Puas nickel tig ntsuab thaum nws tarnishes
Nyob rau hauv lub ntiaj teb ntawm cov hlau, npib tsib xee yog heev prized rau nws cov cim in silvery {}} dawb} cov xim dawb thiab zoo heev corrosion. Nws yog dav siv nyob rau hauv electroplating, alloy raug, roj teeb, thiab lwm thaj chaw. Txawm li cas los xij, thaum cov khoom siv npib tsib xee, cov xim xim hloov ntau dua li xaiv cov lus nug: Puas yog Nickel tiag tiag tig ntsuab tom qab Tarnishing? Lub hauv paus ntsiab lus tshawb fawb tom qab tshwm sim no yog dab tsi?
Cov tshuaj chemical thiab oxidation hauv paus ntawm npib tsib xee
Nickel yog ib qho silvery - cov hlau dawb nrog ferromagnetism. Nyob rau ntawm chav tsev kub, nws ua cov yeeb yaj kiab dense oxide (feem ntau tsim ntawm nio) ntawm nws cov npoo, uas ua tiv thaiv ntxiv oxidation ntawm cov hlau hauv qab. Txawm li cas los xij, thaum cov yeeb yaj kiab oxide yog kev hloov pauv lossis ib puag ncig kev hloov pauv, tus txheej txheem oxidation accelerates, ua rau muaj xim saum npoo. Tshwj xeeb, xim ntawm npib tsib xee cov khoom siv oxidation yog ze rau cov mob oxidation: hauv cov huab cua qhuav, cov oxide zaj duab xis feem ntau tseem muaj xim daj lossis lub teeb txho; Txawm li cas los xij, hauv kev muaj kuab paug lossis muaj kuab paug, cov txheej txheem oxidation yuav tsim cov xim ntsuab.
Cov xwm txheej thiab cov txheej txheem ntawm Nickel Greening tom qab oxidation
Qhov ntsuab ntawm Nickel lub nplaim tsis yog qhov tshwm sim thoob ntiaj teb tab sis cov khoom lag luam hauv cov xwm txheej tshwj xeeb. Cov hauv qab no yog qhov tseem ceeb ntawm qhov uas ua rau Nickel tig ntsuab:
Vaum ib puag ncig thiab chloride ion sib cuam tshuam
Nyob rau hauv ib qho chaw ntub dej, micro {- roj teeb tuaj yeem tsim nyob rau ntawm lub npib tsib xee, ua kom nrawm nroos, ua kom nrawm nroos, ua kom nrawm nroos, ua kom nrawm nroos, ua kom nrawm nroos, ua kom nrawm nroos, ua rau muaj kev ua kom huv. Chloride ions (xws li cov uas nyob hauv dej hiav txwv lossis roj muaj roj uas muaj menyuam yaus los tsim Nickel los tsim Nickel los tsim Nickel los tsim Nickel los tsim Nickel) lossis yooj yim Nickel Chloride (Niclikhh₂o). Cov tebchaw tau yooj yim hydrolyze nyob rau hauv cov huab cua noo, sib sau ntsuab hydroxide (ni (Oh) ₂) lossis yooj yim Nickel carbonate (Nicauj (Oh). For example, nickel products in coastal areas often develop green rust spots due to long-term exposure to sea fog.
Kev rhuav tshem thiab Redeposition hauv Acidic Media
Nickel maj mam yaj nyob rau hauv dilute nitric acid, tsim ntsuab ni²⁺ daws. Yog hais tias cov nickel txheej yog ntxeem tau lossis puas, fe²⁺ tsim los ntawm cov hlau) hauv cov pa roj acidic (xws li cov pa roj acidic) Tsis tas li ntawd, ib qho tsis txaus ntseeg nyob rau hauv cov plating tov rau cov kab mob nickinations (xws li edta-2na plating rau kev tso nyiaj rau cov khoom ntsuab ntawm cov khoom ntsuab corrosion.
High - ecidation kub thiab cov oxide olide
When nickel is exposed to high temperatures (>300 degree) thiab nyob rau hauv ib puag ncig muaj cov impurities xws li cov sulphorus, nws tsim cov nyom ntawm cov neeg tawv dub dawb (ni₃) ₂) lossis nickel sulfide (nis). Piv txwv li, cov khoom siv npib tsib xee uas siv hauv kev siv hluav taws xob tsis muaj-} oxidation kev kho tej zaum yuav tsim muaj tsaus ntuj nti ntsuab- siv.
Piv txwv thiab kev paub txog ntawm ntsuab nickel discoloration
Oxidation cov yam ntxwv ntawm cov phaj ntshiab nickel
Ntshiab Nickel daim phiaj tshwm sim tsis muaj txim rau cov kev sib nqus muaj zog. Oxidation tau tshwm sim hauv cov txiv ntseej - ntsuab rust stain, uas tsis sib thooj nrog cov xim av- xim liab. Qhov ntsuab ntsuab no yog cov khoom ntawm kev sib cuam tshuam ntawm ob npib tsib nrog oxygen thiab dej thiab feem ntau pom nyob rau hauv kev rov ua dua tshiab ntawm scrap nab tsib.
Kev ua tsis tiav ntawm Nickel Plating
Nyob rau hauv thaum ntxov theem ntawm corrosion, lub npib tsib xee plating ua ib lub teeb ci ci - green, hmoov, cov khoom siv xoob. Qhov no yog kev ntxim yuav tsim ib txheej oxide nyob rau hauv kev kub siab. Yog hais tias lub pib steel substrate yog hlau, cov khoom corrosion · (xws li} xim av) tov nrog ntsuab nickel sib xyaw, ua rau lub ntsej muag motion {}} xim av xim.
Kev tshawb fawb muaj teeb meem: ntxhib hluav taws xob hluav taws xob thiab tsis muaj txiaj ntsig
Ib yam electroplating cog cov nroj tsuag kev ua plaub fab thiab siab porosity vim tsawg ion concentration thiab ib qho tsis sib xws nyob rau hauv lub plating da dej. Tom qab peb lub hlis ntawm kev siv, ntsuab xeb vog tau tshwm sim nyob rau saum npoo ntawm cov khoom, uas tau pom tias yog cov nyom ntawm ni (huag) ₂ thiab clr. Cov teeb meem tau daws los ntawm kev ua kom zoo dua cov plating da dej rau 60 g / l thiab ntxiv cov pos- kev kho cov kauj ruam.
Yuav ua li cas tiv thaiv npib tsib xee los ntawm tig ntsuab vim oxidation?
Kev tswj hwm ib puag ncig: Tsis txhob muaj ntev ntev ntawm cov khoom noj npib tsib xee rau noo, chlorine {{}}}}} acidic ib puag ncig. Siv ntim khoom lossis xuv npe yog tias tsim nyog.
Kev kho deg: Passivate txheej npib tsib xee (piv txwv li, chromate passivation) lossis siv ib zaj yeeb yaj kiab organic (piv txwv li, uas ua rau cov neeg sawv cev rov qab).
Txheej Txheem Txhim Kho Kom Zoo Dua: Thaum Electropating, nruj me ntsis ion thiab ion concentration, Ph, qhov ceev ceev) thiab tam sim no kom txo porosity. Rau electroless npib tsib xee plating, tsis tu ncua mus kuaj qhov kev ruaj ntseg kom tiv thaiv cov kev sib txuam ntawm cov paug tsis huv xws li Edta-2NA.
Seb Nickel hloov ntsuab tom qab tarnishing nyob ntawm oxidation tej yam kev mob thiab lub xub ntiag ntawm impurities. Hauv noo, chlorine -}} muaj cov npe nyob ib puag ncig, Nickel tuaj yeem ua tiav cov npib ntsuab hydroxide, Nickel chloride, lossis cov oxel oxoide, lossis cov oxaws. Hauv qhuav lossis nruab nrab ib puag ncig, cov oxide zaj duab xis feem ntau tseem muaj xim tsis muaj xim lossis grey. Nkag siab txog cov txheej txheem no tsis tsuas yog pab txheeb xyuas lub xeev corrosion ntawm Nickel cov khoom tab sis kuj muab kev tshawb fawb rau lawv txoj kev pabcuam.
