Gkev kho kom zoo nkauj
Cov yam ntxwv:
Zinc ruaj khov heev nyob rau hauv huab cua qhuav thiab tsis yooj yim hloov xim. Hauv dej thiab qhov chaw noo noo, nws cuam tshuam nrog oxygen lossis carbon dioxide los tsim cov oxide lossis alkaline zinc carbonate zaj duab xis, uas tuaj yeem tiv thaiv zinc kom tsis txhob txuas ntxiv oxidize thiab muab kev tiv thaiv.
Zinc muaj zog tiv taus xeb hauv cov kua qaub, alkalis, thiab sulfides. Feem ntau, cov txheej galvanized yuav tsum tau kho passivation. Tom qab passivation hauv chromic acid lossis chromate kua, zaj duab xis passivation uas tsim los tsis yooj yim raug rau huab cua noo, ua rau nws muaj peev xwm tiv thaiv xeb zoo heev. Rau cov khoom caij nplooj ntoos hlav, cov khoom nyias nyias (phab ntsa tuab <0.5m), thiab cov khoom hlau uas xav tau lub zog siab, yuav tsum tau tshem tawm hydrogen, thaum cov khoom tooj liab thiab tooj liab alloy tej zaum yuav tsis xav tau tshem tawm hydrogen.
Kev pleev xim galvanizing muaj tus nqi qis, yooj yim ua, thiab muaj txiaj ntsig zoo. Lub peev xwm txheem ntawm zinc yog qhov tsis zoo, yog li txheej zinc yog txheej anodized rau ntau yam hlau.
Kev siv galvanization dav dav hauv cov huab cua thiab lwm yam chaw zoo. Tab sis nws tsis haum rau kev siv ua cov khoom sib txhuam.
Ckev plating chrome
Cov yam ntxwv: Rau cov khoom uas kov tau huab cua hauv dej hiav txwv lossis dej hiav txwv, thiab hauv dej kub saum 70℃, cadmium plating yog qhov ruaj khov, muaj zog tiv taus corrosion, lubrication zoo, thiab yaj qeeb hauv dilute hydrochloric acid, tab sis nws yaj tau zoo hauv nitric acid thiab insoluble hauv alkali. Nws cov oxide kuj tsis yaj hauv dej. Cadmium txheej yog softer dua li zinc txheej, nrog tsawg dua hydrogen embrittlement thiab muaj zog adhesion.
Ntxiv mus, nyob rau hauv qee qhov xwm txheej electrolytic, cov txheej cadmium tau txais yog qhov zoo nkauj dua li cov txheej zinc. Tab sis cov pa roj tsim los ntawm cadmium thaum lub sijhawm yaj yog lom, thiab cov ntsev cadmium uas yaj tau kuj yog lom. Nyob rau hauv cov xwm txheej ib txwm muaj, cadmium ua haujlwm ua cov txheej cathodic ntawm cov hlau thiab ua cov txheej anodic hauv dej hiav txwv thiab huab cua kub.
Feem ntau nws yog siv los tiv thaiv cov khoom los ntawm kev xeb hauv huab cua los ntawm dej hiav txwv lossis cov tshuaj ntsev zoo sib xws, nrog rau cov pa dej hiav txwv uas saturated. Ntau qhov chaw hauv kev lag luam dav hlau, kev caij nkoj, thiab kev lag luam hluav taws xob, cov caij nplooj ntoos hlav, thiab cov khoom siv xov yog plated nrog cadmium. Nws tuaj yeem polished, phosphated, thiab siv ua lub hauv paus xim, tab sis tsis tuaj yeem siv ua cov khoom siv.
Kev plating chromium
cov yam ntxwv:
Chromium ruaj khov heev nyob rau hauv cov huab cua noo, alkaline, nitric acid, sulfide, carbonate kua, thiab cov organic acids, thiab yooj yim soluble hauv hydrochloric acid thiab kub concentrated sulfuric acid. Nyob rau hauv qhov kev ua ntawm tam sim no ncaj qha, yog tias chromium txheej ua haujlwm ua anode, nws yooj yim soluble hauv caustic soda kua.
Cov txheej chromium muaj cov nplaum zoo, siab hardness, 800-1000V, zoo hnav tsis kam, muaj zog reflection, thiab kub tsis kam. Nws tsis hloov xim hauv qab 480℃, pib oxidize saum 500℃, thiab txo qhov nyuaj ntawm 700℃Nws qhov tsis zoo yog tias chromium nyuaj, tawg yooj yim, thiab yooj yim tawg, tshwj xeeb tshaj yog thaum raug kev cuam tshuam sib txawv. Thiab nws muaj porosity.
Cov hlau chromium yooj yim raug passivation hauv huab cua, ua rau muaj zaj duab xis passivation thiab yog li hloov pauv lub peev xwm ntawm chromium. Yog li ntawd, chromium dhau los ua ib txheej cathodic ntawm hlau.
Nws tsis zoo tagnrho los siv cov chrome plating ncaj qha ua ib txheej tiv thaiv xeb rau ntawm qhov chaw ntawm cov hlau. Feem ntau, ntau txheej electroplating (piv txwv li tooj liab plating→nickel plating→chromium plating) yog qhov yuav tsum tau ua kom tiav lub hom phiaj ntawm xeb
kev tiv thaiv thiab kho kom zoo nkauj. Tam sim no siv dav hauv kev txhim kho kev hnav tsis kam ntawm cov khoom, kho qhov ntev, kev cuam tshuam lub teeb, thiab teeb pom kev zoo nkauj.
Nickel plating
cov yam ntxwv:
Nickel muaj kev ruaj khov tshuaj zoo hauv huab cua thiab alkaline kua, tsis yooj yim discolored, thiab tsuas yog oxidized ntawm qhov kub siab tshaj 600° C. Nws yaj qeeb qeeb hauv sulfuric acid thiab hydrochloric acid, tab sis yooj yim yaj hauv dilute nitric acid. Nws yooj yim passivated hauv concentrated nitric acid thiab yog li ntawd muaj kev tiv thaiv corrosion zoo.
Nickel plating muaj qhov nyuaj siab, yooj yim rau txhuam, muaj kev cuam tshuam lub teeb siab, thiab tuaj yeem ua rau kom zoo nkauj dua. Nws qhov tsis zoo yog tias nws muaj porosity. Txhawm rau kov yeej qhov tsis zoo no, ntau txheej hlau txheej tuaj yeem siv, nrog nickel ua txheej nruab nrab.
Nickel yog ib txheej cathodic rau hlau thiab ib txheej anode rau tooj liab.
Nws feem ntau yog siv los tiv thaiv cov txheej pleev kom zoo nkauj kom tiv thaiv kev xeb thiab ua kom zoo nkauj dua. Kev plating nickel rau cov khoom tooj liab yog qhov zoo tagnrho rau kev tiv thaiv kev xeb, tab sis vim muaj nickel ntau, cov hlau tooj liab tin feem ntau siv hloov nickel plating.
Lub sijhawm tshaj tawm: Kaum Ib Hlis-14-2024
