1、Designation: E2905/E2905M 13Standard Practice forExamination of Mill and Kiln Girth Gear TeethElectromagnetic Methods1This standard is issued under the fixed designation E2905/E2905M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision,
2、 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 a two-part procedure for electro-magnetic evaluation on gear teeth on mill and k
3、iln gear drivesand pinions. The first part of this practice details the ability todetect 100 % of surface-breaking discontinuities only in theaddendum, dedendum, and root area on both the drive side andnon-drive side of the gear tooth using an eddy current array.The second part of the examination is
4、 to size or measureaccurately the length and depth of any cracks found in theseareas using electromagnetic methods. No other practice ad-dresses the use of electromagnetic methods for the detectionand sizing of surface-breaking discontinuities on mill and kilnring gear teeth.1.2 This practice is use
5、d only for crack detection, alignmentissues, wear patterns, and early signs of macro-pitting. It willnot illustrate a full gear tooth analysis. Visual examination byan experienced gear technician is the only way to analyze fullygear teeth wear patterns and potential failure.1.3 Two technicians, or o
6、ne technician and a technicalassistant, are typically required for this practice. One technicalassistant guides the probe and the technician operates thecomputer/software and analyzes the gear teeth condition.1.4 It is important that the appropriate method standards,such as Guide E709 and Practice E
7、2261, if the alternatingcurrent field measurement approach is used for crack sizing,accompany the technician when performing the examination.1.5 It is recommended that the technician reviews theappendixes in this practice in advance of starting the job.1.6 A clean gear is recommended for a complete
8、gearanalysis. Depending on the lubrication used, the technician, indiscussion with the client, shall determine the appropriatecleaning procedure, if cleaning is required. If an oil bathlubrication system is used, ensure the gear teeth surface isclean. If an asphaltic-based or synthetic-based lubrica
9、nt isused, refer to the annexes and appendices in this practice.1.7 UnitsThe values stated in either SI units or inch-pound units are to be regarded separately as standard. Thevalues stated in each system may not be exact equivalents;therefore, each system shall be used independently of the other.Co
10、mbining values from the two systems may result in noncon-formance with the standard.1.8 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 and
11、 determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E709 Guide for Magnetic Particle TestingE1316 Terminology for Nondestructive ExaminationsE2261 Practice for Examination of Welds Using the Alter-nating Current Field Measurement TechniqueE
12、2884 Guide for Eddy Current Testing of Electrically Con-ducting Materials Using Conformable Sensor Arrays2.2 AIA Standard:3NAS 410 Certification and Qualification of NondestructiveTest Personnel2.3 ANSI/AGMA Standards:4AGMA 912-A04 Mechanisms of Gear Tooth FailuresInformation SheetANSI/AGMA 1010 E-9
13、5 Standard for Appearance of GearTeethTerminology of Wear and FailureANSI/AGMA 1012 G-05 Gear Nomenclature, Definition ofTerms1This test method is under the jurisdiction of ASTM Committee E07 onNondestructive Testing and is the direct responsibility of Subcommittee E07.07 onElectromagnetic Method.Cu
14、rrent edition approved Dec. 1, 2013. Published December 2013. Originallyappeared in 2012. Last previous edition appeared in 2012 as E2905/E2905M 12.DOI: 10.1520/E2905_E2905M-13.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. F
15、or Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from Aerospace Industries Association of America, Inc. (AIA), 1000Wilson Blvd., Suite 1700,Arlington, VA22209-3928, http:/www.aia-aerospace.org.4Available from American Nati
16、onal Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.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 States12.4 ANSI/ASNT Standards
17、:4ANSI/ASNT-CP-189 Qualification and Certification of Non-destructive Testing PersonnelSNT-TC-1A Recommended Practice for Personnel Qualifi-cation and Certification in Nondestructive Testing3. Terminology3.1 DefinitionsFor definitions of terms relating to thisguide refer to Terminology E1316, Practi
18、ce E2261, and GuideE2884. For definitions of general terms relating to gearexaminations refer to Guide E709, ANSI/AGMA 1012 G-05,and ANSI/AGMA 1010 E-95.NOTE 1Different equipment manufacturers may use slightly differentterminology. Reference should be made to the equipment manufacturersdocumentation
19、 for clarification.3.2 Eddy Current Array Method:3.2.1 basic concepts of eddy current array, ECA, neddycurrent array (ECA) technology provides the ability to measureelectronically multiple eddy current sensing coils placed sideby side in the same probe assembly. Example eddy currentarrays have disti
20、nct drive coils associated with each sense coilor a drive coil with a linear conductor that is parallel to a lineararray of sense coils. Depending upon the instrumentation, theresponse for each sense element can be measured in parallel ora multiplexer can be used to switch between one or more of the
21、sense coils. Typically, a multiplexer is used when the numberof sense coils is greater than the number of data acquisitionchannels for impedance measurement. When using eddy cur-rent sensor arrays with multiple drive coils and multiplesensing coils, undesired coupling between the individual coilsis
22、likely to take place. It may be necessary to use a multiplexerwith a special multiplexing pattern to avoid such undesiredcoupling. Most conventional eddy current flaw detection tech-niques can be reproduced with an ECA examination. With thebenefits of single-pass coverage, and enhanced imagingcapabi
23、lities, ECA technology provides a remarkably powerfultool and significant time savings during inspections comparedto raster scanning with a single coil probe. (See Fig. 1.)3.2.1.1 DiscussionIn this standard, the use of the eddycurrent array is for crack detection, early signs of macro-pittingalignme
24、nt issues, and wear patterns. Although ECA will showwear patterns, the proper method for interpreting contact andwear patterns should be used. Refer to AGMA 912-A04,section 3.3.3.2. LimitationsThe eddy current array will notreveal backlash problems, lubrication issues, tip to rootinterface, and so f
25、orth. Visual interpretation is the typicalmethod used to analyze these conditions. It is also veryimportant that the technician has an education in gear analysis.Basic eddy current experience does not provide the knowledgerequired to interpret gear teeth issues or the understanding ofECA. The knowle
26、dge of the defect type helps in determiningthe root causes and the potential solutions, resulting in a higherstandard of examination.3.2.2 eddy current array probes, nprobes can be designedto detect a specific type of discontinuity and to conform to theshape of the part under examination (see Fig. 2
27、).3.2.2.1 DiscussionProbes can be designed to detect aspecific type of discontinuity and conform to the shape of thegear tooth under examination.Also notice that the center of theroot would actually be scanned twice. In this examination,there is no saturation performed. Surface probes are made withc
28、oils designed to be driven at relatively high frequencies(typically 50 to 500 kHz). Using higher frequencies results inless penetration of the eddy current field into the test partallowing full coverage of any surface-breaking discontinuitiesof the component to be examined. In addition, the higherfr
29、equencies provide a higher resolution for the detection ofsmaller defects. For this practice, a surface array probe, withthe ability of detecting all surface discontinuitiesincludingcracks, is required for a successful examination.3.2.3 reference standard, nshall contain at least one longreference i
30、ndicator to standardize all the channels of the arrayat once and also representative defects for flaw characterizationduring the examination.3.2.4 set screws, nconformable and substantially noncon-ducting set screws on the probe that are used to allow smalllift-off adjustments or excursions on surfa
31、ce response.3.2.5 system performance verification, nuse of a measure-ment of one or more response values, typically physicalproperty values for a reference standard to confirm that theresponse values are within specified tolerances to validate thesystem standardization and verify proper instrument o
32、peration.3.2.5.1 DiscussionProbe qualityProbe life varies de-pending on the environmental conditions within the work area.Some of these environmental factors are temperature, moisture,cleanliness, and the main factor being surface roughness.4. Summary of Practice4.1 Gear-Cleaning ProcedureTypically,
33、 mill operationsdoes the cleaning or supervises the cleaning. Mill maintenanceremoves the guards for access to the gear. Nondestructiveevaluation (NDE) mill girth gear examinations are provided formaintenance. Visual interpretation is also a common methodused to analyze gear teeth condition, such as
34、 contact patternsand wear patterns. For visual inspection, a cleaned gear ismandatory. Another reason for a cleaned gear tooth is that it isvery hard for the ECAprobe to maintain the geometry of a geartooth that is covered with lubricant, especially if the lubricantis asphaltic-based or synthetic. I
35、f asphaltic or sythetic lubrica-tion is used, refer to Appendix X2 for cleaning procedures.4.1.1 ECAECA is used for nondestructively locating andcharacterizing surface-breaking discontinuities in conductingFIG. 1 Eddy Current Single Coil Probe Compared to Eddy CurrentArray Probe CoilsE2905/E2905M 13
36、2materials to electrically conductive materials. For use in thispractice, the properly designed ECAprobe has proven to detectall surface-breaking discontinuities from 0.76 mm (0.03 in.)and larger on the addendum, dedendum, and root of girth gearteeth. The examination is performed by scanning a confo
37、rm-able eddy current sensor array over the surface of theaddendum, dedendum, and root of the gear tooth beingexamined in one pass. The drive side of the tooth is referred toas the A side and the nondrive side of the tooth is referred to asthe B side of the tooth. The measured responses and locationi
38、nformation are then used, typically in the form of a displayedimage (C-scan), to determine the presence and characteristicsof discontinuities.4.1.2 Alternating Current Field Measurement MethodAlternating current field measurement is used if a crack isfound. Alternative electromagnetic methods can al
39、so be usedfor sizing cracks.4.1.3 Alternating Current Field Measurement for Nonde-structive Testing Detection and Sizing of Surface-BreakingCracksIt works on all metals, ferrous or nonferrous.Asensorprobe is placed on the surface to be examined and analternating current is induced into the surface.
40、When no defectsare present the alternating current produces a uniform magneticfield above the surface. Any defect present will perturb thecurrent, forcing it to flow around and underneath the defect;this causes the magnetic field to become non-uniform andsensors in the alternating current field meas
41、urement probemeasure these field variations. Two components of this mag-netic field are measuredone provides information about thedepth or aspect ratio of the defect(s) and the other shows thepositions of the defects ends. The two signals are used toconfirm the presence of a defect and, together wit
42、h a sizingalgorithm, measure its length and depth. The main advantagesof alternating current field measurement for this practice arethe speed of sizing cracks and that it provides both depth andlength information. Defects up to 25 mm (1 in.) in depth can besized accurately.4.1.4 Magnetic Particle Ex
43、aminationMagnetic particle isused when a crack is found. It is used to illustrate the crack forthe picture in the report. (See Fig. 3.) It is also used whenexcessive lift-off prevents the ECA probe from receiving asignal.5. Significance and Use5.1 Visual interpretation of gear teeth condition is dif
44、ferentfrom examining for cracks or early signs of macro-pitting.Visual interpretation is referred to ANSI/AGMA 1010 E-95.5.1.1 The purpose of using an eddy current array for millgirth gear teeth examination is it drastically reduces theexamination time; covers a large area in one single pass;provide
45、s real-time cartography of the examined region, facili-tating data interpretation; and improves reliability and prob-ability of detection (POD). One tooth can be examined in lessthan 30 seconds.FIG. 2 Coverage of a Flexible ProbeRoot, Dedendum, and AddendumFIG. 3 Two cracks on a tooth just above the
46、 root that were onlyobserved visually after being revealed by the ECA examination.In this example, the cracks were not apparent visually until MTwas performed.E2905/E2905M 133NOTE 2In this standard, ECA is used as a discontinuity finding tool(see Fig. 3) and a presentation aid as support once proble
47、ms arediscovered and photographed. Colors and three-dimensional (3D) images(see Fig. 4) that help with visualization are invaluable in such circum-stances.5.1.2 The purpose of using alternating current field mea-surement is to size surface-breaking cracks electronically.5.1.3 This practice is a usef
48、ul tool for a condition-basedmonitoring program.5.2 The examination results may then be used by qualifiedpersonnel or organizations to assess remaining service life orother engineering characteristics (beyond the scope of thispractice). This practice is not intended for the examination ofnon-surface
49、-breaking discontinuities.6. Basis of Application6.1 The following item is subject to contractual agreementbetween the parties using or referencing this practice.6.1.1 Personnel QualificationIf specified in the contrac-tual agreement, personnel performing examinations to thispractice shall be qualified in accordance with a nationally orinternationally recognized NDT personnel qualification prac-tice or standard such as ANSI/ASNT-CP-189, SNT-TC-1A,NAS-410, or a similar document and certified by the employeror certifying agency, as applicable. The practi
