Vim li cas qee qhov ci galvanized nto tsim cov pob dub tom qab passivation?

Qhov tshwm sim ntawm cov pob dub nyob rau hauv passivated, kaj galvanized nto ntawm kub-dip galvanized steel kav yog feem ntau vim impurities xws li tooj liab, hlau, thiab arsenic tam sim no nyob rau hauv lub galvanized txheej. Thaum passivation, cov impurities no tshwm sim raws li cov pob dub. Tsis tas li ntawd, chromium oxide, tsim thaum chromic acid txo, tshwm ntsuab; thaum hlau dichromate, tsim los ntawm cov tshuaj tiv thaiv ntawm chromic acid thiab hlau, tshwm xim av. Thaum ob lub tebchaw sib tov, lawv tig dub (qhia tias cov tshuaj passivation muaj hnub nyoog). Yog hais tias cov txheej galvanized tsis yog rinsed tom qab passivation, dub thaj ua rau thaj yuav nyob twj ywm rau saum npoo.