Ua tsaug rau koj tuaj xyuas Nature.com. Koj siv lub browser version uas muaj kev txhawb nqa CSS tsawg. Rau qhov kev paub zoo tshaj plaws, peb xav kom koj siv lub browser hloov tshiab (lossis kaw Compatibility Mode hauv Internet Explorer). Tsis tas li ntawd, kom ntseeg tau tias muaj kev txhawb nqa tas mus li, peb qhia lub xaib tsis muaj cov qauv thiab JavaScript.
Tso saib ib daim carousel uas muaj peb daim slides ib zaug. Siv cov nyees khawm Yav dhau los thiab Tom ntej kom txav mus los ntawm peb daim slides ib zaug, lossis siv cov nyees khawm slider thaum kawg kom txav mus los ntawm peb daim slides ib zaug.
Cov hlau tsis xeb uas siv dav dav thiab nws cov qauv ua los ntawm cov hlau tsis xeb feem ntau tiv taus xeb hauv cov huab cua ib puag ncig vim yog txheej passivation uas muaj chromium oxide. Kev xeb thiab kev yaig ntawm cov hlau feem ntau cuam tshuam nrog kev puas tsuaj ntawm cov txheej no, tab sis tsis tshua muaj qhov tshwm sim ntawm qhov tsis sib xws ntawm qhov chaw, nyob ntawm qib microscopic. Hauv txoj haujlwm no, nanoscale tshuaj lom neeg qhov sib txawv ntawm qhov chaw, pom los ntawm spectroscopic microscopy thiab chemometric tsom xam, tsis tau xav txog qhov tawg thiab xeb ntawm cov hlau txias dov cerium hloov kho super duplex stainless hlau 2507 (SDSS) thaum nws kub deformation. Txawm hais tias X-ray photoelectron microscopy qhia txog kev npog sib npaug ntawm cov txheej Cr2O3 ntuj, qhov kev ua tau zoo passivation ntawm SDSS txias dov tsis zoo vim yog qhov kev faib tawm hauv zos ntawm Fe3 + nplua nuj nanoislands ntawm Fe / Cr oxide txheej. Qhov kev paub txog atomic scale no muab kev nkag siab tob txog kev xeb ntawm cov hlau tsis xeb thiab xav tias yuav pab tiv thaiv kev xeb ntawm cov hlau zoo sib xws.
Txij li thaum muaj kev tsim cov hlau tsis xeb, cov khoom tiv thaiv xeb ntawm ferrochrome tau raug suav hais tias yog chromium, uas tsim cov oxides / oxyhydroxides muaj zog thiab ua rau muaj kev coj cwj pwm passivating hauv feem ntau ib puag ncig. Piv rau cov hlau tsis xeb ib txwm muaj (austenitic thiab ferritic) 1, 2, 3, super duplex stainless steels (SDSS) muaj kev tiv thaiv xeb zoo dua thiab cov khoom siv kho tshuab zoo heev. Kev muaj zog kho tshuab ntxiv ua rau cov qauv tsim sib dua thiab me dua. Qhov sib piv, SDSS pheej yig muaj kev tiv thaiv siab rau kev xeb pitting thiab crevice, ua rau lub neej ua haujlwm ntev dua, yog li nthuav nws daim ntawv thov rau kev tswj hwm kev ua qias tuaj, cov thawv tshuaj, thiab kev lag luam roj thiab roj av hauv hiav txwv4. Txawm li cas los xij, qhov ntau thiab tsawg ntawm qhov kub thiab txias kho cua sov thiab kev ua tsis zoo cuam tshuam lawv daim ntawv thov dav dav. Yog li ntawd, SDSS tau hloov kho kom txhim kho kev ua tau zoo saum toj no. Piv txwv li, Ce kev hloov kho tau qhia hauv SDSS 2507 (Ce-2507) nrog cov ntsiab lus nitrogen siab6,7,8. Cov khoom tsis tshua muaj av (Ce) ntawm qhov concentration tsim nyog ntawm 0.08 wt.% muaj cov txiaj ntsig zoo rau cov khoom siv kho tshuab ntawm DSS, vim nws txhim kho kev ua kom zoo ntawm cov noob thiab lub zog ciam teb ntawm cov noob. Kev hnav thiab kev tiv thaiv corrosion, lub zog tensile thiab lub zog tso zis, thiab kev ua haujlwm kub kuj tau txhim kho9. Cov nitrogen ntau tuaj yeem hloov cov ntsiab lus nickel kim, ua rau SDSS pheej yig dua10.
Tsis ntev los no, SDSS tau raug hloov pauv plastically ntawm ntau qhov kub thiab txias (cryogenic, txias thiab kub) kom ua tiav cov khoom siv kho tshuab zoo heev6,7,8. Txawm li cas los xij, qhov kev tiv thaiv corrosion zoo heev ntawm SDSS vim muaj cov zaj duab xis oxide nyias nyias ntawm qhov chaw raug cuam tshuam los ntawm ntau yam xws li qhov sib txawv ntawm qhov sib txawv vim muaj cov theem sib txawv nrog cov ciam teb sib txawv, cov av tsis xav tau thiab cov lus teb sib txawv. deformations ntawm austenitic thiab ferritic theem7. Yog li ntawd, kev kawm txog cov khoom siv microscopic ntawm cov yeeb yaj kiab zoo li no mus txog rau theem ntawm cov qauv hluav taws xob ua qhov tseem ceeb rau kev nkag siab txog kev xeb SDSS thiab xav tau cov txheej txheem sim nyuaj. Txog tam sim no, cov txheej txheem rhiab heev ntawm qhov chaw xws li Auger electron spectroscopy11 thiab X-ray photoelectron spectroscopy12,13,14,15 thiab nyuaj X-ray photoemission microscopy (HAX-PEEM)16 feem ntau tsis tau pom qhov sib txawv ntawm cov tshuaj lom neeg hauv cov khaubncaws sab nraud povtseg. cov xwm txheej tshuaj lom neeg ntawm tib lub ntsiab lus hauv ntau qhov chaw ntawm qhov chaw nanoscale. Ob peb txoj kev tshawb fawb tsis ntev los no tau muaj kev sib raug zoo ntawm qhov chaw oxidation ntawm chromium nrog rau qhov kev coj cwj pwm corrosion ntawm austenitic stainless hlau17, martensitic steels18 thiab SDSS19,20. Txawm li cas los xij, cov kev tshawb fawb no tau tsom mus rau qhov cuam tshuam ntawm Cr heterogeneity (piv txwv li, Cr3 + oxidation xeev) ntawm kev tiv thaiv corrosion. Lateral heterogeneity hauv cov xeev oxidation ntawm cov ntsiab lus tuaj yeem tshwm sim los ntawm cov sib xyaw sib txawv nrog cov khoom sib xws, xws li hlau oxides. Cov sib xyaw no, uas tau txais ib qho me me vim yog kev kho thermomechanical, nyob ze rau ib leeg, tab sis txawv hauv cov khoom sib xyaw thiab oxidation xeev16,21. Yog li ntawd, txhawm rau ntes tau qhov tawg ntawm cov yeeb yaj kiab oxide thiab tom qab ntawd pitting, nws yog qhov tsim nyog los nkag siab txog qhov heterogeneity ntawm qhov chaw ntawm qib microscopic. Txawm hais tias muaj cov kev xav tau no, kev kwv yees ntau xws li lateral heterogeneity hauv oxidation, tshwj xeeb tshaj yog rau Fe ntawm qhov ntsuas nano- thiab atomic, tseem tsis txaus, thiab nws txoj kev sib raug zoo nrog kev tiv thaiv corrosion tseem tsis tau tshawb nrhiav. Txog thaum tsis ntev los no, lub xeev tshuaj lom neeg ntawm ntau yam ntsiab lus, xws li Fe thiab Ca22, ntawm cov qauv hlau tau raug ntsuas kom muaj nuj nqis siv cov khoom siv X-ray photoelectron microscopy (X-PEEM) hauv cov chaw siv hluav taws xob nanoscale synchrotron. Ua ke nrog cov tshuaj lom neeg rhiab heev X-ray absorption spectroscopy (XAS), X-PEEM ua rau kev ntsuas XAS nrog qhov kev daws teeb meem siab thiab spectral, muab cov ntaub ntawv tshuaj lom neeg txog cov khoom sib xyaw thiab lawv lub xeev tshuaj lom neeg nrog qhov kev daws teeb meem qis mus rau nees nkaum peb nanometer scale. . Qhov kev soj ntsuam spectromicroscopic ntawm qhov pib no pab txhawb kev soj ntsuam tshuaj lom neeg hauv zos thiab tuaj yeem qhia txog kev hloov pauv tshuaj lom neeg hauv qhov chaw ntawm cov txheej hlau uas tsis tau tshawb nrhiav yav dhau los.
Txoj kev tshawb fawb no nthuav dav cov txiaj ntsig ntawm PEEM hauv kev ntes cov tshuaj sib txawv ntawm nanoscale thiab nthuav tawm txoj kev tshuaj xyuas qhov chaw atomic-level kom nkag siab txog tus cwj pwm corrosion ntawm Ce-2507. Nws siv txoj hauv kev clustered K-means24 chemometric los kos duab lub ntiaj teb tshuaj lom neeg (hetero) homogeneity ntawm cov ntsiab lus koom nrog, uas cov xwm txheej tshuaj lom neeg tau nthuav tawm hauv kev sawv cev suav lej. Hauv kev sib piv rau corrosion pib los ntawm kev puas tsuaj ntawm cov yeeb yaj kiab chromium oxide hauv cov ntaub ntawv ib txwm muaj, tsawg dua passivation thiab qis dua corrosion tsis kam tam sim no yog vim muaj Fe3 + nplua nuj nanoislands nyob ze ntawm Fe / Cr oxide txheej, uas tej zaum yuav yog cov khoom tiv thaiv. Cov oxide rhuav tshem cov yeeb yaj kiab dotted thiab ua rau corrosion.
Tus cwj pwm corrosive ntawm deformed SDSS 2507 tau raug soj ntsuam thawj zaug siv kev ntsuas electrochemical. Hauv daim duab 1 qhia txog Nyquist thiab Bode curves rau cov qauv xaiv hauv cov kua qaub (pH = 1) ntawm FeCl3 ntawm chav tsev kub. Cov electrolyte xaiv ua haujlwm ua tus neeg sawv cev oxidizing muaj zog, piav qhia txog qhov nyiam ntawm zaj duab xis passivation kom tawg. Txawm hais tias cov khoom tsis tau dhau los ua pitting ruaj khov ntawm chav tsev kub, qhov kev tshuaj xyuas tau muab kev nkag siab rau cov xwm txheej tsis ua haujlwm thiab tom qab ntawd corrosion. Lub voj voog sib npaug (Daim duab 1d) tau siv los haum rau electrochemical impedance spectroscopy (EIS) spectrum, thiab cov txiaj ntsig sib xws tau pom hauv Rooj 1. Cov semicircles tsis tiav tshwm sim hauv cov kua-kho thiab cov qauv kub-ua haujlwm, thaum cov compressed semicircles tshwm sim hauv cov khoom sib npaug txias-rolled (Daim duab 1b). Hauv EIS spectroscopy, lub voj voog ntawm semicircle tuaj yeem suav hais tias yog polarization tsis kam (Rp) 25,26. Rp ntawm txoj kev khiav uas tau kho nrog cov tshuaj hauv Rooj 1 yog li ntawm 135 kΩ cm-2, txawm li cas los xij, cov nqi ntawm txoj kev khiav kub thiab txoj kev khiav txias dov qis dua, 34.7 thiab 2.1 kΩ cm-2, raws li. Qhov kev txo qis tseem ceeb hauv Rp qhia txog qhov cuam tshuam tsis zoo ntawm kev hloov pauv yas ntawm kev ua kom tsis muaj zog thiab kev tiv thaiv xeb, raws li tau pom hauv cov ntawv ceeb toom dhau los 27, 28, 29, 30.
a Nyquist, b, c Bode impedance thiab phase diagrams, thiab d cov qauv sib npaug ntawm lub voj voog sib npaug, qhov twg RS yog qhov tsis kam ntawm electrolyte, Rp yog qhov tsis kam polarization, thiab QCPE yog oxide ntawm cov khoom siv theem tas mus li uas siv los ua qauv rau qhov tsis zoo tagnrho capacitance (n). Kev ntsuas EIS yog ua ntawm qhov qhib circuit potential.
Cov kev hloov pauv tas mus li tau pom hauv daim duab Bode, nrog rau lub tiaj tiaj hauv qhov ntau zaus siab uas sawv cev rau qhov tsis kam ntawm electrolyte RS26. Thaum qhov zaus txo qis, qhov impedance nce ntxiv thiab lub kaum sab xis tsis zoo pom, qhia txog kev tswj hwm capacitance. Lub kaum sab xis nce ntxiv, khaws cia qhov siab tshaj plaws ntawm qhov ntau zaus dav, thiab tom qab ntawd txo qis (Daim Duab 1c). Txawm li cas los xij, hauv tag nrho peb qhov xwm txheej, qhov siab tshaj plaws no tseem tsawg dua 90 °, qhia txog tus cwj pwm tsis zoo tagnrho vim yog kev sib cais capacitive. Yog li, QCPE constant phase element (CPE) yog siv los sawv cev rau kev faib tawm capacitance interfacial uas tshwm sim los ntawm qhov roughness ntawm qhov chaw lossis inhomogeneity, tshwj xeeb tshaj yog ntawm qhov ntsuas atomic, fractal geometry, electrode porosity, non-uniform potential, thiab geometry nrog cov duab ntawm electrodes31,32. CPE impedance:
qhov twg j yog tus lej xav thiab ω yog lub zaus angular. QCPE yog qhov zaus tsis hloov pauv uas yog proportional rau thaj chaw qhib zoo ntawm electrolyte. n yog tus lej zog dimensionless piav qhia txog qhov sib txawv ntawm lub capacitor los ntawm lub peev xwm zoo tagnrho, piv txwv li qhov ze dua n yog rau 1, qhov ze dua CPE yog rau lub capacitive purely, thaum yog tias n ze rau xoom, nws zoo li resistive. Cov kev hloov pauv me me ntawm n, ze rau 1, qhia txog tus cwj pwm tsis zoo tagnrho ntawm qhov chaw tom qab kev sim polarization. QCPE ntawm SDSS dov txias yog siab dua li nws cov counterparts, txhais tau tias qhov zoo ntawm qhov chaw tsis sib xws.
Zoo ib yam li feem ntau cov khoom tiv thaiv corrosion ntawm cov hlau tsis xeb, cov ntsiab lus Cr siab ntawm SDSS feem ntau ua rau muaj kev tiv thaiv corrosion zoo heev ntawm SDSS vim muaj cov zaj duab xis oxide tiv thaiv passivating ntawm qhov chaw17. Cov zaj duab xis passivating no feem ntau nplua nuj hauv Cr3 + oxides thiab / lossis hydroxides, feem ntau ua ke nrog Fe2 +, Fe3 + oxides thiab / lossis (oxy) hydroxides33. Txawm hais tias qhov sib npaug ntawm qhov chaw, txheej oxide passivating, thiab tsis pom qhov tawg ntawm qhov chaw raws li kev ntsuas microscopic6,7, tus cwj pwm corrosion ntawm kub-ua haujlwm thiab txias-dov SDSS yog txawv, yog li kev kawm tob txog cov yam ntxwv microstructural yog qhov tsim nyog rau cov hlau deformation.
Cov qauv me me ntawm cov hlau tsis xeb uas tsis zoo li qub tau raug kawm txog ntau yam siv cov duab X-rays uas muaj zog heev thiab sib xyaw ua ke (Cov Duab Ntxiv 1, 2). Kev tshuaj xyuas ntxaws ntxaws tau muab rau hauv Cov Ntaub Ntawv Ntxiv. Txawm hais tias muaj kev pom zoo dav dav txog hom theem tseem ceeb, qhov sib txawv ntawm cov feem pua ​​​​​​ntawm cov theem loj tau pom, uas tau teev nyob rau hauv Cov Lus Qhia Ntxiv 1. Cov kev sib txawv no yuav yog vim muaj cov feem pua ​​​​​​ntawm cov theem tsis sib xws ntawm qhov chaw thiab hauv qhov ntim, uas raug cuam tshuam los ntawm qhov tob ntawm X-ray diffraction (XRD) sib txawv.) nrog cov khoom siv zog sib txawv ntawm cov duab photons34. Cov feem pua ​​​​​​ntawm austenite siab hauv cov qauv dov txias txiav txim siab los ntawm XRD los ntawm qhov chaw kuaj mob qhia txog kev ua kom zoo dua thiab tom qab ntawd zoo dua corrosion resistance35, thaum cov txiaj ntsig tseeb dua thiab cov ntaub ntawv qhia txog kev sib txawv hauv cov feem pua ​​​​​​ntawm theem. Tsis tas li ntawd, qhov kev tiv thaiv corrosion ntawm hlau kuj nyob ntawm qib ntawm kev ua kom zoo dua ntawm cov noob, txo qhov loj ntawm cov noob, nce hauv microdeformations thiab dislocation density uas tshwm sim thaum lub sijhawm kho thermomechanical36,37,38. Cov qauv ua haujlwm kub tau qhia txog qhov xwm txheej ntau dua, qhia txog cov noob me me ntawm micron, thaum cov nplhaib du uas pom hauv cov qauv dov txias (Daim Duab Ntxiv 3) qhia txog kev ua kom zoo dua qub rau nanosize hauv kev ua haujlwm dhau los. Qhov no yuav tsum txhawb nqa zaj duab xis passive. kev tsim thiab kev nce ntawm kev tiv thaiv corrosion. Qhov ceev ntawm dislocation siab dua feem ntau cuam tshuam nrog kev tiv thaiv qis dua rau pitting, uas pom zoo zoo nrog kev ntsuas electrochemical.
Kev hloov pauv hauv lub xeev tshuaj lom neeg ntawm cov microdomains ntawm cov ntsiab lus tseem ceeb tau raug kawm tsis tu ncua siv X-PEEM. Txawm hais tias muaj ntau cov ntsiab lus alloying, Cr, Fe, Ni thiab Ce39 raug xaiv ntawm no, vim Cr yog lub ntsiab lus tseem ceeb rau kev tsim cov zaj duab xis passive, Fe yog lub ntsiab lus tseem ceeb rau hlau, thiab Ni txhim kho passivation thiab sib npaug ntawm ferrite-austenitic theem. Cov qauv thiab kev hloov kho yog lub hom phiaj ntawm Ce. Los ntawm kev kho lub zog synchrotron beam, XAS ntes tau cov yam ntxwv tseem ceeb ntawm Cr (L2.3 ntug), Fe (L2.3 ntug), Ni (L2.3 ntug), thiab Ce (M4.5 ntug) los ntawm qhov chaw. -2507 SDSS. Kev tshuaj xyuas cov ntaub ntawv tsim nyog tau ua los ntawm kev suav nrog kev ntsuas lub zog nrog cov ntaub ntawv luam tawm (piv txwv li XAS ntawm Fe L2, 3 ribs40,41).
Hauv daim duab 2, daim duab 2 qhia txog cov duab X-PEEM ntawm cov hlau kub ua haujlwm (Daim duab 2a) thiab cov hlau txias dov (Daim duab 2d) Ce-2507 SDSS thiab cov npoo XAS Cr thiab Fe L2,3 sib xws ntawm cov chaw cim ib leeg. Ntug L2,3 XAS tshawb nrhiav cov xeev 3d tsis muaj neeg nyob ntawm cov electrons tom qab photoexcitation ntawm 2p3/2 (L3 ntug) thiab 2p1/2 (L2 ntug) spin-orbit splitting theem. Cov ntaub ntawv hais txog lub xeev valence ntawm Cr tau txais los ntawm X-ray diffraction kev tshuaj xyuas ntawm ntug L2,3 hauv daim duab 2b, d. Kev sib piv txuas. 42, 43 qhia tau tias plaub lub ncov A (578.3 eV), B (579.5 eV), C (580.4 eV), thiab D (582.2 eV) tau pom ze ntawm ntug L3, cuam tshuam octahedral Cr3+ ions, sib xws Cr2O3. Cov spectra sim yog nyob rau hauv kev pom zoo nrog cov kev xam lej theoretical, raws li qhia nyob rau hauv panels b thiab e, tau los ntawm ntau qhov kev xam lej crystal teb ntawm Cr L2.3 interface siv lub teb crystal ntawm 2.0 eV44. Ob qho tib si nto ntawm kub-ua haujlwm thiab txias-dov SDSS yog coated nrog ib tug sib npaug txheej ntawm Cr2O3.
a Duab Thermal ntawm X-PEEM kub-ua SDSS sib raug rau ntug b Cr L2.3 thiab ntug c Fe L2.3, d Duab Thermal X-PEEM ntawm txias-dov SDSS sib raug rau ntug e Cr L2.3 thiab f Fe L2.3 ntawm sab (e). Cov XAS spectra plotted ntawm ntau qhov chaw cim rau ntawm cov duab thermal (a, d) los ntawm cov kab dotted txiv kab ntxwv hauv (b) thiab (e) sawv cev rau simulated XAS spectra ntawm Cr3 + nrog tus nqi crystal teb ntawm 2.0 eV. Rau cov duab X-PEEM, lub thermal palette yog siv los txhim kho kev nyeem duab, qhov twg xim los ntawm xiav mus rau liab yog proportional rau qhov muaj zog ntawm X-ray absorption (los ntawm qis mus rau siab).
Txawm hais tias qhov chaw ib puag ncig tshuaj lom neeg ntawm cov khoom siv hlau no li cas los xij, lub xeev tshuaj lom neeg ntawm kev ntxiv Ni thiab Ce alloying elements rau ob qho qauv tseem zoo li qub. Daim duab ntxiv. Ntawm daim duab 5-9 qhia cov duab X-PEEM thiab cov spectra XAS sib xws rau Ni thiab Ce ntawm ntau qhov chaw ntawm qhov chaw ntawm cov qauv kub-ua haujlwm thiab txias-dov. Ni XAS qhia txog lub xeev oxidation ntawm Ni2+ hla tag nrho qhov chaw ntsuas ntawm cov qauv kub-ua haujlwm thiab txias-dov (Kev Sib Tham Ntxiv). Nws yog qhov tsim nyog tias nyob rau hauv cov ntaub ntawv ntawm cov qauv kub-ua haujlwm, lub teeb liab XAS ntawm Ce tsis raug pom, thaum lub spectrum ntawm Ce3+ ntawm cov qauv txias-dov tau pom ntawm ib qho taw tes. Kev soj ntsuam ntawm Ce cov chaw hauv cov qauv txias-dov qhia tau hais tias Ce feem ntau muaj nyob rau hauv daim ntawv ntawm precipitates.
Hauv SDSS uas raug hloov pauv los ntawm cua sov, tsis muaj kev hloov pauv hauv zos hauv XAS tau pom ntawm ntug Fe L2.3 (Daim Duab 2c). Txawm li cas los xij, raws li pom hauv daim duab 2f, Fe matrix hloov pauv nws lub xeev tshuaj lom neeg ntawm xya qhov chaw xaiv tsis raug hauv SDSS dov txias. Tsis tas li ntawd, txhawm rau kom tau txais lub tswv yim tseeb ntawm kev hloov pauv hauv lub xeev Fe ntawm qhov chaw xaiv hauv Daim Duab 2f, kev tshawb fawb hauv zos tau ua tiav (Daim Duab 3 thiab Daim Duab Ntxiv 10) uas cov cheeb tsam me me tau xaiv. Cov XAS spectra ntawm ntug Fe L2,3 ntawm α-Fe2O3 systems thiab Fe2+ octahedral oxides tau ua qauv siv cov lej suav teb siv siv cov teb siv lead ua ntawm 1.0 (Fe2+) thiab 1.0 (Fe3+)44. Peb pom tias α-Fe2O3 thiab γ-Fe2O3 muaj cov symmetries sib txawv hauv zos45,46, Fe3O4 muaj kev sib xyaw ua ke ntawm Fe2+ & Fe3+,47, thiab FeO45 ua ib qho divalent Fe2+ oxide (3d6). Peb pom tias α-Fe2O3 thiab γ-Fe2O3 muaj cov symmetries sib txawv hauv zos45,46, Fe3O4 muaj kev sib xyaw ua ke ntawm Fe2+ & Fe3+,47, thiab FeO45 ua ib qho divalent Fe2+ oxide (3d6).Nco ntsoov tias α-Fe2O3 thiab γ-Fe2O3 muaj cov symmetries hauv zos sib txawv45,46, Fe3O4 sib xyaw ob qho tib si Fe2+ thiab Fe3+,47 thiab FeO45 ua ke hauv daim ntawv ntawm cov oxide divalent Fe2+ (3d6).Nco ntsoov tias α-Fe2O3 thiab γ-Fe2O3 muaj cov symmetries sib txawv hauv zos 45,46, Fe3O4 muaj kev sib xyaw ua ke ntawm Fe2+ thiab Fe3+,47 thiab FeO45 ua haujlwm ua ib qho kev sib xyaw ua ke Fe2+ oxide (3d6). Tag nrho Fe3+ ions hauv α-Fe2O3 tsuas muaj Oh txoj haujlwm xwb, thaum γ-Fe2O3 feem ntau yog qhia ua Fe3+ t2g [Fe3+5/3V1/3]eg O4 spinel nrog cov chaw seem hauv eg txoj haujlwm. Yog li ntawd, Fe3+ ions hauv γ-Fe2O3 muaj ob qho tib si Td thiab Oh txoj haujlwm. Raws li tau hais hauv cov haujlwm dhau los, txawm hais tias qhov sib piv ntawm ob qho sib txawv, lawv qhov sib piv eg/t2g yog ≈1, thaum nyob rau hauv cov ntaub ntawv no qhov sib piv pom eg/t2g yog li 1. Qhov no txiav txim siab qhov ua tau ntawm tsuas yog Fe3+ nyob rau hauv cov ntaub ntawv no. Xav txog qhov teeb meem ntawm Fe3O4 nrog kev sib xyaw ua ke ntawm Fe2+ thiab Fe3+, nws paub tias qhov tsis muaj zog (muaj zog) thawj qhov tshwj xeeb hauv L3 ntug ntawm Fe qhia txog qhov tsis muaj neeg nyob me dua (loj dua) hauv lub xeev t2g. Qhov no siv rau Fe2+ (Fe3+), uas qhia txog kev nce hauv thawj lub cim qhia txog kev nce hauv cov ntsiab lus ntawm Fe2+47. Cov txiaj ntsig no qhia tau tias Fe2+ thiab γ-Fe2O3, α-Fe2O3 thiab/lossis Fe3O4 muaj nyob rau ntawm cov nplaim txias ntawm cov khoom sib xyaw.
Cov duab thermal electron photoemission loj dua ntawm (a, c) thiab (b, d) XAS spectra hla ntug Fe L2,3 ntawm ntau qhov chaw hauv thaj chaw xaiv 2 thiab E hauv daim duab 2d.
Cov ntaub ntawv sim tau txais (Daim Duab 4a thiab Daim Duab Ntxiv 11) tau raug plotted thiab piv nrog cov ntawm cov sib xyaw ntshiab 40, 41, 48. Yeej, peb hom sib txawv ntawm Fe L-edge XAS spectra (XAS-1, XAS-2 thiab XAS-3: Daim Duab 4a) tau raug pom ntawm qhov chaw sib txawv. Tshwj xeeb, ib qho spectrum zoo ib yam li 2-a (qhia ua XAS-1) hauv Daim Duab 3b tau raug pom thoob plaws thaj tsam ntawm kev txaus siab, ua raws li 2-b spectrum (labeled XAS-2), thaum ib qho spectrum zoo ib yam li E-3 tau raug pom hauv daim duab 3d (hu ua XAS-3) tau raug pom hauv qee qhov chaw hauv zos. Feem ntau, plaub qhov kev ntsuas tau siv los txheeb xyuas cov xeev valence uas muaj nyob hauv cov qauv probe: (1) L3 thiab L2 spectral nta, (2) lub zog txoj haujlwm ntawm L3 thiab L2 nta, (3) L3-L2 lub zog sib txawv, (4) L2 qhov sib piv /L3. Raws li kev soj ntsuam pom (Daim Duab 4a), tag nrho peb yam khoom Fe, uas yog Fe0, Fe2+, thiab Fe3+, muaj nyob rau ntawm qhov chaw ntawm SDSS uas tau kawm. Qhov piv ntawm qhov muaj zog L2/L3 kuj qhia txog qhov muaj tag nrho peb yam khoom.
a Tau pom peb cov ntaub ntawv sib txawv ntawm kev sim (cov kab khov kho XAS-1, XAS-2 thiab XAS-3 sib xws rau 2-a, 2-b thiab E-3 hauv daim duab 2 thiab daim duab 3) piv rau cov qauv sib piv XAS simulated, octahedrons Fe2+, Fe3+, cov nqi teb siv lead ua ke ntawm 1.0 eV thiab 1.5 eV, feem, b–d Cov ntaub ntawv sim ntsuas (XAS-1, XAS-2, XAS-3) thiab cov ntaub ntawv LCF zoo sib xws (kab dub khov kho), thiab kev sib piv XAS-3 spectra nrog Fe3O4 (lub xeev sib xyaw ntawm Fe) thiab Fe2O3 (Fe3+ ntshiab) cov qauv.
Ib qho kev sib xyaw ua ke (LCF) ntawm peb tus qauv 40, 41, 48 tau siv los ntsuas qhov sib xyaw ntawm cov hlau oxide. LCF tau siv rau peb qhov xaiv Fe L-edge XAS spectra uas qhia qhov sib piv siab tshaj plaws, uas yog XAS-1, XAS-2 thiab XAS-3, raws li pom hauv daim duab 4b-d. Rau LCF fittings, 10% Fe0 tau txiav txim siab hauv txhua kis vim yog lub qhov me me uas peb tau pom hauv txhua cov ntaub ntawv thiab qhov tseeb tias hlau ferrous yog cov khoom tseem ceeb ntawm hlau. Tseeb tiag, qhov tob ntawm X-PEEM rau Fe (~ 6 nm) 49 loj dua qhov kwv yees ntawm cov txheej oxidation tuab (me ntsis > 4 nm), uas tso cai rau kev kuaj pom cov teeb liab los ntawm cov hlau matrix (Fe0) hauv qab cov txheej passivation. Tseeb tiag, qhov tob ntawm X-PEEM rau Fe (~ 6 nm) 49 loj dua qhov kwv yees ntawm cov txheej oxidation tuab (me ntsis > 4 nm), uas tso cai rau kev kuaj pom cov teeb liab los ntawm cov hlau matrix (Fe0) hauv qab cov txheej passivation. Действительно, пробная глубина X-PEEM для Fe (~ 6 нм)49 больше, чем предполагаемая толщмна слоя 4 яки ( что позволяет обнаружить сигнал от железной матрицы (Fe0) под пассивирующим слоем. Tseeb tiag, qhov tob ntawm qhov probe X-PEEM rau Fe (~ 6 nm) 49 yog ntau dua li qhov tuab ntawm cov txheej oxidation (me ntsis > 4 nm), uas ua rau nws muaj peev xwm ntes tau lub teeb liab los ntawm cov hlau matrix (Fe0) nyob rau hauv cov txheej passivation.Qhov tseeb, X-PEEM ntes tau Fe (~ 6 nm) 49 tob dua li qhov tuab ntawm cov txheej oxide (tsuas yog ntau dua 4 nm), uas tso cai rau kev ntes cov teeb liab los ntawm cov hlau matrix (Fe0) hauv qab cov txheej passivation. Ntau yam kev sib xyaw ua ke ntawm Fe2 + thiab Fe3 + tau ua tiav los nrhiav qhov kev daws teeb meem zoo tshaj plaws rau cov ntaub ntawv sim uas tau pom. Hauv daim duab 4b qhia txog kev sib xyaw ua ke ntawm Fe2 + thiab Fe3 + hauv XAS-1 spectrum, qhov twg cov feem pua ​​ntawm Fe2 + thiab Fe3 + ze, kwv yees li 45%, uas qhia txog lub xeev oxidation sib xyaw ntawm Fe. Thaum rau XAS-2 spectrum, feem pua ​​ntawm Fe2 + thiab Fe3 + dhau los ua ~ 30% thiab 60%, feem. Cov ntsiab lus ntawm Fe2 + qis dua li ntawm Fe3 +. Qhov sib piv ntawm Fe2 + rau Fe3 ntawm 1: 2 txhais tau tias Fe3O4 tuaj yeem tsim tau ntawm tib qho piv ntawm Fe ions. Ntxiv mus, rau XAS-3 spectrum, feem pua ​​ntawm Fe2+ thiab Fe3+ tau hloov mus rau ~10% thiab 80%, qhia txog kev hloov pauv siab dua ntawm Fe2+ mus rau Fe3+. Raws li tau hais los saum toj no, Fe3+ tuaj yeem los ntawm α-Fe2O3, γ-Fe2O3 lossis Fe3O4. Txhawm rau kom nkag siab txog qhov chaw feem ntau ntawm Fe3+, XAS-3 spectra tau plotted nrog ntau yam Fe3+ tus qauv hauv daim duab 4e qhia txog kev zoo sib xws nrog txhua ob tus qauv thaum Peak B raug xav txog. Txawm li cas los xij, qhov muaj zog ntawm lub xub pwg nyom (A: los ntawm Fe2+) thiab qhov sib piv ntawm qhov muaj zog B/A qhia tias qhov spectrum ntawm XAS-3 ze rau tab sis tsis zoo ib yam li ntawm γ-Fe2O3. Piv rau bulk γ-Fe2O3, qhov muaj zog Fe 2p XAS ntawm A SDSS ncov siab dua me ntsis (Daim duab 4e), uas qhia txog qhov muaj zog Fe2+ siab dua. Txawm hais tias qhov spectrum ntawm XAS-3 zoo ib yam li ntawm γ-Fe2O3, qhov twg Fe3+ muaj nyob rau hauv ob qho tib si Oh thiab Td txoj haujlwm, kev txheeb xyuas cov xeev valence sib txawv thiab kev sib koom tes tsuas yog los ntawm L2,3 ntug lossis L2/L3 qhov sib piv tseem yog ib qho teeb meem. ib qho kev sib tham rov tshwm sim vim qhov nyuaj ntawm ntau yam tseem ceeb koom nrog hauv qhov kawg spectrum41.
Ntxiv rau qhov kev sib cais ntawm cov tshuaj lom neeg ntawm cov cheeb tsam xaiv uas tau piav qhia saum toj no, qhov sib txawv ntawm cov tshuaj lom neeg thoob ntiaj teb ntawm cov ntsiab lus tseem ceeb Cr thiab Fe tau raug soj ntsuam los ntawm kev faib tawm txhua qhov XAS spectra tau txais ntawm qhov chaw ntawm cov qauv siv txoj kev K-txhais tau tias clustering. Cov ntug profiles Cr L tau teeb tsa rau hauv txoj hauv kev uas tsim ob lub pawg zoo tshaj plaws faib rau hauv cov qauv kub-ua haujlwm thiab txias-dov qhia hauv Figs. 5. Nws yog qhov tseeb tias tsis muaj kev hloov pauv hauv zos tau pom, txij li ob lub centroids ntawm XAS Cr spectra zoo sib xws heev. Cov duab spectral no ntawm ob lub pawg yuav luag zoo ib yam li cov uas sib xws rau Cr2O342, uas txhais tau tias cov txheej Cr2O3 tau faib sib npaug zos hla SDSS.
ib pawg ntawm K-txhais tau tias L-ntug Cr cheeb tsam, b sib raug rau XAS centroids. Cov txiaj ntsig ntawm K-txhais tau tias X-PEEM kev sib piv ntawm txias-dov SDSS: c pawg ntawm K-txhais tau tias ntug cheeb tsam ntawm Cr L2,3 thiab d sib raug rau XAS centroids.
Txhawm rau piav qhia txog daim ntawv qhia ntug FeL uas nyuaj dua, plaub thiab tsib lub pawg zoo tshaj plaws thiab lawv cov centroids (spectral distributions) raug siv rau cov qauv kub thiab txias dov, raws li. Yog li ntawd, feem pua ​​(%) ntawm Fe2 + thiab Fe3 + tuaj yeem tau txais los ntawm kev kho LCF uas pom hauv daim duab 4. Lub peev xwm pseudoelectrode Epseudo ua haujlwm ntawm Fe0 tau siv los qhia txog qhov tsis sib xws ntawm cov yeeb yaj kiab oxide saum npoo. Epseudo raug kwv yees los ntawm txoj cai sib xyaw,
qhov twg \(\rm{E}_{\rm{Fe}/\rm{Fe}^{2 + (3 + )}}\) sib npaug \(\rm{Fe} + 2e^ – \to\rm { Fe}^{2 + (3 + )}\), uas yog 0.440 thiab 0.036 V, raws li. Cov cheeb tsam uas muaj peev xwm qis dua muaj cov ntsiab lus siab dua ntawm Fe3+ cov sib xyaw. Qhov kev faib tawm peev xwm hauv cov qauv deformed thermally muaj tus cwj pwm layered nrog qhov kev hloov pauv siab tshaj plaws ntawm kwv yees li 0.119 V (Daim duab 6a,b). Qhov kev faib tawm peev xwm no muaj feem cuam tshuam nrog qhov chaw saum npoo av (Daim duab 6a). Tsis muaj lwm qhov kev hloov pauv ntsig txog qhov chaw tau pom hauv qab lamellar sab hauv (Daim duab 6b). Ntawm qhov tsis sib xws, rau kev sib xyaw ua ke ntawm cov oxides sib txawv nrog cov ntsiab lus sib txawv ntawm Fe2+ thiab Fe3+ hauv SDSS txias-dov, qhov xwm txheej tsis sib xws ntawm pseudopotential tuaj yeem pom (Daim duab 6c, d). Fe3+ oxides thiab/lossis (oxy)hydroxides yog cov khoom tseem ceeb ntawm kev xeb hauv cov hlau thiab muaj peev xwm nkag mus rau hauv cov pa oxygen thiab dej 50. Hauv qhov no, nws tuaj yeem pom tias cov kob nplua nuj hauv Fe3+ tau faib tawm hauv zos thiab tuaj yeem suav tias yog thaj chaw xeb. Hauv qhov no, qhov gradient hauv thaj chaw muaj peev xwm, es tsis yog tus nqi ntawm lub peev xwm, tuaj yeem suav hais tias yog qhov qhia rau qhov chaw ntawm cov cheeb tsam xeb nquag 51. Qhov kev faib tawm tsis sib xws ntawm Fe2+ thiab Fe3+ ntawm qhov chaw ntawm SDSS txias dov tuaj yeem hloov cov khoom siv tshuaj lom neeg hauv zos thiab muab thaj chaw zoo dua hauv kev tawg zaj duab xis oxide thiab kev xeb, yog li tso cai rau cov hlau matrix hauv qab kom txuas ntxiv xeb, ua rau muaj kev tsis sib xws sab hauv. thiab txo cov yam ntxwv tiv thaiv ntawm cov txheej passivating.
Cov pawg K-txhais tau tias ntawm Fe L2,3 ntug cheeb tsam thiab cov XAS centroids sib xws rau a-c kub-ua haujlwm X-PEEM thiab d-f txias-rolled SDSS. a, d K-txhais tau tias cov phiaj xwm pawg overlaid rau ntawm daim duab X-PEEM. Kwv yees cov peev xwm pseudoelectrode (epseudo) tau hais nrog rau K-txhais tau tias cov duab pawg. Qhov ci ntsa iab ntawm daim duab X-PEEM xws li xim hauv daim duab 2 yog sib npaug ncaj qha rau qhov muaj zog nqus X-ray.
Cr sib npaug zos tab sis cov tshuaj lom neeg sib txawv ntawm Fe ua rau muaj keeb kwm sib txawv ntawm cov zaj duab xis oxide tawg thiab cov qauv xeb hauv cov hlau kub thiab txias Ce-2507. Cov khoom no ntawm cov hlau txias Ce-2507 paub zoo. Hais txog kev tsim cov oxides thiab hydroxides ntawm Fe hauv huab cua, cov tshuaj tiv thaiv hauv qab no raug kaw hauv txoj haujlwm no ua cov tshuaj tiv thaiv tsis muaj zog:
Raws li kev ntsuas ntawm X-PEEM, qhov kev tshuaj tiv thaiv saum toj no tau tshwm sim hauv cov xwm txheej hauv qab no. Ib lub xub pwg me me uas sib raug rau Fe0 yog txuam nrog cov hlau hlau hauv qab. Qhov kev tshuaj tiv thaiv ntawm cov hlau Fe nrog ib puag ncig ua rau muaj txheej Fe(OH)2 (equation (5)), uas ua kom lub teeb liab Fe2+ hauv XAS ntawm ntug L ntawm Fe loj dua. Kev raug cua ntev ntev yuav ua rau muaj Fe3O4 thiab/lossis Fe2O3 oxides tom qab Fe(OH)252,53. Ob hom Fe ruaj khov, Fe3O4 thiab Fe2O3, kuj tuaj yeem tsim hauv txheej tiv thaiv nplua nuj Cr3+, qhov twg Fe3O4 nyiam cov qauv sib xws thiab sib koom ua ke. Qhov muaj ob qho tib si ua rau muaj cov xwm txheej oxidation sib xyaw (XAS-1 spectrum). XAS-2 spectrum feem ntau sib raug rau Fe3O4. Txawm hais tias XAS-3 spectra pom ntawm ntau qhov chaw qhia txog kev hloov pauv tag nrho rau γ-Fe2O3. Vim tias cov duab X-ray uas tsis tau qhwv muaj qhov tob nkag mus txog li 50 nm, lub teeb liab los ntawm txheej hauv qab ua rau muaj zog dua ntawm lub ncov A.
Lub XRD spectrum qhia tau hais tias Fe Cheebtsam hauv zaj duab xis oxide muaj cov qauv txheej txheem, uas tau ua ke nrog Cr oxide txheej. Hauv kev sib piv rau qhov passivation yam ntxwv ntawm xeb vim yog qhov tsis sib xws hauv zos ntawm Cr2O317, txawm hais tias muaj txheej sib xws ntawm Cr2O3 hauv txoj kev tshawb fawb no, kev tiv thaiv xeb qis tau pom hauv qhov no, tshwj xeeb tshaj yog rau cov qauv dov txias. Tus cwj pwm pom tau tuaj yeem nkag siab tias yog qhov sib txawv ntawm lub xeev oxidation tshuaj ntawm txheej sab saud (Fe) cuam tshuam rau kev ua haujlwm xeb. Kev hloov pauv qeeb ntawm cov hlau lossis cov pa oxygen hauv lub lattice vim yog tib lub stoichiometry ntawm cov txheej sab saud (Fe oxide) thiab cov txheej qis dua (Cr oxide) 52,53 ua rau muaj kev sib cuam tshuam zoo dua (kev nplaum) ntawm lawv. Qhov no, ua rau txhim kho kev tiv thaiv xeb. Yog li ntawd, stoichiometry txuas ntxiv mus, piv txwv li ib lub xeev oxidation ntawm Fe, zoo dua rau kev hloov pauv stoichiometric sai sai. Thermally deformed SDSS muaj qhov chaw sib xws ntau dua thiab txheej tiv thaiv denser, uas muab kev tiv thaiv xeb zoo dua. Txawm li cas los xij, rau SDSS uas tau dov txias, qhov muaj Fe3 +-nplua nuj kob nyob rau hauv cov txheej tiv thaiv ua rau puas tsuaj rau qhov chaw thiab ua rau galvanic corrosion ntawm cov substrate ze, uas ua rau txo qis hauv Rp (Rooj 1) hauv EIS spectra thiab nws qhov corrosion. tsis kam. Yog li ntawd, cov kob faib hauv zos nplua nuj hauv Fe3 + vim yog cov yas deformation feem ntau cuam tshuam rau kev ua haujlwm tiv thaiv corrosion, uas yog qhov kev tawg hauv txoj haujlwm no. Yog li ntawd, txoj kev tshawb fawb no nthuav qhia spectromicrographs ntawm kev txo qis hauv kev tiv thaiv corrosion vim yog cov yas deformation ntawm cov qauv SDSS uas tau kawm.
Ntxiv mus, thaum cov hlau tsis tshua muaj alloying hauv cov hlau ob theem ua tau zoo dua, kev sib cuam tshuam ntawm cov khoom ntxiv no nrog cov hlau matrix ib leeg hauv cov nqe lus ntawm kev coj tus cwj pwm corrosion tseem tsis meej raws li kev soj ntsuam spectroscopic microscopy. Lub teeb liab Ce (raws li XAS M-ntug) tsuas yog tshwm sim ntawm ob peb qhov chaw thaum lub sijhawm dov txias, tab sis ploj mus thaum lub sijhawm kub deformation ntawm SDSS, qhia txog kev tso nyiaj hauv zos ntawm Ce hauv cov hlau matrix es tsis yog homogeneous alloying. Txawm hais tias cov khoom siv kho tshuab ntawm SDSS tsis tau txhim kho6,7, qhov muaj REE txo qhov loj ntawm cov khoom suav nrog thiab xav tias yuav tiv thaiv pitting ntawm keeb kwm54.
Xaus lus, txoj haujlwm no qhia txog qhov cuam tshuam ntawm qhov sib txawv ntawm qhov chaw ntawm qhov xeb ntawm 2507 SDSS hloov kho nrog cerium los ntawm kev ntsuas cov tshuaj lom neeg ntawm cov khoom nanoscale. Peb teb cov lus nug ntawm vim li cas cov hlau tsis xeb txawm tias thaum coated nrog ib txheej oxide tiv thaiv los ntawm kev kawm txog qhov microstructure, lub xeev tshuaj lom neeg ntawm cov yam ntxwv ntawm qhov chaw thiab kev ua cov teeb liab siv K-txhais tau tias clustering. Nws tau tsim tsa tias Fe3 +-nplua nuj kob, suav nrog lawv cov octahedral thiab tetrahedral sib koom tes thoob plaws hauv cov qauv ntawm sib xyaw Fe2 + / Fe3 +, yog qhov chaw ntawm oxide zaj duab xis puas tsuaj thiab qhov chaw ntawm corrosion ntawm txias-rolled SDSS. Nanoislands dominated los ntawm Fe3 + ua rau tsis zoo corrosion tsis kam txawm tias nyob rau hauv lub xub ntiag ntawm txaus stoichiometric Cr2O3 passivating txheej. Ntxiv nrog rau cov kev nce qib methodological ua nyob rau hauv kev txiav txim siab qhov cuam tshuam ntawm nanoscale tshuaj lom neeg heterogeneity ntawm corrosion, tam sim no txoj haujlwm yuav tsum txhawb cov txheej txheem engineering los txhim kho qhov corrosion tsis kam ntawm stainless hlau thaum lub sijhawm steelmaking.
Txhawm rau npaj cov Ce-2507 SDSS ingots siv rau hauv txoj kev tshawb no, cov khoom sib xyaw, suav nrog Fe-Ce master alloy kaw nrog cov raj hlau ntshiab, tau yaj hauv 150 kg nruab nrab zaus induction cub kom tsim cov hlau molten thiab nchuav rau hauv cov pwm casting. Cov tshuaj sib xyaw ntsuas (wt%) tau teev nyob rau hauv Supplementary Table 2. Lub ingot yog thawj zaug kub tsim rau hauv blocks. Tom qab ntawd cov hlau tau annealed ntawm 1050 ° C rau 60 feeb rau cov tshuaj khov, thiab tom qab ntawd quenched hauv dej mus rau chav tsev kub. Cov qauv kawm tau kawm tiav hauv kev nthuav dav siv TEM thiab DOE los kawm cov theem, qhov loj me ntawm cov noob thiab morphology. Cov ntaub ntawv ntxaws ntxiv txog cov qauv thiab cov txheej txheem ntau lawm tuaj yeem pom hauv lwm qhov chaw 6,7.
Ua cov qauv cylindrical (φ10 mm × 15 mm) rau kev nias kub nrog lub axis ntawm lub tog raj kheej sib luag rau qhov kev taw qhia deformation ntawm lub block. Kev nias kub siab tau ua tiav ntawm qhov nrawm tas li ntawm 0.01-10 s-1 ntawm ntau qhov kub hauv qhov ntau ntawm 1000-1150 ° C siv Gleeble-3800 thermal simulator. Ua ntej deformation, cov qauv tau cua sov ntawm qhov kub xaiv ntawm tus nqi ntawm 10 ° C s-1 rau 2 feeb kom tshem tawm qhov kub gradient. Tom qab ua tiav qhov kub sib xws, cov qauv tau deformed rau qhov tseeb strain nqi ntawm 0.7. Tom qab deformation, nws tam sim ntawd quenched nrog dej kom tswj tau cov qauv deformed. Tom qab ntawd cov qauv hardened tau txiav sib luag rau qhov kev taw qhia ntawm compression. Rau qhov kev tshawb fawb tshwj xeeb no, peb tau xaiv cov qauv deformed thermally ntawm 1050 ° C, 10 s-1 vim muaj qhov microhardness pom ntau dua li lwm cov qauv7.
Cov qauv loj (80 × 10 × 17 mm3) ntawm cov khoom siv khov Ce-2507 tau sim rau ntawm lub tshuab deformation peb-theem asynchronous ob-yob LG-300, uas muab cov khoom siv kho tshuab zoo tshaj plaws ntawm txhua chav kawm deformation6. Tus nqi strain thiab thickness txo yog 0.2 m·s-1 thiab 5% rau txhua txoj kev, raws li.
Ib lub chaw ua haujlwm hluav taws xob Autolab PGSTAT128N tau siv los ntsuas electrochemically SDSS tom qab dov txias mus rau 90% txo qhov tuab (1.0 sib npaug qhov tseeb siab) thiab kub nias rau 0.7 qhov tseeb siab ntawm 1050 oC thiab 10 s-1. Lub chaw ua haujlwm muaj peb-electrode cell nrog lub electrode calomel saturated ua lub electrode siv, lub electrode counter graphite, thiab SDSS qauv ua lub electrode ua haujlwm. Cov qauv tau txiav rau hauv lub tog raj kheej nrog lub cheeb ntawm 11.3 hli, rau sab ntawm cov xov tooj liab tau soldered. Tom qab ntawd cov qauv tau nchuav nrog epoxy resin, tawm hauv thaj chaw ua haujlwm qhib ntawm 1 cm2 ua lub electrode ua haujlwm (qhov chaw qis dua ntawm cov qauv cylindrical). Siv kev ceev faj thaum kho cov epoxy thiab thaum lub sijhawm xuab zeb thiab polishing tom qab kom tsis txhob tawg. Qhov chaw ua haujlwm yog lapped thiab polished nrog pob zeb diamond polishing suspension nrog qhov loj me ntawm 1 micron, ntxuav nrog dej distilled thiab ethanol thiab ziab hauv huab cua txias. Ua ntej ntsuas electrochemical, cov qauv polished tau raug rau huab cua rau ob peb hnub los tsim cov zaj duab xis oxide ntuj. Ib qho kua dej ntawm FeCl3 (6.0 wt.%), ruaj khov nrog HCl rau pH = 1.0 ± 0.01, tau siv los ua kom cov hlau tsis xeb 55 sai dua, vim nws pom nyob rau hauv qhov chaw muaj zog uas muaj chloride ions nrog lub zog oxidizing muaj zog thiab pH qis raws li ASTM tau teev tseg. Cov qauv pom zoo yog G48 thiab A923. Cov qauv tau muab tso rau hauv cov kua kuaj rau 1 teev ua ntej kev ntsuas tau coj los ua kom mus txog lub xeev ze rau qhov ruaj khov. Rau cov kua khov, cov qauv kub-ua haujlwm thiab cov qauv dov txias, qhov ntsuas impedance zaus yog 1 × 105 ~ 0.1 Hz, thiab lub peev xwm qhib-circuit (OPS) yog 5 mV, uas yog 0.39, 0.33, thiab 0.25 VSCE, raws li. Txhua qhov kev sim electrochemical ntawm txhua tus qauv tau rov ua dua tsawg kawg peb zaug nyob rau hauv tib qho xwm txheej kom ntseeg tau tias cov ntaub ntawv rov ua dua.
Rau kev ntsuas HE-SXRD, 1 × 1 × 1.5 mm3 cov hlau duplex rectangular tau ntsuas ntawm kab Brockhouse wiggler siab ntawm CLS, Canada los ntsuas qhov sib xyaw ua ke ntawm theem 56. Kev sau cov ntaub ntawv tau ua tiav ntawm chav tsev kub hauv Debye-Scherrer geometry lossis kev thauj mus los geometry. Qhov wavelength ntawm X-rays calibrated rau LaB6 calibrant yog 0.212561 Å, uas sib raug rau 58 keV, uas yog siab dua li ntawm Cu Kα (8 keV) feem ntau siv ua qhov chaw X-ray hauv chaw kuaj mob. Cov qauv raug tso rau ntawm qhov deb ntawm 740 hli ntawm lub tshuab ntes. Qhov ntim ntes ntawm txhua tus qauv yog 0.2 × 0.3 × 1.5 mm3, uas yog txiav txim siab los ntawm qhov loj ntawm lub teeb thiab qhov tuab ntawm cov qauv. Txhua cov ntaub ntawv no tau sau los ntawm kev siv lub Perkin Elmer area detector, flat panel X-ray detector, 200 µm pixels, 40 × 40 cm2, siv lub sijhawm raug teeb tsa ntawm 0.3 vib nas this thiab 120 thav duab.
Kev ntsuas X-PEEM ntawm ob lub qauv xaiv tau ua tiav ntawm qhov chaw nres tsheb PEEM kawg ntawm kab Beamline MAXPEEM hauv chav kuaj MAX IV (Lund, Sweden). Cov qauv tau npaj tib yam li kev ntsuas electrochemical. Cov qauv npaj tau khaws cia rau hauv huab cua rau ob peb hnub thiab degassed hauv lub tshuab nqus tsev ultrahigh ua ntej raug irradiated nrog synchrotron photons. Lub zog daws teeb meem ntawm lub beam tau txais los ntawm kev ntsuas cov ion tso zis spectrum los ntawm N 1 s mus rau 1\(\pi _g^\ast\) ntawm thaj chaw excitation nrog hv = 401 eV hauv N2 thiab kev vam khom ntawm lub zog photon ntawm E3/2.57. Spectral fit tau muab ΔE (spectral linewidth) ~0.3 eV hla qhov ntsuas zog. Yog li ntawd, qhov kev daws teeb meem ntawm lub zog ntawm lub teeb tau kwv yees tias yog E/∆E = 700 eV/0.3 eV > 2000 thiab flux ≈1012 ph/s los ntawm kev siv lub tshuab SX-700 monochromator uas tau hloov kho nrog Si 1200-kab mm−1 grating rau ntug Fe 2p L2,3, ntug Cr 2p L2,3, ntug Ni 2p L2,3, thiab ntug Ce M4,5. Yog li ntawd, qhov kev daws teeb meem ntawm lub zog ntawm lub teeb tau kwv yees tias yog E/∆E = 700 eV/0.3 eV > 2000 thiab flux ≈1012 ph/s los ntawm kev siv lub tshuab SX-700 monochromator uas tau hloov kho nrog lub grating Si 1200-kab mm−1 rau ntug Fe 2p L2.3, ntug Cr 2p L2.3, ntug Ni 2p L2.3, thiab ntug Ce M4.5. Таким образом, энергетическое разрешение канала пучка было оценено как E/∆E = 700 эВ/0,3 э∉ 2000 от 2000 и 2000 при использовании модифицированного монохроматора SX-700 с решеткой Si 1200 штрихов/мм для Fe кромка, 2p, 2 кромка, 2p, L2, 2 кромка Ni 2p L2,3 и кромка Ce M4,5. Yog li, qhov kev daws teeb meem zog ntawm lub beam channel tau kwv yees li E/∆E = 700 eV/0.3 eV > 2000 thiab flux ≈1012 f/s siv lub SX-700 monochromator hloov kho nrog Si grating ntawm 1200 kab/hli rau Fe ntug 2p L2, 3, Cr ntug 2p L2.3, Ni ntug 2p L2.3, thiab Ce ntug M4.5.因此，光束线能量分辨率估计为E/ΔE = 700 eV/0.3 eV > 2000 和通量≈1012 ph/s 通过乽用单色器和Si 1200 线mm−1 光栅用于Fe 2p L2,3 边缘、Cr 2p L2,3 边缘、Ni 2p L2,3 边缘和Ce M4,5因此 ， 光束线 能量 分辨率 为 为 δe = 700 EV/0.3 EV> 2000 和 ≈1012 PH/S 通0X过单色器 和 SI 1200 线 mm-1 光栅 于 Fe 2P 2P 2P L2.3 边缘、Cr 2p L2.3 边缘、Ni 2p L2.3 边缘 缘 。Yog li ntawd, thaum siv lub tshuab SX-700 monochromator uas tau hloov kho thiab 1200 kab Si grating. 3, Cr ntug 2p L2.3, Ni ntug 2p L2.3 thiab Ce ntug M4.5.Nthuav lub zog photon hauv 0.2 eV kauj ruam. Ntawm txhua lub zog, cov duab PEEM tau kaw tseg siv TVIPS F-216 CMOS detector nrog 2 x 2 binning fiber optic kev sib txuas muab 1024 × 1024 pixels hauv 20 µm teb pom. Lub sijhawm raug ntawm cov duab yog 0.2 vib nas this, nruab nrab 16 thav duab. Lub zog duab photoelectron raug xaiv rau hauv txoj hauv kev kom muab lub teeb liab electron theem nrab siab tshaj plaws. Txhua qhov kev ntsuas tau ua tiav ntawm qhov tshwm sim ib txwm ntawm lub teeb photon linearly polarized. Yog xav paub ntxiv txog kev ntsuas, saib kev kawm yav dhau los 58. Tom qab kawm txog tag nrho cov electron yield (TEY) 59 hom kev kuaj pom thiab nws daim ntawv thov hauv X-PEEM, qhov tob ntawm kev kuaj pom ntawm txoj kev no kwv yees li ntawm ~ 4–5 nm rau lub teeb liab Cr thiab ~ 6 nm rau lub teeb liab Fe. Qhov tob Cr yog ze heev rau qhov tuab zaj duab xis oxide (~ 4 nm) 60,61 thaum qhov tob Fe loj dua qhov tuab zaj duab xis oxide. XAS uas tau sau ze ntawm ntug Fe L yog qhov sib xyaw ntawm cov hlau oxide XAS thiab FeO los ntawm lub matrix. Hauv thawj qhov xwm txheej, qhov muaj zog ntawm cov electrons uas tau tso tawm yog vim txhua hom electrons uas ua rau TEY. Txawm li cas los xij, lub teeb liab hlau ntshiab xav tau lub zog kinetic siab dua rau cov electrons kom dhau los ntawm txheej oxide, mus txog saum npoo, thiab raug sau los ntawm lub tshuab ntsuas. Hauv qhov no, lub teeb liab Fe0 feem ntau yog vim LVV Auger electrons thiab cov electrons theem nrab uas lawv tso tawm. Tsis tas li ntawd, qhov muaj zog TEY uas tau pab los ntawm cov electrons no lwj thaum txoj kev khiav tawm ntawm electron49 ntxiv txo qhov kos npe spectral ntawm Fe0 hauv daim ntawv qhia hlau XAS.
Kev koom ua ke cov ntaub ntawv mining rau hauv cov ntaub ntawv cubes (X-PEEM cov ntaub ntawv) yog ib kauj ruam tseem ceeb hauv kev rho tawm cov ntaub ntawv tseem ceeb (cov khoom siv tshuaj lom neeg lossis lub cev) hauv ntau txoj kev. K-txhais tau tias clustering yog siv dav hauv ntau qhov chaw, suav nrog kev pom tshuab, kev ua duab, kev paub txog tus qauv tsis muaj tus saib xyuas, kev txawj ntse dag, thiab kev tshuaj xyuas kev faib tawm24. Piv txwv li, K-txhais tau tias clustering yog siv tau zoo rau kev sib sau ua ke cov ntaub ntawv duab hyperspectral62. Hauv paus ntsiab lus, rau ntau yam khoom, K-txhais tau tias algorithm tuaj yeem yooj yim sib sau ua ke raws li cov ntaub ntawv hais txog lawv cov cwj pwm (cov yam ntxwv ntawm lub zog photon). K-txhais tau tias clustering yog ib qho algorithm iterative rau kev faib cov ntaub ntawv rau hauv K pawg tsis sib tshooj (clusters), qhov twg txhua pixel koom nrog ib pawg tshwj xeeb nyob ntawm qhov kev faib tawm ntawm cov tshuaj lom neeg tsis sib xws hauv cov khoom siv hlau microstructural. K-txhais tau tias algorithm muaj ob kauj ruam: kauj ruam thawj zaug xam K centroids, thiab kauj ruam thib ob muab txhua qhov taw tes rau ib pawg nrog cov centroids nyob sib ze. Qhov chaw nruab nrab ntawm lub ntiajteb txawj nqus ntawm ib pawg yog txhais tias yog qhov nruab nrab ntawm cov ntsiab lus ntaub ntawv (XAS spectra) ntawm pawg ntawd. Muaj ntau qhov deb sib txawv los txhais cov centroids nyob sib ze ua qhov deb Euclidean. Rau daim duab nkag ntawm px,y (x thiab y yog qhov kev daws teeb meem hauv pixels), CK yog qhov chaw nruab nrab ntawm lub ntiajteb txawj nqus ntawm pawg; daim duab no tuaj yeem raug faib ua pawg (clustered) rau hauv K pawg siv K-means63. Cov kauj ruam kawg ntawm K-means clustering algorithm yog:
Kauj Ruam 2. Xam qhov degree ntawm kev koom tes ntawm txhua lub pixels raws li lub centroid tam sim no. Piv txwv li, nws yog xam los ntawm Euclidean nrug d ntawm lub plawv thiab txhua pixel:
Kauj Ruam 3 Muab txhua lub pixel rau qhov chaw ze tshaj plaws. Tom qab ntawd rov xam cov chaw ntawm K centroid raws li hauv qab no:
Kauj Ruam 4. Rov ua cov txheej txheem (equations (7) thiab (8)) kom txog thaum cov centroids sib sau ua ke. Cov txiaj ntsig zoo kawg ntawm pawg muaj feem cuam tshuam nrog qhov kev xaiv zoo tshaj plaws ntawm cov centroids pib 63. Rau cov qauv ntaub ntawv PEEM ntawm cov duab hlau, feem ntau X (x × y × λ) yog lub voos xwmfab ntawm cov ntaub ntawv 3D array, thaum cov x thiab y axes sawv cev rau cov ntaub ntawv spatial (pixel resolution) thiab λ axis sib raug rau hom spectral zog ntawm photons. K-txhais tau siv los tshawb nrhiav thaj chaw txaus siab rau cov ntaub ntawv X-PEEM los ntawm kev sib cais pixels (clusters lossis sub-blocks) raws li lawv cov yam ntxwv spectral thiab rho tawm qhov zoo tshaj plaws centroid (XAS spectral curve) rau txhua analyte (cluster). Nws yog siv los kawm txog kev faib tawm spatial, kev hloov pauv spectral hauv zos, tus cwj pwm oxidation thiab lub xeev tshuaj lom neeg. Piv txwv li, K-txhais tau siv rau Fe L-ntug thiab Cr L-ntug thaj chaw hauv cov kub-ua haujlwm thiab txias-dov X-PEEM. Ntau tus lej ntawm K-clusters (cov cheeb tsam microstructural) tau raug sim kom nrhiav tau cov clusters thiab centroids zoo tshaj plaws. Thaum daim duab qhia tau pom, cov pixels raug xa rov qab mus rau cov cluster centroids kom raug. Txhua qhov kev faib tawm xim sib raug rau qhov chaw ntawm lub cluster, qhia txog qhov chaw ntawm cov khoom siv tshuaj lom neeg lossis lub cev. Cov centroids uas tau rho tawm yog cov kab sib xyaw ua ke ntawm cov spectra ntshiab.
Cov ntaub ntawv txhawb nqa cov txiaj ntsig ntawm txoj kev tshawb fawb no muaj los ntawm tus sau WC raws li qhov kev thov tsim nyog.
Sieurin, H. & Sandström, R. Kev tawg ntawm lub zog ntawm cov hlau tsis xeb duplex. Sieurin, H. & Sandström, R. Kev tawg ntawm lub zog ntawm cov hlau tsis xeb duplex. Sieurin, H. & Sandström, R. Вязкость разрушения сварной дуплексной нержавеющей стали. Sieurin, H. & Sandström, R. Kev tawg ntawm cov hlau tsis xeb duplex welded. Sieurin, H. & Sandström, R. 焊接双相不锈钢的断裂韧性. Sieurin, H. & Sandstrom, R. 焊接双相不锈钢的断裂韧性. Sieurin, H. & Sandström, R. Вязкость разрушения сварных дуплексных нержавеющих сталей. Sieurin, H. & Sandström, R. Kev tawg ntawm cov hlau tsis xeb duplex welded.project. fractal. plaub. 73, 377–390 (2006).
Adams, FV, Olubambi, PA, Potgieter, JH & Van Der Merwe, J. Kev tiv thaiv xeb ntawm cov hlau duplex stainless hlau hauv cov organic acids xaiv thiab cov organic acid / chloride ib puag ncig. Adams, FV, Olubambi, PA, Potgieter, JH & Van Der Merwe, J. Kev tiv thaiv xeb ntawm cov hlau duplex stainless hlau hauv cov organic acids xaiv thiab cov organic acid / chloride ib puag ncig.Adams, FW, Olubambi, PA, Potgieter, J. Kh. thiab Van Der Merwe, J. Kev tiv thaiv xeb ntawm duplex stainless hlau hauv cov chaw ib puag ncig nrog qee cov organic acids thiab cov organic acids / chlorides. Adams, FV, Olubambi, PA, Potgieter, JH & Van Der Merwe, J. Adams, FV, Olubambi, PA, Potgieter, JH & Van Der Merwe, J.Adams, FW, Olubambi, PA, Potgieter, J. Kh. thiab Van Der Merwe, J. Kev tiv thaiv xeb ntawm duplex stainless hlau hauv cov chaw ib puag ncig nrog qee cov organic acids thiab cov organic acids / chlorides.tiv thaiv xeb. Txoj Kev Mater 57, 107–117 (2010).
Barella S. et al. Cov yam ntxwv ntawm kev xeb thiab oxidizing ntawm Fe-Al-Mn-C duplex alloys. Cov ntaub ntawv 12, 2572 (2019).
Levkov, L., Shurygin, D., Dub, V., Kosyrev, K. & Balikoev, A. Tiam tshiab ntawm cov hlau super duplex rau cov khoom siv roj thiab roj tsim. Levkov, L., Shurygin, D., Dub, V., Kosyrev, K. & Balikoev, A. Tiam tshiab ntawm cov hlau super duplex rau cov khoom siv roj thiab roj tsim.Levkov L., Shurygin D., Dub V., Kosyrev K., Balikoev A. Tiam tshiab ntawm cov hlau super duplex rau cov khoom siv roj thiab roj av.Levkov L., Shurygin D., Dub V., Kosyrev K., Balikoev A. Tiam tshiab ntawm cov hlau super duplex rau cov khoom siv roj thiab roj. E3S webinar. 121, 04007 (2019).
Kingklang, S. & Uthaisangsuk, V. Kev tshawb nrhiav txog tus cwj pwm kub deformation ntawm duplex stainless hlau qib 2507. Metall. Kingklang, S. & Uthaisangsuk, V. Kev tshawb nrhiav txog tus cwj pwm kub deformation ntawm duplex stainless hlau qib 2507. Metall. Kingklang, S. & Uthaisangsuk, V. Исследование поведения горячей деформации дуплексной нержавеющей стали марки 2507. Metall Kingklang, S. & Uthaisangsuk, V. Ib txoj kev tshawb fawb txog kev hloov pauv kub ntawm Hom 2507 Duplex Stainless Steel. Metall. Kingklang, S. & Uthaisangsuk, V. 2507 级双相不锈钢的热变形行为研究. Kingklang, S. & Uthaisangsuk, V. 2507Kingklang, S. thiab Utaisansuk, V. Kev Tshawb Fawb Txog Kev Hloov Pauv Kub ntawm Hom 2507 Duplex Stainless Steel. Hlau.Tsev kawm ntawv qub. trance. A 48, 95–108 (2017).
Zhou, T. et al. Cov nyhuv ntawm kev tswj hwm txias dov rau ntawm microstructure thiab cov khoom siv kho tshuab ntawm cerium-modified super-duplex SAF 2507 stainless hlau. alma mater. qhov kev tshawb fawb. project. A 766, 138352 (2019).
Zhou, T. et al. Cov qauv kub-deformation-induced thiab cov khoom siv kho tshuab ntawm cerium-modified super-duplex SAF 2507 stainless hlau. J. Alma mater. lub tank cia khoom. thev naus laus zis. 9, 8379–8390 (2020).
Zheng, Z., Wang, S., Long, J., Wang, J. & Zheng, K. Cov nyhuv ntawm cov khoom tsis tshua muaj nyob rau ntawm qhov kub siab oxidation tus cwj pwm ntawm austenitic hlau. Zheng, Z., Wang, S., Long, J., Wang, J. & Zheng, K. Cov nyhuv ntawm cov khoom tsis tshua muaj nyob rau ntawm qhov kub siab oxidation tus cwj pwm ntawm austenitic hlau.Zheng Z., Wang S., Long J., Wang J. thiab Zheng K. Kev cuam tshuam ntawm cov khoom tsis tshua muaj nyob rau ntawm tus cwj pwm ntawm austenitic hlau nyob rau hauv qhov kub siab oxidation. Zheng, Z., Wang, S., Long, J., Wang, J. & Zheng, K. 稀土元素对奥氏体钢高温氧化行为的影响. Zheng, Z., Wang, S., Long, J., Wang, J. & Zheng, K.Zheng Z., Wang S., Long J., Wang J. thiab Zheng K. Kev cuam tshuam ntawm cov khoom tsis tshua muaj nyob rau ntawm tus cwj pwm ntawm cov hlau austenitic ntawm qhov kub siab oxidation.xeb. kev tshawb fawb. 164, 108359 (2020).