplex grain sizes into one of two distinct classes,
E930 Test Methods for Estimating the Largest Grain Ob-
then into specific types within those classes, and provide
served in a Metallographic Section (ALA Grain Size)
systems for grain size characterization of each type.
2.2 ASTM Adjuncts:
3
1.2 Units—The values stated in SI units are to be regarded
Comparison Chart for Estimation of Area Fractions
as standard. No other units of measurement are included in this
3. Terminology
standard.
1.3 This standard may involve hazardous materials, 3.1 Definitions:
3.1.1 All terms used in these test methods are either defined
operations, and equipment. This standard does not purport to
in Terminology E7, or are discussed in 3.2.
address all of the safety concerns associated with its use. It is
3.2 Definitions of Terms Specific to This Standard:
the responsibility of the user of this standard to consult
3.2.1 bands or banding— in grain size, alternating areas of
appropriate safety and health practices and determine the
significantly different grain sizes. These areas are usually
applicability of regulatory limitations prior to its use.
elongated in a direction parallel to the direction of working.
2. Referenced Documents
3.2.2 grain size—equivalent in meaning to the average of a
2
2.1 ASTM Standards:
distribution of grain sizes.
E3 Guide for Preparation of Metallographic Specimens
3.2.3 necklace or necklace structure—individual coarse
E7 Terminology Relating to Metallography
grains surrounded by rings of significantly finer grains.
E112 Test Methods for Determining Average Grain Size
3.2.4 topologically varying—varying nonrandomly, in some
definable pattern; that pattern may be related to the shape of the
1
These test methods are under the jurisdiction of ASTM Committee E04 on
specimen or product being examined.
Metallography and are the direct responsibility of Subcommittee E04.08 on Grain
Size.
4. Summary of Test Method
Current edition approved Oct. 1, 2015. Published November 2015. Originally
ɛ1
approved in 1987. Last previous edition approved in 2008 as E1181–02(2008) .
4.1 These test methods provide means for recognizing the
DOI: 10.1520/E1181-02R15.
presence of duplex grain size. The test methods separate duplex
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
3
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, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
E1181 − 02 (2015)
grain sizes into two classes (randomly varying, and topologi- does not adequately characterize the appearance of that
cally varying), and define specific types of duplex grain sizes specimen, and may even misrepresent its appearance. For
within these classes. The test methods provide means for example, averaging two distinctly different grain sizes may
estimating area fractions occupied by distinct grain sizes, and re
...

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 2015)
Standard Test Methods for
1
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.
1
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
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:
3
Comparison Chart for Estimation of Area Fractions
1
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, 2008Oct. 1, 2015. Published October 2008 November 2015. Originally approved in 1987. Last previous edition approved in 20022008
ɛ1
as E1181E1181–02(2008) –02. DOI: 10.1520/E1181-02R08E01.10.1520/E1181-02R15.
2
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.
3
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

---------------------- Page: 1 ----------------------
E1181 − 02 (2015)
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
...