Cov txheej txheem tshuaj degreasing yog immersing cov kav dej rau hauv lub tank ua los ntawm cov hlau phaj, nrog rau cov phab ntsa hauv kab nrog polyvinyl chloride (PVC) lossis polyethylene. A 12-15% nitric acid tov yog siv rau tshuaj degreasing ntawm qhov kub ntawm 40 degree txog 60 degree rau 2 mus rau 4 teev. Thaum muab cov galvanized steel kav rau hauv lub tank, yuav tsum tau them nyiaj mloog mus rau lawv qhov chaw kom tsis txhob muaj cua nkag hauv cov kav dej. Thaum lub sij hawm soaking, cov kav dej yuav tsum tau txav mus los los yog flipped kom tsis tu ncua hloov cov tshuaj nyob rau hauv lub puab kab noj hniav, txhim khu kev ua tau zoo.
Yog tias tsim nyog, cov kav dej yuav tsum tau muab tshem tawm, yaug nrog dej, thiab rov ua dua. Tshuaj degreasing txuas ntxiv mus txog rau thaum lub npoo ntawm cov kav dej galvanized yog tag nrho los ntawm dej. Tom qab yaug nrog dej kub, cov kav dej degreased raug tshem tawm ntawm lub tank degreasing thiab muab tso rau hauv lub tank dej kub ntawm kwv yees li 40-60 degree rau 5-20 feeb. Lub tank dej kub kuj tseem ua los ntawm cov hlau phaj nrog PVC lossis polyethylene hauv ob sab phlu, thiab cov ntsiab lus chloride ion hauv dej yuav tsum tsawg dua 25ppm. Cov dej kub-rinsed galvanized steel kav yog tom qab ntawd yaug nrog dej siab, rov ua kom cov chloride ion ntsiab lus qis dua 25ppm. Lub tank immersion txoj kev yog xaiv rau passivation, nrog rau passivation tov mis thiab immersion lub sij hawm raws li cov specifications.
Lub tank passivation yog ua los ntawm passivated steel daim hlau nrog acid-resistant yas hauv ob sab phlu rau sab hauv phab ntsa. Thaum muab tso rau hauv cov kav dej, yuav tsum tau saib xyuas nrog lawv qhov chaw kom tsis txhob muaj cua nkag. Thaum lub sij hawm immersion, cov kav dej yuav tsum tau tsiv los yog flipped mus tas li hloov cov tshuaj nyob rau hauv, txhim kho cov nyhuv passivation. Yog tias tsim nyog, cov kav dej galvanized tuaj yeem raug tshem tawm, yaug nrog dej, thiab rov ua dua. Yog hais tias cov kav dej qhuav lawm, cov kav dej tsis muaj zog galvanized yuav tsum tau tshuab kom qhuav nrog cov cua huv huv los yog nitrogen, tso cai rau lub sijhawm txaus rau ntuj passivation hauv huab cua.
Kev tshuaj xyuas zoo ua raws li, nrog rau kev tshuaj xyuas tus kheej thiab kev tshuaj xyuas kev sib koom ua ke tom qab passivation, thiab cov kav dej xa mus rau cov neeg soj ntsuam zoo raws li qhov xav tau. Rau kev ntim khoom thiab kev saib xyuas, yog tias sab nrauv ntawm cov kav hlau galvanized yuav tsum tau pleev xim, nws yuav tsum tau ua raws li kev xa khoom. Tom qab kev tshuaj xyuas, cov kav dej galvanized steel tau muab ntim nrog cov yas ntsaws, qhwv nrog peb daim ntaub pov thawj rau kev saib xyuas, thiab sau npe raws li.
