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 nruj heev etchant rau stainless hlau.Ntxiv mus, cov kws tshuaj qib WFI yog cycled ntawm kub kub (80 ° C) kom tsis muaj menyuam.Muaj qhov sib txawv me ntsis ntawm kev txo qhov kub txaus los txhawb cov kab mob nyob rau hauv cov khoom thiab "txhim kho cov xim av muaj pes tsawg leeg." piping system Cheebtsam.Dirt thiab hlau oxides tej zaum yuav yog lub ntsiab Cheebtsam, tab sis ntau hom hlau, chromium thiab npib tsib xee kuj tseem muaj.Lub xub ntiag ntawm rouge yog lethal rau qee cov khoom thiab nws lub xub ntiag tej zaum 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 khoom tso rau ntawm vuam thiab HAZs thaum vuam, tshwj xeeb yog cuam tshuam, thiab cuam tshuam nrog kev tsim cov rouge hauv cov dej tshuaj.Chromium oxide tsim tuaj yeem ua rau kub kub, tawm hauv qab chromium-depleted txheej uas yog cuam tshuam los ntawm kev sib tsoo ntawm cov hlau, nrog rau kev sib tsoo ntawm cov hlau. dag 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 muaj kev puas tsuaj rau saum npoo tiav.Passivation ntawm cov kav dej 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 cov kev pab cuam electron, passivation. , hlau, npib tsib xee thiab manganese uas tshwm sim nyob rau hauv lub weld thiab tshav kub cuam tshuam cheeb tsam mus rau lub pre-weld xeev.Txawm li cas los xij, passivation tsuas yog cuam tshuam rau txheej txheej txheej thiab tsis nkag mus rau hauv qab 50 angstroms, whereas 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 tsum tau sim txwv kev vuam thiab fabrication-induced kev puas tsuaj rau qib uas yuav tsum tau zoo zoo los ntawm passivation.Qhov no yuav tsum tau siv ib tug purge gas nrog tsawg kawg nkaus oxygen cov ntsiab lus thiab xa mus rau lub sab hauv txoj kab uas hla ntawm lub welded sib koom tsis muaj paug los ntawm atmospheric oxygen los yog kev tiv thaiv ntawm cov cua sov thaum lub sij hawm welding tseem ceeb. s ntawm corrosion resistance.Tswj cov txheej txheem tsim khoom kom ua tiav cov khoom siv zoo sib xws thiab zoo ib yam, nrog rau kev ua tib zoo tuav cov kav hlau stainless thiab cov khoom siv thaum lub sij hawm tsim khoom los tiv thaiv kev sib kis, yog qhov tseem ceeb rau cov kav dej zoo uas tiv thaiv corrosion thiab muab kev pab cuam lub neej ntev.
Cov khoom siv hauv high-purity biopharmaceutical stainless hlau piping tshuab tau dhau los ua qhov 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 kev txhim kho dua cov tooj liab siv yav dhau los.Qhov tseeb, 300 series stainless hlau fusion tshuab tsis tuaj yeem ua tau yooj yim rau kev siv cov tshuab tsis muaj corrosion, thiab tsis tuaj yeem ua tau yooj yim rau cov tshuab tsis muaj corrosion. 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 li ntawm 2% molybdenum, uas ho txhim kho 316's corrosion resistance.Types 3,4L, thiab lwm yam. 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 qhov tsim ntawm chromium carbide, uas depletes lub grain ciam teb ntawm cov chromium puag hlau, ua rau nws raug rau corrosion.Lub sij hawm loj ntawm carbide, hu ua chromium carbide. Peb tau pom tias orbital vuam ntawm super-austenitic stainless hlau AL-6XN muab cov corrosion resistant welds ntau dua li cov welds ua los ntawm tes.Qhov no yog vim orbital vuam muab meej tswj ntawm amperage, pulsation thiab lub sij hawm, uas ua rau ib tug qis dua thiab ntau uniform cua sov input tshaj li phau ntawv welding.Orbital 3 thiab 3 grade welding. nag lossis daus 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 cua kub uas yuav tsum tau vuam stainless hlau los ntawm tshav kub mus rau cua sov.A kub tooj yog ntau tus lej muab rau ib qho tshwj xeeb stainless hlau yaj ntawm lub Hoobkas.Cov tshuaj lom neeg muaj pes tsawg leeg ntawm txhua pawg yog kaw rau ntawm TR Factory Test 1. 538 ° 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 txoj lw ntsiab tam sim no.Vim tias tsis muaj ob heats ntawm stainless hlau yuav muaj raws nraim tib concentration ntawm txhua lub caij, welding 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 tsuas yog 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 nrog ib tug siab tshaj plaws sulfur ntsiab lus ntawm 0.030%. VIM + VAR), nws tau dhau los ua cov hlau tshwj xeeb hauv cov txheej txheem hauv qab no.lawv cov tshuaj lom neeg muaj pes tsawg leeg.Nws tau raug sau tseg tias cov khoom ntawm cov vuam pas dej hloov pauv thaum cov ntsiab lus ntawm cov tooj liab ntawm cov hlau yog 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 zoo sib xws welds ua nyob rau hauv nruab nrab sulfur cov ntaub ntawv. Welds ua nyob rau hauv tsawg sulfur stainless hlau yeeb nkab yuav muaj dav welds, thaum nyob rau hauv thicker phab ntsa yeeb nkab (0.065 ntiv tes, los yog 1.66 hli los yog ntau tshaj) welding yuav muaj txaus tam sim no. 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 ntau 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, qhov zoo tagnrho sulfur cov ntsiab lus ntawm kwv yees li 7% 0.00 A. 270 S2 rau tshuaj zoo tubing.
Cov neeg tsim khoom ntawm electropolished stainless hlau yeeb nkab tau pom tias txawm tias theem nrab ntawm cov sulfur 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 sab hauv qhov chaw.Kev siv cov tshuaj electron microscopy los xyuas qhov smoothness ntawm lub raj nto tiav rau hauv cov hlau tsis muaj sulfides ntau dua. 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 ntau dua rau pitting dua li cov ntaub ntawv uas tsis tshua muaj siv tau.
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 nrog cov ntsiab lus sulfur siab dua tuaj yeem tsim teeb meem welding, vim hais tias cov ntsiab lus ntawm cov ntsiab lus ntawm arcs yuav raug txo qis. ration ua ntxaum nyob rau hauv qis-sulfur sab dua nyob rau hauv high-sulfur sab, uas yog qhov opposite ntawm dab tsi tshwm sim thaum vuam kav nrog txuam sulfur concentrations.Thaum kawg, lub weld hlaws yuav kiag li nkag mus rau hauv cov khoom uas tsis muaj sulfur thiab tawm sab hauv lub weld kiag li unfused (Fihey thiab Simeneau, 1982). ter 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 fittings thiab lwm yam khoom tsim los ua welded rau cov kav dej uas tsis tshua muaj leej faj.Welding ob qho khoom uas tsis tshua muaj sulfur rau ib leeg yog yooj yim dua li sulfur welding.
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 semiconductor kev lag luam thiab biotech/pharmaceutical kev lag luam, SEMI, thaum sau cov semiconductor kev lag luam specification, teev tias 316L tubing rau cov txheej txheem roj 0.0% sulfur kev ua tau zoo ntawm tes. , hloov kho lawv cov ASTM 270 specification kom suav nrog cov tshuaj-qib tubing uas txwv cov ntsiab lus sulfur mus rau thaj tsam ntawm 0.005 txog 0.017%.Qhov no yuav tsum ua rau muaj teeb meem vuam tsawg dua piv rau qis qis sulfur.Txawm li cas los xij, nws yuav tsum tau muab sau tseg tias txawm nyob rau hauv qhov kev txwv no, arc deflection tseem tuaj yeem tshwm sim thaum vuam cov yeeb nkab uas tsis tshua muaj hluav taws xob los yog cov khoom siv sulfur. 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 zoo ntawm cov tshuaj sulfur.High qib ntawm txhuas tuaj yeem tiv thaiv cov txiaj ntsig zoo ntawm cov tshuaj sulfur penetration.Manganese volatilizes ntawm vuam kub thiab deposits nyob rau hauv lub vuam tshav kub-cuam tshuam cheeb tsam.Cov manganese deposits yog txuam nrog kev poob ntawm corrosion kuj.(1conorhen, semi-tshuaj kev lag luam thiab cov txiv neej). -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 txhuas rau silicon hauv cov hlau hauv lub hauv paus hlau cuam tshuam rau kev tsim slag.Txhim kho cov ntsiab lus ntawm slag.0. 10% 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 tuaj yeem ua rau cov ntaub ntawv tsis sib xws. 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 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. Tab sis tsis muaj kev sib hloov tshwm sim.Tom qab qhov kev sib hloov qeeb, cov electrode tig ib ncig ntawm qhov sib koom ua ke kom txog rau thaum lub weld koom los yog sib tshooj thawj feem ntawm lub vuam thaum lub sij hawm kawg ntawm welding.Thaum qhov kev sib txuas ua tiav, tam sim no tapers tawm hauv lub sij hawm 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 synchronized nrog cov hlab ntsha, yog li lub rotor yog nyob ruaj ruaj thaum lub sij hawm tam sim no pulses. siv lub sij hawm mem tes ntev, ntawm qhov kev txiav txim ntawm 0.5 mus rau 1.5 vib nas this, piv rau qhov thib kaum los yog pua pua ntawm lub sijhawm thib ob rau cov pa welding.Cov txheej txheem no tuaj yeem ua tau zoo weld 0.154 "los yog 6" tuab 40 gauge 40 nyias phab ntsa yeeb nkab nrog 0.154 "los yog 6" phab ntsa tuab. Raws li cov yeeb nkab fittings rau cov kav dej uas tej zaum yuav muaj qhov sib txawv ntawm qhov ntev, qee qhov kev tsis sib haum xeeb lossis cov khoom siv thermal incompatibility.Qhov no hom vuam yuav tsum tau kwv yees li ob zaug lub sij hawm arc ntawm cov pa welding thiab tsis haum rau ultra-high-purity (UHP) daim ntaub ntawv vim qhov dav, rougher seam.
Programmable variables.Cov tiam tam sim no ntawm vuam hwj chim 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 welded, nrog rau lub sij hawm tshem tawm, vuam tam sim no, mus ncig teb chaws ceev (RPM), cov txheej txheem thiab sij hawm ib txheej, pulse lub sij hawm sau, thiab lwm yam kev pab cuam lub sij hawm welding. hlau pub ceev, hluav taws xob oscillation amplitude thiab nyob lub sij hawm, AVC (arc voltage tswj los muab qhov arc qhov sib txawv), thiab upslope.To ua fusion vuam, nruab lub vuam taub hau nrog rau qhov tsim nyog electrode thiab cov yeeb nkab clamp inserts rau ntawm cov yeeb nkab thiab nco qab lub vuam lub sij hawm los yog cov kev pab cuam los ntawm lub hwj chim qhov chaw nco.Cov welding ib theem zuj zus ntawm cov neeg ua hauj lwm los yog welding tseem ceeb.
Tsis yog-programmable variables.Yuav kom tau zoo zoo weld zoo, cov vuam tsis zoo yuav tsum tau ua tib zoo tswj.Qhov no yog ua tiav los ntawm qhov tseeb ntawm vuam fais fab qhov chaw thiab vuam qhov kev pab cuam, uas yog ib txheej ntawm cov lus qhia nkag mus rau hauv lub hwj chim qhov chaw, muaj xws li welding tsis, welding ib tug tshwj xeeb loj ntawm cov yeeb nkab los yog cov kav dej. thiab kev tswj kom zoo los xyuas kom meej 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 txwv yuav tsum tau ua tib zoo tswj.Cov khoom no suav nrog kev siv cov khoom siv zoo kawg nkaus, kev tu thiab kev coj ua zoo, qhov ntev ntev ntawm cov tubing lossis lwm qhov chaw raug welded, zoo ib yam tungsten hom thiab qhov loj me, cov khoom siv zoo purified.
Kev npaj 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 vuam yog feem ntau square taub qab pob qij txha. Kom ua 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 OD vel thickness uas yuav tsum tau muaj (ID vels) los yog tsis sib txawv ntawm phab ntsa. es.
Cov yeeb nkab kawg yuav tsum haum ua ke rau hauv lub taub hau weld kom tsis muaj qhov sib txawv ntawm qhov kawg ntawm lub pob tw pob tw.Txawm hais tias welded pob qij txha nrog qhov 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 soldering.Pipe cov yeeb nkab ua haujlwm thiab lwm cov yeeb nkab ua tiav. 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 rau kev 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 tiv thaiv lub arc thiab ntxuav sab hauv ntawm qhov sib koom ua ke, cov roj purging qhov sib koom ua ke, siv lub taub hau, thiab lwm yam. Cov ntaub ntawv tseem ceeb.Peb hu cov "non-programmable" variables thiab sau lawv nyob rau hauv lub sij hawm vuam.Piv txwv li, hom roj yog suav hais tias yog ib qho tseem ceeb variable nyob rau hauv Welding Procedure Specification (WPS) rau cov txheej txheem vuam kom ua raws li ASME Tshooj IX Boiler thiab Pressure Vessel Code.Kev hloov pauv hauv cov roj hom lossis cov pa roj sib xyaw kom siv tau qhov feem pua ​​​​ntawm cov txheej txheem welding.
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 purity ntawm cov pa GT. Yog tias cov roj lim dej tsis zoo tshaj plaws lossis yog tias lub tshuab ntxuav tsis huv tsis muaj paug tawm tag nrho xws li cov pa me me ntawm cov pa tawm mus rau hauv lub tshuab ntxuav, cov oxidation tej zaum yuav yog lub teeb daj lossis xiav. Yog lawm, tsis muaj kev ntxuav yuav ua rau lub crusty dub nto feem ntau xa mus rau hauv . 9 s. 996-99.997% ntshiab, nyob ntawm tus neeg muag 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 lub tog raj kheej lossis kua argon nyob rau hauv ib tug ntshiab impurities ntawm 10 ppm 9. m oxygen.CEEB TOOM: Cov roj purifiers xws li Nanochem lossis Gatekeeper tuaj yeem siv thaum lub sij hawm purging kom txo tau cov kab mob sib kis 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 adventuring ntawm carbon dioxide kev lag luam. ing gases rau UHP applications.Hydrogen sib tov muaj ntau qhov zoo, tab sis kuj muaj qee qhov tsis zoo.Qhov qhov zoo yog tias nws tsim cov av ntub dej thiab cov npoo smoother, uas yog qhov zoo tshaj plaws rau kev siv cov tshuab hluav taws xob ultra-siab siab nrog rau lub puab nto zoo li qhov ua tau.Lub xub ntiag ntawm hydrogen muab ib qho kev txo cua sov, yog li yog tias cov pa paug ntawm cov pa uas muaj cov pa ntshiab dua li cov pa sib xyaw ua ke, qhov no yog qhov zoo tshaj plaws rau kev siv cov pa roj carbon monoxide. Cov nyhuv 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 shielding roj yog nqaim, tshwj tsis yog tias cov hlau tsis muaj leej faj cov ntsiab lus tsawg heev thiab tsim kom muaj cua sov ntau hauv cov vuam ntau dua li qhov sib xyaw tam sim no nrog cov argon tsis sib xyaw.Ib qho tsis zoo ntawm argon / hydrogen sib tov yog tias cov arc tsis ruaj khov dua li cov ntshiab argon, thiab muaj kev nyiam rau cov arc los ua kom tsis muaj dej txaus, thaum siv cov khoom sib txawv txaus. Tej zaum yuav tshwm sim los ntawm kev sib kis los yog kev sib tov tsis zoo.Vim tias cov cua kub uas tsim los ntawm cov arc sib txawv nrog cov hydrogen concentration, qhov tsis tu ncua 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 tau luv heev thaum siv hydrogen sib tov.While tau tshaj tawm tias yog vim li cas ntawm cov roj sib xyaw ua ke. rc 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 rau nws 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 tsis tshua muaj hauv ntiaj teb rc oxides, xws li oxides pib thiab oxide. stability.Ntshiab tungsten 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 qhov sib txawv ntawm 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 los yog lub neej ntev. bital welding, nws yog ib qho tseem ceeb rau mechanically grind lub electrode tip kom paub tseeb tias repeatability ntawm tungsten geometry thiab weld repeatability.Lub blunt tip force the arc from the weld to the same place on the tungsten.The tip inch controls the shape of the arc and the amount of penetration at a particular current .The taper volt ung at the specifications of the current/Taper voltage t. Nws yog ib qho tseem ceeb vim hais tias ib tug paub ntev ntawm tungsten yuav siv tau los teem lub arc gap.Qhov arc qhov sib txawv rau ib tug tshwj xeeb tam sim no tus nqi txiav txim qhov voltage thiab yog li lub hwj chim thov 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 lub taub, nws yuav plam hlau los ntawm lub ntsis, thiab siv cov electrodes nrog lub taub taub uas loj dhau rau tam sim no yuav ua rau arc drift.Peb qhia cov electrode thiab cov taub diameters los ntawm cov phab ntsa thickness ntawm cov weld sib koom thiab siv 0.062 "txhua yam yuav luag siv 0.062 "txoj kab uas hla. nrog 0.040 "txoj kab uas hla electrodes rau vuam me me precision Components.For repeatability ntawm cov txheej txheem vuam, tungsten hom thiab tiav, ntev, taper lub kaum sab xis, txoj kab uas hla, taub txoj kab uas hla thiab arc qhov sib txawv yuav tsum tau teev thiab tswj.Rau 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 tshaj li lwm yam hom thiab muaj zoo heev arcignition.
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.