Ua tsaug rau koj tuaj xyuas Nature.com.Koj siv lub browser version nrog kev txhawb nqa CSS tsawg.Rau qhov kev paub zoo tshaj plaws, peb xav kom koj siv qhov browser tshiab (lossis lov tes taw Compatibility Hom hauv Internet Explorer).Tsis tas li ntawd, txhawm rau xyuas kom muaj kev txhawb nqa tsis tu ncua, peb qhia lub vev xaib tsis muaj qauv thiab JavaScript.
Qhia ib lub carousel ntawm peb slides ib zaug.Siv cov nyees khawm dhau los thiab Tom ntej kom txav mus los ntawm peb qhov swb ib zaug, lossis siv cov khawm slider thaum kawg kom txav mus los ntawm peb qhov swb ib zaug.
Duplex 2205 stainless hlau (DSS) muaj qhov zoo corrosion kuj vim nws cov qauv duplex, tab sis qhov hnyav dua CO2-muaj roj thiab roj ib puag ncig ua rau muaj kev sib txawv ntawm kev xeb, tshwj xeeb tshaj yog pitting, uas cuam tshuam rau kev nyab xeeb thiab kev ntseeg siab ntawm cov roj thiab ntuj. gas siv.gas kev loj hlob.Hauv kev ua haujlwm no, kev sim raus dej thiab kev sim electrochemical yog siv ua ke nrog laser confocal microscopy thiab X-ray photoelectron spectroscopy.Cov txiaj ntsig tau pom tias qhov nruab nrab qhov kub thiab txias rau pitting 2205 DSS yog 66.9 ° C.Thaum qhov kub thiab txias siab tshaj 66.9 ℃, pitting breakdown muaj peev xwm, lub sij hawm passivation thiab tus kheej-corrosion peev xwm raug txo, qhov loj passivation tam sim no ceev yog nce, thiab pitting rhiab heev yog nce.Nrog rau qhov kub thiab txias ntxiv, lub vojvoog ntawm lub capacitive arc 2205 DSS txo qis, qhov kev tiv thaiv saum npoo thiab kev them nqi hloov pauv maj mam txo qis, thiab qhov ceev ntawm tus neeg pub khoom thiab tus neeg nqa khoom nqa hauv cov txheej txheem ntawm cov khoom nrog n + p-bipolar yam ntxwv kuj nce, cov ntsiab lus ntawm Cr oxides nyob rau hauv lub puab txheej ntawm cov zaj duab xis txo, tsub kom cov ntsiab lus ntawm Fe oxides nyob rau hauv lub txheej txheej, dissolution ntawm cov zaj duab xis txheej nce, stability txo, tus naj npawb ntawm pits thiab pore loj nce.
Nyob rau hauv cov ntsiab lus ntawm kev loj hlob sai ntawm kev lag luam thiab kev sib raug zoo thiab kev vam meej, kev thov rau cov khoom siv roj thiab roj txuas ntxiv mus ntxiv, yuam cov roj thiab roj kev txhim kho maj mam hloov mus rau sab qab teb sab hnub poob thiab sab ntug dej hiav txwv nrog cov xwm txheej hnyav dua thiab ib puag ncig, yog li kev ua haujlwm ntawm downhole tubing ua ntau dua thiab hnyav dua..Deterioration 1,2,3.Hauv kev tshawb nrhiav roj thiab roj, thaum qhov nce hauv CO2 4 thiab salinity thiab chlorine cov ntsiab lus 5, 6 hauv cov kua ua kua, 7 carbon steel yeeb nkab zoo tib yam yuav raug corrosion hnyav, txawm tias cov tshuaj tiv thaiv corrosion tau nkag mus rau hauv cov yeeb nkab hlua, corrosion tsis tuaj yeem ua tau zoo suppressed steel tsis tuaj yeem ua tau raws li qhov yuav tsum tau ua ntawm kev ua haujlwm ntev hauv qhov hnyav corrosive CO28,9,10 ib puag ncig.Cov kws tshawb fawb tau tig mus rau duplex stainless hlau (DSS) nrog zoo corrosion kuj.2205 DSS, cov ntsiab lus ntawm ferrite thiab austenite nyob rau hauv cov hlau yog hais txog 50%, muaj zoo heev mechanical zog thiab corrosion kuj, nto passivation zaj duab xis yog ntom, muaj zoo heev uniform corrosion kuj, tus nqi yog qis dua li cov nickel-raws li alloys 11. , 12. Yog li, 2205 DSS feem ntau yog siv los ua lub nkoj siab hauv ib puag ncig corrosive, roj zoo casing nyob rau hauv corrosive CO2 ib puag ncig, dej txias rau condensing system nyob rau hauv offshore roj thiab tshuaj teb 13, 14, 15, tab sis 2205 DSS kuj muaj corrosive perforation. hauv kev pabcuam.
Tam sim no, ntau cov kev tshawb fawb ntawm CO2- thiab Cl-pitting corrosion 2205 DSS tau ua nyob rau hauv lub teb chaws thiab txawv teb chaws [16,17,18].Ebrahimi19 pom tias ntxiv cov poov tshuaj dichromate ntsev rau cov tshuaj NaCl tuaj yeem cuam tshuam 2205 DSS pitting, thiab ua kom cov concentration ntawm potassium dichromate nce qhov kub thiab txias ntawm 2205 DSS pitting.Txawm li cas los xij, lub peev xwm pitting ntawm 2205 DSS nce vim qhov sib ntxiv ntawm qee qhov concentration ntawm NaCl rau potassium dichromate thiab txo qis nrog nce NaCl concentration.Han20 qhia tau hais tias ntawm 30 mus rau 120 ° C, cov qauv ntawm 2205 DSS passivating zaj duab xis yog sib xyaw ntawm Cr2O3 txheej txheej, FeO txheej txheej, thiab nplua nuj Cr;Thaum qhov kub nce mus txog 150 ° C, cov zaj duab xis passivation dissolves., cov qauv sab hauv hloov mus rau Cr2O3 thiab Cr (OH) 3, thiab txheej txheej txheej hloov mus rau Fe (II, III) oxide thiab Fe (III) hydroxide.Peguet21 pom tias nyob ruaj ruaj pitting ntawm S2205 stainless hlau nyob rau hauv NaCl tov feem ntau tshwm sim tsis qis dua qhov tseem ceeb pitting kub (CPT) tab sis nyob rau hauv transformation kub ntau yam (TTI).Thiadi22 xaus lus tias raws li qhov concentration ntawm NaCl nce, qhov corrosion kuj ntawm S2205 DSS txo qis, thiab ntau qhov tsis zoo ntawm cov ntaub ntawv siv tau, qhov tsis zoo ntawm cov khoom siv corrosion.
Nyob rau hauv tsab xov xwm no, dynamic muaj peev xwm scanning, impedance spectroscopy, tas li muaj peev xwm, Mott-Schottky nkhaus thiab optical electron microscopy tau siv los kawm txog cov nyhuv ntawm salinity siab, siab Cl- concentration thiab kub ntawm tus cwj pwm corrosion ntawm 2205 DSS.thiab photoelectron spectroscopy, uas muab lub hauv paus theoretical rau kev nyab xeeb ntawm 2205 DSS hauv cov roj thiab roj ib puag ncig uas muaj CO2.
Cov khoom siv kuaj tau raug xaiv los ntawm cov tshuaj kho steel 2205 DSS (steel qib 110ksi), thiab cov tshuaj lom neeg muaj pes tsawg leeg yog qhia hauv Table 1.
Qhov loj ntawm cov qauv electrochemical yog 10 hli × 10 hli × 5 hli, nws yog ntxuav nrog acetone kom tshem tawm cov roj thiab tsis muaj ethanol thiab qhuav.Sab nraub qaum ntawm daim ntawv xeem yog soldered los txuas qhov tsim nyog ntev ntawm tooj liab hlau.Tom qab vuam, siv lub multimeter (VC9801A) los xyuas cov hluav taws xob conductivity ntawm welded xeem daim, thiab tom qab ntawd muab khi rau qhov tsis ua hauj lwm nto nrog epoxy.Siv 400 #, 600 #, 800 #, 1200 #, 2000 # silicon carbide dej xuab zeb los txhuam cov chaw ua haujlwm ntawm lub tshuab polishing nrog 0.25um polishing tus neeg saib xyuas kom txog rau thaum qhov roughness Ra≤1.6um, thiab thaum kawg ntxuav thiab muab tso rau hauv lub ntsuas kub. .
Lub Priston (P4000A) electrochemical workstation nrog peb-electrode system tau siv.Lub platinum electrode (Pt) nrog thaj tsam ntawm 1 cm2 tau txais kev pabcuam electrode, DSS 2205 (nrog thaj tsam ntawm 1 cm2) tau siv los ua cov khoom siv hluav taws xob ua haujlwm, thiab cov khoom siv electrode (Ag / AgCl) yog siv.Cov qauv kev daws teeb meem siv hauv kev sim tau npaj raws li (Table 2).Ua ntej qhov kev sim, cov tshuaj N2 high-purity (99.99%) tau dhau mus rau 1 h, thiab tom qab ntawd CO2 tau dhau 30 feeb kom deoxygenate cov tshuaj., thiab CO2 nyob rau hauv cov tshuaj yog ib txwm nyob rau hauv lub xeev ntawm saturation.
Ua ntej, muab cov qauv tso rau hauv lub tank uas muaj cov tshuaj ntsuam xyuas, thiab muab tso rau hauv chav dej kub tas li.Thawj qhov ntsuas kub yog 2 ° C, thiab qhov kub nce siab yog tswj ntawm tus nqi ntawm 1 ° C / min, thiab qhov ntsuas kub yog tswj.ntawm 2-80 ° C.Celsius.Qhov kev sim pib ntawm qhov muaj peev xwm tsis tu ncua (-0.6142 Vs.Ag/AgCl) thiab qhov ntsuas nkhaus yog qhov nkhaus.Raws li qhov tseem ceeb pitting kub ntsuas tus qauv, Nws nkhaus tuaj yeem paub.Qhov kub ntawm qhov tam sim no ceev nce mus rau 100 μA / cm2 yog hu ua qhov tseem ceeb pitting kub.Qhov nruab nrab kub tseem ceeb rau pitting yog 66.9 ° C.Kev ntsuas kub rau lub polarization nkhaus thiab qhov impedance spectrum raug xaiv los ua 30 ° C, 45 ° C, 60 ° C thiab 75 ° C, raws li, thiab qhov kev sim tau rov ua peb zaug nyob rau hauv cov qauv qub kom txo tau qhov sib txawv.
Ib qho piv txwv hlau raug rau cov tshuaj yog thawj polarized ntawm lub peev xwm cathode (-1.3 V) rau 5 min ua ntej kuaj cov potentiodynamic polarization nkhaus kom tshem tawm cov oxide zaj duab xis tsim rau ntawm qhov chaw ua hauj lwm ntawm cov qauv, thiab tom qab ntawd ntawm qhov qhib Circuit Court muaj peev xwm ntawm 1 h kom txog thaum lub corrosion voltage yuav tsis tsim.Tus nqi scan ntawm lub zog muaj peev xwm polarization nkhaus tau teeb tsa rau 0.333mV / s, thiab lub sijhawm scan lub sijhawm tau teem rau -0.3 ~ 1.2V vs. OCP.Txhawm rau kom ntseeg tau qhov tseeb ntawm qhov kev xeem, tib yam kev xeem tau rov ua dua 3 zaug.
Impedance spectrum kuaj software - Versa Studio.Qhov kev ntsuam xyuas tau ua thawj zaug ntawm qhov qhib-circuit muaj peev xwm, qhov amplitude ntawm qhov hloov pauv kev cuam tshuam voltage tau teem rau 10 mV, thiab qhov ntsuas zaus tau teem rau 10-2-105 Hz.spectrum cov ntaub ntawv tom qab kuaj.
Tam sim no lub sij hawm nkhaus kuaj txheej txheem: xaiv qhov sib txawv passivation muaj peev xwm raws li cov txiaj ntsig ntawm anodic polarization nkhaus, ntsuas qhov nws nkhaus ntawm qhov muaj peev xwm tas li, thiab haum rau ob chav logarithm nkhaus los xam qhov nqes ntawm qhov nkhaus haum rau kev tsom xam zaj duab xis.lub mechanism ntawm kev tsim cov zaj duab xis passivating.
Tom qab qhib Circuit Court voltage stabilizes, ua ib qho kev kuaj Mott-Schottky nkhaus.Kuaj peev xwm scan ntau 1.0 ~ -1.0V (vS.Ag/AgCl), scan tus nqi 20mV/s, kuaj zaus teem rau 1000Hz, excitation teeb liab 5mV.
Siv X-ray photoelectron spectroscopy (XPS) (ESCALAB 250Xi, UK) los ntsuas cov tshuaj muaj pes tsawg leeg thiab tshuaj lom neeg lub xeev ntawm cov zaj duab xis passivation tom qab 2205 DSS zaj duab xis tsim thiab ua cov ntaub ntawv ntsuas peak-fit ua siv software superior.piv nrog cov databases ntawm atomic spectra thiab lwm yam ntaub ntawv23 thiab calibrated siv C1s (284.8 eV).Lub morphology ntawm corrosion thiab qhov tob ntawm pits ntawm cov qauv yog tus cwj pwm siv lub ultra-deep optical digital microscope (Zeiss Smart Zoom5, Lub teb chaws Yelemees).
Cov qauv raug kuaj ntawm tib lub peev xwm (-0.6142 V rel. Ag / AgCl) los ntawm txoj kev muaj peev xwm tsis tu ncua thiab cov kab hluav taws xob tam sim no tau kaw nrog lub sijhawm.Raws li tus qauv CPT xeem, qhov polarization tam sim no ceev maj mam nce nrog nce kub.1 qhia qhov tseem ceeb pitting kub ntawm 2205 DSS hauv cov tshuaj simulated uas muaj 100 g / L Cl- thiab saturated CO2.Nws tuaj yeem pom tau tias ntawm qhov ntsuas kub ntawm qhov kev daws teeb meem, qhov ceev tam sim no xyaum tsis hloov nrog nce lub sijhawm kuaj.Thiab thaum qhov kub ntawm cov tshuaj tau nce mus rau ib qho txiaj ntsig, qhov ceev tam sim no tau nce sai, qhia tias tus nqi ntawm kev sib cais ntawm cov yeeb yaj kiab passivating tau nce nrog qhov nce ntawm qhov kub ntawm cov tshuaj.Thaum qhov kub ntawm cov khoom tov yog nce los ntawm 2 ° C mus txog 67 ° C, polarization tam sim no ceev ntawm 2205DSS nce mus rau 100µA / cm2, thiab qhov nruab nrab pitting kub ntawm 2205DSS yog 66.9 ° C, uas yog hais txog 16.6 ° C. siab tshaj 2205DSS.standard 3.5 qw.% NaCl (0.7 V) 26.Qhov tseem ceeb pitting kub nyob ntawm seb muaj peev xwm siv tau thaum lub sijhawm ntsuas: qhov qis dua qhov siv tau, qhov siab dua qhov ntsuas qhov ntsuas pitting kub.
Pitting qhov ntsuas kub tseem ceeb ntawm 2205 duplex stainless hlau hauv cov tshuaj simulated uas muaj 100 g / L Cl- thiab saturated CO2.
Ntawm daim duab.2 qhia ac impedance cov phiaj xwm ntawm 2205 DSS hauv cov kev daws teeb meem simulated uas muaj 100 g / L Cl- thiab saturated CO2 ntawm ntau qhov kub thiab txias.Nws tuaj yeem pom tias daim duab Nyquist ntawm 2205DSS ntawm ntau qhov kub thiab txias muaj xws li high-frequency, mid-frequency thiab low-frequency resistance-capacitance arcs, and the resistance-capacitance arcs are not semicircular.Lub vojvoog ntawm lub capacitive arc qhia txog tus nqi tiv thaiv ntawm cov yeeb yaj kiab passivating thiab tus nqi ntawm cov nqi hloov pauv thaum lub sij hawm cov tshuaj tiv thaiv electrode.Nws feem ntau lees txais tias qhov loj dua lub vojvoog ntawm lub capacitive arc, qhov zoo dua qhov corrosion kuj ntawm cov hlau substrate nyob rau hauv kev daws 27.Ntawm qhov ntsuas kub ntawm 30 ° C, lub vojvoog ntawm lub capacitive arc ntawm daim duab Nyquist thiab lub kaum sab xis ntawm daim duab ntawm impedance modulus |Z|Bode yog qhov siab tshaj plaws thiab 2205 DSS corrosion yog qhov qis tshaj.Raws li qhov ntsuas kub nce, qhov |Z|impedance modulus, arc vojvoog thiab kev daws teeb meem txo qis, ntxiv rau, lub kaum sab xis theem kuj txo qis los ntawm 79 Ω mus rau 58 Ω nyob rau hauv thaj tsam nruab nrab zaus, uas qhia lub ncov dav thiab cov txheej sab hauv ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom txheej txheej txheej txheej txheej yog qhov tseem ceeb. nta ntawm inhomogeneous passive film28.Yog li ntawd, thaum kub nce, cov zaj duab xis passivating tsim nyob rau saum npoo ntawm cov hlau substrate dissolves thiab tawg, uas tsis muaj zog tiv thaiv cov khoom ntawm lub substrate thiab deteriorates corrosion kuj ntawm cov khoom29.
Siv ZSimDeme software kom haum rau cov ntaub ntawv impedance spectrum, qhov sib npaug sib npaug Circuit Court yog pom nyob rau hauv daim duab 330, qhov twg Rs yog cov simulated tov tshuaj tiv thaiv, Q1 yog cov zaj duab xis capacitance, Rf yog qhov tsis kam ntawm cov generated passivating zaj duab xis, Q2 yog ob npaug. txheej capacitance, thiab Rct yog tus nqi hloov pauv tsis kam.Los ntawm cov txiaj ntsig ntawm kev sib haum hauv lub rooj.3 qhia tau hais tias raws li qhov kub ntawm cov tshuaj simulated nce, tus nqi ntawm n1 txo los ntawm 0.841 mus rau 0.769, uas qhia tias qhov sib txawv ntawm ob-txheej capacitors thiab txo qhov ceev.Tus nqi hloov pauv tsis kam Rct maj mam txo los ntawm 2.958 × 1014 mus rau 2.541 × 103 Ω cm2, uas qhia tias maj mam txo qis hauv cov khoom siv corrosion.Kev ua haujlwm ntawm cov tshuaj Rs txo qis los ntawm 2.953 mus rau 2.469 Ω cm2, thiab capacitance Q2 ntawm cov zaj duab xis passivating poob los ntawm 5.430 10-4 mus rau 1.147 10-3 Ω cm2, conductivity ntawm cov tshuaj tau nce, stability ntawm passivating zaj duab xis txo. , thiab cov tshuaj Cl-, SO42-, thiab lwm yam) nyob rau hauv nruab nrab nce, uas accelerates kev puas tsuaj ntawm passivating film31.Qhov no ua rau txo qis hauv cov yeeb yaj kiab tsis kam Rf (los ntawm 4662 txog 849 Ω cm2) thiab txo qis hauv polarization tsis kam Rp (Rct + Rf) tsim rau saum npoo ntawm duplex stainless hlau.
Yog li ntawd, qhov kub ntawm cov tshuaj cuam tshuam rau corrosion kuj ntawm DSS 2205. Ntawm qhov kub thiab txias ntawm cov tshuaj, cov txheej txheem tshuaj tiv thaiv tshwm sim ntawm cathode thiab anode nyob rau hauv lub xub ntiag ntawm Fe2 +, uas ua rau kom ceev ceev dissolution thiab corrosion ntawm lub. anode, raws li zoo raws li lub passivation ntawm zaj duab xis tsim nyob rau saum npoo, ntau tiav thiab ntau dua ntom, ntau dua kuj nqi hloov ntawm cov kev daws teeb meem, slows down lub dissolution ntawm cov hlau matrix thiab exhibits zoo corrosion kuj.Raws li qhov kub ntawm cov tshuaj nce, qhov kev tiv thaiv kom them nqi hloov Rct txo, tus nqi ntawm cov tshuaj tiv thaiv ntawm ions nyob rau hauv cov tshuaj accelerates, thiab tus nqi ntawm diffusion ntawm aggressive ions accelerates, thiaj li hais tias cov thawj corrosion khoom yog rov tsim nyob rau saum npoo ntawm cov tshuaj. lub substrate los ntawm qhov chaw ntawm cov hlau substrate.Ib daim duab thinner passivating tsis muaj zog tiv thaiv cov khoom ntawm substrate.
Ntawm daim duab.Daim duab 4 qhia txog qhov muaj peev xwm polarization nkhaus ntawm 2205 DSS hauv cov kev daws teeb meem simulated uas muaj 100 g / L Cl- thiab saturated CO2 ntawm ntau qhov kub thiab txias.Nws tuaj yeem pom los ntawm daim duab uas thaum lub peev xwm nyob rau hauv thaj tsam ntawm -0.4 txog 0.9 V, lub anode nkhaus ntawm qhov sib txawv ntawm qhov kub thiab txias muaj cov cheeb tsam passivation pom tseeb, thiab tus kheej-corrosion peev xwm yog li -0.7 txog -0.5 V. Qhov ceev nce mus txog 100 μA / cm233 qhov nkhaus anode feem ntau hu ua pitting peev xwm (Eb lossis Etra).Raws li qhov kub thiab txias, qhov passivation luv nqi txo qis, qhov kev sib cav tam sim no yog qhov nce ntxiv, thiab cov polarization nkhaus tau tsim los ntawm DSS 2205 hauv kev daws teeb meem tau nquag kev ua si.Cov ntsiab lus ntawm 100 g / l Cl- thiab saturated CO2, nce rhiab heev rau pitting corrosion, yog yooj yim puas los ntawm ions txhoj puab heev, uas ua rau muaj zog corrosion ntawm cov hlau matrix thiab txo nyob rau hauv corrosion kuj.
Nws tuaj yeem pom los ntawm Table 4 tias thaum qhov kub nce ntawm 30 ° C mus rau 45 ° C, qhov sib txuam overpassivation muaj peev xwm txo qis me ntsis, tab sis qhov passivation tam sim no ceev ntawm qhov sib thooj loj nce ntxiv, qhia tias kev tiv thaiv ntawm cov yeeb yaj kiab passivating hauv qab no. tej yam kev mob nce nrog nce kub.Thaum qhov kub nce mus txog 60 ° C, qhov sib thooj pitting muaj peev xwm txo qis, thiab qhov sib txawv no yuav tshwm sim ntau dua thaum qhov kub nce.Nws yuav tsum tau muab sau tseg tias nyob rau ntawm 75 ° C ib qho tseem ceeb nyob rau tam sim no ncov tshwm nyob rau hauv daim duab, qhia tau hais tias muaj metastable pitting corrosion ntawm tus qauv nto.
Yog li ntawd, nrog kev nce hauv qhov kub thiab txias ntawm cov tshuaj, cov pa oxygen yaj hauv cov tshuaj txo qis, pH tus nqi ntawm cov zaj duab xis nto txo, thiab kev ruaj ntseg ntawm cov zaj duab xis passivating txo.Tsis tas li ntawd, qhov kub ntawm cov tshuaj ntau dua, qhov kev ua haujlwm ntawm cov ions txhoj puab heev nyob rau hauv cov kev daws teeb meem ntau dua thiab qhov siab dua qhov kev puas tsuaj rau cov yeeb yaj kiab txheej txheej ntawm cov substrate.Oxides tsim nyob rau hauv cov zaj duab xis txheej yooj yim poob tawm thiab hnov mob nrog cations nyob rau hauv cov zaj duab xis txheej los ua soluble tebchaw, ua rau muaj feem yuav pitting.Txij li cov txheej txheej zaj duab xis rov tsim dua yog qhov xoob, qhov kev tiv thaiv ntawm lub substrate yog qhov tsawg, uas ua rau kom muaj corrosion ntawm hlau substrate.Cov txiaj ntsig ntawm dynamic polarization muaj peev xwm kuaj tau zoo ib yam nrog cov txiaj ntsig ntawm impedance spectroscopy.
Ntawm daim duab.Daim duab 5a qhia Nws nkhaus rau 2205 DSS hauv cov qauv kev daws teeb meem uas muaj 100 g / L Cl- thiab saturated CO2.Lub passivation tam sim no ceev raws li kev ua haujlwm ntawm lub sijhawm tau txais tom qab polarization ntawm ntau qhov kub thiab txias rau 1 h ntawm lub peev xwm ntawm -300 mV (kwv yees rau Ag / AgCl).Nws tuaj yeem pom tau tias qhov kev hloov pauv tam sim no qhov ntom ntom ntawm 2205 DSS ntawm tib lub peev xwm thiab qhov sib txawv ntawm qhov kub thiab txias yog qhov zoo ib yam, thiab cov qauv maj mam txo nrog lub sijhawm thiab zoo li du.Raws li qhov kub thiab txias maj mam nce, qhov passivation tam sim no ceev ntawm 2205 DSS tau nce, uas yog raws li cov txiaj ntsig ntawm polarization, uas kuj tau qhia tias cov yam ntxwv tiv thaiv ntawm cov yeeb yaj kiab txheej ntawm cov hlau substrate txo qis nrog kev kub siab ntxiv.
Potentiostatic polarization nkhaus ntawm 2205 DSS ntawm tib zaj duab xis tsim muaj peev xwm thiab sib txawv kub.(a) Qhov ceev tam sim no piv rau lub sijhawm, (b) Passive zaj duab xis loj hlob logarithm.
Tshawb xyuas qhov kev sib raug zoo ntawm qhov passivation tam sim no ceev thiab lub sij hawm ntawm qhov sib txawv ntawm qhov kub thiab txias rau tib zaj duab xis tsim muaj peev xwm, raws li qhia hauv (1) 34:
Qhov twg kuv yog qhov passivation tam sim no ntom ntawm zaj duab xis tsim muaj peev xwm, A / cm2.A yog thaj tsam ntawm kev ua haujlwm electrode, cm2.K yog txoj kab nqes ntawm qhov nkhaus haum rau nws.t sij,s
Ntawm daim duab.5b qhia logI thiab logt nkhaus rau 2205 DSS ntawm qhov sib txawv ntawm qhov sib txawv ntawm tib zaj duab xis tsim muaj peev xwm.Raws li cov ntaub ntawv cov ntaub ntawv, 35 thaum kab slopes K = -1, zaj duab xis txheej tsim nyob rau saum npoo ntawm substrate yog denser thiab muaj zoo corrosion kuj rau cov hlau substrate.Thiab thaum txoj kab ncaj nraim K = -0.5, zaj duab xis txheej tsim nyob rau saum npoo yog xoob, muaj ntau qhov me me thiab tsis zoo corrosion kuj rau cov hlau substrate.Nws tuaj yeem pom tau hais tias ntawm 30 ° C, 45 ° C, 45 ° C, thiab 75 ° C, thiab 75 ° C, thiab 75 ° C, thiab 75 ° pores kom xoob txoj kab uas raug xaiv.Raws li Point Defect Model (PDM) 36,37 nws tuaj yeem pom tias lub peev xwm siv tau thaum lub sijhawm kuaj tsis cuam tshuam rau qhov ceev tam sim no, qhia tias qhov kub thiab txias cuam tshuam ncaj qha rau kev ntsuas ntawm anode tam sim no ntom ntom thaum lub sijhawm kuaj, yog li tam sim no. nce nrog nce kub.daws, thiab qhov ceev ntawm 2205 DSS nce, thiab corrosion kuj txo.
Cov khoom semiconductor ntawm nyias zaj duab xis txheej tsim nyob rau hauv DSS cuam tshuam rau nws corrosion resistance38, hom semiconductor thiab cov cab kuj ceev ntawm nyias zaj duab xis txheej cuam tshuam lub cracking thiab pitting ntawm nyias zaj duab xis txheej DSS39,40 qhov twg lub capacitance C thiab E ntawm lub peev xwm nyias zaj duab xis txheej txaus siab rau kev sib raug zoo MS, qhov chaw them nqi ntawm lub semiconductor yog xam raws li hauv qab no:
Nyob rau hauv cov mis, ε yog permittivity ntawm passivating zaj duab xis nyob rau hauv chav tsev kub, sib npaug rau 1230, ε0 yog lub nqus permittivity, sib npaug rau 8.85 × 10-14 F / cm, E yog tus nqi thib ob (1.602 × 10-19 C) ;ND yog qhov ceev ntawm n-hom semiconductor pub, cm–3, NA yog qhov lees txais qhov ntom ntawm p-hom semiconductor, cm–3, EFB yog lub tiaj-band muaj peev xwm, V, K yog Boltzmann qhov tas li, 1.38 × 10–3 .23 J / K, T - kub, K.
Txoj kab nqes thiab cuam tshuam ntawm txoj kab haum tuaj yeem suav tau los ntawm kev sib cais ntawm cov kab sib cais mus rau qhov ntsuas MS nkhaus, siv cov concentration (ND), txais kev pom zoo (NA), thiab tiaj tus peev xwm (Efb) 42.
Ntawm daim duab.6 qhia txog Mott-Schottky nkhaus ntawm txheej saum npoo ntawm 2205 DSS zaj duab xis tsim hauv cov tshuaj simulated uas muaj 100 g / l Cl- thiab saturated nrog CO2 ntawm lub peev xwm (-300 mV) rau 1 teev.Nws tuaj yeem pom tau tias tag nrho cov txheej nyias nyias tsim ntawm qhov kub sib txawv muaj cov yam ntxwv ntawm n + p-hom bipolar semiconductors.N-hom semiconductor muaj kev daws teeb meem anion xaiv, uas tuaj yeem tiv thaiv cov hlau tsis huv cations los ntawm diffusing mus rau hauv cov tshuaj los ntawm passivation zaj duab xis, thaum lub p-type semiconductor muaj cation selectivity, uas tuaj yeem tiv thaiv cov corrosive anions hauv kev daws los ntawm passivation crossings. tawm ntawm qhov chaw ntawm lub substrate 26.Nws kuj tseem tuaj yeem pom tau tias muaj kev hloov pauv ntawm ob txoj kev nkhaus, zaj duab xis yog nyob rau hauv lub tiaj tiaj tiaj, thiab lub tiaj tiaj tiaj muaj peev xwm Efb tuaj yeem siv los txiav txim siab txoj haujlwm ntawm lub zog band ntawm ib lub semiconductor thiab ntsuas nws cov electrochemical. stability 43..
Raws li MC nkhaus haum cov txiaj ntsig tau pom nyob rau hauv Table 5, qhov tawm mus concentration (ND) thiab qhov tau txais concentration (NA) thiab lub tiaj tiaj muaj peev xwm Efb 44 ntawm tib qhov kev txiav txim ntawm qhov loj tau suav.Qhov ceev ntawm daim ntawv thov cov cab kuj tam sim no feem ntau qhia qhov tsis xws luag hauv qhov chaw them nqi txheej thiab lub peev xwm pitting ntawm cov yeeb yaj kiab passivating.Qhov siab dua qhov concentration ntawm cov khoom siv thauj khoom, qhov yooj yim ntawm cov zaj duab xis txheej tawg thiab qhov ntau dua qhov ua tau ntawm substrate corrosion45.Tsis tas li ntawd, nrog kev maj mam nce hauv qhov kub ntawm cov tshuaj, ND emitter concentration nyob rau hauv cov zaj duab xis txheej tau nce los ntawm 5.273 × 1020 cm-3 mus rau 1.772 × 1022 cm-3, thiab NA host concentration nce los ntawm 4.972 × 1021 mus rau 4.592. × 1023.cm - raws li qhia hauv daim duab.3, lub tiaj tiaj tiaj muaj peev xwm nce ntawm 0.021 V mus rau 0.753 V, cov neeg nqa khoom hauv cov tshuaj nce ntxiv, cov tshuaj tiv thaiv ntawm ions hauv cov tshuaj intensifies, thiab stability ntawm cov zaj duab xis txheej txo.Raws li qhov ntsuas kub ntawm cov tshuaj nce ntxiv, qhov me me ntawm qhov tseeb ntawm txoj kab nqes ntawm txoj kab kwv yees, qhov ntau dua qhov ceev ntawm cov cab kuj nyob rau hauv cov tshuaj, qhov ntau dua tus nqi ntawm diffusion ntawm ions, thiab ntau dua tus naj npawb ntawm ion vacancies ntawm lub nto ntawm zaj duab xis txheej., yog li txo cov hlau substrate, stability thiab corrosion kuj 46,47.
Cov tshuaj lom neeg muaj pes tsawg leeg ntawm cov yeeb yaj kiab muaj qhov cuam tshuam tseem ceeb rau kev ruaj ntseg ntawm cov hlau cations thiab kev ua haujlwm ntawm cov khoom siv hluav taws xob, thiab qhov kev hloov ntawm qhov kub thiab txias muaj qhov cuam tshuam tseem ceeb ntawm kev tsim cov yeeb yaj kiab stainless hlau.Ntawm daim duab.Daim duab 7 qhia tag nrho XPS spectrum ntawm txheej txheej saum npoo ntawm 2205 DSS zaj duab xis hauv cov tshuaj simulated uas muaj 100 g / L Cl- thiab saturated CO2.Cov ntsiab lus tseem ceeb hauv cov yeeb yaj kiab tsim los ntawm cov chips ntawm qhov sib txawv ntawm qhov kub thiab txias yog qhov zoo ib yam, thiab cov khoom tseem ceeb ntawm cov yeeb yaj kiab yog Fe, Cr, Ni, Mo, O, N, thiab C. Yog li ntawd, cov khoom tseem ceeb ntawm txheej zaj duab xis yog Fe. , Cr, Ni, Mo, O, N thiab C. Thawv nrog Cr oxides, Fe oxides thiab hydroxides thiab ib qho me me ntawm Ni thiab Mo oxides.
Tag Nrho XPS 2205 DSS spectra coj ntawm ntau qhov kub thiab txias.(a) 30 ° C, (b) 45 ° C, (c) 60 ° C, (d) 75 ° C.
Lub ntsiab muaj pes tsawg leeg ntawm zaj duab xis yog muaj feem xyuam rau cov thermodynamic zog ntawm cov tebchaw nyob rau hauv lub passivating zaj duab xis.Raws li kev khi lub zog ntawm cov ntsiab lus tseem ceeb hauv txheej zaj duab xis, muab rau hauv rooj.6, nws tuaj yeem pom tias cov yam ntxwv spectral peaks ntawm Cr2p3/2 muab faib ua hlau Cr0 (573.7 ± 0.2 eV), Cr2O3 (574.5 ± 0.3 eV), thiab Cr (OH) 3 (575.4 ± 0. 1 eV) raws li pom nyob rau hauv daim duab 8a, nyob rau hauv uas cov oxide tsim los ntawm lub Cr keeb yog lub ntsiab tivthaiv nyob rau hauv cov zaj duab xis, uas plays ib tug tseem ceeb luag hauj lwm nyob rau hauv lub corrosion kuj ntawm cov zaj duab xis thiab nws cov electrochemical kev ua tau zoo.Tus txheeb ze ncov siv ntawm Cr2O3 nyob rau hauv zaj duab xis txheej yog siab dua li ntawm Cr (OH) 3.Txawm li cas los xij, raws li cov kua dej kub nce ntxiv, cov txheeb ze ncov ntawm Cr2O3 maj mam poob qis, thaum cov txheeb ze ncov ntawm Cr (OH) 3 maj mam nce, uas qhia tau hais tias qhov kev hloov pauv ntawm lub ntsiab Cr3 + hauv zaj duab xis txheej los ntawm Cr2O3 rau Cr (OH) 3, thiab qhov kub ntawm qhov kev daws teeb meem nce.
Lub zog khi ntawm lub ncov ntawm cov yam ntxwv spectrum ntawm Fe2p3/2 feem ntau yog muaj plaub lub ncov ntawm lub xeev hlau Fe0 (706.4 ± 0.2 eV), Fe3O4 (707.5 ± 0.2 eV), FeO (709.5 ± 0.1 eV) thiab Fe. eV) ± 0.3 eV), raws li qhia hauv daim duab 8b, Fe feem ntau yog tam sim no nyob rau hauv cov zaj duab xis tsim nyob rau hauv daim ntawv ntawm Fe2+ thiab Fe3+.Fe2+ los ntawm FeO dominates Fe(II) nyob rau hauv qis binding zog peaks, thaum Fe3O4 thiab Fe(III) FeOOH tebchaw dominates siab dua binding zog peaks48,49.Qhov txheeb ze ntawm Fe3 + ncov siab dua li ntawm Fe2+, tab sis qhov txheeb ze ntawm Fe3 + ncov txo qis nrog kev daws qhov kub thiab txias, thiab qhov txheeb ze ntawm Fe2+ ncov nce, qhia txog kev hloov pauv hauv cov khoom tseem ceeb hauv cov yeeb yaj kiab txheej los ntawm Fe3 + rau Fe2 + kom qhov kub thiab txias ntawm cov tshuaj.
Cov yam ntxwv spectral peaks ntawm Mo3d5/2 mas muaj ob lub ncov txoj hauj lwm Mo3d5/2 thiab Mo3d3/243.50, thaum Mo3d5/2 muaj xws li hlau Mo (227.5 ± 0.3 eV), Mo4+ (228.9 ± 0.2 eV) thiab Mo6.3 + (eV2). ), thaum Mo3d3/2 kuj muaj hlau Mo (230.4 ± 0.1 eV), Mo4+ (231.5 ± 0.2 eV) thiab Mo6+ (232, 8 ± 0.1 eV) raws li qhia hauv daim duab 8c, yog li Mo cov ntsiab lus muaj nyob rau hauv peb lub valence. lub xeev ntawm zaj duab xis txheej.Lub zog khi ntawm cov yam ntxwv spectral peaks ntawm Ni2p3/2 muaj Ni0 (852.4 ± 0.2 eV) thiab NiO (854.1 ± 0.2 eV), raws li qhia hauv daim duab 8g feem.Tus yam ntxwv N1s ncov muaj N (399.6 ± 0.3 eV), raws li qhia hauv daim duab 8d.Cov yam ntxwv ntawm O1s peaks suav nrog O2- (529.7 ± 0.2 eV), OH- (531.2 ± 0.2 eV) thiab H2O (531.8 ± 0.3 eV), raws li qhia hauv daim duab. Cov khoom tseem ceeb ntawm cov txheej txheem yog (OH- thiab O2 -) , uas yog tsuas yog siv rau oxidation los yog hydrogen oxidation ntawm Cr thiab Fe nyob rau hauv cov zaj duab xis txheej.Tus txheeb ze ncov siab ntawm OH- nce ntxiv vim qhov kub nce ntawm 30 ° C mus rau 75 ° C.Yog li ntawd, nrog rau qhov kub thiab txias, cov khoom tseem ceeb ntawm O2- nyob rau hauv zaj duab xis txheej hloov ntawm O2- rau OH- thiab O2-.
Ntawm daim duab.Daim duab 9 qhia tau hais tias lub microscopic nto morphology ntawm cov qauv 2205 DSS tom qab dynamic muaj peev xwm polarization nyob rau hauv cov qauv tov uas muaj 100 g / L Cl- thiab saturated CO2.Nws tuaj yeem pom tau tias nyob rau saum npoo ntawm cov qauv polarized ntawm qhov sib txawv ntawm qhov kub thiab txias, muaj qhov corrosion ntawm qhov sib txawv ntawm qhov sib txawv, qhov no tshwm sim hauv kev daws teeb meem ntawm ions aggressive, thiab nrog kev nce hauv qhov kub ntawm cov tshuaj, qhov corrosion loj dua tshwm sim ntawm qhov kev daws teeb meem ntawm ions. nto ntawm cov qauv.substrate.Tus naj npawb ntawm pitting pits ib cheeb tsam thiab qhov tob ntawm qhov chaw corrosion nce.
Corrosion curves ntawm 2205 DSS hauv cov qauv kev daws teeb meem uas muaj 100 g / l Cl- thiab saturated CO2 ntawm qhov kub sib txawv (a) 30 ° C, (b) 45 ° C, (c) 60 ° C, (d) 75 ° C.
Yog li ntawd, qhov kub thiab txias yuav ua rau muaj kev ua haujlwm ntawm txhua yam ntawm DSS, nrog rau kev ua kom muaj zog ntawm ions nyob rau hauv ib qho kev txhoj puab heev, ua rau muaj qee qhov kev puas tsuaj rau cov qauv saum npoo, uas yuav ua rau kom muaj zog pitting., thiab qhov tsim ntawm corrosion pits yuav nce.Tus nqi ntawm cov khoom tsim yuav nce thiab corrosion kuj ntawm cov khoom yuav txo 51,52,53,54,55.
Ntawm daim duab.10 qhia txog morphology thiab pitting qhov tob ntawm 2205 DSS qauv polarized nrog rau qhov tob tob ntawm thaj chaw kho qhov muag digital microscope.Los ntawm fig.10a qhia tau hais tias me me corrosion pits kuj tshwm nyob ib ncig ntawm lub pits loj, qhia tau hais tias lub passivating zaj duab xis nyob rau hauv cov qauv saum npoo yog ib feem puas nrog cov tsim ntawm corrosion pits ntawm ib tug muab tam sim no ceev, thiab lub siab tshaj plaws pitting qhov tob yog 12.9 µm.raws li qhia hauv daim duab 10b.
DSS qhia tau hais tias zoo corrosion kuj, lub ntsiab yog vim li cas cov zaj duab xis tsim nyob rau saum npoo ntawm cov hlau yog zoo tiv thaiv nyob rau hauv kev daws, Mott-Schottky, raws li cov saum toj no XPS tau thiab lwm yam ntaub ntawv 13,56,57,58, zaj duab xis mas dhau los ntawm cov hauv qab no Qhov no yog cov txheej txheem ntawm oxidation ntawm Fe thiab Cr.
Fe2+ tau yooj yim yaj thiab precipitates ntawm lub interface 53 ntawm cov zaj duab xis thiab kev daws, thiab cov txheej txheem cathodic cov tshuaj tiv thaiv yog raws li nram no:
Nyob rau hauv lub xeev corroded, ib tug ob-txheej txheej txheej zaj duab xis yog tsim, uas feem ntau muaj ib tug puab txheej ntawm hlau thiab chromium oxides thiab ib tug txheej hydroxide txheej, thiab ions feem ntau loj hlob nyob rau hauv lub pores ntawm zaj duab xis.Cov tshuaj muaj pes tsawg leeg ntawm cov zaj duab xis passivating muaj feem xyuam rau nws cov khoom semiconductor, raws li muaj pov thawj los ntawm Mott-Schottky nkhaus, qhia tias muaj pes tsawg leeg ntawm cov zaj duab xis passivating yog n + p-hom thiab muaj cov yam ntxwv bipolar.XPS cov txiaj ntsig tau pom tias txheej txheej txheej ntawm cov zaj duab xis passivating feem ntau yog tsim los ntawm Fe oxides thiab hydroxides nthuav tawm cov khoom n-hom semiconductor, thiab cov txheej sab hauv yog tsim los ntawm Cr oxides thiab hydroxides nthuav tawm p-hom semiconductor zog.
2205 DSS muaj kev tiv thaiv siab vim nws cov ntsiab lus Cr17.54 siab thiab nthuav tawm qhov sib txawv ntawm pitting vim microscopic galvanic corrosion55 ntawm cov qauv duplex.Pitting corrosion yog ib qho ntawm ntau hom kev xeb hauv DSS, thiab qhov kub thiab txias yog ib qho tseem ceeb cuam tshuam tus cwj pwm ntawm pitting corrosion thiab muaj kev cuam tshuam rau cov txheej txheem thermodynamic thiab kinetic ntawm DSS cov tshuaj tiv thaiv 60,61.Feem ntau, nyob rau hauv ib tug simulated tov nrog ib tug siab concentration ntawm Cl- thiab saturated CO2, qhov kub kuj muaj feem xyuam rau lub tsim ntawm pitting thiab pib ntawm cov kab nrib pleb thaum muaj kev ntxhov siab corrosion cracking nyob rau hauv kev nyuaj siab corrosion cracking, thiab qhov tseem ceeb kub ntawm pitting yog txiav txim siab los soj ntsuam. qhov corrosion kuj.DSS.Cov khoom siv, uas qhia txog qhov rhiab heev ntawm cov hlau matrix rau qhov kub thiab txias, feem ntau yog siv los ua ib qho tseem ceeb hauv kev xaiv cov khoom siv hauv engineering.Qhov nruab nrab qhov tseem ceeb pitting kub ntawm 2205 DSS nyob rau hauv lub simulated tov yog 66.9 ° C, uas yog 25.6 ° C siab tshaj cov Super 13Cr stainless hlau nrog 3.5% NaCl, tab sis qhov siab tshaj pitting qhov tob mus txog 12.9 µm62.Cov txiaj ntsig electrochemical ntxiv tau lees paub tias cov cheeb tsam kab rov tav ntawm lub kaum sab xis theem thiab zaus nqaim nrog nce qhov kub thiab txias, thiab raws li lub kaum sab xis ntawm theem qis ntawm 79 ° txog 58 °, tus nqi ntawm |Z|txo los ntawm 1.26 × 104 mus rau 1.58 × 103 Ω cm2.tus nqi hloov pauv tsis kam Rct txo los ntawm 2.958 1014 txog 2.541 103 Ω cm2, kev daws teeb meem Rs txo los ntawm 2.953 txog 2.469 Ω cm2, zaj duab xis kuj Rf txo los ntawm 5.430 10-4 cm2 rau 1.147 10-3 cm2.Lub conductivity ntawm cov tshuaj aggressive nce, stability ntawm cov hlau matrix zaj duab xis txheej txo, nws dissolves thiab tawg yooj yim.Tus kheej-corrosion tam sim no ceev tau nce los ntawm 1.482 mus rau 2.893 × 10-6 A cm-2, thiab tus kheej-corrosion peev xwm poob ntawm -0.532 rau -0.621V.Nws tuaj yeem pom tias qhov kev hloov pauv ntawm qhov kub thiab txias cuam tshuam rau kev ncaj ncees thiab qhov ntom ntom ntawm cov yeeb yaj kiab txheej.
Ntawm qhov tsis sib xws, cov ntsiab lus siab ntawm Cl- thiab cov tshuaj saturated ntawm CO2 maj mam nce lub peev xwm adsorption ntawm Cl- nyob rau saum npoo ntawm cov yeeb yaj kiab passivating nrog qhov kub thiab txias, kev ruaj ntseg ntawm cov yeeb yaj kiab passivation yuav tsis ruaj khov, thiab kev tiv thaiv zoo ntawm cov yeeb yaj kiab. substrate yuav qaug zog thiab susceptibility rau pitting nce.Nyob rau hauv cov ntaub ntawv no, cov kev ua ntawm corrosive ions nyob rau hauv cov kev daws tsub kom, cov ntsiab lus ntawm cov pa oxygen txo, thiab cov zaj duab xis nto ntawm cov khoom corroded yog ib qho nyuaj rau rov qab sai sai, uas tsim ib tug ntau haumxeeb yam ntxwv rau ntxiv adsorption ntawm corrosive ions nyob rau saum npoo.Cov khoom siv txo 63.Robinson thiab al.[64] pom tias nrog kev nce hauv qhov kub ntawm cov tshuaj, qhov kev loj hlob ntawm cov pits accelerates, thiab tus nqi ntawm diffusion ntawm ions hauv cov tshuaj kuj nce.Thaum qhov kub nce mus txog 65 ° C, qhov kev sib cais ntawm cov pa oxygen hauv cov tshuaj uas muaj Cl-ions ua rau qeeb qeeb ntawm cov txheej txheem cathodic, tus nqi ntawm pitting yog txo.Han20 tshawb xyuas qhov kub thiab txias ntawm tus cwj pwm corrosion ntawm 2205 duplex stainless hlau hauv ib puag ncig CO2.Cov txiaj ntsig tau pom tias qhov ntsuas kub nce ntxiv ntawm cov khoom siv corrosion thiab thaj tsam ntawm shrinkage kab noj hniav nyob rau saum npoo ntawm cov khoom.Ib yam li ntawd, thaum kub nce mus txog 150 ° C, cov oxide zaj duab xis ntawm qhov chaw tawg, thiab qhov ceev ntawm cov craters yog siab tshaj.Lu4 tshawb xyuas qhov cuam tshuam ntawm qhov kub thiab txias ntawm tus cwj pwm corrosion ntawm 2205 duplex stainless hlau los ntawm passivation mus rau kev ua kom nyob rau hauv ib puag ncig geothermal uas muaj CO2.Lawv cov txiaj ntsig tau pom tias ntawm qhov ntsuas kub qis dua 150 ° C, cov yeeb yaj kiab tsim muaj cov qauv amorphous, thiab sab hauv muaj cov txheej txheem npib tsib xee, thiab ntawm qhov kub ntawm 300 ° C, cov khoom siv corrosion muaj cov qauv nanoscale. .-polycrystalline FeCr2O4, CrOOH thiab NiFe2O4.
Ntawm daim duab.11 yog daim duab ntawm cov txheej txheem corrosion thiab zaj duab xis ntawm 2205 DSS.Ua ntej siv, 2205 DSS ua ib zaj duab xis passivating nyob rau hauv qhov chaw.Tom qab muab tso rau hauv ib puag ncig uas simulates ib qho kev daws teeb meem nrog cov ntsiab lus siab ntawm Cl- thiab CO2, nws qhov chaw tau nrawm nrawm los ntawm ntau yam ions txhoj puab heev (Cl-, CO32-, thiab lwm yam).).J. Banas 65 tau xaus lus tias nyob rau hauv ib puag ncig uas CO2 nyob rau tib lub sijhawm tam sim no, kev ruaj ntseg ntawm cov zaj duab xis passivating ntawm cov khoom siv yuav txo nrog lub sijhawm, thiab cov tsim carbonic acid nyhav nce cov conductivity ntawm ions hauv passivating. txheej.zaj duab xis thiab acceleration ntawm dissolution ntawm ions nyob rau hauv ib tug passivating zaj duab xis.zaj duab xis passivating.Yog li, cov zaj duab xis txheej ntawm cov qauv saum npoo yog nyob rau hauv ib tug dynamic equilibrium theem ntawm dissolution thiab repassivation66, Cl- txo tus nqi ntawm tsim ntawm txheej zaj duab xis nto, thiab me me pitting pits tshwm rau ntawm qhov chaw nyob ib sab ntawm zaj duab xis nto, raws li qhia hauv daim duab 3. Qhia.Raws li pom hauv daim duab 11a thiab b, cov pits tsis ruaj khov me me tshwm sim tib lub sijhawm.Raws li qhov kub thiab txias, qhov kev ua ntawm corrosive ions nyob rau hauv kev daws ntawm cov zaj duab xis txheej nce, thiab qhov tob ntawm cov me me tsis ruaj tsis khov pits nce mus txog rau thaum cov zaj duab xis txheej yog kiag li nkag mus rau hauv lub pob tshab, raws li qhia nyob rau hauv daim duab 11c.Nrog rau kev nce ntxiv ntawm qhov kub ntawm qhov nruab nrab dissolving, cov ntsiab lus ntawm yaj CO2 nyob rau hauv cov tshuaj accelerates, uas ua rau ib tug txo nyob rau hauv pH tus nqi ntawm cov tshuaj, ib qho kev nce nyob rau hauv qhov ceev ntawm qhov tsawg tshaj plaws corrosion pits ntawm SPP nto. , qhov tob ntawm qhov pib corrosion pits expands thiab deepens, thiab passivating zaj duab xis nyob rau hauv cov qauv nto Raws li cov thickness txo, lub passivating zaj duab xis yuav ntau prone rau pitting raws li qhia nyob rau hauv daim duab 11d.Thiab cov txiaj ntsig electrochemical ntxiv tau lees paub tias qhov kev hloov pauv ntawm qhov kub thiab txias muaj qee yam cuam tshuam rau kev ncaj ncees thiab qhov ntom ntawm cov yeeb yaj kiab.Yog li, nws tuaj yeem pom tias corrosion hauv cov kev daws teeb meem saturated nrog CO2 uas muaj cov ntsiab lus siab ntawm Cl- yog qhov sib txawv ntawm corrosion nyob rau hauv cov kev daws teeb meem uas tsis muaj concentration ntawm Cl-67,68.
Corrosion txheej txheem 2205 DSS nrog kev tsim thiab kev puas tsuaj ntawm ib zaj duab xis tshiab.(a) Txheej Txheem 1, (b) Txheej Txheem 2, (c) Txheej Txheem 3, (d) Txheej Txheem 4.
Qhov nruab nrab tseem ceeb pitting kub ntawm 2205 DSS nyob rau hauv ib tug simulated tov uas muaj 100 g / l Cl- thiab saturated CO2 yog 66.9 ℃, thiab qhov siab tshaj pitting qhov tob yog 12.9 µm, uas txo cov corrosion kuj ntawm 2205 DSS thiab tsub kom lub rhiab heev rau pitting.kub nce.
Post lub sij hawm: Feb-16-2023