Cov txheej txheem tiv thaiv ib txwm ntawm cov khoom siv corrosion
Monel 400 feem ntau tsim cov oxide ruaj khov thiab hydroxide txheej uas muaj npib tsib xee thiab tooj liab thaum lub sij hawm ib txwm corrosion, xws li npib tsib xee oxide, npib tsib xee hydroxide, thiab tooj liab oxides. Cov khoom no yog ntom thiab adherent rau lub substrate nto. Lawv ua raws li lub cev tiv thaiv kom cais cov hauv paus hlau los ntawm oxygen, noo noo, thiab corrosive ions nyob rau hauv nruab nrab, slowing down ntxiv corrosion tshwm sim. Cov txheej txheem passive no yog kho tus kheej rau qee yam hauv qhov tsis muaj oxidizing, nruab nrab, thiab alkaline ib puag ncig, tswj kev ruaj khov mus ntev thiab tiv thaiv cov khoom tawg sai.
Cov xwm txheej qhov twg Corrosion Products tuaj yeem cuam tshuam qhov cuam tshuam thib ob
Localized tawg ntawm corrosion khoom txheej
Yog tias cov khoom siv corrosion pib ua tsis tiav, tawg, lossis ntxeem tau (piv txwv li, ntawm cam khwb cia Monel 400 nrog cov khoom tsis xws luag, los yog nyob rau hauv ib puag ncig uas muaj chloride ions, sulfides, los yog oxidizing tus neeg sawv cev zoo li chlorates), corrosive media tuaj yeem nkag mus los ntawm qhov tsis xws luag thiab tiv tauj cov hlau tshiab. Qhov no tsim cov roj teeb hauv zos corrosion nruab nrab ntawm cheeb tsam npog thiab raug, ua rau pitting corrosion thiab crevice corrosion. Cov khoom siv xoob xoob xoob hauv qab ntawm qhov pits tsis tuaj yeem cuam tshuam ion tsiv teb tsaws, tab sis es tsis txhob ntxiab cov khoom corrosive, ua rau lub zos acidification thiab oxidation, thiab accelerating propagation ntawm corrosion.
Galvanic teebmeem tshwm sim los ntawm cov theem tooj liab nplua nuj nyob rau hauv cov khoom siv corrosion
Monel 400 muaj cov ntsiab lus tooj liab siab. Thaum xaiv corrosion, tooj liab-nplua nuj compounds tuaj yeem sau rau ntawm qhov chaw. Hauv cov khoom siv electrolytes, cov khoom siv tooj liab no tuaj yeem tsim cov kab mob me me nrog cov nickel-nplua nuj matrix. Txij li thaum tooj liab muaj txiaj ntsig zoo dua li npib tsib xee, thaj chaw npib tsib xee-nplua nuj nyob ib puag ncig lawv dhau los ua anodes thiab ua kom nrawm nrawm, txhawb kev txhim kho hauv zos theem nrab. Cov nyhuv no kuj tsis muaj zog nyob rau hauv nruab nrab thiab alkaline ib puag ncig tab sis dhau los ua ntau tshaj tawm nyob rau hauv acidic tej yam kev mob los yog nyob rau hauv lub xub ntiag ntawm active halide ions.
Deposition ntawm corrosive impurities
Hauv kev lag luam xov xwm, cov khoom siv corrosion yuav adsorb lossis co-precipitate nrog teeb meem impurities xws li chlorides, sulfides, thiab acidic tshuaj. Cov kab mob uas raug kaw no tswj hwm qhov chaw nruj heev hauv zos, tiv thaiv kev tsim cov yeeb yaj kiab ua tiav thiab ua kom muaj kev tiv thaiv tsis tu ncua.
Hauv cov ntsiab lus, Monel 400 corrosion khoom yog feem ntau tiv thaiv thiab tsis ua rau autocatalytic ceev corrosion nyob rau hauv feem ntau cov qauv siv. Txawm li cas los xij, nyob rau hauv ib puag ncig hnyav uas muaj cov oxidants muaj zog, halides, los yog nyob rau hauv acidic tej yam kev mob, puas los yog non-uniform corrosion khoom yuav ua rau lub zos theem nrab corrosion.
