1、Designation: E1571 11Standard Practice forElectromagnetic Examination of Ferromagnetic Steel WireRope1This standard is issued under the fixed designation E1571; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revis
2、ion. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This practice covers the application and standardizationof instruments that use the electromagnetic, the magnetic flux,and the
3、magnetic flux leakage examination method to detectflaws and changes in metallic cross-sectional areas in ferro-magnetic wire rope products.1.1.1 This practice includes rope diameters up to 2.5 in.(63.5 mm). Larger diameters may be included, subject toagreement by the users of this practice.1.2 Units
4、The values stated in inch-pound units are to beregarded as standard. The values given in parentheses aremathematical conversions to SI units are provided for infor-mation only and are not considered standard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated
5、with its use. It is theresponsibility of the user of this standard to 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 Nondestruc-tive Testi
6、ngE1316 Terminology for Nondestructive Examinations2.2 Other Documents:ANSI/ASNT-CP-189 ASNT Standard for Qualification andCertification of Nondestructive Testing Personnel3SNT-TC-1A Recommended Practice for Personnel Qualifi-cation and Certification in Nondestructive Testing3NAS-410 Certification a
7、nd Qualification of NondestructivePersonnel (Quality Assurance Committee)43. Terminology3.1 DefinitionsFor definitions of terms used in this prac-tice, refer to Terminology E1316.3.2 Definitions of Terms Specific to This Standard:3.2.1 dual-function instrumenta wire rope NDT instru-ment designed to
8、detect and display changes of metalliccross-sectional area on one channel and local flaws on anotherchannel of a dual-channel strip chart recorder or anotherappropriate device.3.2.2 local flaw (LF)a discontinuity in a rope, such as abroken or damaged wire, a corrosion pit on a wire, a grooveworn int
9、o a wire, or any other physical condition that degradesthe integrity of the rope in a localized manner.3.2.3 loss of metallic cross-sectional area (LMA)a rela-tive measure of the amount of material (mass) missing from alocation along the wire rope and is measured by comparing apoint with a reference
10、 point on the rope that representsmaximum metallic cross-sectional area, as measured with aninstrument.3.2.4 single-function instrumenta wire rope NDT instru-ment designed to detect and display either changes in metalliccross-sectional area or local flaws, but not both, on a strip chartrecorder or a
11、nother appropriate device.4. Summary of Practice4.1 The principle of operation of a wire rope nondestructiveexamination instrument is as follows:4.1.1 Direct Current and Permanent Magnet (MagneticFlux) InstrumentsDirect current (dc) and permanent magnetinstruments (Figs. 1 and 2) supply a constant f
12、lux thatmagnetizes a length of rope as it passes through the sensor head(magnetizing circuit). The total axial magnetic flux in the ropecan be measured either by Hall effect sensors, an encircling(sense) coil, or by any other appropriate device that canmeasure absolute magnetic fields or variations
13、in a steadymagnetic field. The signal from the sensors is electronically1This practice is under the jurisdiction of ASTM Committee E07 on Nonde-structive Testing and is the direct responsibility of Subcommittee E07.07 onElectromagnetic Method.Current edition approved Dec. 1, 2011. Published January
14、2012. Originallypublished as E1571 93. Last previous edition E1571 06. DOI: 10.1520/E1571-11.2For 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
15、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 Aerospace Industries Association of America, Inc. (AIA), 1000Wilson Blvd., Suite 1700,Arlington, VA22209-3
16、928, http:/www.aia-aerospace.org.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.processed, and the output voltage is proportional to the volumeof steel or the change
17、in metallic cross-sectional area, withinthe region of influence of the magnetizing circuit. This type ofinstrument measures changes in metallic cross-sectional area.4.1.2 Magnetic Flux Leakage InstrumentA direct currentor permanent magnet instrument (Fig. 3) is used to supply aconstant flux that mag
18、netizes a length of rope as it passesthrough the sensor head (magnetizing circuit). The magneticflux leakage created by a discontinuity in the rope, such as abroken wire, can be detected with a differential sensor, such asa Hall effect sensor, sensor coils, or by any other appropriatedevice. The sig
19、nal from the sensor is electronically processedand recorded. This type of instrument measures LFs. While theinformation is not quantitative as to the exact nature andmagnitude of the causal flaws, valuable conclusions can bedrawn as to the presence of broken wires, internal corrosion,and fretting of
20、 wires in the rope.”4.2 The examination is conducted using one or more tech-niques discussed in 4.1. Loss of metallic cross-sectional areacan be determined by using an instrument operating accordingto the principle discussed in 4.1.1. Broken wires and internal(or external) corrosion can be detected
21、by using a magnetic fluxleakage instrument as described in 4.1.2. The examinationprocedure must conform to Section 9. One instrument mayincorporate both magnetic flux and magnetic flux leakageprinciples.FIG. 1 Schematic Representation of a Permanent Magnet Equipped Sensor-Head Using a Sense Coil to
22、Measure the Loss of MetallicCross-Sectional AreaFIG. 2 Schematic Representation of a Permanent Magnet Equipped Sensor-Head Using Hall Devices to Measure the Loss of MetallicCross-Sectional AreaFIG. 3 Illustration of the Leakage Flux Produced by a Broken WireE1571 1125. Significance and Use5.1 This p
23、ractice outlines a procedure to standardize aninstrument and to use the instrument to examine ferromagneticwire rope products in which the magnetic flux and magneticflux leakage methods are used. If properly applied, the mag-netic flux method is capable of detecting the presence, location,and magnit
24、ude of metal loss from wear, broken wires, andcorrosion, and the magnetic flux leakage method is capable ofdetecting the presence and location of flaws such as brokenwires and corrosion pits.5.2 The instruments response to the ropes fabrication,installation, and in-service-induced flaws can be signi
25、ficantlydifferent from the instruments response to artificial flaws suchas wire gaps or added wires. For this reason, it is preferable todetect and mark (using set-up standards that represent) realin-service-induced flaws whose characteristics will adverselyaffect the serviceability of the wire rope
26、.6. Basis of Application6.1 The following items require agreement by the users ofthis practice and should be included in the rope examinationcontract:6.1.1 Acceptance criteria.6.1.2 Determination of LMA, or the display of LFs, or both.6.1.3 Extent of rope examination (that is, full length thatmay re
27、quire several setups or partial length with one setup).6.1.4 Standardization method to be used: wire rope refer-ence standard, rod reference standards, or a combinationthereof.6.1.5 Maximum time interval between equipment standard-izations.6.2 Personnel QualificationIf specified in the contractualag
28、reement, personnel performing examinations in accordancewith this test method shall be qualified in accordance with anationally or internationally recognized NDT personnel quali-fication practice or standard such as ANSI/ASNT CP-189,SNT-TC-1A, NAS-410, or a similar document and certified bythe emplo
29、yer or certifying agency as applicable. The practiceor standard used and its applicable revision shall be specified inthe contractual agreement between the using parties.6.3 Qualification of Nondestructive AgenciesIf specifiedin the contractual agreement, NDT agencies shall be qualifiedand evaluated
30、 as described in E543. The applicable edition ofE543 shall be specified in the contractual agreement.6.4 Wire Rope Reference Standard (Fig. 4):6.4.1 Type, dimension, location, and number of artificialanomalies to be placed on a wire rope reference standard.6.4.2 Methods of verifying dimensions of ar
31、tificial anoma-lies placed on a wire rope reference standard and allowabletolerances.6.4.3 Diameter and construction of wire rope(s) used for awire rope reference standard.6.5 Rod Reference Standards (Fig. 5):6.5.1 Rod reference standard use, whether in the laboratoryor in the field, or both.6.5.2 Q
32、uantity, lengths, and diameters of rod referencestandards.7. Limitations7.1 General Limitations:7.1.1 This practice is limited to the examination of ferro-magnetic steel ropes.7.1.2 It is difficult, if not impossible, to detect flaws at ornear rope terminations and ferromagnetic steel connections.7.
33、1.3 Deterioration of a purely metallurgical nature (brittle-ness, fatigue, etc.) may not be easily distinguishable.7.1.4 A given size sensor head accommodates a limitedrange of rope diameters, the combination (between ropeoutside diameter and sensor head inside diameter) of whichprovides an acceptab
34、le minimum air gap to assure a reliableexamination.7.2 Limitations Inherent in the Use of Magnetic FluxMethods:7.2.1 Instruments designed to measure changes in metalliccross-sectional area are capable of showing changes relative tothat point on the rope where the instrument was standardized.7.2.2 Th
35、e sensitivity of these methods may decrease withthe depth of the flaw from the surface of the rope and withdecreasing gaps between the ends of the broken wires.7.3 Limitations Inherent in the Use of the Magnetic FluxLeakage Method:7.3.1 It may be impossible to discern relatively small-diameter broke
36、n wires, broken wires with small gaps, orindividual broken wires within closely-spaced multiple breaks.It may be impossible to discern broken wires from wires withcorrosion pits.7.3.2 Because deterioration of a purely metallurgical naturemay not be easily distinguishable, more frequent examinationsF
37、IG. 4 Example of a Wire Rope Reference StandardFIG. 5 Example of a Rod Reference StandardE1571 113may be necessary after broken wires are detected to determinewhen the rope should be retired, based on percent rate ofincrease of broken wires.8. Apparatus8.1 The equipment used shall be specifically de
38、signed toexamine ferromagnetic wire rope products.8.1.1 The energizing unit within the sensor head shallconsist of permanent magnets or dc solenoid coils configuredto allow application to the rope at the location of service.8.1.2 The energizing unit shall be capable of magneticallysaturating the ran
39、ge (size and construction) of ropes for whichit was designed.8.1.3 The sensor head, containing the energizing and detect-ing units, and other components, should be designed toaccommodate different rope diameters. The rope should beapproximately centered in the sensor head.8.1.4 The instrument should
40、 have connectors, or othermeans, for transmitting output signals to strip chart recorders,data recorders, or a multifunction computer interface. Theinstrument may also contain meters, bar indicators, or otherdisplay devices, necessary for instrument setup, standardiza-tion, and examination.8.1.5 The
41、 instrument should have an examination distanceand rope speed output indicating the current examinationdistance traveled and rope speed or, whenever applicable, havea proportional drive chart control that synchronizes the chartspeed with the rope speed.8.2 Auxiliary EquipmentThe examination results
42、shall be recorded on a permanentbasis by either8.2.1 a strip chart recorder8.2.2 and/or by an other type of data recorder8.2.3 and/or by a multifunctional computer interface.9. Examination Procedure9.1 The electronic system shall have a pre-examinationstandardization procedure.9.2 The wire rope shal
43、l be examined for LFs or LMA, orboth, as specified in the agreement by the users of this practice.The users may select the instrument that best suits the intendedpurpose of the examination. The examination should be con-ducted as follows:9.2.1 The rope may need to be demagnetized before anexaminatio
44、n. If a magnetic flux or a magnetic flux leakageinstrument is used, it may be necessary to repeat the examina-tion to homogenize the magnetization of the rope.9.2.2 The sensor head must be approximately centeredaround the wire rope.9.2.3 The instrument must be adjusted in accordance with aprocedure.
45、 The sensitivity setting should be verified prior tostarting the examination by inserting a ferromagnetic steel rodor wire of known cross-sectional area. This standardizationsignal should be permanently recorded for future reference.9.2.4 The wire rope must be examined by moving the head,or the rope
46、, at a relatively uniform speed. Relevant signal(s)must be recorded on suitable media, such as on a strip chartrecorder, on a tape recorder, or on computer file(s), for thepurpose of both present and future replay/analysis.9.2.5 The following information shall be recorded as exami-nation data for an
47、alysis:9.2.5.1 Date of examination,9.2.5.2 Examination number,9.2.5.3 Customer identification,9.2.5.4 Rope identification (use, location, reel and ropenumber, etc.),9.2.5.5 Rope diameter and construction,9.2.5.6 Instrument serial number,9.2.5.7 Instrument standardization settings,9.2.5.8 Strip chart
48、 recorder settings,9.2.5.9 Strip chart speed,9.2.5.10 Location of sensor head with respect to a well-defined reference point along the rope, both at the beginning ofthe examination and when commencing a second set-up run,9.2.5.11 Direction of rope or sensor head travel,9.2.5.12 Total length of rope
49、examined, and9.2.5.13 Examination speed.9.2.6 To assure repeatability of the examination results, twoor more operational passes are required.9.2.7 When more than one setup is required to examine thefull working length of the rope, the sensor head should bepositioned to maintain the same magnetic polarity with respectto the rope for all setups. For strip chart alignment purposes, atemporary marker should be placed on the rope at a pointcommon to the two adjacent runs. (A ferromagnetic markershows an indication on a recording device.) The same instru-ment detection
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