Editor's Note: Pharmaceutical Online txaus siab los nthuav tawm plaub tshooj lus ntawm orbital welding ntawm bioprocess piping los ntawm cov kws tshaj lij kev lag luam Barbara Henon ntawm Arc Machines.Cov kab lus no tau hloov kho los ntawm Dr. Henon qhov kev nthuav qhia ntawm ASME lub rooj sib tham xyoo tas los.
Tiv thaiv kom tsis txhob muaj corrosion.High purity dej xws li DI los yog WFI yog ib tug heev txhoj puab heev etchant rau stainless hlau. Tsis tas li ntawd, cov tshuaj qib WFI yog cycled ntawm kub kub (80 ° C) kom tsis muaj menyuam.Muaj qhov sib txawv me ntsis ntawm qhov kub thiab txias txaus los txhawb cov kab mob ua kom tuag rau cov khoom lag luam thiab "txhim kho qhov kub ntawm cov yeeb yaj kiab." los ntawm corrosion ntawm stainless hlau piping system Cheebtsam.Dirt thiab hlau oxides tej zaum yuav lub ntsiab Cheebtsam, tab sis ntau hom hlau, chromium thiab npib tsib xee kuj tseem muaj.Qhov muaj rouge yog tuag rau qee cov khoom thiab nws lub xub ntiag yuav ua rau corrosion ntxiv, txawm hais tias nws muaj nyob rau hauv lwm lub tshuab zoo nkaus li zoo benign.
Vuam tuaj yeem cuam tshuam rau kev tiv thaiv corrosion.Kub xim yog qhov tshwm sim ntawm oxidizing cov ntaub ntawv tso rau ntawm vuam thiab HAZs thaum lub sij hawm vuam, tshwj xeeb yog detrimental, thiab yog txuam nrog cov tsim ntawm rouge nyob rau hauv cov tshuaj dej systems.Chromium oxide tsim yuav ua rau ib tug kub tint, tawm hauv qab ib tug chromium-depleted txheej uas yog detrimentable los ntawm kev sib tsoo cov hlau thiab hlau. nto, nrog rau cov hauv paus chromium-depleted txheej, thiab rov kho corrosion kuj mus rau theem ze rau hauv paus hlau theem.Txawm li cas los xij, pickling thiab sib tsoo yog detrimental rau saum npoo tiav.Passivation ntawm piping system nrog nitric acid los yog chelating tus neeg sawv cev formulations yog ua kom kov yeej cov teeb meem tsis zoo ntawm vuam thiab fabrication ua ntej lub piping system yog muab tso rau hauv qhov kev pab cuam. Kev hloov pauv hauv kev faib cov pa oxygen, chromium, hlau, npib tsib xee thiab manganese uas tshwm sim hauv thaj chaw weld thiab tshav kub cuam tshuam rau lub xeev pre-weld.Txawm li cas los xij, passivation tsuas yog cuam tshuam rau txheej txheej txheej thiab tsis nkag mus rau hauv qab 50 angstroms, qhov thermal coloration tuaj yeem ncav cuag 1000 angstroms lossis ntau dua hauv qab ntawm qhov chaw.
Yog li ntawd, txhawm rau txhawm rau txhim kho corrosion-resistant piping systems ze rau unwelded substrates, nws yog ib qho tseem ceeb uas yuav tau sim txwv kev vuam thiab fabrication-vim kev puas tsuaj rau qib uas tuaj yeem rov qab tau zoo los ntawm passivation.Qhov no yuav tsum tau siv cov pa purge nrog cov pa oxygen tsawg thiab xa mus rau sab hauv txoj kab uas hla ntawm cov welded sib koom ua ke yam tsis muaj kev sib kis los ntawm atmospheric oxygen los yog kev tswj ntawm cov cua sov thaum lub sij hawm welding. Kuj tseem ceeb heev los tiv thaiv kev poob ntawm corrosion kuj.Tswj cov txheej txheem tsim khoom kom ua tau zoo dua thiab zoo ib yam welds, nrog rau kev ua tib zoo tuav cov kav hlau stainless thiab cov khoom siv thaum tsim khoom los tiv thaiv kev sib kis, yog qhov tseem ceeb ntawm cov kav dej zoo uas tiv thaiv corrosion thiab muab kev pab cuam lub neej ntev.
Cov ntaub ntawv siv hauv high-purity biopharmaceutical stainless steel piping systems tau dhau los ua ib qho kev hloov pauv mus rau kev txhim kho corrosion nyob rau xyoo kaum xyoo dhau los.Feem ntau stainless hlau siv ua ntej xyoo 1980 yog 304 stainless hlau vim nws pheej yig thiab txhim kho dua cov tooj liab siv yav dhau los.Qhov tseeb, 300 series stainless hlau fusion tshuab tau yooj yim und welded. tsis kam, thiab tsis tas yuav tsum tau tshwj xeeb preheat thiab tom qab kev kho cua sov.
Tsis ntev los no, kev siv 316 stainless hlau nyob rau hauv high-purity piping daim ntaub ntawv tau nce.Type 316 zoo ib yam nyob rau hauv muaj pes tsawg leeg rau hom 304, tab sis ntxiv rau cov chromium thiab npib tsib xee alloying ntsiab rau ob qho tib si, 316 muaj txog 2% molybdenum, uas ho txhim kho 316's corrosion resistance.Types 3. Cov qib, muaj cov ntsiab lus qis dua li cov qauv qib (0.035% vs. 0.08%).Qhov kev txo qis hauv cov ntsiab lus carbon no yog tsim los txo cov carbide nag lossis daus uas yuav tshwm sim vim kev vuam.Qhov no yog tsim ntawm chromium carbide, uas depletes cov ciaj ciam ntawm cov chromium puag hlau, ua rau nws "ssceptible for formensitrom" carbide. Lub sij hawm thiab qhov kub thiab txias nyob ntawm thiab yog qhov teeb meem loj dua thaum siv tes soldering.Peb tau pom tias orbital vuam ntawm super-austenitic stainless hlau AL-6XN muab cov corrosion resistant welds ntau dua li cov welds zoo sib xws ua los ntawm tes. 304 thiab 316 zoo li tshem tawm cov nag lossis daus los ntawm carbide ua ib qho tseem ceeb hauv kev txhim kho corrosion hauv cov kav dej.
Thaum tshav kub kub hloov pauv ntawm stainless hlau.Txawm hais tias vuam tsis thiab lwm yam tseem tuaj yeem khaws cia tsis pub dhau nruj nruj, tseem muaj qhov sib txawv ntawm cov khoom siv hluav taws xob uas yuav tsum tau vuam stainless hlau los ntawm tshav kub mus rau cua sov.Ib tug xov tooj cua sov yog ntau tus naj npawb muab rau ib qho tshwj xeeb stainless hlau yaj ntawm lub hoobkas.Cov tshuaj lom neeg muaj pes tsawg leeg ntawm txhua batch yog kaw rau ntawm TR Factory Test . melts ntawm 1538 ° C (2800 ° F), thaum alloyed hlau yaj nyob rau hauv ib tug ntau ntawm qhov kub thiab txias, nyob ntawm seb hom thiab concentration ntawm txhua alloy los yog ib tug kab nyob rau hauv tam sim no.Vim tias tsis muaj ob heats ntawm stainless hlau yuav muaj raws nraim tib concentration ntawm txhua lub caij, vuam yam ntxwv yuav txawv ntawm lub cub tawg rau lub cub tawg.
SEM ntawm 316L yeeb nkab orbital welds ntawm AOD yeeb nkab (sab saum toj) thiab EBR cov ntaub ntawv (hauv qab) pom qhov sib txawv tseem ceeb hauv qhov smoothness ntawm weld hlaws.
Thaum ib txoj kev vuam ib leeg tuaj yeem ua haujlwm rau feem ntau cov cua sov uas zoo sib xws OD thiab phab ntsa tuab, qee qhov cua sov yuav tsum muaj tsawg dua amperage thiab qee qhov yuav tsum tau siab dua amperage dua li ib txwm.Vim li no, cua sov ntawm cov khoom sib txawv ntawm qhov chaw ua haujlwm yuav tsum tau ua tib zoo taug qab kom tsis txhob muaj teeb meem. Feem ntau, cov cua sov tshiab yuav tsum tau hloov me me hauv amperage kom ua tiav cov txheej txheem vuam zoo.
Sulfur teeb meem.Elemental sulfur yog cov hlau ore-txog impurity uas feem ntau raug tshem tawm thaum lub sij hawm steelmaking txheej txheem.AISI hom 304 thiab 316 stainless steels tau teev tseg nrog ib tug siab tshaj plaws sulfur ntsiab lus ntawm 0.030%. Arc Remelting (VIM + VAR), nws tau dhau los ua cov hlau uas tshwj xeeb hauv cov hauv qab no.lawv cov tshuaj muaj pes tsawg leeg.Nws tau raug sau tseg tias cov khoom ntawm lub pas dej vuam hloov pauv thaum cov ntsiab lus ntawm cov tooj liab ntawm cov hlau qis dua li ntawm 0.008%.
Ntawm qhov tsis tshua muaj sulfur concentrations (0.001% - 0.003%), qhov nkag mus ntawm lub weld puddle yuav dav heev piv rau cov welds zoo sib xws ntawm cov ntaub ntawv uas muaj leej faj.Welds uas tsis muaj sulfur stainless hlau yeeb nkab yuav muaj welds dav dua, thaum nyob rau ntawm phab ntsa tuab (0.065 ntiv tes, los yog 1.66 hli los yog ntau dua). welding tam sim no yog txaus los tsim ib tug tag nrho nkag mus rau weld.Qhov no ua rau cov ntaub ntawv uas tsis tshua muaj leej faj cov ntsiab lus nyuaj rau weld, tshwj xeeb tshaj yog nrog thicker phab ntsa.Thaum lub siab kawg ntawm cov sulfur concentration nyob rau hauv 304 los yog 316 stainless hlau, lub weld hlaws nyhav yuav tsis tshua muaj kua nyob rau hauv tsos thiab rougher tshaj li nruab nrab leej faj cov ntaub ntawv. Yog li ntawd, rau weldability ntawm 0% cov ntsiab lus ntawm sulfur yuav zoo tagnrho. 0.017%, raws li tau teev tseg hauv ASTM A270 S2 rau kev siv tshuaj zoo tubing.
Cov neeg tsim khoom ntawm electropolished stainless hlau yeeb nkab tau pom tias txawm tias theem nrab ntawm leej faj hauv 316 lossis 316L stainless hlau ua rau nws nyuaj rau kev ua kom tau raws li cov kev xav tau ntawm lawv cov semiconductor thiab biopharmaceutical cov neeg siv khoom kom du, pit-free tha xim sab hauv. manganese sulfide (MnS) "stringers" uas raug tshem tawm thaum lub sij hawm electropolishing thiab tawm voids nyob rau hauv 0.25-1.0 micron ntau.
Cov neeg tsim khoom thiab cov chaw muag khoom ntawm cov raj electropolished yog tsav kev lag luam mus rau kev siv cov khoom siv ultra-low sulfur kom ua tau raws li lawv cov kev xav tau ntawm qhov chaw tiav.Txawm li cas los xij, qhov teeb meem tsis txwv rau cov raj electropolished, xws li hauv cov raj uas tsis yog electropolished cov inclusions raug tshem tawm thaum lub sij hawm passivation ntawm cov kav dej.Voids tau pom tias muaj kev cuam tshuam rau pitting dua li qhov sib txawv ntawm qhov chaw qis-yog li muaj qee qhov sib txawv. cov ntaub ntawv.
Arc deflection.Ntxiv rau kev txhim kho lub weldability ntawm stainless hlau, lub xub ntiag ntawm ib co sulfur kuj txhim kho machinability.Vim li ntawd, manufacturers thiab manufacturers nyiam xaiv cov ntaub ntawv nyob rau hauv lub siab kawg ntawm cov ntsiab lus sulfur cov ntsiab lus.Welding tubing uas tsis tshua muaj sulfur concentrations rau fittings, li qub los yog lwm yam tubing uas muaj cov ntsiab lus sulfur siab dua tuaj yeem tsim teeb meem welding vim hais tias cov ntsiab lus ntawm cov sulfur tsis tshua muaj siab. tshwm sim, qhov nkag mus tob rau ntawm qhov qis-sulfur sab dua li ntawm qhov siab-sulfur sab, uas yog qhov sib txawv ntawm qhov tshwm sim thaum vuam cov kav dej nrog kev sib txuam sulfur concentrations.Thaum qhov xwm txheej hnyav, cov hlaws hlaws tuaj yeem nkag mus rau cov khoom siv uas tsis tshua muaj sulfur thiab tawm hauv cov khoom siv hauv cov hlau tsis huv (Fihey thiab Simeneau, 1982 rau sulfur ntsiab lus ntawm sulfur). cov yeeb nkab, Lub Tuam Txhab Cov Hlau Hlau ntawm Car-penter Technology Corporation ntawm Pennsylvania tau qhia ib qho tsis tshua muaj leej faj (0.005% max) 316 bar Tshuag (Hom 316L-SCQ) (VIM + VAR) ) rau kev tsim cov khoom fittings thiab lwm yam khoom tsim los ua welded rau qis sulfur kav dej.Welding ob qho tib si sulfur tsawg dua cov khoom siv ntau dua li sulfur. sulfur ib.
Kev hloov mus rau kev siv cov raj uas tsis tshua muaj sulfur feem ntau yog vim qhov xav tau kom tau txais cov electropolished inner tube surfaces.While deg tiav thiab electropolishing yog ib qho tseem ceeb rau ob qho tib si kev lag luam semiconductor thiab biotech/pharmaceutical kev lag luam, SEMI, thaum sau cov semiconductor kev lag luam specification, teev tias 316L tubing rau cov txheej txheem roj 00% sulfur cap. ends.ASTM, ntawm qhov tod tes, hloov kho lawv cov ASTM 270 specification kom suav nrog cov tshuaj-qib tubing uas txwv cov ntsiab lus sulfur mus rau ntau yam ntawm 0.005 txog 0.017%. fittings, thiab installers yuav tsum ua tib zoo taug qab cov cua sov ntawm cov khoom thiab xyuas ua ntej fabrication Solder compatibility ntawm cua sov.Production ntawm welds.
Lwm yam kab kawm.Trace ntsiab suav nrog sulfur, oxygen, aluminium, silicon thiab manganese tau pom tias muaj kev cuam tshuam rau kev nkag mus.Trace cov nyiaj ntawm txhuas, silicon, calcium, titanium thiab chromium tam sim no nyob rau hauv lub hauv paus hlau li oxide inclusions yog txuam nrog slag tsim thaum vuam.
Cov teebmeem ntawm ntau lub ntsiab lus yog cumulative, yog li muaj cov pa oxygen tuaj yeem cuam tshuam qee qhov tsis muaj leej faj cuam tshuam.High qib ntawm txhuas tuaj yeem tiv thaiv cov txiaj ntsig zoo ntawm cov sulfur penetration.Manganese volatilizes ntawm vuam kub thiab deposits nyob rau hauv vuam tshav kub-tshem tawm tsam.Cov manganese deposits yog txuam nrog kev poob ntawm corrosion kuj.(1console 9). manganese thiab txawm tias ultra-tsawg manganese 316L cov ntaub ntawv los tiv thaiv qhov poob ntawm corrosion kuj.
Slag formation.Slag Islands qee zaus tshwm sim ntawm cov hlaws stainless hlau rau qee qhov cua sov.Qhov no yog qhov teeb meem ntawm cov khoom siv, tab sis qee zaum kev hloov pauv ntawm cov vuam tsis tuaj yeem txo qhov no, lossis kev hloov pauv hauv cov argon / hydrogen sib tov tuaj yeem txhim kho cov weld.Pollard pom tias qhov piv ntawm aluminium rau silicon hauv lub hauv paus hlau cuam tshuam rau kev tsim slag. Txhawm rau tiv thaiv cov ntsiab lus ntawm slag. ntawm 0.010% thiab cov ntsiab lus silicon ntawm 0.5% Txawm li cas los xij, thaum Al / Si piv yog siab dua qib no, spherical slag yuav tsim ntau dua li cov quav hniav.Cov hom slag no tuaj yeem tawm hauv qhov pits tom qab electropolishing, uas yog tsis tsim nyog rau high-purity daim ntaub ntawv.Slag Islands uas tsim nyob rau hauv OD ntawm lub weld penufration tuaj yeem ua rau tsis muaj kev cuam tshuam ntawm ID. Kev nkag mus.Cov slag Islands tuaj rau ntawm ID weld hlaws tej zaum yuav raug rau corrosion.
Ib leeg-khiav weld nrog pulsation.Standard tsis siv neeg orbital raj welding yog ib zaug dhau weld nrog pulsed tam sim no thiab tas li ceev rotation.Cov txheej txheem no yog tsim rau cov yeeb nkab nrog sab nraud diameters ntawm 1/8 "mus rau kwv yees li 7" thiab phab ntsa thicknesses ntawm 0.083 "thiab hauv qab no. arcing yog tam sim no tab sis tsis muaj kev sib hloov tshwm sim.Tom qab qhov kev ncua sij hawm no, cov electrode rotates nyob ib ncig ntawm lub vuam sib txuas kom txog rau thaum lub weld koom los yog overlaps cov thawj feem ntawm cov weld thaum lub sij hawm kawg ntawm welding.Thaum qhov kev twb kev txuas yog tiav, tam sim no tapers tawm nyob rau hauv ib tug timed poob.
Kauj ruam hom ("synchronized" vuam).Rau fusion vuam ntawm cov ntaub ntawv tuab phab ntsa, feem ntau ntau dua 0.083 nti, fusion vuam fais fab qhov chaw yuav siv tau nyob rau hauv synchronous los yog kauj ruam hom.In synchronous los yog kauj ruam hom, lub vuam tam sim no mem tes yog synchronized nrog lub stroke, yog li lub rotor yog nyob ruaj ruaj thaum lub sij hawm tam sim no siab tshaj plaws nyob rau hauv p penetration. pulses.Synchronous cov txheej txheem siv lub sij hawm mem tes ntev, ntawm qhov kev txiav txim ntawm 0.5 mus rau 1.5 vib nas this, piv rau lub thib kaum los yog pua pua ntawm ib tug thib ob mem tes lub sij hawm rau cov pa welding.Cov txheej txheem no tau zoo weld 0.154 "los yog 6" tuab 40 gauge 40 nyias phab ntsa yeeb nkab nrog 0.154 ". Cov txheej txheem ua 6 "faulted phab ntsa thickness. Kev ua siab ntev thiab muaj txiaj ntsig zoo rau kev sib txuas tsis tu ncua xws li cov yeeb nkab fittings rau cov kav dej uas yuav muaj qhov sib txawv ntawm qhov ntev ntev, qee qhov kev tsis zoo lossis cov khoom siv thermal incompatibility.Qhov kev vuam no yuav tsum tau kwv yees li ob zaug lub sij hawm arc ntawm cov pa welding thiab tsis tshua haum rau ultra-high-purity (UHP) daim ntaub ntawv vim qhov dav, rougher seam.
Programmable variables.Lub tiam tam sim no ntawm vuam fais fab qhov chaw yog microprocessor-raws li thiab khw cov kev pab cuam uas qhia cov zauv qhov tseem ceeb rau vuam tsis rau ib tug tshwj xeeb txoj kab uas hla (OD) thiab phab ntsa thickness ntawm cov yeeb nkab yuav tsum welded, nrog rau lub sij hawm ntxuav, vuam tam sim no, mus txawv tebchaws ceev (RPM) ), tus naj npawb ntawm cov khaubncaws sab nraud povtseg thiab sij hawm ib txheej, pulse lub sij hawm sau ntawv, thiab lwm yam kev pab cuam lub sij hawm welding. Cov kev txwv yuav suav nrog cov xaim pub ceev, hluav taws xob oscillation amplitude thiab lub sijhawm nyob hauv, AVC (arc voltage tswj kom muab qhov sib txawv arc tas li), thiab upslope.To ua fusion vuam, nruab lub vuam taub hau nrog cov electrode tsim nyog thiab cov yeeb nkab clamp ntxig rau ntawm cov yeeb nkab thiab nco qab lub sijhawm vuam los yog kev pab cuam los ntawm lub hwj chim qhov chaw nco. kev cuam tshuam tus neeg teb xov tooj.
Tsis yog-programmable variables.Yuav kom tau txais kev sib txuas zoo zoo, cov vuam tsis zoo yuav tsum tau ua tib zoo tswj.Qhov no yog ua tiav los ntawm qhov tseeb ntawm cov vuam fais fab thiab cov kev pab cuam vuam, uas yog ib txheej ntawm cov lus qhia nkag mus rau hauv lub hwj chim qhov chaw, muaj xws li vuam tsis, rau welding ib tug loj npaum li cas ntawm cov yeeb nkab los yog cov yeeb nkab. Kev soj ntsuam vuam thiab kev tswj xyuas zoo kom ntseeg tau tias vuam ua tau raws li cov qauv kev pom zoo.Txawm li cas los xij, qee yam thiab cov txheej txheem uas tsis yog vuam tsis zoo yuav tsum tau ua tib zoo tswj.Cov khoom no suav nrog kev siv cov cuab yeej zoo kawg, kev tu thiab tuav tau zoo, zoo qhov ntev ntawm cov tubing lossis lwm qhov chaw raug welded, zoo ib yam tungsten purified hom thiab loj.
Cov txheej txheem kev npaj rau cov yeeb nkab kawg vuam yog qhov tseem ceeb tshaj rau orbital vuam tshaj li phau ntawv welding.Welded pob qij txha rau orbital yeeb nkab welding feem ntau yog square taub qab pob qij txha.Ua kom tiav cov repeatability xav nyob rau hauv orbital welding, meej, zoo ib yam, machined kawg npaj yog yuav tsum tau.Vim lub vuam tam sim no nyob ntawm phab ntsa thickness, qhov kawg yuav tsum yog tus ID los yog tsis muaj ID. ua rau cov phab ntsa sib txawv.
Cov yeeb nkab kawg yuav tsum haum ua ke hauv lub taub hau weld kom tsis muaj qhov sib txawv ntawm qhov kawg ntawm lub pob tw pob tw.Txawm hais tias cov pob qij txha nrog cov khoob me me tuaj yeem ua tiav, weld zoo yuav cuam tshuam tsis zoo.Qhov loj dua qhov sib txawv, qhov ntau yuav muaj teeb meem. Kev sib dhos tsis zoo tuaj yeem ua rau tsis ua tiav ntawm cov yeeb nkab vuam thiab lwm tus. tib lub lag luam, los yog portable kawg npaj lathes zoo li cov uas ua los ntawm Protem, Wachs, thiab lwm yam, feem ntau siv los ua du kawg orbital welds haum rau machining .Chop saws, hacksaws, band saws thiab tubing cutters tsis haum rau lub hom phiaj no.
Ntxiv nrog rau qhov tsis sib xws ntawm cov khoom siv hluav taws xob rau vuam, muaj lwm qhov sib txawv uas tuaj yeem muaj txiaj ntsig zoo ntawm vuam, tab sis lawv tsis yog ib feem ntawm cov txheej txheem vuam tiag tiag.Qhov no suav nrog hom thiab qhov loj ntawm tungsten, hom thiab purity ntawm cov roj siv los thaiv cov arc thiab tshem tawm sab hauv ntawm qhov sib koom ua ke, cov roj siv hluav taws xob siv rau kev siv lub taub hau, cov roj purging qhov chaw siv rau lub taub hau. sib koom ua ke, thiab lwm yam ntaub ntawv tseem ceeb.Peb hu cov "non-programmable" variables thiab sau lawv nyob rau hauv lub sij hawm welding.Piv txwv li, hom roj yog suav hais tias yog ib qho tseem ceeb variable nyob rau hauv Vuam txheej txheem Specification (WPS) rau vuam cov txheej txheem ua raws li ASME Tshooj IX Boiler thiab Pressure Vessel Code.Changes nyob rau hauv revalidation ntawm cov khoom siv los yog gaskets. txheej txheem vuam.
welding gas.Stainless steel yog resistant rau atmospheric oxygen oxidation nyob rau hauv chav tsev kub.Thaum nws yog rhuab mus rau nws melting point (1530 ° C los yog 2800 ° F rau cov hlau ntshiab) nws yog yooj yim oxidized.Inert argon feem ntau yog siv raws li ib tug shielding roj thiab rau purging internal welded pob qij txha los ntawm lub orbital cov txheej txheem ntawm AW. oxidation-induced discoloration uas tshwm sim nyob rau hauv los yog nyob ze ntawm lub vuam tom qab vuam.Yog hais tias lub purge gas tsis yog lub siab tshaj plaws zoo los yog yog hais tias lub purge system tsis kiag li xau dawb xws li hais tias ib tug me me npaum li cas ntawm cov pa tawm mus rau hauv lub purification system, lub oxidation tej zaum yuav lub teeb teal los yog bluish. Tau kawg, tsis muaj kev tu yuav ua rau lub crusty dub nto raws li cov khoom siv feem ntau xa mus. Lub tog raj kheej yog 99.996-99.997% ntshiab, nyob ntawm tus neeg xa khoom, thiab muaj 5-7 ppm ntawm cov pa oxygen thiab lwm yam impurities, suav nrog H2O, O2, CO2, hydrocarbons, thiab lwm yam, rau tag nrho ntawm 40 ppm qhov siab tshaj plaws.High-purity argon nyob rau hauv ib lub tog raj kheej los yog 9% dej argon. ppm tag nrho cov impurities, nrog rau qhov siab tshaj plaws ntawm 2 ppm oxygen.CEEB TOOM: Cov pa roj purifiers xws li Nanochem lossis Gatekeeper tuaj yeem siv thaum lub sij hawm purging kom txo tau cov pa paug mus rau qhov chaw ib billion (ppb) ntau.
Mixed composition.Gas mixs xws li 75% helium / 25% argon thiab 95% argon / 5% hydrogen yuav siv tau los ua shielding gases rau tshwj xeeb daim ntaub ntawv.Qhov ob mixs ua kub welds tshaj cov ua nyob rau hauv tib qhov kev pab cuam chaw raws li argon.Helium mixtures yog tshwj xeeb tshaj yog haum rau siab tshaj plaws nkag los ntawm fusion welding ib nrab ntawm cov pa roj carbon dioxide kev lag luam. Kev sib xyaw ua ke raws li kev tiv thaiv roj rau UHP daim ntawv thov.Hydrogen sib tov muaj ntau qhov zoo, tab sis kuj muaj qee qhov tsis zoo.Qhov qhov zoo yog tias nws ua rau cov dej ntub dej thiab cov npoo smoother, uas yog qhov zoo tshaj plaws rau kev siv lub tshuab hluav taws xob ultra-siab siab nrog rau lub ntsej muag zoo li qhov ua tau.Lub xub ntiag ntawm hydrogen muab qhov chaw txo qis, yog li yog tias cov pa paug ntawm cov pa sib xyaw ua kom zoo dua qub, peb yuav saib cov pa roj carbon monoxide kom huv. Cov pa oxygen zoo sib xws hauv cov ntshiab argon.Cov nyhuv no yog qhov zoo ntawm kwv yees li 5% hydrogen cov ntsiab lus.Qee siv 95/5% argon / hydrogen sib tov ua tus ID tshem tawm los txhim kho cov tsos ntawm cov hlaws sab hauv.
Lub weld hlaws siv hydrogen sib tov raws li cov roj shielding yog nqaim, tshwj tsis yog tias cov hlau tsis muaj leej faj cov ntsiab lus tsawg heev thiab ua kom muaj cua sov ntau hauv cov vuam ntau dua li qhov sib xyaw tam sim no nrog argon tsis sib xyaw.Ib qho teeb meem tseem ceeb ntawm argon / hydrogen sib tov yog tias cov arc tsis ruaj khov dua li cov ntshiab argon, thiab muaj kev nyiam rau cov arc kom tsis sib haum, qhov sib txawv ntawm qhov sib txawv yog qhov txaus ntshai. siv, tawm tswv yim tias nws yuav tshwm sim los ntawm kev sib kis los yog kev sib xyaw tsis zoo.Vim tias cov cua sov tsim los ntawm cov arc sib txawv nrog cov hydrogen concentration, qhov tseem ceeb yog qhov tseem ceeb kom ua tiav cov welds rov ua dua, thiab muaj qhov sib txawv ntawm cov roj fwj ua ntej sib xyaw.Lwm qhov tsis zoo yog tias lub neej ntawm tungsten yog luv heev thaum lub hydrogen sib xyaw ua ke ntawm cov khoom siv los ntawm qhov sib xyaw ntawm Wh. tsis tau txiav txim siab, nws tau raug tshaj tawm tias qhov arc yog qhov nyuaj dua thiab cov tungsten yuav tsum tau hloov tom qab ib lossis ob lub welds.Argon / hydrogen sib tov tsis tuaj yeem siv los vuam cov hlau lossis titanium.
Ib qho tshwj xeeb ntawm cov txheej txheem TIG yog tias nws tsis haus electrodes.Tungsten muaj qhov siab tshaj plaws melting point ntawm tej hlau (6098 ° F; 3370 ° C) thiab yog ib tug zoo electron emitter, ua tshwj xeeb tshaj yog haum rau siv raws li ib tug uas tsis yog-consumable electrode.Nws cov khoom yog txhim kho los ntawm kev ntxiv 2% ntawm tej yam tsawg ntiaj teb oxides xws li oxides. arc pib thiab arc stability.Ntshiab tungsten yog tsis tshua muaj siv nyob rau hauv GTAW vim yog superior zog ntawm cerium tungsten, tshwj xeeb tshaj yog rau orbital GTAW applications.Thorium tungsten yog siv tsawg dua yav dhau los vim hais tias lawv yog me ntsis radioactive.
Electrodes nrog polished tiav yog ntau yam sib xws hauv qhov loj.Ib qhov chaw du yog ib txwm nyiam rau qhov ntxhib lossis tsis sib xws, vim qhov sib xws hauv electrode geometry yog qhov tseem ceeb rau kev sib xws, cov txiaj ntsig zoo sib xws.Electrons emitted los ntawm lub ntsis (DCEN) hloov tshav kub los ntawm tungsten tip mus rau weld.A finer tip tso cai rau lub sij hawm luv luv, tab sis yuav ua rau muaj kev kub ntxhov ntau. lifetime.For orbital welding, nws yog ib qho tseem ceeb rau mechanically grind lub electrode tip kom paub meej tias repeatability ntawm tungsten geometry thiab weld repeatability.Lub blunt tip yuam lub arc los ntawm weld mus rau tib qhov chaw ntawm lub tungsten.Lub taub txoj kab uas hla tswj cov duab ntawm lub arc thiab tus nqi ntawm kev nkag mus rau ntawm ib tug tej yam tam sim no. tswj.Qhov ntev ntawm lub tungsten yog ib qho tseem ceeb vim hais tias ib tug paub ntev ntawm tungsten yuav siv tau los teem lub arc gap.Qhov arc sib txawv rau ib tug tshwj xeeb tam sim no tus nqi txiav txim qhov voltage thiab yog li lub hwj chim thov mus rau lub weld.
Cov electrode loj thiab nws lub taub txoj kab uas hla yog xaiv raws li qhov vuam tam sim no siv.Yog tias qhov tam sim no siab dhau rau cov electrode los yog nws cov ntsis, nws yuav plam hlau los ntawm lub ntsis, thiab siv cov electrodes nrog ib lub taub taub uas loj heev rau qhov tam sim no yuav ua rau arc drift.Peb qhia cov electrode thiab cov taub diameters los ntawm phab ntsa thickness ntawm lub weld ob leeg thiab siv 0.062 "txhua yam thickness mus txog 0.0625". yog tsim los siv nrog 0.040 "txoj kab uas hla electrodes rau vuam me me precision Cheebtsam.Rau repeatability ntawm vuam txheej txheem, tungsten hom thiab tiav, ntev, taper lub kaum sab xis, txoj kab uas hla, tip txoj kab uas hla thiab arc sib txawv yuav tsum tau teev tag nrho thiab tswj.For raj vuam daim ntaub ntawv, cerium tungsten yog ib txwm pom zoo vim hais tias hom no muaj ib tug ntev kev pab cuam lub neej. tsis muaj hluav taws xob.
Yog xav paub ntxiv, thov hu rau Barbara Henon, Technical Publications Manager, Arc Machines, Inc., 10280 Glenoaks Blvd., Pacoima, CA 91331.Phone: 818-896-9556.Fax: 818-890-3724.