ASTM E1351-01(2020)

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: E1351 − 01 (Reapproved 2020)
Standard Practice for
Production and Evaluation of Field Metallographic Replicas
This standard is issued under the fixed designation E1351; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
Replication is a nondestructive sampling procedure which records and preserves the topography of
a metallographic specimen as a negative relief on a plastic film. The microstructural replica can be
examined using a light microscope (LM) or scanning electron microscope (SEM) for subsequent
analysis. Specimens examined in the SEM are vacuum coated with vaporized carbon or a suitable
metal to provide contrast and conductivity. The convenience of the replication process makes it
suitable for obtaining microstructures from field locations for subsequent examination and analysis in
a laboratory. The proper preparation of the test surface and of the replica itself is of paramount
importance and must receive careful attention. Because of the diversity of metallographic equipment
available and the wide range of environments in which replication is conducted, the preparation of
replicas of high quality should be viewed as a skilled process for which there exists a variety of
techniques that achieve satisfactory results.
This practice presents some guidelines on the preparation of metallic surfaces and production of
replicas and guidelines on evaluation of replica quality. It does not attempt to limit the variations in
technique developed by skilled metallographers, each of which may produce acceptable replicas.
1. Scope 1.5 This international standard was developed in accor-
dance with internationally recognized principles on standard-
1.1 This practice covers recognized methods for the prepa-
ization established in the Decision on Principles for the
ration and evaluation of cellulose acetate or plastic film
Development of International Standards, Guides and Recom-
replicas which have been obtained from metallographically
mendations issued by the World Trade Organization Technical
prepared surfaces. It is designed for the evaluation of replicas
Barriers to Trade (TBT) Committee.
to ensure that all significant features of a metallographically
prepared surface have been duplicated and preserved on the
2. Referenced Documents
replica with sufficient detail to permit both LM and SEM
2.1 ASTM Standards:
examination with optimum resolution and sensitivity.
A335/A335MSpecification for Seamless Ferritic Alloy-
1.2 This practice may be used as a controlling document in
Steel Pipe for High-Temperature Service
commercial situations.
E3Guide for Preparation of Metallographic Specimens
1.3 The values stated in SI units are to be regarded as the
E7Terminology Relating to Metallography
standard. Inch-pound units given in parentheses are for infor-
E407Practice for Microetching Metals and Alloys
mation only.
3. Terminology
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the 3.1 Definitions—For definitions of terms used in this
responsibility of the user of this standard to establish appro- practice, refer to Terminology E7.
priate safety, health, and environmental practices and deter-
4. Significance and Use
mine the applicability of regulatory limitations prior to use.
4.1 Replication is a nondestructive sampling procedure that
records and preserves the topography of a metallographically
This practice is under the jurisdiction of ASTM Committee E04 on Metallog-
raphy and is the direct responsibility of Subcommittee E04.01 on Specimen
Preparation. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Nov. 1, 2020. Published November 2020. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1990. Last previous edition approved in 2012 as E1351–01(2012). Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/E1351-01R20. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E1351 − 01 (2020)
prepared surface as a negative relief on a plastic film (replica). 6.3 Prepare the surface to be replicated using the methods
The replica permits the examination and analysis of the suggestedinMethodsE3modifiedforfielduse,asappropriate,
metallographically prepared surface on the LM or SEM. in such a way as to obtain a surface free of deformation,
scratches,polishingdefects,etchpits,andotherartifactswhich
4.2 Enhancement procedures for improving replica contrast
may obscure the true microstructural features.
for microscopic examination are utilized and sometimes nec-
essary (see 8.1).
NOTE 3—The presence of decarburization can be detected with a
portable hardness tester during the grinding steps. Further grinding to
NOTE 1—It is recommended that the purchaser of a field replication
reachasurfacefreeofdecarburizationcanbemonitoredwiththehardness
service specify that each replicator demonstrate proficiency by providing
tester.Areplicamayalsobemadeonthedecarburizedsurface,ifitserves
field prepared replica metallography and direct LM and SEM comparison
the purpose of the investigation.
to laboratory prepared samples of an identical material by grade and
service exposure.
6.4 Do not remove any precipitates, carbides, nonmetallic
inclusions such as oxides and sulfides during the polishing or
5. Evaluation Methods
etching operations.
5.1 A suitable replica should accurately reproduce all the
6.5 Etchingproceduresforsurfacemetallographicexamina-
microstructural features present on the surface that was repli-
tion should be performed in accordance with Practice E407.
cated.
6.6 The quality of the surface preparation should be con-
5.2 No visible loss of resolution is permitted over the
trolled by the use of a portable field microscope.
normal range of magnifications on the LM as shown in Figs.
1-3.
6.7 To prevent possible contamination of any components,
the etched area should be prepared carefully and thoroughly
5.3 The resolution of the structural detail in the replica
washed after replication.
should exceed 0.1 µm to permit SEM examination at high
magnifications (up to 5000×). See Figs. 4-6.
7. Replication Technique
6. Metal Surface Preparation
7.1 Ingeneral,areplicatedareaof12by18mm(0.5by0.75
in.) is satisfactory.
6.1 If magnetic particle testing was previously used on the
work-piece, demagnetize the piece before beginning surface
7.2 A replica is produced by one of the two methods
preparation.
described below. All methods produce acceptable replicas.
6.2 Surfacepreparationmaybeaccomplishedusingmanual,
7.2.1 A replica may be produced by wetting one side of a
mechanical, or electrolytic polishing methods.
sheet of plastic film with a suitable solvent, such as acetone or
methyl acetate, and applying the wetted side of the film to the
NOTE 2—Electrolytic preparation always carries the risk of pitting, and
of enlarging existing voids such as creep cavities and porosity. prepared metal surface.
FIG. 1 Example of Replica Microstructure at 100× LM. Material: See Specification A335/A335M, Grade P22. Etchant: 2 % Nital
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