Stainless hlau tsis tas yuav nyuaj rau kev ua haujlwm nrog, tab sis vuam nws yuav tsum tau ua tib zoo saib xyuas kom meej.Nws tsis dissipate cua sov zoo li me me hlau los yog txhuas, thiab nws yuav poob ib co corrosion kuj yog tias koj muab kub ntau rau hauv nws.Cov kev coj ua zoo tshaj plaws pab tswj nws cov corrosion kuj.Image: Miller Electric
Qhov kev tiv thaiv corrosion ntawm stainless hlau ua rau nws yog ib qho kev xaiv zoo rau ntau qhov tseem ceeb tubing daim ntaub ntawv, nrog rau high-purity zaub mov thiab dej haus, tshuaj, siab hlab ntsha, thiab petrochemical daim ntaub ntawv. Txawm li cas los, cov khoom no tsis dissipate tshav kub zoo li me me hlau los yog txhuas, thiab cov vuam tsis zoo yuav txo tau nws cov corrosion kuj.Ua ntau dhau tshav kub input thiab siv tsis ncaj ncees lawm muab tub lim hlau yog ob culprits.
Ua raws li qee qhov kev coj ua zoo tshaj plaws rau stainless hlau vuam tuaj yeem pab txhim kho cov txiaj ntsig thiab ua kom cov hlau khaws nws cov kev tiv thaiv corrosion. Tsis tas li ntawd, kev txhim kho cov txheej txheem vuam tuaj yeem nqa cov txiaj ntsig zoo yam tsis muaj kev cuam tshuam zoo.
Nyob rau hauv stainless hlau welding, muab tub lim hlau xaiv yog ib qho tseem ceeb rau kev tswj cov ntsiab lus carbon.Filler hlau siv rau stainless hlau yeeb nkab vuam yuav tsum txhim khu weld kev ua tau zoo thiab ua tau raws li daim ntawv thov.
Saib rau cov hlau muab tub lim nrog qhov "L" xaiv, xws li ER308L, vim lawv muab cov ntsiab lus qis tshaj plaws uas pab tswj cov kev tiv thaiv corrosion ntawm cov pa roj carbon tsawg stainless hlau alloys.Vuam cov pa roj carbon tsawg hlau nrog cov txheej txheem muab cov hlau ua rau cov ntsiab lus ntawm cov welded sib koom ua ke, ua rau muaj kev pheej hmoo ntawm corrosion. Tsis txhob muab cov hlau ua cim nrog "H" thiab cov ntsiab lus ntawm cov khoom siv kub siab dua.
Thaum welding stainless hlau, nws tseem ceeb heev uas yuav tau xaiv ib tug muab tub lim hlau uas tsis tshua muaj kab (tseem hu ua impurities) ntawm cov khoom.Cov no yog cov khoom seem hauv cov ntaub ntawv raw siv los ua cov hlau, xws li antimony, arsenic, phosphorus thiab sulfur.Lawv tuaj yeem cuam tshuam rau corrosion ntawm cov khoom.
Txij li cov hlau tsis xeb yog qhov nkag siab zoo rau cov cua sov, kev sib koom ua ke thiab kev sib dhos kom zoo ua lub luag haujlwm tseem ceeb hauv kev tswj cov cua sov kom tswj cov khoom siv.Vim qhov khoob ntawm qhov chaw lossis qhov tsis sib xws, lub teeb yuav tsum nyob hauv ib qho chaw ntev dua thiab ntau cov hlau muab tub lim yuav tsum tau ua kom muaj cua sov los tsim nyob rau hauv qhov chaw cuam tshuam, uas tuaj yeem ua rau overheat qhov chaw. Cov khoom tsis zoo kuj tseem ua rau nws nyuaj rau kev kho kom haum rau tus choj. stainless hlau kom ze rau zoo meej li sai tau.
Kev huv ntawm cov khoom no kuj tseem ceeb heev.Qhov me me ntawm cov kab mob los yog av hauv cov pob qij txha tuaj yeem ua rau muaj qhov tsis xws luag uas txo lub zog thiab corrosion tsis kam ntawm cov khoom kawg. Txhawm rau ntxuav lub substrate ua ntej vuam, siv cov txhuam tshwj xeeb stainless hlau uas tsis tau siv rau carbon steel lossis txhuas.
Nyob rau hauv stainless hlau, rhiab heev yog lub ntsiab ua rau poob ntawm corrosion kuj.Qhov no tuaj yeem tshwm sim thaum vuam kub thiab txias tus nqi fluctuate ntau dhau, hloov cov microstructure ntawm cov khoom.
Qhov no OD weld ntawm stainless hlau yeeb nkab, welded siv GMAW thiab tswj hlau deposition (RMD) tsis muaj backflushing ntawm lub hauv paus hla, zoo ib yam li nyob rau hauv tsos thiab zoo rau welds ua nrog backflushed GTAW.
Ib qho tseem ceeb ntawm cov hlau tsis muaj corrosion kuj yog chromium oxide.Tab sis yog tias cov ntsiab lus carbon nyob rau hauv cov vuam yog siab dhau lawm, chromium carbide yuav tsim.Cov no khi cov chromium thiab tiv thaiv kev tsim ntawm qhov xav tau chromium oxide, uas ua rau cov hlau tsis muaj corrosion kuj.
Kev tiv thaiv ntawm rhiab heev los mus rau muab tub lim hlau xaiv thiab tswj cov cua sov input.Raws li tau hais ua ntej lawm, nws yog ib qho tseem ceeb uas yuav tau xaiv cov hlau uas tsis muaj cov pa roj carbon monoxide rau stainless hlau welding.Txawm li cas los xij, cov pa roj carbon qee zaum yuav tsum tau muab lub zog rau qee yam kev siv.Kev tswj cua sov yog qhov tseem ceeb tshwj xeeb tshaj yog thaum cov hlau tsis muaj cov pa roj carbon ntau tsis muaj kev xaiv.
Txo cov sij hawm luv luv ntawm qhov chaw vuam thiab qhov kub thiab txias nyob hauv qhov kub siab - feem ntau suav tias yog 950 txog 1,500 degrees Fahrenheit (500 txog 800 degrees Celsius).Qhov tsawg dua lub sij hawm soldering siv nyob rau hauv qhov ntau, qhov tsawg tshav kub nws generates. Nco ntsoov xyuas thiab soj ntsuam qhov interpass kub nyob rau hauv daim ntawv thov soldering txheej txheem.
Lwm qhov kev xaiv yog siv cov hlau muab tub lim tsim nrog cov khoom siv alloying xws li titanium thiab niobium los tiv thaiv chromium carbide tsim.Vim cov khoom no tseem cuam tshuam rau lub zog thiab tawv, cov hlau muab tub lim no tsis tuaj yeem siv rau hauv txhua daim ntawv thov.
Gas tungsten arc welding (GTAW) rau hauv paus hla yog cov txheej txheem ib txwm siv ntawm vuam stainless hlau yeeb nkab.Qhov no feem ntau yuav tsum tau thim rov qab ntawm argon los pab tiv thaiv oxidation ntawm lub nraub qaum ntawm vuam.Txawm li cas los xij, kev siv cov hlau vuam txheej txheem hauv stainless hlau tubing tau dhau los ua ntau thiab ntau dua. Hauv cov ntawv thov no, nws yog ib qho tseem ceeb kom nkag siab txog qhov cuam tshuam ntawm cov khoom tiv thaiv corrosion.
Thaum welding stainless hlau siv cov roj hlau arc vuam (GMAW) txheej txheem, argon thiab carbon dioxide, sib tov ntawm argon thiab oxygen, los yog ib tug peb-gas sib tov (helium, argon, thiab carbon dioxide) yog ib txwm siv. Feem ntau, cov mixs mas muaj argon los yog helium thiab tsawg tshaj li 5% carbon dioxide, raws li cov pa roj carbon dioxide nce poov tshuaj. tsis pom zoo rau GMAW ntawm stainless hlau.
Flux-cored hlau rau stainless hlau yog tsim los khiav nrog ib txwm sib tov ntawm 75% argon thiab 25% carbon dioxide.Flux muaj cov khoom xyaw tsim los tiv thaiv cov pa roj carbon monoxide los ntawm kev kis kab mob.
Raws li cov txheej txheem GMAW tau hloov zuj zus lawm, lawv tau ua kom yooj yim rau kev vuam ntawm cov hlau tsis muaj steel hlau thiab cov kav dej.Thaum qee qhov kev siv tseem yuav xav tau cov txheej txheem GTAW, cov txheej txheem xaim qib siab tuaj yeem muab cov khoom zoo sib xws thiab cov khoom siv ntau dua hauv ntau daim ntawv thov stainless hlau.
Stainless hlau ID welds ua nrog GMAW RMD zoo ib yam thiab zoo li sib xws OD welds.
Lub hauv paus dhau los siv cov txheej txheem luv luv-circuit GMAW xws li Miller's Regulated Metal Deposition (RMD) tshem tawm cov kev rov qab los ntawm qee qhov austenitic stainless hlau daim ntawv thov.RMD hauv paus hla tuaj yeem ua raws li pulsed GMAW lossis flux-cored arc vuam sau thiab hla dhau - qhov kev hloov pauv uas txuag lub sijhawm thiab nyiaj txiag piv rau kev siv cov yeeb nkab loj .
RMD siv cov kev tswj xyuas luv luv-circuit hlau hloov mus los ua kom muaj kev sib haum xeeb, ruaj khov arc thiab weld puddle.Qhov no muab sijhawm tsawg dua ntawm qhov txias txias los yog tsis muaj fusion, tsawg spatter thiab zoo dua cov yeeb nkab hauv paus pass.Precisely tswj hlau hloov kuj muab ib tug zoo li droplet deposition, ua kom yooj yim los tswj lub weld pas dej ua ke thiab yog li ntawd kub input thiab vuam ceev.
Cov txheej txheem tsis sib xws tuaj yeem ua rau cov khoom siv vuam ntau dua.Thaum siv RMD, qhov vuam ceev tuaj yeem yog 6 txog 12 in./min.Vim cov txheej txheem ua kom cov khoom tsim tau yam tsis muaj cua sov ntxiv ntawm qhov chaw, nws yuav pab tswj cov khoom thiab corrosion kuj ntawm stainless hlau.
Cov txheej txheem GMAW pulsed no muab luv luv arc ntev, nqaim arc cones thiab cov cua sov tsawg dua li cov pa tshuaj tsuag pulse hloov chaw.Vim cov txheej txheem kaw-voj, arc drift thiab tip-to-workpiece nyob deb variations yog zoo tshem tawm.Qhov no muab kev yooj yim dua puddle tswj rau hauv-qhov chaw thiab tawm-ntawm-qhov chaw welding.Finally, lub hauv paus GMAW muab cov txheej txheem kev sib txuas rau kev sib txuas thiab kev sib txuas. yuav tsum tau ua siv ib tug hlau thiab ib tug roj, tshem tawm cov txheej txheem hloov lub sij hawm.
Tube & Pipe Journal tau dhau los ua thawj phau ntawv xov xwm mob siab rau ua haujlwm rau kev lag luam yeeb nkab hlau hauv xyoo 1990.Hnub no, nws tseem yog qhov kev tshaj tawm nkaus xwb hauv North America mob siab rau kev lag luam thiab tau dhau los ua cov ntaub ntawv ntseeg siab tshaj plaws rau cov kws tshaj lij yeeb nkab.
Tam sim no nrog kev nkag mus rau tag nrho cov ntawv digital ntawm FABRICATOR, yooj yim nkag mus rau cov khoom lag luam muaj txiaj ntsig.
Cov ntawv digital ntawm The Tube & Pipe Journal yog tam sim no nkag mus tau yooj yim, muab kev nkag tau yooj yim rau cov khoom lag luam muaj txiaj ntsig.
Txaus siab rau kev nkag mus rau tag nrho cov ntawv luam tawm digital ntawm STAMPING Journal, uas muab cov txheej txheem thev naus laus zis tshiab, kev coj ua zoo tshaj plaws thiab xov xwm kev lag luam rau kev lag luam hlau stamping.
Tam sim no nrog kev nkag mus rau tag nrho cov ntawv digital ntawm Tus Fabricator en Español, nkag tau yooj yim rau kev lag luam muaj txiaj ntsig.