1、Designation: E1351 01 (Reapproved 2012)Standard Practice forProduction and Evaluation of Field Metallographic Replicas1This standard is issued under the fixed designation E1351; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the y
2、ear of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.INTRODUCTIONReplication is a nondestructive sampling procedure which records and preserves the topography ofa metallographi
3、c specimen as a negative relief on a plastic film. The microstructural replica can beexamined using a light microscope (LM) or scanning electron microscope (SEM) for subsequentanalysis. Specimens examined in the SEM are vacuum coated with vaporized carbon or a suitablemetal to provide contrast and c
4、onductivity. The convenience of the replication process makes itsuitable for obtaining microstructures from field locations for subsequent examination and analysis ina laboratory. The proper preparation of the test surface and of the replica itself is of paramountimportance and must receive careful
5、attention. Because of the diversity of metallographic equipmentavailable and the wide range of environments in which replication is conducted, the preparation ofreplicas of high quality should be viewed as a skilled process for which there exists a variety oftechniques that achieve satisfactory resu
6、lts.This practice presents some guidelines on the preparation of metallic surfaces and production ofreplicas and guidelines on evaluation of replica quality. It does not attempt to limit the variations intechnique developed by skilled metallographers, each of which may produce acceptable replicas.1.
7、 Scope1.1 This practice covers recognized methods for the prepa-ration and evaluation of cellulose acetate or plastic filmreplicas which have been obtained from metallographicallyprepared surfaces. It is designed for the evaluation of replicasto ensure that all significant features of a metallograph
8、icallyprepared surface have been duplicated and preserved on thereplica with sufficient detail to permit both LM and SEMexamination with optimum resolution and sensitivity.1.2 This practice may be used as a controlling document incommercial situations.1.3 The values stated in SI units are to be rega
9、rded as thestandard. Inch-pound units given in parentheses are for infor-mation only.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices an
10、d determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2A335/A335M Specification for Seamless Ferritic Alloy-Steel Pipe for High-Temperature ServiceE3 Guide for Preparation of Metallographic SpecimensE7 Terminology Relating to MetallographyE40
11、7 Practice for Microetching Metals and Alloys3. Terminology3.1 DefinitionsFor definitions of terms used in thispractice, refer to Terminology E7.4. Significance and Use4.1 Replication is a nondestructive sampling procedure thatrecords and preserves the topography of a metallographicallyprepared surf
12、ace as a negative relief on a plastic film (replica).The replica permits the examination and analysis of themetallographically prepared surface on the LM or SEM.4.2 Enhancement procedures for improving replica contrastfor microscopic examination are utilized and sometimes nec-essary (see 8.1).1This
13、practice is under the jurisdiction of ASTM Committee E04 on Metallog-raphy and is the direct responsibility of Subcommittee E04.01 on SpecimenPreparation.Current edition approved Oct. 1, 2012. Published October 2012. Originallyapproved in 1990. Last previous edition approved in 2006 as E1351 01(2006
14、).DOI: 10.1520/E1351-01R12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100
15、Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1NOTE 1It is recommended that the purchaser of a field replicationservice specify that each replicator demonstrate proficiency by providingfield prepared replica metallography and direct LM and SEM comparisonto laboratory
16、 prepared samples of an identical material by grade andservice exposure.5. Evaluation Methods5.1 A suitable replica should accurately reproduce all themicrostructural features present on the surface that was repli-cated.5.2 No visible loss of resolution is permitted over thenormal range of magnifica
17、tions on the LM as shown in Figs.1-3.5.3 The resolution of the structural detail in the replicashould exceed 0.1 m to permit SEM examination at highmagnifications (up to 5000). See Figs. 4-6.6. Metal Surface Preparation6.1 If magnetic particle testing was previously used on thework-piece, demagnetiz
18、e the piece before beginning surfacepreparation.6.2 Surface preparation may be accomplished using manual,mechanical, or electrolytic polishing methods.NOTE 2Electrolytic preparation always carries the risk of pitting, andof enlarging existing voids such as creep cavities and porosity.6.3 Prepare the
19、 surface to be replicated using the methodssuggested in Methods E3 modified for field use, as appropriate,in such a way as to obtain a surface free of deformation,scratches, polishing defects, etch pits, and other artifacts whichmay obscure the true microstructural features.NOTE 3The presence of dec
20、arburization can be detected with aportable hardness tester during the grinding steps. Further grinding toreach a surface free of decarburization can be monitored with the hardnesstester.Areplica may also be made on the decarburized surface, if it servesthe purpose of the investigation.6.4 Do not re
21、move any precipitates, carbides, nonmetallicinclusions such as oxides and sulfides during the polishing oretching operations.6.5 Etching procedures for surface metallographic examina-tion should be performed in accordance with Practice E407.6.6 The quality of the surface preparation should be con-tr
22、olled by the use of a portable field microscope.6.7 To prevent possible contamination of any components,the etched area should be prepared carefully and thoroughlywashed after replication.7. Replication Technique7.1 In general, a replicated area of 12 by 18 mm (0.5 by 0.75in.) is satisfactory.7.2 A
23、replica is produced by one of the two methodsdescribed below. All methods produce acceptable replicas.7.2.1 A replica may be produced by wetting one side of asheet of plastic film with a suitable solvent, such as acetone ormethyl acetate, and applying the wetted side of the film to theprepared metal
24、 surface.7.2.2 Alternatively, a replica may be produced by wettingthe prepared metallic surface with a suitable solvent, such asacetone or methyl acetate, and applying the strip of plastic film(usually cellulose acetate) to the wet surface. The film ispressed against the surface for several seconds
25、to ensureadherance.7.2.3 Apply a rubber-based replicating compound to theprepared metal surface. Cover with the materials carrier paper,then use a roller to spread the compound into a uniformly thinlayer under the paper.FIG. 1 Example of Replica Microstructure at 100 LM. Material: See Specification
26、A335/A335M, Grade P22. Etchant: 2 % NitalE1351 01 (2012)27.3 The replica shall be prepared as soon as possible afterspecimen preparation of the original surface is completed, tominimize transfer of post-preparation oxidation and contami-nation to the replicating film.7.4 After the film has dried, re
27、move the replica and perma-nently mount on a rigid slide to facilitate analysis of the replicaand to protect it from damage during subsequent transport andstorage. The mounting may be accomplished using a double-sided adhesive tape, either applied to the back side of the driedreplica film while it r
28、emains on the prepared surface or appliedto the slide before transferring the replica on the tape surface.Using the rounded end of a glass rod to apply the replica on thetape is usually beneficial in reducing air bubbles and ensuringa flat replica. Some metallographers prefer to coat the back sideof
29、 the replica with an opaque substance such as black paint orink prior to applying tape to improve the contrast when thereplica is subsequently examined.7.5 Place identification on the slide, and store it in a durableslide container for safe, contamination-free transfer to theexamination laboratory.F
30、IG. 2 Example of Replica Microstructure at 400 LM. Material: See Specification A335/A335M, Grade P22. Etchant: 2 % NitalFIG. 3 Example of Replica Microstructure at 1000 LM. Material: See Specification A335/A335M, Grade P22. Etchant: 2 % NitalE1351 01 (2012)38. Replica Examination8.1 To enhance contr
31、ast of the replica for microscopicexamination at low magnifications on the LM, the replica maybe placed on an underlying polished surface, such as a mirror,which acts as a reflector. In addition, using a coating of blackink or paint on the back side of the replica can improve thecontrast. In some ca
32、ses, the use of interference illuminationwill also improve contrast; however, optimum contrast for bothLM and SEM can be achieved by coating the replica surfacewith a thin, highly reflective metallic layer material normallydeposited in a vacuum coating unit. Aluminum, carbon, andchromium have been f
33、ound to be satisfactory coatings forreplicas to be evaluated by LM. If the replica is to be examinedin the SEM, however, gold, which yields optimum contrast, ispreferable. ASTM STP 547 is the suggested guide for electronmetallographic techniques.38.2 The coating is generally applied at a 45 angle to
34、provide a light to shadow length of 1 to 1. The coatingthickness should be no greater than that required to provide full3Manual on Electron Metallography Techniques, ASTM STP 547, ASTM, 1973.FIG. 4 Example of Replica Microstructure at 1000 SEM. Material: See Specification A335/A335M, Grade P22. Etch
35、ant: 2 % NitalFIG. 5 Example of Replica Microstructure at 2000 SEM. Material: See Specification A335/A335M, Grade P22. Etchant: 2 % NitalE1351 01 (2012)4contrast in the replicated microstructure when examined in theLM and to prevent charging of the film when examined in theSEM. Documentation of the
36、structural features of interestshould then be made at the appropriate magnifications with theLM or SEM.9. Replica SurfaceNOTE 4Examples of replicated microstructures, (Specification A335/A335M steel, Grade P22 shown, with 2 % Nital etch. This materialexhibits a wide range of microstructures, not all
37、 of which are shown here.)9.1 High quality replicas must meet the criteria listed inSection 5.9.2 No folds or permanent deformation shall be allowed todevelop in the replica film during processing.9.3 Microstructural features should be clearly developedover an area of at least 6 mm (0.25 in.) in dia
38、meter.9.4 Replicas taken at weldments should accurately recordthe base metal, weld metal, and heat-affected-zone microstruc-ture along the fusion line for a distance of at least 13 mm (0.5in.).9.5 All microstructural features shall be accurately renderedand photographic documentation shall be obtain
39、able over therange of magnifications normally used for replica evaluation:50 to 1000X for LM and 500 to 5000X for SEM.9.6 All grain boundaries, grain boundary precipitates,cracks and cavities should be easily identified.9.7 Precipitates and inclusions contained in the material thatare greater than 0
40、.1 m should be accurately recorded on thereplica. In addition, neither precipitates, such as primary andsecondary carbides and carbonitrides, nor nonmetallicinclusions, such as oxides and sulfides, shall be dislodgedduring polishing or etching regardless of their size.10. Documentation10.1 Photomicr
41、ographic documentation of microstructuralfeatures shall be obtainable over the normal range of magnifi-cation: 50 to 1000X LM and 500 to 5000X SEM.10.2 Each replica be adequately identified. Minimum iden-tification should include the job or other identification number,the name, the presence and char
42、acteristics of any coatingapplied to either side of the replica, and the name of thepreparer.10.3 A statement shall be made on the conformance ornon-conformance of the replica to this practice.10.4 Replicas shall remain attached to their carrier slides,and shall be stored in dust-free biological sli
43、de cases, withproper indexing to permit retrieval where required for record.11. Precision and Bias11.1 It is not possible to specify the precision or bias of thispractice because no quantitative results are produced.However, all quantitative results produced through the exami-nation of replicas can
44、be influenced by the replication process.12. Keywords12.1 replica; replicationFIG. 6 Example of Replica Microstructure at 5000 SEM. Material: See Specification A335/A335M, Grade P22. Etchant: 2 % NitalE1351 01 (2012)5ASTM International takes no position respecting the validity of any patent rights a
45、sserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time
46、 by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will re
47、ceive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM In
48、ternational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).E1351 01 (2012)6
