Q: Dab tsi yog pawg tseem ceeb ntawm cov txheej txheem passivation rau galvanized coils raws li lawv cov tshuaj muaj pes tsawg leeg?
A: Lawv feem ntau muab faib ua ob pawg: chromate passivation thiab chromium -dawb passivation. Chromate passivation siv hexavalent chromium tebchaw, uas muaj kev tiv thaiv corrosion zoo heev tab sis muaj tshuaj lom, thiab kev txwv ib puag ncig tau nce zuj zus. Chromium-dawb passivation yog ib qho kev sib raug zoo rau ib puag ncig, thiab ntau hom muaj xws li trivalent chromium passivation, silane passivation, titanium-zirconium ntsev passivation, thiab organic composite passivation.
Q: Dab tsi yog cov yam ntxwv tshwj xeeb thiab cov txheej txheem ntawm chromate passivation?
A: Chromate passivation yog cov txheej txheem ib txwm muaj uas suav nrog immersing lossis yob - txheej galvanized coils nrog cov kua qaub uas muaj hexavalent chromium, tsim cov chromium -zinc composite conversion zaj duab xis ntawm zinc txheej txheej. Cov yeeb yaj kiab no muaj peev xwm kho tau tus kheej - thiab tuaj yeem tiv taus ntsev tsuag rau ntau tshaj 120 teev. Txawm li cas los xij, hexavalent chromium yog carcinogen, thiab kev kho dej khib nyiab yog kim; yog li ntawd, tam sim no nws yog phased tawm.
Q: Dab tsi yog qhov zoo sib xws thiab qhov sib txawv ntawm trivalent chromium passivation thiab hexavalent chromium passivation?
A: Trivalent chromium passivation siv trivalent chromium ntsev es tsis txhob hexavalent chromium thiab tam sim no yog cov txheej txheem kev hloov pauv ntawm ib puag ncig tus phooj ywg. Nws cov txheej txheem tsim cov yeeb yaj kiab zoo sib xws, tab sis cov txheej txheem zaj duab xis tsis muaj peev xwm kho tus kheej, thiab nws cov corrosion kuj yog qis dua li ntawm hexavalent chromium (lub sij hawm ntsev tsuag kwv yees li 72-96 teev). Trivalent chromium muaj toxicity qis thiab ua raws li RoHS cov lus qhia, tab sis cov tshuaj passivation muaj kev ruaj ntseg tsis zoo, yuav tsum tau tswj hwm pH thiab kub.
Q: Lub hauv paus ntsiab lus ua haujlwm ntawm silane passivation yog dab tsi? Dab tsi yog nws cov ntawv thov tsim nyog?
A: Silane passivation siv cov organosilane coupling tus neeg sawv cev uas, tom qab hydrolysis, dhau los ua cov tshuaj tiv thaiv condensation nrog cov hydroxyl pawg ntawm zinc txheej saum npoo, tsim kom muaj Si{0}}O-Zn covalent network. Qhov no ultra- nyias zaj duab xis (50-200 nm) tsis tsuas yog muab lub cev thaiv kev tab sis kuj tseem txhim kho qhov adhesion ntawm cov txheej tom ntej. Nws yog qhov tsim nyog rau cov ntawv thov uas xav tau xoom hlau ion emissions, tab sis xav tau kev ua kom huv huv heev.
Q: Dab tsi yog qhov zoo ntawm titanium-zirconium ntsev composite passivation? Dab tsi ntxiv chromium - cov txheej txheem pub dawb nyob ntawd?
A: Titanium-zirconium ntsev passivation yog ua raws li fluorotitanic acid los yog fluorozirconic acid system, tso cov oxide nanofilm sib xyaw rau ntawm zinc txheej. Nws cov corrosion kuj yog ze rau ntawm trivalent chromium, thiab nws muaj lub neej ntev da dej. Lwm cov chromium- cov txheej txheem pub dawb suav nrog cov organic resin passivation (xws li acrylic thiab epoxy resin coatings) thiab phytic acid passivation. Cov qub blocks corrosive xov xwm los ntawm ib tug organic zaj duab xis, thaum lub tom kawg siv phytic acid rau chelate zinc ions los ua ib tug tuab tiv thaiv txheej, tab sis nws yog kim kim.