Thaum ib daim hlau muab tso rau hauv cov kua nitric acid diluted, nws yuav nquag yaj thiab tawm cov pa taws liab, uas qhia txog kev xeb ntawm cov hlau. Txawm li cas los xij, yog tias cov ntsiab lus nitric acid maj mam ntxiv los ua kom cov kev daws teeb meem siab dua 40%, tus nqi corrosion yuav dheev poob mus rau ib-plaub-txhiab ntawm nws tus nqi qub. Qhov no tshwm sim yog hu ua passivation.
Raws li qee qhov xwm txheej, thaum lub peev xwm ntawm cov hlau hloov tau zoo vim yog siv cov anode tam sim no lossis hauv zos anode tam sim no, qee qhov kev hloov pauv sai sai tshwm sim rau ntawm qhov chaw ntawm cov hlau uas yav dhau los yaj (tsim ntawm oxide zaj duab xis lossis adsorbed zaj duab xis). Vim qhov kev hloov pauv sai sai no, cov kev cai lij choj tswj cov txheej txheem anode dissolution tau dhau los ua qhov kev hloov pauv zoo, thiab tus nqi tawg ntawm cov hlau poob qis heev. Qhov kev hloov tam sim no hauv lub xeev ntawm cov hlau nto yog hu ua passivation.
