Kev vuam cov hlau tsis xeb yuav tsum tau xaiv cov roj tiv thaiv kom tswj tau nws cov khoom sib xyaw ua ke thiab cov khoom siv lub cev thiab lub cev. Cov roj tiv thaiv rau cov hlau tsis xeb feem ntau suav nrog argon, helium, oxygen, carbon dioxide, nitrogen, thiab hydrogen (saib Daim Duab 1). Cov roj no tau muab sib xyaw ua ke hauv ntau qhov sib piv kom haum rau cov kev xav tau ntawm ntau hom kev xa khoom, hom hlau, cov khoom sib xyaw ua ke, cov qauv hlaws xav tau thiab qhov ceev mus ncig.
Vim yog qhov tsis zoo ntawm cov hlau tsis xeb thiab qhov "txias" ntawm kev luv luv-circuit hloov roj hlau arc vuam (GMAW), cov txheej txheem xav tau cov roj "tri-mix" uas muaj 85% txog 90% helium (He), txog li 10% Argon (Ar) thiab 2% txog 5% Carbon Dioxide (CO2). Ib qho sib xyaw triblend feem ntau muaj 90% He, 7-1/2% Ar, thiab 2-1/2% CO2. Lub peev xwm ionization siab ntawm helium txhawb nqa arcing tom qab luv luv Circuit; ua ke nrog nws cov thermal conductivity siab, kev siv He ua rau muaj kev ntws ntawm lub pas dej molten. Lub Ar Cheebtsam ntawm Trimix muab kev tiv thaiv dav dav ntawm lub weld puddle, thaum CO2 ua haujlwm ua ib qho khoom reactive los tswj lub arc (saib Daim Duab 2 rau qhov sib txawv ntawm cov pa roj shielding cuam tshuam li cas rau qhov profile weld bead).
Qee cov khoom sib xyaw ua ke peb hom yuav siv cov pa oxygen ua tus stabilizer, thaum lwm tus siv cov khoom sib xyaw He/CO2/N2 kom ua tiav cov txiaj ntsig zoo ib yam. Qee cov neeg faib roj muaj cov roj sib xyaw uas muab cov txiaj ntsig tau cog lus tseg. Cov neeg muag khoom kuj pom zoo cov khoom sib xyaw no rau lwm hom kev sib kis nrog cov txiaj ntsig zoo ib yam.
Qhov yuam kev loj tshaj plaws uas cov chaw tsim khoom ua yog sim ua kom luv luv cov hlau tsis xeb GMAW nrog tib cov roj sib xyaw (75 Ar/25 CO2) li cov hlau tsis muaj zog, feem ntau vim lawv tsis xav tswj lub tog raj kheej ntxiv. Cov roj sib xyaw no muaj cov pa roj carbon ntau dhau. Qhov tseeb, txhua cov roj tiv thaiv siv rau cov hlau khov kho yuav tsum muaj cov pa roj carbon dioxide ntau tshaj 5%. Kev siv ntau dua ua rau muaj cov hlau uas tsis suav tias yog L-qib alloy (L-qib muaj cov pa roj carbon qis dua 0.03%). Cov pa roj carbon ntau dhau hauv cov roj tiv thaiv tuaj yeem tsim cov chromium carbides, uas txo qhov kev tiv thaiv corrosion thiab cov khoom siv kho tshuab. Cov pa roj av kuj tseem tuaj yeem tshwm sim ntawm qhov chaw vuam.
Ua ib qho lus ceeb toom ntxiv, thaum xaiv cov hlau rau kev luv luv GMAW rau 300 series cov hlau alloys (308, 309, 316, 347), cov chaw tsim khoom yuav tsum xaiv qib LSi. Cov khoom siv LSi muaj cov ntsiab lus carbon tsawg (0.02%) thiab yog li ntawd pom zoo tshwj xeeb tshaj yog thaum muaj kev pheej hmoo ntawm kev xeb intergranular. Cov ntsiab lus silicon siab dua txhim kho cov khoom vuam, xws li kev ntub dej, los pab ua kom lub hau ntawm qhov vuam tiaj tus thiab txhawb kev sib xyaw ntawm tus ntiv taw.
Cov chaw tsim khoom yuav tsum ceev faj thaum siv cov txheej txheem hloov pauv luv luv. Kev sib xyaw tsis tiav tuaj yeem tshwm sim vim yog arc tua, ua rau cov txheej txheem tsis zoo rau cov ntawv thov tseem ceeb. Hauv cov xwm txheej ntim ntau, yog tias cov khoom siv tuaj yeem txhawb nqa nws cov cua sov nkag (≥ 1/16 nti yog kwv yees li cov khoom siv nyias tshaj plaws welded siv hom pulse spray), kev hloov pauv pulse spray yuav yog qhov kev xaiv zoo dua. Qhov twg cov khoom siv tuab thiab qhov chaw vuam txhawb nqa nws, kev hloov pauv tsuag GMAW yog qhov nyiam dua vim nws muab kev sib xyaw zoo dua.
Cov hom kev hloov pauv cua sov siab no tsis xav tau He shielding roj. Rau kev txau hloov pauv vuam ntawm 300 series alloys, ib qho kev xaiv dav dav yog 98% Ar thiab 2% reactive elements xws li CO2 lossis O2. Qee cov roj sib xyaw kuj tseem yuav muaj me ntsis ntawm N2. N2 muaj peev xwm ionization siab dua thiab thermal conductivity, uas txhawb nqa wetting thiab tso cai rau kev mus ncig sai dua lossis txhim kho permeability; nws kuj txo qhov distortion.
Rau kev hloov pauv pulsed spray GMAW, 100% Ar tej zaum yuav yog qhov kev xaiv uas txais tau. Vim tias qhov tam sim no pulsed ua kom lub arc ruaj khov, cov roj tsis tas yuav tsum muaj cov ntsiab lus nquag.
Cov pas dej ua kom yaj qeeb dua rau cov hlau tsis xeb ferritic thiab cov hlau tsis xeb duplex (50/50 piv ntawm ferrite rau austenite). Rau cov hlau no, cov roj sib xyaw xws li ~70% Ar/~30% He/2% CO2 yuav txhawb kom ntub zoo dua thiab ua kom nrawm dua (saib Daim Duab 3). Cov khoom sib xyaw zoo sib xws tuaj yeem siv los vuam cov hlau nickel, tab sis yuav ua rau cov hlau nickel oxides tsim rau ntawm qhov chaw vuam (piv txwv li, ntxiv 2% CO2 lossis O2 txaus kom ua rau cov ntsiab lus oxide nce ntxiv, yog li cov chaw tsim khoom yuav tsum zam lawv lossis npaj siv sijhawm ntau rau lawv). Abrasive vim tias cov oxides no nyuaj heev uas txhuam hlau feem ntau yuav tsis tshem lawv).
Cov chaw tsim khoom siv cov hlau stainless hlau flux-cored rau kev vuam sab nraud vim tias lub kaw lus slag hauv cov hlau no muab "txee" uas txhawb nqa lub pas dej vuam thaum nws khov. Vim tias cov khoom sib xyaw flux txo cov teebmeem ntawm CO2, hlau stainless hlau flux-cored yog tsim los siv nrog 75% Ar / 25% CO2 thiab / lossis 100% CO2 roj sib xyaw. Txawm hais tias hlau flux-cored yuav kim dua ib phaus, nws tsim nyog sau cia tias qhov ceev ntawm kev vuam thiab cov nqi tso tawm ntau dua yuav txo cov nqi vuam tag nrho. Tsis tas li ntawd, hlau flux-cored siv cov hluav taws xob tas li DC tso zis, ua rau lub kaw lus vuam yooj yim pheej yig dua thiab tsis nyuaj dua li cov kab ke GMAW pulsed.
Rau cov hlau 300 thiab 400 series, 100% Ar tseem yog qhov kev xaiv txheem rau roj tungsten arc vuam (GTAW). Thaum lub sijhawm GTAW ntawm qee cov hlau nickel, tshwj xeeb tshaj yog nrog cov txheej txheem mechanized, me me ntawm hydrogen (txog li 5%) yuav raug ntxiv los ua kom nrawm dua (nco ntsoov tias tsis zoo li cov hlau carbon, cov hlau nickel tsis yooj yim rau hydrogen tawg).
Rau kev vuam cov hlau tsis xeb superduplex thiab superduplex, 98% Ar/2% N2 thiab 98% Ar/3% N2 yog cov kev xaiv zoo, raws li. Helium kuj tseem tuaj yeem ntxiv rau kom txhim kho qhov ntub dej li ntawm 30%. Thaum vuam cov hlau tsis xeb super duplex lossis super duplex, lub hom phiaj yog los tsim cov pob qij txha nrog cov qauv sib npaug ntawm kwv yees li 50% ferrite thiab 50% austenite. Vim tias qhov tsim ntawm cov qauv nyob ntawm qhov nrawm txias, thiab vim tias TIG weld pas dej txias sai, cov ferrite ntau dhau tseem nyob thaum siv 100% Ar. Thaum siv cov roj sib xyaw uas muaj N2, N2 yuav sib xyaw rau hauv cov pas dej molten thiab txhawb nqa kev tsim austenite.
Cov hlau tsis xeb yuav tsum tiv thaiv ob sab ntawm qhov sib koom ua ke kom ua tiav qhov vuam nrog qhov tiv taus xeb siab tshaj plaws. Yog tsis tiv thaiv sab nraub qaum tuaj yeem ua rau "saccharification," lossis oxidation ntau heev uas tuaj yeem ua rau solder tsis ua haujlwm.
Cov khoom siv sib txuas uas nruj nrog kev sib haum zoo lossis kev kaw nruj ntawm sab nraub qaum ntawm qhov sib txuas yuav tsis xav tau roj txhawb nqa. Ntawm no, qhov teeb meem tseem ceeb yog tiv thaiv kom tsis txhob muaj xim ntau dhau ntawm thaj chaw kub-cuam tshuam vim muaj oxide tsim, uas tom qab ntawd yuav tsum tau tshem tawm cov tshuab. Technically, yog tias qhov kub sab nraub qaum tshaj 500 degrees Fahrenheit, yuav tsum muaj roj tiv thaiv. Txawm li cas los xij, txoj hauv kev zoo dua yog siv 300 degrees Fahrenheit ua qhov txwv. Qhov zoo tshaj plaws, qhov nraub qaum yuav tsum qis dua 30 PPM O2. Qhov tshwj xeeb yog tias sab nraub qaum ntawm qhov vuam yuav raug gouged, av thiab welded kom ua tiav qhov vuam nkag mus tag nrho.
Ob lub roj txhawb nqa uas xaiv yog N2 (pheej yig tshaj) thiab Ar (kim dua). Rau cov khoom sib dhos me me lossis thaum muaj cov peev txheej Ar, nws yuav yooj yim dua los siv cov roj no thiab tsis tsim nyog rau kev txuag N2. Txog li 5% hydrogen tuaj yeem ntxiv los txo qhov oxidation. Muaj ntau yam kev xaiv lag luam, tab sis cov kev txhawb nqa ua hauv tsev thiab cov pas dej ua kom huv si yog qhov ntau.
Qhov ntxiv 10.5% lossis ntau dua ntawm chromium yog qhov ua rau cov hlau tsis xeb muaj cov yam ntxwv stainless. Kev tswj cov yam ntxwv no xav tau kev siv tshuab zoo hauv kev xaiv cov roj tiv thaiv vuam kom raug thiab tiv thaiv sab nraub qaum ntawm qhov sib koom ua ke. Cov hlau tsis xeb kim heev, thiab muaj cov laj thawj zoo los siv nws. Tsis muaj qhov taw tes hauv kev sim txiav cov ces kaum thaum nws los txog rau cov roj tiv thaiv lossis xaiv cov hlau ntxiv rau qhov no. Yog li ntawd, nws ib txwm ua rau muaj kev nkag siab ua haujlwm nrog tus kws faib roj thiab tus kws tshaj lij hlau ntxiv thaum xaiv cov roj thiab hlau ntxiv rau kev vuam hlau tsis xeb.
Khaws cov xov xwm tshiab, cov xwm txheej thiab thev naus laus zis tshiab tshaj plaws ntawm txhua yam hlau los ntawm peb ob tsab ntawv xov xwm txhua hli sau rau cov chaw tsim khoom hauv Canada!
Tam sim no nrog kev nkag mus rau tag nrho cov ntawv digital ntawm Canadian Metalworking, nkag mus tau yooj yim rau cov peev txheej muaj txiaj ntsig hauv kev lag luam.
Tam sim no nrog kev nkag mus rau tag nrho cov ntawv digital ntawm Made in Canada thiab Welding, nkag mus tau yooj yim rau cov peev txheej muaj txiaj ntsig hauv kev lag luam.