1、Designation: E 215 98 (Reapproved 2004)e1Standard Practice forStandardizing Equipment for Electromagnetic Examinationof Seamless Aluminum-Alloy Tube1This standard is issued under the fixed designation E 215; the number immediately following the designation indicates the year oforiginal adoption or,
2、in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This specification has been approved for use by agencies of the Department of Defense.e1NOTE
3、Reapproved with editorial changes throughout in January 2004.1. Scope1.1 This practice2is intended 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 emp
4、loyed as themeans of standardizing the eddy-current system. Generalrequirements for eddy-current 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 n
5、ominal diameters up to 4 in. 101.6 mm andwall thicknesses up to the standard depth of penetration (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 e
6、ffective depth of penetration (EDP) of eddy currents asspecified by the using party or parties.1.4 The values stated in inch-pound units are to be regardedas the standard.1.5 This practice does not establish acceptance criteria.They must be established by the using party or parties.1.6 This standard
7、 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 limitations prior to use.2. Referenced Documents2.1 ASTM
8、Standards:3E 543 Practice for Agencies Performing NondestructiveTestingE 1316 Terminology for Nondestructive Examinations2.2 Federal Standard:Fed Std. No. 245D Tolerance for Aluminum Alloy andMagnesium Alloy Wrought Products42.3 Other Documents:SNT-TC-1A Recommended Practice for Personnel Qualifi-ca
9、tion 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 Committee)63. Terminology3.1 Standard terminology relatin
10、g to electromagnetic ex-amination may be found in Terminology E 1316, Section C,Electromagnetic Testing.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 frequencies. Theelectr
11、ical 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 Committee E0
12、7 on Nonde-structive Testing and is the direct responsibility of Subcommittee E07.07 onElectromagnetic Methods.Current edition approved January 1, 2004. Published February 2004. Originallyapproved in 1963. Last previous edition approved in 1998 as E 215 - 98.2For ASME Boiler and Pressure Vessel Code
13、 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 page onthe ASTM website.4Availab
14、le from Standardization Documents Order Desk, Bldg. 4 Section D, 700Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.5Available from The American Society for Nondestructive Testing (ASNT), P.O.Box 28518, 1711 Arlingate Ln., Columbus, OH 43228-0518.6Available from Aerospace Industries Associati
15、on of America, Inc., 1250 EyeStreet, N.W., Washington, DC 20005.1Copyright ASTM International, 100 Barr Harbor Drive, PO 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 e
16、ddycurrent sensor. During passage of the tube, the changes in eddycurrent sensor characteristics caused by localized differences inthe tube produce electrical signals which are amplified andmodified to actuate either an audio or visual signalling deviceor a mechanical marker to indicate the position
17、 of discontinui-ties in the tube length. Signals can be produced by disconti-nuities located either on the external or internal surface of thetube or by discontinuities totally contained within the tubewall.4.2 The depth of penetration of eddy currents in the tubewall is influenced by the conductivi
18、ty (alloy) of the materialbeing examined and the excitation frequency employed. Asdefined by the standard depth of penetration equation, theeddy-current penetration depth is inversely related to conduc-tivity and excitation frequency (Note 2). Beyond one standarddepth of penetration (SDP), the capac
19、ity to detect discontinui-ties by eddy currents is reduced. Electromagnetic examinationof seamless aluminum alloy tube is most effective when thewall thickness does not exceed the SDP or in heavier tube wallswhen discontinuities of interest are within one SDP. The limitfor detecting metallurgical or
20、 mechanical discontinuities byway of conventional eddy current sensors is generally acceptedto be approximately three times 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
21、 = one standard depth of penetration,f = frequency, Hz (cycles per second), ands = conductivity, siemens-metre/mm2.or:SDP 5 261fswhere:SDP = one standard depth of penetration, inf = frequency in Hz (cycles per second), ands = conductivity, % IACS.5. Basis of Application5.1 If specified in the contra
22、ctual agreement, personnelperforming examinations to this practice shall be qualified inaccordance with a nationally recognized 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
23、applicable. Thepractice or standard used and its applicable revision shall beidentified in the contractual agreement between 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 c
24、ontractual agreement, NDT agenciesshall be qualified and evaluated in accordance with PracticeE 543. The applicable edition of Practice E 543 shall bespecified in the contractual agreement.6. Apparatus6.1 Electronic ApparatusThe electronic apparatus shallbe capable of energizing eddy current sensors
25、 with alternatingcurrents of suitable frequencies and shall be capable of sensingthe changes in the electromagnetic characteristics of the eddycurrent sensors. Equipment may include a detector, phasediscriminator, filter circuits, gating circuits, and signallingdevices as required for the particular
26、 application.6.2 Eddy Current SensorsEddy current sensors shall becapable of inducing currents in the tube and sensing 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 Th
27、e apparatus shall be adjusted with an appropriatereference standard to ensure that the equipment is operating atthe 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
28、 in Appendix X1.1.7.1.2 Equivalent secondary reference standards, prepared inaccordance with methods described in 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 Examin
29、ations shall not be conducted unless the equip-ment can be set to the levels required by this standardizationprocedure.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-pro
30、priate reference standard prior to examination and check atleast every 4 h during continuous operation, or wheneverimproper functioning of the examination apparatus is sus-pected. If improper functioning occurs, restandardize theapparatus in accordance with Section 7, and reexamine alltubes examined
31、 since the last successful standardization.8.2 Tubes may be examined in the final drawn, annealed, orheat-treated 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 not
32、ches inspecial reference tubes and determining the distance from thetube end at which the signal amplitude from the discontinuitiesbegins to decrease.9. Application9.1 This application covers the electromagnetic examinationof aluminum-alloy seamless tube using primary and secondaryreference standard
33、s.E 215 98 (2004)e129.2 Primary and secondary reference standards, described inAppendixes X1.1 and X2.1, respectively, when used as accep-tance standards, will establish probable detection of defectsthat are of a severity likely to cause leaks or substantialweakening of the tube.9.3 Using electronic
34、 apparatus and eddy current sensorsdescribed in Section 6, the equipment sensitivity shall bestandardized in accordance with Section 7 under the followingexamination conditions:9.3.1 FrequencyThe frequency shall be in the range from1 to 125 kHz. The examination frequency should be adjusted toprovide
35、 optimum penetration of the tube wall or to placediscontinuities of interest within one SDP. Discontinuitieslocated deeper than the SDP point will be detected with lesssensitivity. The SDP point will vary as a function of the tubealloy (conductivity) and examination frequency and may bedetermined by
36、 the depth of penetration equation given inSection 4, Note 2.9.3.2 Speed of ExaminationThe examination rate, orspeed of the tube with respect to the eddy current sensor, mayvary with the application. In encircling coil applications,examination speeds of 15.2 m/min 50 fpm to 152 m/min 500fpm are reco
37、mmended where possible, but examinationspeeds as high as 305 m/min 1000 fpm are permissible. Insurface probe applications, examination 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 a
38、djustments, that is, frequency, phasesetting, filter setting, sensitivity setting, threshold-level setting,etc., shall be made 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
39、.3.3 Phase SettingThe phase setting should be selectedto provide the best signal-to-noise ratio for the referencestandard employed, that is, the maximum ratio of indicationheight from the appropriate artificial discontinuities to theindication height from nondetrimental discontinuities.9.3.4 Filter
40、SettingThe filter setting should be selectedcommensurate with the examination speed to provide optimumfiltering of non-detrimental, time-varying discontinuities suchas geometry, pathline variation, high-frequency noise, etc.9.3.5 Sensitivity SettingThe sensitivity setting shall beadjusted to provide
41、 clearly discernible indications of a conve-nient height for the appropriate accept holes (A or da), but itshall not be high enough 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(r
42、eject level) shall be adjusted to automatically trigger an audioor visual-signalling device or a mechanical marker when theappropriate artificial discontinuity (or discontinuities) of theacceptance standard passes through or by the eddy currentsensor.9.4 When using reference standards as acceptance
43、standardsthe threshold level should be adjusted to accept tubes exhibit-ing eddy-current responses smaller than those obtained fromthe appropriate reject holes (2A or db) and to reject those withresponses equivalent to or greater than those obtained from theappropriate reject holes (2A or db) in the
44、 reference standard.Experience shows that this procedure will aid in the rejectionof severe defects and, at the same time, minimize erroneousrejection of tubes that might exhibit noise from non-detrimental discontinuities.10. Keywords10.1 aluminum alloy; eddy currents; electromagnetic ex-amination;
45、equipment standardization; NDT; nondestructivetesting; tubingAPPENDIXES(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 to
46、 establishacceptable limits of sensitivity, reproducibility, and capabilityfor detecting defects of a severity likely to cause leaks orsubstantial weakening of the tube.X1.1.2 The dimensions of the appropriate primary referencestandard are determined by the size of the tube to be examined.A primary
47、reference standard shall be a tube of the same alloy,temper, outside diameter, D, and wall thickness, t, as the tubeto be examined. This appendix covers the preparation ofprimary standards for test of seamless aluminum-alloy tube.X1.2 DescriptionX1.2.1 The primary reference standard shall contain si
48、xartificial discontinuities in the form of flat-bottomed drilledholes in a 183-cm 6-ft length of tube which is free ofsignificant natural discontinuities. Fig. X1.1 describes theprimary reference standard for aluminum-alloy seamless tube.X1.2.2 The six flat-bottomed holes shall be of equal diam-eter
49、, d, and shall be located in the mid-portion of the tube. Thedistance between adjacent holes is 152 mm 6 in. Theminimum distance between a hole and either end of the tubeshall be approximately 500 mm 20 in.E 215 98 (2004)e13X1.2.3 Three of each of the reference standard holes A and2A shall be drilled consecutively to depths of one third and twothirds the wall thickness, respectively in radial longitudinalplanes 120 6 5 apart.X1.2.4 The diameter, d, of the flat-bottomed drill used tomake a primary reference standard hole shall be determinedmathematicall
