1、Designation: E215 11Standard Practice forStandardizing Equipment for Electromagnetic Testing ofSeamless Aluminum-Alloy Tube1This standard is issued under the fixed designation E215; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, t
2、he year 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.This specification has been approved for use by agencies of the Department of Defense.1. Scope*1.1 This practice2is int
3、ended as a guide for standardizingeddy-current equipment employed in the examination of seam-less aluminum-alloy tube. Artificial discontinuities consistingof flat-bottomed or through holes, or both, are employed as themeans of standardizing the eddy-current system. Generalrequirements for eddy-curr
4、ent examination procedures areincluded.1.2 Procedures for fabrication of reference standards aregiven in Appendixes X1.1 and X2.1.1.3 This practice is intended for the examination of tubularproducts having nominal diameters up to 4 in. 101.6 mm andwall thicknesses up to the standard depth of penetra
5、tion (SDP)of eddy currents for the particular alloy (conductivity) beingexamined and the examination frequency being used.NOTE 1This practice may also be used for larger diameters or heavierwalls up to the effective depth of penetration (EDP) of eddy currents asspecified by the using party or partie
6、s.1.4 This practice does not establish acceptance criteria.They must be established by the using party or parties.1.5 The values stated in inch-pound units are to be regardedas the standard. The values given in parentheses are mathemati-cal conversions to SI units that are provided for informationon
7、ly and are not considered standard.1.6 This standard does not purport to address all of thesafety problems, if any, associated 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 limit
8、ations prior to use.2. Referenced Documents2.1 ASTM Standards:3E543 Specification for Agencies Performing Nondestruc-tive TestingE1316 Terminology for Nondestructive Examinations2.2 Federal Standard:Fed Std. No. 245D Tolerance for Aluminum Alloy andMagnesium Alloy Wrought Products42.3 Other Document
9、s:SNT-TC-1A Recommended Practice for Personnel Qualifi-cation and Certification in Nondestructive Testing5ANSI/ASNT-CP-189 ASNT Standard for Qualification andCertification of Nondestructive Testing Personnel5NAS-410 NAS Certification and Qualification of Nonde-structive Personnel (Quality Assurance
10、Committee)63. Terminology3.1 DefinitionsFor definitions of terms used in this prac-tice, refer to Terminology E1316.4. Significance and Use4.1 The examination is performed by passing the tubelengthwise through or near an eddy current sensor energizedwith alternating current of one or more frequencie
11、s. Theelectrical impedance of the eddy current sensor is modified bythe proximity of the tube. The extent of this modification isdetermined by the distance between the eddy current sensorand the tube, the dimensions, and electrical conductivity of the1This practice is under the jurisdiction of ASTM
12、Committee E07 on Nonde-structive Testing and is the direct responsibility of Subcommittee E07.07 onElectromagnetic Method.Current edition approved July 1, 2011. Published July 2011. Originally approvedin 1963. Last previous edition approved in 2004 as E215 - 98(2004)1. DOI:10.1520/E0215-11.2For ASME
13、 Boiler and Pressure Vessel Code applications see related PracticeSE-215 in the Code.3For 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
14、page onthe ASTM website.4Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http:/dodssp.daps.dla.mil.5Available fromAmerican Society for Nondestructive Testing (ASNT), P.O. Box28518, 1711 Arlingate Ln., Columbus, OH 43228-0
15、518, http:/www.asnt.org.6Available from Aerospace Industries Association of America, Inc. (AIA), 1000Wilson Blvd., Suite 1700,Arlington, VA22209-3928, 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, P
16、O Box C700, West Conshohocken, PA 19428-2959, United States.tube. The presence of metallurgical or mechanical discontinui-ties in the tube will alter the apparent impedance of the eddycurrent sensor. During passage of the tube, the changes in eddycurrent sensor characteristics caused by localized di
17、fferences inthe tube produce electrical signals which are amplified andmodified to actuate either an audio or visual signaling device ora mechanical marker to indicate the position of discontinuitiesin the tube length. Signals can be produced by discontinuitieslocated either on the external or inter
18、nal surface of the tube orby discontinuities totally contained within the tube wall.4.2 The depth of penetration of eddy currents in the tubewall is influenced by the conductivity (alloy) of the materialbeing examined and the excitation frequency employed. Asdefined by the standard depth of penetrat
19、ion equation, theeddy-current penetration depth is inversely related to conduc-tivity and excitation frequency (Note 2). Beyond one standarddepth of penetration (SDP), the capacity to detect discontinui-ties by eddy currents is reduced. Electromagnetic examinationof seamless aluminum alloy tube is m
20、ost effective when thewall thickness does not exceed the SDPor in heavier tube wallswhen discontinuities of interest are within one SDP. The limitfor detecting metallurgical or mechanical discontinuities byway of conventional eddy current sensors is generally acceptedto be approximately three times
21、the SDP point and is referredto as the effective depth of penetration (EDP).NOTE 2The standard depth of penetration is defined by the followingequations:SDP 5 503.31fswhere:SDP = one standard depth of penetration, mf = frequency, Hz (cycles per second), ands = conductivity, Siemens/metre.or:SDP 5 26
22、1fswhere:SDP = one standard depth of penetration, inchesf = frequency in Hz (cycles per second), ands = conductivity, % IACS.5. Basis of Application5.1 If specified in the contractual agreement, personnelperforming examinations to this practice shall be qualified inaccordance with a nationally recog
23、nized NDT personnel quali-fication practice or standard such as ANSI/ASNT-CP-189,SNT-TC-1A, MIL-STD-410, NAS-410, or a similar documentand certified by the certifying agencys as applicable. Thepractice or standard used and its applicable revision shall bespecified in the contractual agreement betwee
24、n the usingparties.NOTE 3MIL-STD-410 is canceled and has been replaced with NAS-410, however, it may be used with agreement between contracting parties.5.2 If specified in the contractual agreement, NDT agenciesshall be qualified and evaluated in accordance with Specifica-tion E543. The applicable e
25、dition of Specification E543 shallbe specified in the contractual agreement.6. Apparatus6.1 Electronic ApparatusThe electronic apparatus shallbe capable of energizing eddy current sensors with alternatingcurrents of suitable frequencies and shall be capable of sensingthe changes in the electromagnet
26、ic characteristics of the eddycurrent sensors. Equipment may include a detector, phasediscriminator, filter circuits, gating circuits, and signalingdevices as required for the particular application.6.2 Eddy Current SensorsEddy current sensors shall becapable of inducing currents in the tube and sen
27、sing changes inthe electrical characteristics of the tube. The eddy currentsensors may be of the encircling coil (annular) type or surfaceprobe type.7. Standardization of Apparatus7.1 The apparatus shall be adjusted with an appropriatereference standard to ensure that the equipment is operating atth
28、e proper level of sensitivity, with the following consider-ations:7.1.1 Primary reference standards employed for this pur-pose shall be prepared in accordance with the methods de-scribed in Appendix X1.1.7.1.2 Equivalent secondary reference standards, prepared inaccordance with methods described in
29、Appendix X2.1, alsomay be employed for standardizing the apparatus.7.1.3 Reference standards normally are of the same alloy,temper, and dimensions as the tube to be examined.7.1.4 Examinations shall not be conducted unless the equip-ment can be set to the levels required by this standardizationproce
30、dure.7.1.5 For practical applications, reference standards alsomay be employed to establish quality control levels.8. Procedure8.1 Standardize the examination instrument using the ap-propriate reference standard prior to examination and check atleast every 4 h during continuous operation, or wheneve
31、rimproper functioning of the examination apparatus is sus-pected. If improper functioning occurs, restandardize theapparatus in accordance with Section 7, and reexamine alltubes examined since the last successful standardization.8.2 Tubes may be examined in the final drawn, annealed, orheat-treated
32、temper, or in the drawn temper prior to the finalanneal or heat treatment.8.3 The length of tube over which end effect is significantmay be determined by placing a series of holes or notches inspecial reference tubes and determining the distance from thetube end at which the signal amplitude from th
33、e discontinuitiesbegins to decrease.8.3.1 When standardizing and testing using secondary stan-dard Method B (X2.5.2), if full length testing is required, thetube must be ordered to be electromagnetic tested in a roughcut length and have the untested 7 in. (175 mm) removed fromeach end.E215 112NOTE 4
34、There is an area near each end which cannot be tested eitherbecause of an alarm from end effect or because end suppression is used toeliminate an alarm from end effect. Up to 7 in. (175 mm) on each end isto be considered untested, regardless of the standard used. Customers mustspecify if they want t
35、hese untested areas removed.9. Application9.1 This application covers the electromagnetic examinationof aluminum-alloy seamless tube using primary and secondaryreference standards.9.2 Primary and secondary reference standards, described inAppendixes X1.1 and X2.1, respectively, when used as accep-ta
36、nce standards, will establish probable detection of defectsthat are of a severity likely to cause leaks or substantialweakening of the tube.9.3 Using electronic apparatus and eddy current sensorsdescribed in Section 6, the equipment sensitivity shall bestandardized in accordance with Section 7 under
37、 the followingexamination conditions:9.3.1 FrequencyThe frequency shall be in the range from1 to 125 kHz. The examination frequency should be adjusted toprovide optimum penetration of the tube wall or to placediscontinuities of interest within one SDP. Discontinuitieslocated deeper than the SDP poin
38、t will be detected with lesssensitivity. The SDP point will vary as a function of the tubealloy (conductivity) and examination frequency and may bedetermined by the depth of penetration equation given inSection 4, Note 2.9.3.2 Speed of ExaminationThe examination rate, orspeed of the tube with respec
39、t to the eddy current sensor, mayvary with the application. In encircling coil applications,examination speeds of 50 ft/min (15 m/min) to 500 ft/min (150m/min) are recommended where possible, but examinationspeeds as high as 1000 ft/min (300 m/min) are permissible. Insurface probe applications, exam
40、ination speeds are inherentlyslower due to reduced surface coverage and the necessity torotate the eddy current sensor or the tube to produce a helicalscan. All instrument adjustments, that is, frequency, phasesetting, filter setting, sensitivity setting, threshold-level setting,etc., shall be made
41、with the reference standard or acceptancestandard or both passing through or by the eddy current sensorat the same speed at which the examination of tube is to beconducted.9.3.3 Phase SettingThe phase setting should be selectedto provide the best signal-to-noise ratio for the referencestandard emplo
42、yed, that is, the maximum ratio of indicationheight from the appropriate artificial discontinuities to theindication height from non-detrimental discontinuities.9.3.4 Filter SettingThe filter setting should be selectedcommensurate with the examination speed to provide optimumfiltering of non-detrime
43、ntal, time-varying discontinuities suchas geometry, pathline variation, high-frequency noise, etc.9.3.5 Sensitivity SettingThe sensitivity setting shall beadjusted to provide clearly discernible indications of a conve-nient height for the appropriate accept holes (A or da), but itshall not be high e
44、nough to cause off-scale or saturatedindications for the appropriate reject holes (2A or db)ofthereference standard.9.3.6 Threshold-Level SettingThe threshold-level setting(reject level) shall be adjusted to automatically trigger an audioor visual-signalling device or a mechanical marker when theapp
45、ropriate artificial discontinuity (or discontinuities) of theacceptance standard passes through or by the eddy currentsensor.9.4 Using Reference Standards as Acceptance Standards:9.4.1 Method A (X2.1) Reference Standards: When usingreference standards as acceptance standards the threshold levelshoul
46、d be adjusted to accept tubes exhibiting eddy-currentresponses smaller than those obtained from the appropriatereject holes (2A or db) and to reject those with responsesequivalent to or greater than those obtained from the appropri-ate reject holes (2A or db) in the reference standard. Experiencesho
47、ws that this procedure will aid in the rejection of severedefects and, at the same time, minimize erroneous rejection oftubes that might exhibit noise from non-detrimental disconti-nuities.9.4.2 Method B (X2.2) Reference Standard Selection: Ref-erence standards selected for use must be the same allo
48、y,temper, diameter, and wall thickness as the material beingtested. The reference standard selected for use must contain theproper size reject holes and must have been fabricated andidentified in accordance with this procedure.9.4.2.1 When using reference standards as acceptance stan-dards the thres
49、hold level should be adjusted as required inX2.5.2.2. Tubes that do not exceed the alarm limits establishedby the reference standard shall be considered as acceptableunder this method.10. Keywords10.1 aluminum alloy; eddy currents; electromagnetic ex-amination; equipment standardization; NDT; nondestructivetesting; tubingE215 113APPENDIXES(Nonmandatory Information)X1. PURPOSE, DESCRIPTION, FABRICATION, AND CHECKING OF PRIMARY REFERENCE STANDARDSX1.1 PurposeX1.1.1 Primary reference standards are used to standardizeexamination equipment under operating conditions
