Qhov no suab zoo dhau los ua qhov tseeb, yog li qhov teeb meem yog dab tsi? Vuam feem ntau yuav tsum tau ua yuav luag txhua yam los ntawm ib qho ntawm ntau tshaj 150 hom stainless hlau. Vuam stainless hlau yog ib txoj haujlwm nyuaj. Qee qhov teeb meem no suav nrog kev muaj chromium oxide, yuav ua li cas tswj cov cua sov, uas siv cov txheej txheem vuam, yuav ua li cas los tswj hexavalent chromium thiab yuav ua li cas kom raug.
Txawm hais tias muaj teeb meem ntawm vuam thiab ua tiav cov khoom siv no, stainless hlau tseem yog qhov nrov thiab qee zaum tsuas yog kev xaiv rau ntau qhov kev lag luam. Paub yuav ua li cas siv nws kom nyab xeeb thiab thaum twg siv txhua txoj kev vuam yog qhov tseem ceeb rau kev ua tiav vuam. Qhov no tuaj yeem yog tus yuam sij rau txoj haujlwm tiav.
Yog li yog vim li cas stainless hlau vuam xws li ib txoj hauj lwm nyuaj? Cov lus teb pib nrog nws tsim li cas. Cov hlau me, tseem hu ua cov hlau me me, yog sib xyaw nrog tsawg kawg 10.5% chromium los tsim cov hlau tsis muaj steel. Cov chromium ntxiv ua ib txheej ntawm chromium oxide nyob rau saum npoo ntawm cov hlau, uas tiv thaiv ntau hom kev xeb thiab xeb. Cov neeg tsim khoom ntxiv ntau qhov sib txawv ntawm chromium thiab lwm yam khoom rau hlau los hloov qhov zoo ntawm cov khoom kawg, thiab tom qab ntawd siv peb tus lej system los sib txawv qib.
Feem ntau siv stainless hlau muaj xws li 304 thiab 316. Qhov pheej yig tshaj ntawm cov no yog 304, uas muaj 18 feem pua ​​​​chromium thiab 8 feem pua ​​​​nickel thiab yog siv rau txhua yam ntawm lub tsheb trim mus rau cov khoom siv hauv chav ua noj. 316 stainless hlau muaj tsawg chromium (16%) thiab ntau nickel (10%), tab sis kuj muaj 2% molybdenum. Qhov kev sib xyaw no muab 316 stainless hlau ntxiv rau cov tshuaj chlorides thiab cov tshuaj chlorine, ua rau nws yog qhov kev xaiv zoo tshaj plaws rau kev lag luam hauv hiav txwv thiab kev lag luam tshuaj thiab tshuaj.
Ib txheej ntawm chromium oxide tuaj yeem ua kom cov hlau tsis zoo, tab sis qhov no yog qhov ua rau cov welder chim siab heev. Qhov no muaj txiaj ntsig barrier ua rau kom qhov nro ntawm cov hlau, ua kom qeeb ntawm kev tsim cov kua hauv pas dej ua ke. Ib qho yuam kev feem ntau yog ua kom cov cua sov nkag, raws li cov cua kub ntau ua rau cov dej ntws ntawm cov dej ntws. Txawm li cas los xij, qhov no tuaj yeem cuam tshuam tsis zoo rau stainless hlau. Cov cua kub ntau dhau tuaj yeem ua rau oxidation ntxiv thiab warp lossis hlawv los ntawm cov hlau hauv paus. Ua ke nrog cov ntawv hlau siv hauv kev lag luam loj xws li kev siv tsheb, qhov no yog qhov tseem ceeb tshaj plaws.
Thaum tshav kub kub rhuav tshem cov corrosion kuj ntawm stainless hlau zoo kawg nkaus. Thaum tshav kub kub ntau dhau yog siv thaum lub vuam los yog qhov chaw nyob ib puag ncig tshav kub cuam tshuam (HAZ) tig iridescent. Oxidized stainless hlau tsim cov xim zoo nkauj xws li kub daj mus rau xiav xiav thiab ntshav. Cov xim no ua rau ib qho kev piav qhia zoo, tab sis yuav qhia tau tias cov welds yuav tsis ua tau raws li qee qhov kev xav tau vuam. Cov lus qhia nruj tshaj plaws tsis nyiam cov xim welding.
Nws feem ntau lees txais tias cov roj-shielded tungsten arc vuam (GTAW) yog qhov zoo tshaj plaws rau cov hlau tsis muaj steel. Keeb kwm, qhov no tau muaj tseeb hauv kev nkag siab dav dav. Qhov no tseem muaj tseeb thaum peb sim coj cov xim bold rau hauv kev kos duab xaws kom tau raws li cov qauv zoo tshaj plaws hauv kev lag luam xws li nuclear fais fab thiab aerospace. Txawm li cas los xij, niaj hnub inverter vuam thev naus laus zis tau ua rau cov roj hlau arc vuam (GMAW) tus qauv rau kev tsim cov hlau tsis muaj steel, tsis yog kev siv tshuab lossis tshuab tshuab xwb.
Txij li thaum GMAW yog ib tug semi-automatic xaim pub txheej txheem, nws muab ib tug siab deposition tus nqi, uas yuav pab txo tau cov cua sov input. Qee tus kws tshaj lij hais tias nws yooj yim dua rau kev siv GTAW vim nws tso siab tsawg dua ntawm kev txawj ntawm cov vuam thiab ntau dua ntawm kev txawj ntawm vuam fais fab. Qhov no yog qhov taw qhia moot, tab sis niaj hnub GMAW cov khoom siv hluav taws xob feem ntau siv cov kab ua ntej kev sib koom ua ke. Cov kev pab cuam no tau tsim los teeb tsa cov kev txwv xws li tam sim no thiab qhov hluav taws xob, nyob ntawm seb cov hlau muab tub lim nkag los ntawm tus neeg siv, cov khoom thickness, hom roj thiab txoj kab uas hla.
Qee cov inverters tuaj yeem kho qhov arc thoob plaws hauv cov txheej txheem vuam kom tsis tu ncua ua qhov tseeb arc, tswj qhov sib txawv ntawm qhov chaw, thiab tswj kom muaj kev mus los siab kom tau raws li cov qauv tsim thiab zoo. Qhov no yog qhov tseeb tshwj xeeb tshaj yog rau kev siv tshuab los yog neeg hlau vuam, tab sis kuj siv tau rau kev tuav vuam. Qee cov khoom siv hluav taws xob hauv kev ua lag luam muaj qhov kov npo interface thiab lub teeb taws rau kev teeb tsa yooj yim.
Vuam stainless hlau yog ib txoj haujlwm nyuaj. Qee qhov teeb meem no suav nrog kev muaj chromium oxide, yuav ua li cas tswj cov cua sov, uas siv cov txheej txheem vuam, yuav ua li cas los tswj hexavalent chromium thiab yuav ua li cas kom raug.
Xaiv cov roj zoo rau GTAW feem ntau yog nyob ntawm qhov kev paub dhau los lossis daim ntawv thov ntawm kev ntsuas vuam. GTAW, tseem hu ua tungsten inert gas (TIG), feem ntau siv tsuas yog cov roj inert, feem ntau yog argon, helium, los yog sib tov ntawm ob qho tib si. Kev txhaj tshuaj tiv thaiv tsis zoo los yog cua sov tuaj yeem ua rau txhua qhov weld dhau los ua cov domed lossis hlua zoo li, thiab qhov no yuav tiv thaiv nws los ntawm kev sib xyaw nrog cov hlau nyob ib puag ncig, ua rau muaj qhov tsis zoo lossis tsis tsim nyog. Kev txiav txim siab qhov sib tov yog qhov zoo tshaj plaws rau txhua qhov vuam tuaj yeem txhais tau tias muaj ntau qhov kev sim thiab ua yuam kev. Sib koom GMAW cov kab ntau lawm pab txo nkim sij hawm nyob rau hauv daim ntawv thov tshiab, tab sis thaum yuav tsum tau nruj tshaj plaws zoo, GTAW vuam txoj kev tseem yog txoj kev nyiam.
Vuam stainless hlau ua rau muaj kev phom sij rau cov neeg uas muaj teeb meem. Qhov txaus ntshai tshaj plaws yog tshwm sim los ntawm cov pa tawm thaum lub sij hawm vuam txheej txheem. Rhaub chromium tsim cov khoom sib xyaw hu ua hexavalent chromium, uas paub tias ua rau lub cev ua pa, ob lub raum, daim siab, tawv nqaij thiab qhov muag thiab ua rau mob qog noj ntshav. Welders yuav tsum hnav cov cuab yeej tiv thaiv ib txwm, nrog rau lub tshuab ua pa, thiab xyuas kom cov chav muaj cua zoo ua ntej pib vuam.
Cov teeb meem nrog stainless hlau tsis xaus tom qab vuam tiav. Stainless hlau kuj xav tau kev saib xyuas tshwj xeeb hauv kev ua tiav. Siv cov txhuam txhuam los yog txhuam txhuam uas muaj cov pa roj carbon steel yuav ua rau cov txheej txheem chromium oxide tiv thaiv. Txawm tias tsis pom kev puas tsuaj, cov kab mob no tuaj yeem ua rau cov khoom tiav tuaj yeem raug xeb lossis lwm yam corrosion.
Terrence Norris yog Senior Applications Engineer ntawm Fronius USA LLC, 6797 Fronius Drive, Portage, IN 46368, 219-734-5500, www.fronius.us.
Rhonda Zatezalo yog tus kws sau ntawv ywj pheej rau Crearies Marketing Design LLC, 248-783-6085, www.crearies.com.
Niaj hnub nimno inverter vuam tshuab tau ua roj GMAW tus qauv rau stainless hlau ntau lawm, tsis yog tsis siv neeg los yog neeg hlau tshuab.
WELDER, yav tas los hu ua Practical Welding Niaj hnub no, sawv cev rau cov neeg tiag tiag uas ua cov khoom peb siv thiab ua haujlwm nrog txhua hnub. Phau ntawv xov xwm no tau ua haujlwm rau cov koom haum vuam hauv North America rau ntau tshaj 20 xyoo.
Tam sim no nrog tag nrho nkag mus rau FABRICATOR cov ntawv luam tawm digital, nkag tau yooj yim rau cov peev txheej 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.
Tau txais tag nrho cov digital nkag mus rau STAMPING Journal, muaj cov 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 rau tag nrho cov kev nkag mus rau Cov Fabricator en Español, koj muaj kev nkag tau yooj yim rau kev lag luam muaj txiaj ntsig.