New Code Requirements For Calculating Heat Input
NEW LAYOUT:Layout 15/7/104:11 PMPage 61New CodeRequirements forCalculating Heat InputWelders, inspectors, and engineers should be aware of the changesto QW-409.1 of ASME IX regarding waveform-controlled weldingBY TERESA MELFIWelding waveforms are used to limitdistortion, weld open roots, and to control HAZ properties. Waveform controlis essential for common processes like uphill GMA pulse welding. Power sourcesthat support pulsing (GMAW-P, GTAWP, etc.) are the most common waveformcontrolled power sources. Those marketed as synergic, programmable, or microprocessor-controlled are also likely tosupport waveform-controlled welding.The correlation between heat inputand mechanical properties is blurredwhen heat input is calculated using current and voltage readings from conventional meters. This includes external meters and even those located on the welding power source. It’s not that the metersare incorrect — in fact, most are calibrated and tested to NIST standards.Rather, the inaccuracy involves the meansof capturing and displaying the data.Conventional DC meters display average voltage and average current. Conventional AC meters display RMS values. Toaccurately indicate the energy input to aweld, the voltage and current readingsmust be multiplied together at very rapidintervals that will capture brief changes inthe welding waveforms. This frequency isin the order of magnitude of 10,000 timesper second. Specialized meters are required to accomplish this.Revisions to ASME Section IX providea new method of calculating heat inputthat allows comparison of the heat inputfrom various welding power sources andvarious welding waveforms. This will allowproduction welding to take place with awelding procedure specification (WPS)that specifies either conventional or waveform-controlled welding, which is sup-ported by a procedure qualification record(PQR) using either conventional or waveform-controlled welding.Calculating Heat InputMany welding codes use the equationshown in Equation 1 to calculate heatinput. Because the welding process(GMAW, SAW, etc.) is an essential variable, a process or efficiency factor is notincluded in the heat input calculation.The new equations that will be in the 2010edition of ASME Section IX are shown inEquations 2 and 3, either of which givesequivalent results. Both equations areshown because some welding powersources and meters display energy values,and others display power values.Voltage Amperage 60Travel Speed (in./min or mm/min)Equation 1: Traditional heat input equation, ASME Section IX QW-409.1 (a).Energy (Joules)Weld Bead Length (in. or mm)Equation 2: New heat input equation formeters displaying energy measurement(Joules), ASME Section IX QW-409.1(c)(1).Power (Joules/s) Arc Time (s)Weld Bead Length (in. or mm)Equation 3: New heat input equation formeters displaying power measurement(Joules/s or W), ASME Section IXQW-409.1 (c)(2).Three examples from GMA weldingare shown in Fig. 1. The axial spray waveforms are essentially constant, and the difference between the measurement methods is minimal. For the two waveformcontrolled procedures, there is an errorbetween the measurement methods thatcan be in a positive or negative direction.It is clear from the significant differenceswhy a new measurement method isneeded.Changes in ASMESection IXASME codes and standards have along history, now in their 125th year. Therules for welding were removed from theconstruction codes when ASME SectionIX was published in 1941. ASME SectionIX has become a global standard, referenced by the ASME construction codes,owners, engineering firms, and other fabrication and construction codes.The ASME IX Standards Committeehas subcommittees that address procedureand performance qualifications, materials,general requirements, and brazing. Morethan three years ago, a task group wasformed to work on issues surrounding welding with complex waveforms from microprocessor-controlled power sources. Thefirst result of this group’s work will be achange to the measurement and calculation method for heat input.QW409.1 is the main Section IX variable that deals with heat input. Currently,there are two ways to calculate heat input.Method (a) is the traditional heat inputequation shown in Equation 1. Method(b) is a measurement of the volume ofTERESA MELFI is with The Lincoln Electric Co., Cleveland, Ohio. She is chair of the AWS A5B Committee on submerged arc welding,a member of the AWS A5 Committee on filler metal specifications, a member of ASME Section IX, including the materials subgroup and aworking group on advanced waveform welding, and is the U.S. delegate to the International Institute of Welding commission that covers pressure vessels, boilers, and pipelines.WELDING JOURNAL61
NEW LAYOUT:Layout 15/7/104:11 PMPage 62Fig. 2 — With the proper software installed,access to the energy reading entails pressingthe menu option “Display Energy.”Fig. 1 — Heat input differences calculated using Equation 1 vs. Equation 2.weld metal deposited. A new method (c)is added in the 2010 edition, which includes Equations 2 and 3.Any of the methods can be used whenwelding following procedures that are notwaveform controlled. When welding following waveform-controlled procedures,only methods (b) or (c) are permitted.With these methods, it is possible to determine the compliance of a productionweld made using a waveform-controlledwelding procedure to an existing qualifiedprocedure, even when the procedure qualification was performed using nonwaveform controlled welding. An appendix toASME Section IX has been provided to62JUNE 2010guide users through these code changes.The appendix provides guidance with newprocedure qualifications, existing qualified procedures, and comparing heat inputs between waveform-controlled andnonwaveform-controlled welding. ASMESection IX does not mandate separateperformance qualifications for waveformcontrolled welding.How to Comply withASME Code ChangesTo use method (c) of the code, a reading of energy (Joules) or power (Joules/s)Fig. 3 — The real-time energy is continuously incremented while welding, and thefinal energy is displayed until the next arcstart.must be obtained using a meter that captures the brief changes in a welding waveform and filters out extraneous noise. Thesimplest place to obtain this is from thewelding power source. Many powersources that output pulsing waveforms willdisplay these readings, although somemight require software upgrades to enable this. Details and software upgradesfor Lincoln Electric’s Powerwave “M” series and several other models are available free of charge at www.powerwave
NEW LAYOUT:Layout 15/7/104:11 PMPage 63Assist Chart for ASME IX QW-409.PQRPQR qualifiedq u a lifie d wwith:ith :Non-waveformNon-waveformcontrolled weldingw e ld in gcontrolledusing conventionalc o n v e n tio n a lusingvvolto lt and ammetersa m m e te rsandand QW-409.1(a)Q W -4 0 9 .1 (a )andN o n -w a v e fo rmNon-waveformcontrolledweldingc o n tr o lle d we ld in gusingusing instantaneousin s ta n ta n e o u senergypowerenergy oror power andaQWQW4 0 9 .1 (c )QW-409.1(c)WaveformWaveform ccontrolledo n tr o lle dwe ld in g us in gweldingusingiinstantaneousn s ta n ta n e o u s en e rg yenergyor pow er and QWWorpowerandQW4 0 9 .1 (c )409.1(c)WaveformWaveform controlledc o n tr o lle dwelding usingu s in gweldingcconventionalonventional voltvolt andandam m e te rs and QWWammetersandQW409.1(a) ((qualifiedq u a lifie d409.1(a)prior ttoo2010 ccodeodeprior2010cchange)hange)QQualifiesualifies forfo r wweldselds producedproduced with:w ith : Non-waveform controlledcontrolled powerpower supplysupply usingusing conventionalconventional voltvolt metersmeters andand ammetersammeters andand QW-409.1(a).QW-409.1(a).Non-waveform Non-waveform controlledc o n tr o lle d power supplysupply displayingdisplaying instantaneousin s ta n ta n e o u s en e rg y oow er me a s u re m e n t and QW-409.1(c).Q W -4 0 9 .1 (c ) .Non-waveformpowerenergyorr ppowermeasurementand Waveform ccontrolledo n tr o lle d power supplysupply displayingdisplaying instantaneousinstantaneous energyenergy oror powerpower measurementmeasurement andand QW-409.1(c).Q W -4 0 9 .1 (c ).Waveformpower Waveform ccontrolledo n tr o lle d power ssupplyupply whichwhich doesdoes notnot displaydisplay iinstantaneousnstantaneous energyenergy oror powerpower measurementmeasurement usingu s in gWaveformpowerexternal metersmeters tthathat display iinstantaneousn s ta n ta n e o u s power oror energyenergy measurementsm e a s u re m e n ts and QW -4 0 9 .1 (c ).externaldisplaypowerandQW-409.1(c). Non-waveform controlledcontrolled powerpower supplysupply usingusing conventionalconventional voltvolt metersmeters andand ammetersammeters andand QW-409.1(a).QW-409.1(a).Non-waveform Non-waveformpowerenergypowerandNon-waveform controlledc o n tr o lle d power ssupplyupply displayingdisplaying instantaneousin s ta n ta n e o u s energy oror power measurementm e a s u re m e n t and QW-409.1(c).Q W -4 0 9 .1 (c ). WaveformpowerWaveform ccontrolledo n tr o lle d power supplysupply displayingdisplaying instantaneousinstantaneous energyenergy oror powerpower measurementmeasurement andand QW-409.1(c).Q W -4 0 9 .1 (c ). WaveformpowerpowerWaveform ccontrolledo n tr o lle d power ssupplyupply whichwhich doesdoes notnot displaydisplay iinstantaneousnstantaneous energyenergy oror power measurementmeasurement usingu s in gexternaldisplaypowerandQW-409.1(c).external metersmeters tthathat display iinstantaneousn s ta n ta n e o u s power oror energyenergy measurementsm e a s u re m e n ts and QW -4 0 9 .1 (c ). Non-waveform controlledcontrolled powerpower supplysupply usingusing conventionalconventional voltvolt metersmeters andand ammetersammeters andand QW-409.1(a).QW-409.1(a).Non-waveform Non-waveform controlledc o n tr o lle d power ssupplyu p p ly displaying instantaneousin s ta n ta n e o u s energy oror power measurementm e a s u re m e n t and QW-409.1(c).Q W -4 0 9 .1 (c ).Non-waveformpowerdisplayingenergypowerand Waveform ccontrolledo n tr o ll e d power supplysupply displayingdisplaying instantaneousinstantaneous energyenergy oror powerpower measurementmeasurement andand QW-409.1(c).Q W -4 0 9 .1 (c ).Waveformpower Waveform ccontrolledo n tr o lle d power ssupplyupply whichwhich doesdoes notnot displaydisplay instantaneousin s ta n ta n e o u s en e rg y oower measurementmeasurement usingu s in gWaveformpowerenergyorr ppowerexternal metersmeters tthathat display iinstantaneousn s ta n ta n e o u s power oror energyenergy measurementsm e a s u r e m e n ts and QW -4 0 9 .1 (c ).externaldisplaypowerandQW-409.1(c). Non-waveform controlledc o n tr o lle d power supplysupply usingusing conventionalconventional voltvolt metersmeters andand ammetersammeters andand QW-409.1(a).QW-409.1(a).Non-waveformpower Non-waveform ccontrolledo n tr o lle d power ssupplyu p p ly displaying instantaneousin s ta n ta n e o u s en e rg y oow er me a s u re m e n t and QW -4 0 9 .1 (c ).Non-waveformpowerdisplayingenergyorr ppowermeasurementandQW-409.1(c). Waveform ccontrolledo n tr o lle d power supplysupply displayingdisplaying instantaneousinstantaneous energyenergy oror powerpower measurementmeasurement andand QW-409.1(c).Q W -4 0 9 .1 (c ).Waveformpower Waveform ccontrolledo n tr o lle d power ssupplyu p p ly which doesdoes notnot displaydisplay iinstantaneousn s ta n ta n e o u s en e rg y oower measurementmeasurement usingu s in gWaveformpowerwhichenergyorr ppowerex te rn a l meters tthathat display iinstantaneousn s ta n ta n e o u s power oror energy measurementsm e a s u re m e n ts and QW -4 0 9 .1 (c ote: IInn ssomeome ccases,ases, itit mightmight benefitbenefit thethe useruser toto append a PQR toto showshow thethe heatheat inputinput ccalculateda lc u la te d using iinstantaneousn s ta n ta n e o u sNote:PQRusingpower on e rg y . This ccanan be donedone byby weldingwelding a simplesimple beadbead onpla te using thethe ssameam e parameters ((modem ode oro g ra m ,powerorr eenergy.Thisbeonplateusingparametersorr pprogram,vvoltage,oltage, ccurrent,u rre n t, etc)c) as werewere usedused inin tthehe procedure qualification.q u a lific a tio n . Utiliz in g eith e r a we ld in g power ssourceource oror externale x te rn a letc)asprocedureUtilizingeitherweldingpowermeter tthathat displays iinstantaneousn s ta n ta n e o u s energy oror power, thethe heatheat inputinput maymay bebe calculatedc a lc u la te d per QW--409.1(c) bWased on asedonrreadings.e a d in g s .welding may be used to support weldingwith waveform or nonwaveform-controlled procedures and QW-409.1(a) orQW-409.1(c). This can be downloadedfrom www.lincolnelectric.com.SummaryFig. 4 — The heat input is calculated by taking the final energy value and dividing it by thelength of the weld.software.com. For a power source thatdoesn’t support the display of energy orpower, external meters are available. Ameter with demonstrated accuracy in thisapplication is the Fluke 345 Power Quality Clamp Meter.With the proper software installed, itis simple to access the energy reading —Fig. 2. In the setup menu, enable the option to “Display Energy.” When an arc isstarted, the energy value will begin to increment. The value will continue to increase, showing the real-time energy putinto that weld — Fig. 3. When the welding stops, the final energy value will bedisplayed until welding resumes again.This value represents the amount of energy that went into that weld, from arcstart to arc stop.To calculate the heat input, the finalvalue is simply divided by the length of theweld — Fig. 4. In this case, the heat inputwould be 22.3 kJ/3.6 in., or 6.2 kJ/in.A detailed matrix has been developedshowing how a PQR qualified with eitherwaveform or nonwaveform-controlledThe ASME Section IX welding andbrazing standard is widely used by publicagencies and private companies concerned about the safety and integrity ofwelds. Just as specifications change whennew materials are developed, ASME Section IX has changed to recognize modernwelding waveforms. The changes involvethe measurement of energy or powermade at very rapid intervals, and the useof these to calculate heat input. Thesecode changes establish the relationshipbetween heat input across a range ofpower sources and welding waveforms.Welders, inspectors, and engineersshould be aware of the new ways to calculate heat input. While no code can guarantee good workmanship, these changesmake it easier for welders to use waveforms that help improve their welds. Thenew method will allow flexibility in theway one compares the heat input used inprocedure qualification and in productionwelding.oWELDING JOURNAL63
[in. (mm)][in. (mm)]
PQR qualified with:Non-waveformcontrolled weldingusing conventionalvolt and ammetersand QW-409.1(a)Non-waveformcontrolled weldingusing instantaneousenergy or power andQW-409.1(c)Waveform controlledwelding usinginstantaneous energyor power and QW409.1(c)Waveform controlledwelding usingconventional volt andammeters and QW409.1(a) (qualifiedprior to 2010 codechange)Qualifies for welds produced with: Non-waveform controlled welding procedure using conventional volt meters and ammeters and QW-409.1(a). Non-waveform controlled welding procedure displaying instantaneous energy or power measurement and QW-409.1(c). Waveform controlled welding procedure displaying instantaneous energy or power measurement and QW-409.1(c). Waveform controlled welding procedure which does not display instantaneous energy or power measurement usingexternal meters that display instantaneous power or energy measurements and QW-409.1(c). Non-waveform controlled welding procedure using conventional volt meters and ammeters and QW-409.1(a). Non-waveform controlled welding procedure displaying instantaneous energy or power measurement and QW-409.1(c). Waveform controlled welding procedure displaying instantaneous energy or power measurement and QW-409.1(c). Waveform controlled welding procedure which does not display instantaneous energy or power measurement usingexternal meters that display instantaneous power or energy measurements and QW-409.1(c). Non-waveform controlled welding procedure using conventional volt meters and ammeters and QW-409.1(a). Non-waveform controlled welding procedure displaying instantaneous energy or power measurement and QW-409.1(c). Waveform controlled welding procedure displaying instantaneous energy or power measurement and QW-409.1(c). Waveform controlled welding procedure which does not display instantaneous energy or power measurement usingexternal meters that display instantaneous power or energy measurements and QW-409.1(c). Non-waveform controlled welding procedure using conventional volt meters and ammeters and QW-409.1(a). Non-waveform controlled welding procedure displaying instantaneous energy or power measurement and QW-409.1(c). Waveform controlled welding procedure displaying instantaneous energy or power measurement and QW-409.1(c). Waveform controlled welding procedure which does not display instantaneous energy or power measurement usingexternal meters that display instantaneous power or energy measurements and QW-409.1(c).Note: In some cases, it might benefit the user to append a PQR to show the heat input calculated using instantaneouspower or energy. This can be done by welding a simple bead on plate using the same parameters (mode or program,voltage, current, etc) as were used in the procedure qualification. Utilizing either a welding power source or external meterthat displays instantaneous energy or power, the heat input may be calculated per QW-409.1(c) based on those readings.
welding procedure specification (WPS) that specifies either conventional or wave-form-controlled welding, which is sup-ported by a procedure qualification record (PQR) using either conventional or wave-form-controlled welding. Calculating Heat Input Many welding codes use
Bruksanvisning för bilstereo . Bruksanvisning for bilstereo . Instrukcja obsługi samochodowego odtwarzacza stereo . Operating Instructions for Car Stereo . 610-104 . SV . Bruksanvisning i original
10 tips och tricks för att lyckas med ert sap-projekt 20 SAPSANYTT 2/2015 De flesta projektledare känner säkert till Cobb’s paradox. Martin Cobb verkade som CIO för sekretariatet för Treasury Board of Canada 1995 då han ställde frågan
service i Norge och Finland drivs inom ramen för ett enskilt företag (NRK. 1 och Yleisradio), fin ns det i Sverige tre: Ett för tv (Sveriges Television , SVT ), ett för radio (Sveriges Radio , SR ) och ett för utbildnings program (Sveriges Utbildningsradio, UR, vilket till följd av sin begränsade storlek inte återfinns bland de 25 största
Hotell För hotell anges de tre klasserna A/B, C och D. Det betyder att den "normala" standarden C är acceptabel men att motiven för en högre standard är starka. Ljudklass C motsvarar de tidigare normkraven för hotell, ljudklass A/B motsvarar kraven för moderna hotell med hög standard och ljudklass D kan användas vid
LÄS NOGGRANT FÖLJANDE VILLKOR FÖR APPLE DEVELOPER PROGRAM LICENCE . Apple Developer Program License Agreement Syfte Du vill använda Apple-mjukvara (enligt definitionen nedan) för att utveckla en eller flera Applikationer (enligt definitionen nedan) för Apple-märkta produkter. . Applikationer som utvecklas för iOS-produkter, Apple .
och krav. Maskinerna skriver ut upp till fyra tum breda etiketter med direkt termoteknik och termotransferteknik och är lämpliga för en lång rad användningsområden på vertikala marknader. TD-seriens professionella etikettskrivare för . skrivbordet. Brothers nya avancerade 4-tums etikettskrivare för skrivbordet är effektiva och enkla att
Den kanadensiska språkvetaren Jim Cummins har visat i sin forskning från år 1979 att det kan ta 1 till 3 år för att lära sig ett vardagsspråk och mellan 5 till 7 år för att behärska ett akademiskt språk.4 Han införde två begrepp för att beskriva elevernas språkliga kompetens: BI
**Godkänd av MAN för upp till 120 000 km och Mercedes Benz, Volvo och Renault för upp till 100 000 km i enlighet med deras specifikationer. Faktiskt oljebyte beror på motortyp, körförhållanden, servicehistorik, OBD och bränslekvalitet. Se alltid tillverkarens instruktionsbok. Art.Nr. 159CAC Art.Nr. 159CAA Art.Nr. 159CAB Art.Nr. 217B1B
