Qhov no zoo li zoo dhau los ua qhov tseeb, yog li qhov teeb meem yog dab tsi? Feem ntau yuav tsum tau vuam kom ua tau txhua yam los ntawm ib qho ntawm ntau dua 150 hom hlau tsis xeb. Kev vuam hlau tsis xeb yog ib txoj haujlwm nyuaj. Qee qhov teeb meem no suav nrog qhov muaj chromium oxide, yuav ua li cas tswj cov cua sov nkag, cov txheej txheem vuam twg yuav tsum siv, yuav ua li cas tswj hexavalent chromium thiab yuav ua li cas ua kom raug.
Txawm hais tias muaj teeb meem ntawm kev vuam thiab ua kom tiav cov khoom siv no, cov hlau tsis xeb tseem yog ib qho nrov thiab qee zaum tsuas yog kev xaiv rau ntau lub lag luam. Kev paub siv nws kom muaj kev nyab xeeb thiab thaum twg yuav tsum siv txhua txoj kev vuam yog qhov tseem ceeb rau kev vuam kom zoo. Qhov no tuaj yeem yog tus yuam sij rau kev ua haujlwm kom zoo.
Yog li ntawd, vim li cas kev vuam hlau tsis xeb thiaj li nyuaj ua luaj? Cov lus teb pib nrog nws tau tsim li cas. Cov hlau tsis xeb, tseem hu ua cov hlau tsis xeb, yog sib xyaw nrog tsawg kawg 10.5% chromium los tsim cov hlau tsis xeb. Cov chromium ntxiv rau hauv cov hlau ua ib txheej ntawm chromium oxide rau ntawm qhov chaw ntawm cov hlau, uas tiv thaiv feem ntau hom kev xeb thiab xeb. Cov chaw tsim khoom ntxiv ntau yam chromium thiab lwm yam khoom rau cov hlau kom hloov qhov zoo ntawm cov khoom kawg, thiab tom qab ntawd siv peb tus lej system los sib txawv qib.
Cov hlau tsis xeb uas siv ntau suav nrog 304 thiab 316. Qhov pheej yig tshaj plaws ntawm cov no yog 304, uas muaj 18 feem pua ​​chromium thiab 8 feem pua ​​nickel thiab siv rau txhua yam los ntawm kev kho kom zoo nkauj hauv tsheb mus rau cov khoom siv hauv chav ua noj. 316 hlau tsis xeb muaj chromium tsawg dua (16%) thiab nickel ntau dua (10%), tab sis kuj muaj 2% molybdenum. Cov tshuaj no muab 316 hlau tsis xeb ntxiv rau kev tiv thaiv chlorides thiab chlorine cov tshuaj, ua rau nws yog qhov kev xaiv zoo tshaj plaws rau cov chaw nyob hauv dej hiav txwv thiab kev lag luam tshuaj lom neeg thiab tshuaj.
Ib txheej ntawm chromium oxide tuaj yeem ua kom cov hlau tsis xeb zoo, tab sis qhov no yog qhov ua rau cov neeg vuam chim siab heev. Qhov kev thaiv no ua rau qhov nro ntawm cov hlau nce ntxiv, ua rau qeeb qeeb ntawm kev tsim cov kua dej vuam. Ib qho yuam kev feem ntau yog ua kom cov cua sov nkag mus ntau dua, vim tias cua sov ntau dua ua rau cov kua dej ntawm cov dej ntws ntau dua. Txawm li cas los xij, qhov no tuaj yeem cuam tshuam tsis zoo rau cov hlau tsis xeb. Kub ntau dhau tuaj yeem ua rau oxidation ntxiv thiab warp lossis hlawv los ntawm cov hlau hauv paus. Ua ke nrog cov hlau ntawv siv hauv kev lag luam loj xws li cov pa tawm hauv tsheb, qhov no dhau los ua qhov tseem ceeb tshaj plaws.
Kub ua rau cov hlau tsis xeb puas tsuaj zoo kawg nkaus. Kub ntau dhau thaum qhov vuam lossis thaj chaw kub uas cuam tshuam los ntawm cua sov (HAZ) tig mus ua iridescent. Cov hlau tsis xeb uas tau oxidized tsim cov xim zoo kawg nkaus xws li kub daj mus rau xiav tsaus thiab ntshav. Cov xim no ua rau muaj kev piav qhia zoo, tab sis tej zaum yuav qhia txog qhov vuam uas yuav tsis ua tau raws li qee qhov kev xav tau vuam. Cov lus qhia nruj tshaj plaws tsis nyiam cov xim vuam.
Feem ntau lees txais tias kev vuam tungsten arc uas siv roj los tiv thaiv (GTAW) zoo tshaj plaws rau cov hlau tsis xeb. Keeb kwm, qhov no tau muaj tseeb hauv kev nkag siab dav dav. Qhov no tseem muaj tseeb thaum peb sim coj cov xim ci ntsa iab no rau hauv kev kos duab kom ua tau raws li cov qauv zoo tshaj plaws hauv kev lag luam xws li lub zog nuclear thiab aerospace. Txawm li cas los xij, cov thev naus laus zis vuam inverter niaj hnub no tau ua rau kev vuam hlau arc (GMAW) ua tus qauv rau kev tsim cov hlau tsis xeb, tsis yog tsuas yog cov tshuab tsis siv neeg lossis cov tshuab robotic xwb.
Vim tias GMAW yog ib qho txheej txheem pub hlau semi-automatic, nws muab cov nqi tso tawm siab, uas pab txo cov cua sov nkag. Qee cov kws tshaj lij hais tias nws yooj yim dua rau siv dua li GTAW vim nws tsis tas yuav siv lub peev xwm ntawm tus welder thiab siv lub peev xwm ntawm lub zog vuam. Qhov no yog ib qho moot point, tab sis feem ntau cov khoom siv fais fab GMAW niaj hnub no siv cov kab synergy ua ntej. Cov kev pab cuam no yog tsim los teeb tsa cov kev txwv xws li tam sim no thiab voltage, nyob ntawm cov hlau filler nkag los ntawm tus neeg siv, cov khoom siv tuab, hom roj thiab txoj kab uas hla ntawm cov hlau.
Qee cov inverters tuaj yeem kho qhov arc thoob plaws hauv cov txheej txheem vuam kom tsim tau qhov arc raug, tswj cov qhov sib txawv ntawm cov khoom, thiab tswj kev mus ncig ceev kom ua tau raws li cov qauv tsim khoom thiab zoo. Qhov no yog qhov tseeb tshwj xeeb rau kev vuam tsis siv neeg lossis robotic, tab sis kuj siv rau kev vuam tes. Qee cov khoom siv fais fab hauv khw muaj lub vijtsam kov thiab cov tswj lub teeb rau kev teeb tsa yooj yim.
Kev vuam cov hlau tsis xeb yog ib txoj haujlwm nyuaj heev. Qee qhov teeb meem no suav nrog kev muaj chromium oxide, yuav ua li cas tswj cov cua sov nkag, yuav siv cov txheej txheem vuam twg, yuav ua li cas tswj hexavalent chromium thiab yuav ua li cas ua kom raug.
Kev xaiv cov roj zoo rau GTAW feem ntau nyob ntawm qhov kev paub dhau los lossis kev siv ntawm qhov kev sim vuam. GTAW, tseem hu ua tungsten inert gas (TIG), feem ntau tsuas yog siv cov roj inert, feem ntau yog argon, helium, lossis sib xyaw ntawm ob qho tib si. Kev txhaj tshuaj tsis raug ntawm cov roj tiv thaiv lossis cua sov tuaj yeem ua rau txhua qhov vuam ua 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 qhov vuam tsis zoo lossis tsis haum. Kev txiav txim siab qhov sib xyaw twg zoo tshaj plaws rau txhua qhov vuam tuaj yeem txhais tau tias ntau qhov kev sim thiab yuam kev. Cov kab ntau lawm GMAW sib koom pab txo lub sijhawm pov tseg hauv cov ntawv thov tshiab, tab sis thaum xav tau qhov zoo tshaj plaws, txoj kev vuam GTAW tseem yog txoj hauv kev nyiam.
Kev vuam hlau tsis xeb ua rau muaj kev phom sij rau kev noj qab haus huv rau cov neeg uas muaj teeb. Qhov txaus ntshai tshaj plaws yog cov pa phem uas tso tawm thaum lub sijhawm vuam. Cov chromium kub tsim cov tshuaj hu ua hexavalent chromium, uas paub tias ua rau lub cev ua pa puas tsuaj, raum, siab, tawv nqaij thiab qhov muag thiab ua rau mob qog noj ntshav. Cov neeg vuam yuav tsum hnav cov khoom siv tiv thaiv, suav nrog lub tshuab ua pa, thiab xyuas kom meej tias chav tsev muaj cua nkag zoo ua ntej pib vuam.
Cov teeb meem nrog cov hlau tsis xeb tsis xaus tom qab vuam tiav. Cov hlau tsis xeb kuj xav tau kev saib xyuas tshwj xeeb hauv cov txheej txheem tiav. Kev siv txhuam hlau lossis daim txhuam txhuam uas muaj cov hlau carbon uas muaj kuab paug yuav ua rau cov txheej txheem chromium oxide tiv thaiv puas tsuaj. Txawm tias qhov puas tsuaj tsis pom los xij, cov kuab paug no tuaj yeem ua rau cov khoom tiav yooj yim rau xeb lossis lwm yam xeb.
Terrence Norris yog Tus Kws Tsim Kho Daim Ntawv Thov Qib Siab 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.
Cov thev naus laus zis niaj hnub inverter vuam tau ua rau roj GMAW ua tus qauv rau kev tsim cov hlau tsis xeb, tsis yog tsuas yog cov tshuab tsis siv neeg lossis cov tshuab robotic xwb.
WELDER, yav tas los hu ua Practical Welding Today, sawv cev rau cov neeg tiag tiag uas ua cov khoom uas peb siv thiab ua haujlwm nrog txhua hnub. Phau ntawv xov xwm no tau pab cov zej zog vuam hauv North America tau ntau tshaj 20 xyoo.
Tam sim no nrog kev nkag mus rau tag nrho cov ntawv digital ntawm The FABRICATOR, yooj yim nkag mus rau cov peev txheej muaj txiaj ntsig hauv kev lag luam.
Cov ntawv xov xwm digital ntawm The Tube & Pipe Journal tam sim no nkag tau tag nrho, muab kev nkag mus tau yooj yim rau cov peev txheej muaj txiaj ntsig hauv kev lag luam.
Tau txais kev nkag mus rau STAMPING Journal tag nrho, uas muaj cov thev naus laus zis tshiab, cov 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 The Fabricator en Español tag nrho, koj muaj kev nkag mus rau cov peev txheej muaj txiaj ntsig zoo hauv kev lag luam.