1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS EN ISO 14744-3:2001 Th
2、e European Standard EN ISO 14744-3:2000 has the status of a British Standard ICS 25.160.30 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Welding Acceptance inspection of electron beam welding machines Part 3: Measurement of beam current characteristicsThis British Standard,
3、having been prepared under the direction of the Engineering Sector Committee, was published under the authority of the Standards Committee and comes into effect on 15 April 2001 BSI 04-2001 ISBN 0 580 34196 8 BS EN ISO 14744-3:2001 Amendments issued since publication Amd. No. Date Comments National
4、foreword This British Standard is the official English language version of EN ISO 14744-3:2000. It is identical with ISO 14744-3:2000. The UK participation in its preparation was entrusted to Technical Committee WEE/47, Miscellaneous welding standards, which has the responsibility to: aid enquirers
5、to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represe
6、nted on this committee can be obtained on request to its secretary. Cross-references Attention is drawn to the fact that CEN and CENELEC Standards normally include an annex which lists normative references to international publications with their corresponding European publications. The British Stan
7、dards which implement these international or European publications may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to
8、include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, t
9、he EN ISO title page, pages 2 to 8, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued.EUROPEANSTANDARD NORMEEUROPENNE EUROPISCHENORM ENISO147443 April2000 ICS25.160.00 Englishversion WeldingAcceptanceinspectionofele
10、ctronbeamwelding machinesPart3:Measurementofbeamcurrentcharacteristics (ISO147443:2000) SoudageEssaisderceptiondesmachinesdesoudage parfaisceaudlectronsPartie3:Mesuredes caractristiquesdelintensitdufaisceau(ISO14744 3:2000) SchweienAbnahmeprfungvonElektronenstrahl SchweimaschinenTeil3:MessendesStrah
11、lstrom Kenngren(ISO147443:2000) ThisEuropeanStandardwasapprovedbyCENon3January2000. CENmembersareboundtocomplywiththeCEN/CENELECInternalRegulationswhichstipulatetheconditionsforgivingthisEurope an Standardthestatusofanationalstandardwithoutanyalteration.Uptodatelistsandbibliographicalreferencesconce
12、rnings uchnational standardsmaybeobtainedonapplicationtotheCentralSecretariatortoanyCENmember. ThisEuropeanStandardexistsinthreeofficialversions(English,French,German).Aversioninanyotherlanguagemadebytra nslation undertheresponsibilityofaCENmemberintoitsownlanguageandnotifiedtotheCentralSecretariath
13、asthesamestatusast heofficial versions. CENmembersarethenationalstandardsbodiesofAustria,Belgium,CzechRepublic,Denmark,Finland,France,Germany,Greece, Iceland,Ireland,Italy,Luxembourg,Netherlands,Norway,Portugal,Spain,Sweden,SwitzerlandandUnitedKingdom. EUROPEANCOMMITTEEFORSTANDARDIZATION COMITEUROPE
14、NDENORMALISATION EUROPISCHESKOMITEEFRNORMUNG CentralSecretariat:ruedeStassart,36B1050Brussels 2000CEN Allrightsofexploitationinanyformandbyanymeansreserved worldwideforCENnationalMembers. Ref.No.ENISO147443:2000EPage2 ENISO147443:2000 Contents Page Foreword. 3 1 Scope 4 2 Normativereferences. 4 3 Te
15、rmsanddefinitions 4 4 Testarrangement 4 4.1 General . 4 4.2 Faradaycupandelectricalconnections. 6 5 Measurementprocedure 7 5.1 General . 7 5 . 2 C u r r e n t l o s s e s . 7 5 . 3 M e a s u r i n g t h e r i p p l e 7 5.4 Measuringthestability. 7 5.5 Measuringthereproducibility 7 6 Problemsinmeasur
16、ement. 8 7 Evaluation. 8Page3 ENISO147443:2000 Foreword ThetextofENISO147443:2000hasbeenpreparedbyTechnicalCommitteeCEN/TC121“Welding“,the secretariatofwhichisheldbyDS,incollaborationwithTechnicalCommitteeISO/TC44“Weldingandallied processes“. ThisEuropeanStandardshallbegiventhestatusofanationalstand
17、ard,eitherbypublicationofanidenticaltextor byendorsement,atthelatestbyOctober2000,andconflictingnationalstandardsshallbewithdrawnatthelatest byOctober2000. AccordingtotheCEN/CENELECInternalRegulations,thenationalstandardsorganizationsof thefollowing countriesareboundtoimplementthisEuropeanStandard:A
18、ustria,Belgium,CzechRepublic,Denmark,Finland, France,Germany,Greece,Iceland,Ireland,Italy,Luxembourg,Netherlands,Norway,Portugal,Spain,Sweden, SwitzerlandandtheUnitedKingdom. ThisdraftEuropeanStandardiscomposedofthesixfollowingparts: Part1:Principlesandacceptanceconditions; Part2:Measurementofaccele
19、ratingvoltagecharacteristics; Part3:Measurementofbeamcurrentcharacteristics; Part4:Measurementofweldingspeed; Part5:Measurementofrunoutaccuracy; Part6:Measurementofstabilityofspotposition.Page4 ENISO147443:2000 1Scope Thisstandardisintendedforusewhenthebeamcurrentofelectronbeamweldingmachinescomplyi
20、ngwith ENISO147441:2000istobemeasuredinconnectionwithanacceptanceinspection.Itprovidesessential informationontheprocedureandapparatustobeusedformakingthemeasurements. Thebeamcurrentisoneofthesignificantparametersinelectronbeamwelding.Whenthebeamcurrentimpinges ontheworkpiece,itshouldbestableandrepro
21、duciblewithingivenshorttermandlongtermlimits.Thepurposeof themeasurementisthustocheckwhetherthevariationsinbeamcurrentarewithintheselimits. 2Normativereferences ThisEuropeanStandardincorporatesbydatedorundatedreference,provisionsfromotherpublications.These normativereferencesarecitedattheappropriate
22、placesinthetextandthepublicationsarelistedhereafter.For datedreferences,subsequentamendmentstoorrevisionsofanyofthesepublicationsapplytothisEuropean Standardonlywhenincorporatedinitbyamendmentorrevision.Forundatedreferencesthelatesteditionofthe publicationreferredtoapplies. ENISO147441:2000 WeldingA
23、cceptanceinspectionofelectronbeamweldingmachinesPart1:Principlesandacceptance conditions(ISO147441:2000) 3Termsanddefinitions ForthepurposesofthisEuropeanStandard,thefollowingtermanddefinitionapplies, 3.1 Beamcurrent currentproducedbythesumoftheacceleratedelectronsbeforetheseimpingeontheworkpiece,me
24、asuredata distanceroughlycorrespondingtotheworkdistance NOTE Althoughthiscurrentissomewhatlowerthantheelectroncurrentemittedfromthecathode,itisthefactor crucialtotheweldingprocedure. 4Testarrangement 4.1General Thebeamcurrentistobemeasuredatspecifiedlevelscoveringtheentirepowerrangeoftheweldingmachi
25、ne. Asthereisnosolidconductor,aFaradaycupshallbeusedthat,asfaraspossible,collectsalltheelectronsemitted fromthecathodeandcausesthemtoflowtoearththrougharesistorofgivenrating(seefigure1). TheFaradaycupshallbedesignedsothatit: a)sustainsthethermalloadevenathighbeampowersoveraperiodequaltoseveraltimest
26、hemeasurement period; b)prevents,asfaraspossible,theescapeofprimaryandsecondaryelectronsandchargedvapour.Page5 ENISO147443:2000 Key 1 Electronbeam 4 Insulation 7 Screenedcabletooscilloscope 2 Faradaycup 5 Worktable 8 Feedthroughtopasscablethroughwork chamberwall 3 Faradaycuporifice 6 Resistor Figure
27、1DiagrammaticrepresentationofbeamcurrentmeasurementusingaFaradaycupPage6 ENISO147443:2000 4.2Faradaycupandelectricalconnections Figure2andtable1providerecommendeddimensionsonthedesignofFaradaycupsofcopperforvariousbeam powersupto30kWwhichmaybeadaptedtomeetpracticalrequirements.Forbeampowersabove15kW
28、,water coolingisnecessary. Table1Faradaycup.Recommendeddimensions(seefigure2) valuesinmm Maximum acceleratingvoltage, inkV Maximum beampower, inkW d 1 D l L n d 2 60 15 6 100 90 220 106 60 30 10 170 270 445 1010 150 6 6 100 100 200 106 150 30 10 100 300 500 1010 NOTE1Dimension d 1 shouldbekeptsmalle
29、noughjusttoaccommodateafocusedelectronbeamincluding fringebeam,whilepreventingtheescapeofelectrons. Key 1Electronbeam 2Copper 3Ceramicinsulator Figure2Faradaycupassembly NOTE2TheboresaroundtheFaradaycupbarrelallowarapidescapeofmetalvapourwhilstavoiding escapeofelectrons.Page7 ENISO147443:2000 TheFar
30、adaycupshallbeinsulatedelectricallyfromtheworktablebymeansofaceramicinsulator. AresistorshallbeconnectedbetweentheFaradaycupandearthatasufficientdistancetopreventitbeing thermallyinfluenced.Asshowninfigure1,ascreenedcableshallbepassedtothemeasuringinstrumentviaafeed throughintheworkchamberwall. 5Mea
31、surementprocedure 5.1General Themeasurementsshallbecarriedoutwiththeweldingmachinesetasspecifiedin6.2ofENISO147441:2000. 5.2Currentlosses ThebeamcurrententeringtheFaradaycupshallbemeasuredandcomparedwiththeemissioncurrent(i.e.the ratedbeamcurrent).Excessivedeviationsindicateinaccuratepositioningofth
32、eelectronbeamwithrespecttothe diameteroftheFaradaycuporifice, d 1 ,oradjustmenterrorsinthebeamsourcewhicharetobecorrected.Forall operations,whenusingtheFaradaycup,theelectronbeamshallbefocusedonthecentreoftheorifice(see figure2).BeamparametersandpositionoftheFaradaycupshallbeadjustedtoobtainmaximumm
33、onitoredvoltage priortotesting. 5.3Measuringtheripple Anoscilloscopeshallbeusedtodeterminethemaximumrange(peaktopeakvalue)intheinstantaneousvalue U b ofthemonitoredvoltage, U b . Thepercentagedeviationshallbecalculatedasfollows: where U bmax , U bmin and U b aremaximum,minimumandaveragevaluesobserve
34、dduringtheperiodofobservation (seefigure3). 5.4Measuringthestability Theaveragevoltageshallberecordedcontinuouslyforagivenoperatingperiod,usinganinstrumenteliminating ripple. Thepercentagedeviationshallbecalculatedasfollows: whicheveristhelargestandwhere U bmax and U bmin aremaximumandminimumobserve
35、dvaluesand U b istheinitial value. 5.5Measuringthereproducibility Thebeamcurrentshallbeswitchedonandtheaveragemonitoredvoltageshallbemeasured,usinganinstrument eliminatingripple. Thespecifiedbeamcurrentshallsubsequentlybeswitchedoffandonseveraltimesandthecorrespondingaverage monitoredvoltagesshallbe
36、recorded. Thereproducibilityshallbecalculatedasfollows: whicheveristhegreaterwhere U bmax and U bmin aremaximumandminimumaveragevaluesobservedand U b isthe initialvalue.Page8 ENISO147443:2000 a)Measurementof U b b)Measurementofpeaktopeakvalue(greater sensitivityofindicationintheYdirectionthan forite
37、ma) Figure3Screenindicationsformeasuringthebeamcurrentripple 6Problemsinmeasurement Theproblemmostfrequentlymetwith,particularlywhenmeasuringhighbeamcurrents,isahighfrequency fluctuationofthebeamcurrentonthedisplay,whichisassociatedwithanoverlargefusionareainthebottomof theFaradaycup.Suchproblemsare
38、bestovercomebykeepingtoshortmeasurementtimesandprovidingforlong coolingintervals,orifpossibleusingawatercooledFaradaycup. 7Evaluation Themeasuredvaluesofripple,stabilityandreproducibilityshallbeassessedbycomparingthemwiththelimit deviationsspecifiedinENISO147441:2000.BS EN ISO 14744-3:2001 BSI 389 C
39、hiswick High Road London W4 4AL | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BSI British St
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