1、Designation: E2096/E2096M 16Standard Practice forIn Situ Examination of Ferromagnetic Heat-Exchanger TubesUsing Remote Field Testing1This standard is issued under the fixed designation E2096/E2096M; the number immediately following the designation indicates the yearof original adoption or, in the ca
2、se 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*1.1 This practice describes procedures to be followed duringremote field examination of insta
3、lled ferromagnetic heat-exchanger tubing for baseline and service-induced discontinui-ties.1.2 This practice is intended for use on ferromagnetic tubeswith outside diameters from 0.500 to 2.000 in. 12.70 to 50.80mm, with wall thicknesses in the range from 0.028 to 0.134 in.0.71 to 3.40 mm.1.3 This p
4、ractice does not establish tube acceptance criteria;the tube acceptance criteria must be specified by the usingparties.1.4 UnitsThe values stated in either inch-pound units orSI units are to be regarded separately as standard. The valuesstated in each system may not be exact equivalents; therefore,e
5、ach system shall be used independently of the other. Combin-ing values from the two systems may result in nonconformancewith the standard.1.5 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 practice to
6、establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E543 Specification for Agencies Performing NondestructiveTestingE1316 Terminology for Nondestructive Examinations2.2 ASNT Documents:3S
7、NT-TC-1A Recommended Practice for Personnel Qualifi-cation and Certification in Nondestructive TestingANSI/ASNT-CP-189 Standard for Qualification and Certifi-cation of Nondestructive Testing Personnel2.3 Other Documents:Can CGSB-48.9712-95 Qualification of NondestructiveTesting Personnel, Natural Re
8、sources Canada4ISO 9712 Nondestructive TestingQualification and Certi-fication of Nondestructive Testing Personnel5NAS-410 Certification and Qualification of NondestructiveTesting Personnel63. Terminology3.1 GeneralDefinitions of terms used in this practice canbe found in Terminology E1316, Section
9、A, “Common NDTTerms,” and Section C, “Electromagnetic Testing.”3.2 Definitions:3.2.1 detector, none or more coils or elements used tosense or measure magnetic field; also known as a receiver.3.2.2 exciter, na device that generates a time-varyingelectromagnetic field, usually a coil energized with al
10、ternatingcurrent (ac); also known as a transmitter.3.2.3 nominal tube, na tube or tube section meeting thetubing manufacturers specifications, with relevant propertiestypical of a tube being examined, used for reference ininterpretation and evaluation.3.2.4 remote field, n as applied to nondestructi
11、ve testing,the electromagnetic field which has been transmitted throughthe test object and is observable beyond the direct couplingfield of the exciter.1This practice is under the jurisdiction of ASTM Committee E07 on Nonde-structive Testing and is the direct responsibility of Subcommittee E07.07 on
12、Electromagnetic Method.Current edition approved Feb. 1, 2016. Published February 2016. Originallyapproved in 2000. Last previous edition approved in 2010 as E2096 - 10. DOI:10.1520/E2096_E2096M-16.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service a
13、t serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available fromAmerican Society for Nondestructive Testing (ASNT), P.O. Box28518, 1711 Arlingate Ln., Columbus, OH 43228-0518, http:/www.asnt.org.4Available from CG
14、SB Sales Centre; Place du Portage, Phase 3, 6B1; 11 LaurierStreet, Hull QC, Canada K1A 1G6.5Available from International Organization for Standardization (ISO), ISOCentral Secretariat, BIBC II, Chemin de Blandonnet 8, CP 401, 1214 Vernier,Geneva, Switzerland, http:/www.iso.org.6Available from Aerosp
15、ace Industries Association (AIA), 1000 Wilson Blvd.,Suite 1700, Arlington, VA 22209, http:/www.aia-aerospace.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.2.5 re
16、mote field testing, na nondestructive test methodthat measures changes in the remote field to detect andcharacterize discontinuities.3.2.6 using parties, nthe supplier and purchaser.3.2.6.1 DiscussionThe party carrying out the examinationis referred to as the “supplier,” and the party requesting the
17、examination is referred to as the “purchaser,” as required inForm and Style for ASTM Standards, April 2004. In commonusage outside this practice, these parties are often referred to asthe “operator” and “customer,” respectively.3.3 Definitions of Terms Specific to This Standard:3.3.1 flaw characteri
18、zation standard, na standard used inaddition to the RFT system reference standard, with artificial orservice-induced flaws, used for flaw characterization.3.3.2 nominal point, na point on the phase-amplitudediagram representing data from nominal tube.3.3.3 phase-amplitude diagram, na two-dimensional
19、 rep-resentation of detector output voltage, with angle representingphase with respect to a reference signal, and radius represent-ing amplitude (Fig. 1a and 1b).3.3.3.1 DiscussionIn this practice, care has been taken touse the term “phase angle” (and “phase”) to refer to an angularequivalent of tim
20、e displacement, as defined in TerminologyE1316. When an angle is not necessarily representative of time,the general term “angle of an indication on the phase-amplitudediagram” is used.3.3.4 RFT system, nthe electronic instrumentation,probes, and all associated components and cables required forperfo
21、rming RFT.3.3.5 RFT system reference standard, na reference stan-dard with specified artificial flaws, used to set up and standard-ize a remote field system and to indicate flaw detectionsensitivity.3.3.6 sample ratethe rate at which data is digitized fordisplay and recording, in data points per sec
22、ond.3.3.7 strip chart, na diagram that plots coordinates ex-tracted from points on a phase-amplitude diagram versus timeor axial position (Fig. 1c).3.3.8 zero point, na point on the phase-amplitude diagramrepresenting zero detector output voltage.FIG. 1 A and B: Typical Phase-Amplitude Diagrams Used
23、 in RFT; C: Generic Strip Chart With FlawE2096/E2096M 1623.3.8.1 DiscussionData on the phase-amplitude diagramare plotted with respect to the zero point. The zero point isseparate from the nominal point unless the detector is config-ured for zero output in nominal tube. The angle of a flawindication
24、 is measured about the nominal point.3.4 Acronyms:3.4.1 RFT, nremote field testing4. Summary of Practice4.1 The RFT data is collected by passing a probe througheach tube. The electromagnetic field transmitted from theexciter to the detector is affected by discontinuities; by thedimensions and electr
25、omagnetic properties of the tube; and byobjects in and around the tube that are ferromagnetic orconductive. System sensitivity is verified using the RFT systemreference standard. System sensitivity and settings are checkedand recorded prior to and at regular intervals during theexamination. Data and
26、 system settings are recorded in amanner that allows archiving and later recall of all data andsystem settings for each tube. Interpretation and evaluation arecarried out using one or more flaw characterization standards.The supplier generates a final report detailing the results of theexamination.5
27、. Significance and Use5.1 The purpose of RFT is to evaluate the condition of thetubing. The evaluation results may be used to assess thelikelihood of tube failure during service, a task which is notcovered by this practice.5.2 Principle of Probe OperationIn a basic RFT probe,the electromagnetic fiel
28、d emitted by an exciter travels outwardsthrough the tube wall, axially along the outside of tube, andback through the tube wall to a detector7(Fig. 2a).5.2.1 Flaw indications are created when (1) in thin-walledareas, the field arrives at the detector with less attenuation andless time delay, (2) dis
29、continuities interrupt the lines ofmagnetic flux, which are aligned mainly axially, or (3) discon-tinuities interrupt the eddy currents, which flow mainly cir-cumferentially. A discontinuity at any point on the through-transmission path can create a perturbation; thus RFT hasapproximately equal sens
30、itivity to flaws on the inner and outerwalls of the tube.75.3 Warning Against Errors in Interpretation. Characteriz-ing flaws by RFT may involve measuring changes from7Schmidt, T. R., “The Remote Field Eddy Current Inspection Technique,”Materials Evaluation, Vol. 42, No. 2, Feb. 1984, pp. 225-230.NO
31、TE 1Arrows indicate flow of electromagnetic energy from exciter to detector. Energy flow is perpendicular to lines of magnetic flux.FIG. 2 RFT ProbesE2096/E2096M 163nominal (or baseline), especially for absolute coil data. Thechoice of a nominal value is important and often requiresjudgment. Practit
32、ioners should exercise care to use for nominalreference a section of tube that is free of damage (see definitionof “nominal tube” in 3.2.3). In particular, bends used asnominal reference must be free of damage, and tube supportplates used as nominal reference should be free of metal loss inthe plate
33、 and in adjacent tube material. If necessary, a comple-mentary technique (as described in 11.12) may be used toverify the condition of areas used as nominal reference.5.4 Probe ConfigurationThe detector is typically placedtwo to three tube diameters from the exciter, in a locationwhere the remote fi
34、eld dominates the direct-coupling field.7Other probe configurations or designs may be used to optimizeflaw detection, as described in 9.3.5.5 Comparison with Conventional Eddy-Current TestingConventional eddy-current test coils are typically configured tosense the field from the tube wall in the imm
35、ediate vicinity ofthe emitting element, whereas RFT probes are typically de-signed to detect changes in the remote field.6. Basis of Application6.1 The following items are subject to contractual agree-ment between the parties using or referencing this standard.6.2 Personnel QualificationIf specified
36、 in the contractualagreement, personnel performing examinations to this standardshall be qualified in accordance with a nationally or interna-tionally recognized NDT personnel qualification practice orstandard such asANSI/ASNT-CP-189, SNT-TC-1A, NAS-410,ISO 9712, or a similar document and certified
37、by the employeror certifying agency, as applicable. The practice or standardused and its applicable revision shall be identified in thecontractual agreement between the using parties.6.3 Qualification of Nondestructive Testing AgenciesIfspecified in the contractual agreement, NDT agencies shall bequ
38、alified and evaluated as specified in Practice E543, withreference to sections on electromagnetic testing. The appli-cable edition of Practice E543 shall be specified in thecontractual agreement.7. Job Scope and Requirements7.1 The following items may require agreement between theusing parties and s
39、hould be specified in the purchase documentor elsewhere:7.1.1 Location and type of tube component to be examined,design specifications, degradation history, previous nonde-structive examination results, maintenance history, processconditions, and specific types of flaws that are required to bedetect
40、ed, if known.7.1.2 The maximum window of opportunity for work.(Detection of small flaws may require a slower probe pullspeed, which will affect productivity.)7.1.3 Size, material grade and type, and configuration oftubes to be examined.7.1.4 A tube numbering or identification system.7.1.5 Extent of
41、examination, for example: complete orpartial coverage, which tubes and to what length, whetherstraight sections only, and the minimum radius of bends thatcan be examined.7.1.6 Means of access to tubes, and areas where access maybe restricted.7.1.7 Type of RFT instrument and probe; and description of
42、reference standards used, including such details as dimensionsand material.7.1.8 Required operator qualifications and certification.7.1.9 Required tube cleanliness.7.1.10 Environmental conditions, equipment, and prepara-tions that are the responsibility of the purchaser; commonsources of noise that
43、may interfere with the examination.NOTE 1Nearby welding activities may be a major source of interfer-ence.7.1.11 Complementary methods or techniques (includingpossible tube removal) that may be used to obtain additionalinformation.7.1.12 Acceptance criteria to be used in evaluating flawindications.7
44、.1.13 Disposition of examination records and referencestandards.7.1.14 Format and outline contents of the examinationreport.8. Interferences8.1 This section describes items and conditions which maycompromise RFT.8.2 Material Properties:8.2.1 Variations in the material properties of ferromagnetictube
45、s are a potential source of inaccuracy. Impurities,segregation, manufacturing process, grain size, stress history,present stress patterns, temperature history, presenttemperature, magnetic history, and other factors will affect theelectromagnetic response measured during RFT. The conduc-tivity and p
46、ermeability of tubes with the same grade of materialare often measurably different. It is common to find that someof the tubes to be examined are newer tubes with differentmaterial properties.8.2.2 Permeability variations may occur at locations wherethere was uneven temperature or stress during tube
47、manufacture, near welds, at bends, where there were unevenheat transfer conditions during service, at areas where there iscold working (such as that created by an integral finningprocess), and in other locations. Indications from permeabilityvariations may be mistaken for, or obscure flaw indication
48、s.Effects may be less severe in tubes that were stress-relievedduring manufacture.8.2.3 Residual stress, with accompanying permeabilityvariations, may be present when discontinuities are machinedinto a reference standard, or during the integral finning process.8.2.4 RFT is affected by residual magne
49、tism in the tubing,including residual magnetism created during a previous exami-nation using another magnetic method. Tubes with significantresidual magnetism should be demagnetized prior to RFT.8.3 Ferromagnetic and Conductive Objects:E2096/E2096M 1648.3.1 Objects near the tube that are ferromagnetic or con-ductive may reduce the sensitivity and accuracy of flawcharacterization in their immediate vicinity. Such objects mayin some cases be mistaken for flaws. Knowledge of themechanical layout of the component to be examined is recom-mended. Exam
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