Kev soj ntsuam ntawm cov zaj duab xis passivation qhia tias nws feem ntau muaj trivalent chromium, ua raws li dej, hexavalent chromium, thiab lwm yam khoom xws li sulfate, zinc, thiab sodium. Yog li ntawd, cov yeeb yaj kiab chromate feem ntau yog tsim los ntawm trivalent chromium, hexavalent chromium, thiab dej, nrog rau cov qauv dav dav:
xCr₂O₃·yCrO₈·zH₂O
Cov chromate muaj nyob rau hauv cov tshuaj colloidal nyob rau hauv daim ntawv ntawm chromium oxyacid chromate (CrOa-Cr₂Oa-nH₂O los yog xCr₂Oa-yCrOa-zH₂O) nyob rau saum npoo ntawm txheej galvanized. Ntawm qhov tod tes, thaum chromic acid reacts nrog zinc, nws dhau los ua zinc chromate (ZnCrO₂) thiab txuas rau zaj duab xis. Txij li nws yog soluble nyob rau hauv dej, nws muaj nyob rau hauv ib tug aqueous tov nrog rau chromic acid thiab yuav yaj nyob deb ntawm lub galvanized nto thaum lub sij hawm dej yaug. Nws lub xub ntiag yog kev puas tsuaj rau zaj duab xis. Yog li ntawd, nws yog pov thawj tias chromium tivthaiv nyob rau hauv cov zaj duab xis passivation muab cov nyhuv tiv thaiv.
Lub hauv paus ntsiab lus ntawm kev tiv thaiv corrosion los ntawm passivation zaj duab xis feem ntau yog nyob rau hauv nws cov ntsiab lus siab ntawm trivalent chromium. Cov zaj duab xis passivation yog qhov nyuaj rau yaj hauv dej, yog li nws npog cov txheej txheem galvanized zoo li lub pob tshab zaj duab xis, tiv thaiv kev nkag mus ntawm oxygen thiab noo noo los ntawm huab cua mus rau hauv txheej galvanized thiab nws qhov hws. Tsis tas li ntawd, lub xub ntiag ntawm ib qho me me ntawm hexavalent chromium tuaj yeem kho cov yeeb yaj kiab uas tsis muaj zog, rov kho cov yeeb yaj kiab torn rau lawv qhov qub kev ncaj ncees thiab tiv thaiv anodic dissolution ntawm galvanized txheej.
