Txoj siv tawv pluas noj feem ntau yog siv rau hauv qhov chaw tseem ceeb ntawm kev sib khi, thiab nws yog qhwv ib ncig ntawm lub duav thiab lwm txoj kev. Qhov tseeb, muaj qee yam khiav hauv lub sijhawm ntawm qhov chaw sib khi. Cov chaw tsim khoom ntawm cov khoom siv raw cov pluas noj ceeb toom tias cov pluas noj nyoos yuav tsum tsis txhob siv nrawm nrawm thaum lub sijhawm ua haujlwm, kom tsis txhob cuam tshuam rau lub neej kev pabcuam.
Thaum qhov kev sib txhuam ntawm cov plua plav plua plav yog nyob rau hauv kev khiav hauv theem, kev sib txhuam, hnav thiab kev sib txhuam kub hloov tau zoo heev thaum lub sijhawm no, thiab tom qab ntawd nkag mus rau theem ruaj khov. Lub sijhawm no, tus nqi hnav me me thiab yuav luag tsis hloov pauv, uas yog, lub sijhawm ua haujlwm ib txwm muaj ntawm lub foob, uas yog qhov hnyav hnyav. Vim tias qhov chaw puas lawm, qhov kub thiab txias tau nce, thiab cov kev hloov pauv ntawm cov khoom siv hauv cov khoom ua rau cov khoom hnav tau nce siab, uas ua rau cov dej xau ntau tshaj qhov tso cai. Rau cov qauv foob sib txawv thiab kev ua haujlwm, txoj cai hnav ntawm kev sib txhuam ntawm cov khoom siv raw khoom siv foob kuj sib txawv, yog li cov txheej txheem hnav cuam tshuam rau lub foob kuj sib txawv.
Muaj ntau hom kev hnav cov khoom siv raw, nrog rau kev hnav cov nplaum, hnav abrasive, hnav corrosion, qaug zog hnav thiab fretting hnav. Daim ntawv hnav hnyav dua yog abrasive hnav, uas yog, cov khoom raug txiav los yog khawb thaum cov khoom tawv tawv txawv teb chaws nkag mus rau hauv qhov chaw sib khi, lossis lub xeev cov dej ntws zoo li qub raug puas tsuaj vim yog cov nyhuv scouring ntawm cov khoom uas tau muab tshem tawm los ntawm cov kua. Tsis tas li ntawd, corrosion hnav los ntawm tshuaj lom neeg los yog electrochemical cov tshuaj tiv thaiv ntawm kev sib txhuam cov ntaub ntawv thiab cov xov xwm ib puag ncig kuj yog ib qho kev hnav khaub ncaws hauv cov ntsaws ruaj ruaj.
Thaum cov khoom siv raw siv hla lub sijhawm khiav, qhov kev sib khi yuav ncav cuag qhov siab. Cov lus piav qhia ntawm cov khoom tseem yuav qhia tshwj xeeb txog cov teeb meem ntawm kev khiav haujlwm hauv lub sijhawm kom ntseeg tau tias siv tau.
