Qhov sib txawv tseem ceeb ntawm pickling thiab passivation yog tias pickling yog txheej txheem uas peb siv los tshem tawm impurities ntawm ib tug hlau nto whereas lub passivation yog tiv thaiv ib tug hlau nto tiv thaiv corrosion.
Ob qho tib si pickling thiab passivation yog cov txheej txheem uas peb tuaj yeem siv los tiv thaiv cov hlau nto. Peb siv lo lus pickling txog zaub mov thiab. Txawm li cas los xij, ntawm no, pickling yog ib hom kev kho mob hlau. Ntawm no, peb ntxuav cov hlau nto. Passivation, ntawm qhov tod tes, yog ua cov khoom "passive" rau corrosion. Tsis zoo li hauv pickling, ntawm no peb tiv thaiv cov hlau nto ua ntej nws tau txais tej impurity.
Pickling yog dab tsi?
Pickling yog txheej txheem ntawm kev kho cov hlau nto kom tshem tawm cov impurities ntawm qhov chaw. Cov impurities yuav muaj xws li stain, xeb, nplai, inorganic contaminants, thiab lwm yam. Cov hlau uas peb siv cov txheej txheem no yog hlau thiab nws cov alloys, tooj liab, precious hlau xws li nyiaj, txhuas alloys, thiab lwm yam.
Cov tshuaj uas peb siv hauv cov txheej txheem no yog "pickle cawv". Nws feem ntau muaj cov kua qaub; muaj zog acids xws li HCl thiab sulfuric acid yog ntau. Nws muaj qee yam khoom xyaw thiab. Piv txwv li, cov neeg ua dej ntub dej, cov tshuaj tiv thaiv corrosion, thiab lwm yam. Cov txheej txheem pickling no muaj ntau hauv kev tu cov hlau hauv cov txheej txheem steelmaking. Qhov xav tau ntawm cov txheej txheem no yog tshem tawm cov khoom ntawm cov hlau nto uas yuav cuam tshuam rau kev ua haujlwm ntxiv ntawm cov hlau xws li plating thiab pleev xim. Descaling yog ib kauj ruam tseem ceeb ntawm cov txheej txheem no. Ntau cov txheej txheem kub ua haujlwm tawm ntawm cov txheej txheem oxide discoloring (scale) rau ntawm cov hlau. Peb tuaj yeem tshem tawm cov txheej txheem no los ntawm dipping rau hauv ib lub vat ntawm cov cawv txiv hmab.
Txawm li cas los xij, muaj qee qhov tsis zoo rau cov txheej txheem no. Ntawm tag nrho cov, cov txheej txheem no yog qhov nyuaj los daws vim tias cov cawv txiv hmab txiv ntoo yog corrosive (nws muaj cov kua qaub muaj zog). Ntxiv mus, hydrogen embrittlement yog lwm qhov teeb meem rau qee cov alloys. Raws li lwm qhov tsis zoo, nws tsim cov sludge pickle ua cov khoom pov tseg ntawm cov txheej txheem no. Piv txwv li: siv cov cawv txiv hmab yog cov pov tseg uas muaj kev phom sij.
Passivation yog dab tsi?
Passivation yog txheej txheem ntawm kev ua cov khoom "passive" rau corrosion. Nyob rau hauv lwm yam lus, nws tiv thaiv ib tug hlau nto los ntawm corrosion. Tom qab passivation ntawm ib tug hlau, cov hlau ua tsis tshua muaj kev cuam tshuam los ntawm ib puag ncig. Nyob rau hauv cov txheej txheem no, peb tsim ib txheej txheej raws li cov ntaub thaiv npog. Peb tuaj yeem siv nws ua microcoating. Peb tuaj yeem siv cov txheej txheem no los ntawm kev siv tshuaj lom neeg lossis ua cov tshuaj tiv thaiv ib puag ncig (peb tuaj yeem khaws cov hlau hauv huab cua rau oxidation). Ntxiv mus, passivation ntawm hlau tshwm sim tsuas yog nyob rau hauv tej yam kev mob. Nws yog ib qho tseem ceeb heev los khaws cov tsos ntawm cov hlau.
Daim duab 01: Nyiaj Tarnished
Cov hlau uas dhau los ntawm cov txheej txheem no suav nrog aluminium, ferrous cov ntaub ntawv, stainless hlau thiab npib tsib xee. Feem ntau ntawm cov hlau tsim ib txheej oxide thaum peb nthuav tawm rau huab cua ib txwm muaj, piv txwv li tarnishing cov nyiaj. Tab sis hauv qee cov hlau xws li hlau, xeb tsim tshwm sim hauv huab cua qhib. Qhov no tuaj yeem txo cov hlau. Cov txheej txheej corrosion yog qhov tseem ceeb ntawm no vim tias nws txo qis qhov corrosion ntxiv.
Qhov txawv ntawm Pickling thiab Passivation yog dab tsi?
Pickling yog txheej txheem ntawm kev kho cov hlau nto kom tshem tawm cov impurities ntawm qhov chaw. Peb tuaj yeem ua qhov no siv cov cawv txiv hmab. Yog li, nws tiv thaiv ib tug hlau nto tiv thaiv impurities ntawm hlau nto. Passivation yog txheej txheem ntawm kev ua cov khoom "passive" rau corrosion. Qhov no yog qhov sib txawv tseem ceeb ntawm pickling thiab passivation. Ntxiv mus, passivation yog qee zaum ua rau tus kheej thiab ntuj tsim (ex "tsim ntawm oxide txheej hauv huab cua qhib), lossis peb tuaj yeem ua qhov no los ntawm cov tshuaj tiv thaiv. Tsis tas li ntawd, nws tiv thaiv cov hlau nto txawm tias ua ntej nws raug huab cua.
Summary – Pickling vs Passivation
Hlau yog feem ntau ntawm cov sij hawm, heev reactive thaum peb nthuav nws mus rau ib txwm huab cua. Pickling thiab passivation yog ob txoj kev uas peb tuaj yeem siv los tiv thaiv cov hlau nto. Qhov txawv ntawm pickling thiab passivation yog tias lub pickling yog cov txheej txheem uas peb siv los tshem tawm impurities ntawm ib tug hlau nto whereas lub passivation yog kev tiv thaiv ntawm ib tug hlau nto tiv thaiv corrosion.
