1.Dab tsi yog qhov tshwm sim ntawm qhov ploj lossis tsis ua tiav txheej txheej passivation?
Mechanism: Txhawm rau tiv thaiv oxidation (xeb dawb) thaum lub sijhawm khaws cia thiab kev thauj mus los, galvanized coils feem ntau dhau los ua cov txheej txheem passivation ua ntej tawm hauv lub hoobkas. Passivation forms an extremely thin, dense protective film (usually a trivalent or hexavalent chromium passivation film or a chromium-free passivation film) on the zinc surface. Yog tias:
Tsis muaj kev kho mob passivation: Galvanized coils raug huab cua, tshwj xeeb tshaj yog nyob rau hauv ib puag ncig ntub, yuav sai sai nrog ya raws thiab carbon dioxide nyob rau hauv cov huab cua los tsim zinc carbonate (tseem hu ua dawb xeb). Nyob rau hauv tej yam kev mob (xws li kaw, unventilated ib puag ncig), cov khoom no corrosion yuav tshwm tsaus grey los yog dub.
Cov zaj duab xis tsis tiav lossis tsis muaj txiaj ntsig: Tsis sib npaug ntawm cov tshuaj passivation, daim ntawv thov tsis sib xws, lossis tsis tiav ziab tuaj yeem ua rau nyias lossis ua tsis tau zoo hauv qee qhov chaw, ua rau cov chaw no corrode thiab tig dub ua ntej.
2.Dab tsi yog qhov tshwm sim ntawm kev cia thiab kev thauj mus los tsis zoo?
Mechanism: Qhov no yog qhov ncaj qha ua rau passivation txheej tsis ua hauj lwm.
Humidity: Ntau cov av noo nyob rau hauv lub warehouse los yog thaum lub sij hawm kev thauj mus los yog ib tug thawj mob rau zinc corrosion.
Sealed Packaging: If galvanized coils are tightly wound and wrapped in airtight plastic film, moisture cannot escape between the coil layers, creating a "humid box" environment that is highly susceptible to "black rust" or "wet storage stain." Qhov tshwm sim blackening no feem ntau pom pom ntawm cov txheej sab hauv ntawm lub kauj tom qab unwinding.
Condensation: Yog tias cov coils tau thauj mus los ntawm qhov chaw txias mus rau qhov chaw sov, qhov chaw ntub dej, qhov hws yuav tshwm sim rau ntawm qhov chaw, ua rau muaj kev xeb hauv cheeb tsam thiab blackening.
Tiv tauj nrog Corrosive Substances: Kev sib cuag ncaj qha nrog cov pob zeb hauv pem teb, ntoo (tshwj xeeb yog cov ntoo uas tsis tau kho), los yog muaj cov roj corrosive xws li acids, alkalis, thiab ntsev tsuag.
3.Cov teeb meem dab tsi yuav tshwm sim hauv cov txheej txheem galvanizing nws tus kheej?
Cov ntsiab lus siab xws li txhuas thiab antimony nyob rau hauv txheej: Thaum kub -dip galvanizing, txhuas los yog antimony nyob rau hauv zinc da dej tuaj yeem ua rau zinc txheej los ua cov spangles loj thaum lub sij hawm txias thiab crystallization. Cov ntsiab lus ntau dhau ntawm cov ntsiab lus no tuaj yeem ua rau tsub zuj zuj ntawm cov qoob loo ciam teb ntawm spangles. Hauv qhov chaw ntub dej, cov chaw no corrode nyiam, ua rau grey -dub tsos.
Deg residues: Tom qab-galvanizing tu tej zaum yuav ua rau cov seem zinc ntsev los yog flux nyob rau saum npoo. Cov tshuaj no nqus dej noo thiab corrode zinc txheej tom qab, ua rau cov xim dub.
Overbaking: Rau qee cov coils uas yuav tsum tau pleev xim tom qab galvanizing (xws li ua ntej-painted substrates), overbaking tuaj yeem ua rau oxidation thiab blackening ntawm zinc txheej.
4.Dab tsi yog qhov cuam tshuam los ntawm kev sib cuag nrog lwm cov ntaub ntawv?
Mechanism: Electrochemical corrosion los yog cov kab mob ncaj qha los ntawm kev sib cuag nrog lwm cov hlau lossis tsis yog- cov khoom siv hlau.
Kev sib cuag nrog tooj liab: Yog tias galvanized coils tuaj rau hauv kev sib cuag nrog tooj liab lossis tooj liab alloy cov khoom (xws li tooj dag) nyob rau hauv lub xub ntiag ntawm electrolyte (xws li dej nag), cov ntaub ntawv galvanic cell, ua rau corrosion sai ntawm zinc txheej thiab tsim cov khoom siv dub corrosion.
Sib cuag nrog Carbon Steel: Yog hais tias galvanized coils tuaj rau hauv kev sib cuag nrog ungalvanized hlau, hlau filings los yog plua plav poob mus rau moist zinc nto tuaj yeem ua rau electrochemical corrosion. Xeb (hlau oxide) tuaj yeem stain lub zinc nto, ua rau nws muaj xim liab -xim av lossis xim dub.
5.Dab tsi yog qhov laj thawj feem ntau yog vim li cas qhov chaw ntawm galvanized coil tig dub?
Lub blackening ntawm galvanized coil nto feem ntau yog vim "storage corrosion," hauv paus hauv qhov tsis muaj kev tiv thaiv kev tiv thaiv zoo thiab tsis tsim nyog, av noo, thiab nyob ib puag ncig cia. Qhov no qhia thaum ntxov corrosion ntawm zinc txheej. Thaum qhov no feem ntau tsis cuam tshuam rau cov qauv kev tiv thaiv corrosion tam sim ntawd, nws tuaj yeem cuam tshuam rau cov tsos thiab muaj peev xwm loj hlob mus rau hauv cov xim dawb loj dua, uas tuaj yeem ua rau muaj kev puas tsuaj rau kev ua haujlwm tom ntej, xws li kev pleev xim.