1. General corrosion
Uniform corrosion tshwm sim nyob rau saum npoo ntawm cov qauv titanium lossis cov khoom ua haujlwm, tsim cov txheej txheem corrosion nrog cov tuab tuab, nruj nreem txuas rau titanium nto, thiab feem ntau tsis nthuav tawm sab hauv nrog lub sijhawm, tab sis muaj kev zam. Hauv ntau cov xov xwm corrosive, kev ua haujlwm corrosion ntawm titanium zoo li zoo lossis zoo dua li ntawm lwm cov hlau nrog cov txheej tiv thaiv. Qhov corrosion ntawm titanium feem ntau yog electrolytic, yog li muaj kev sib raug zoo ntawm corrosion thiab electrode peev xwm thiab electromotive tam sim no. Lub anodic thiab cathodic polarization kuj muaj zog cuam tshuam rau corrosion mechanism thiab tus nqi. Lub peev xwm ntawm titanium feem ntau nyob ntawm cov khoom insulating ntawm oxide zaj duab xis. Yog li ntawd, cov yam ntxwv ntawm oxide zaj duab xis ntawm lub titanium nto ua si lub luag hauj lwm txiav txim siab nyob rau hauv nws corrosion kuj. Txhua yam uas tuaj yeem txhim kho qhov compactness ntawm oxide zaj duab xis, nce lub thickness ntawm cov oxide zaj duab xis, thiab txhim kho cov insulating zog ntawm oxide zaj duab xis yog tag nrho cov conducive rau kev txhim kho corrosion kuj. Ntawm qhov tsis sib xws, txhua yam uas txo qis kev tiv thaiv muaj peev xwm ntawm oxide zaj duab xis, txawm tias nws yog tshuab lossis tshuaj, yuav ua rau corrosion kuj ntawm titanium poob sharply.
2. Local corrosion
Lub corrosion ntawm titanium nyob rau hauv feem ntau yog nyob rau hauv lub zos nyob rau hauv cov xwm, thiab cov degree ntawm corrosion ntawm ib tug taw tes yog heev txawv ntawm qhov ntawm lwm yam. Crevice corrosion, cavitation corrosion, kev nyuaj siab corrosion cracking, thiab lwm yam yog localized corrosion. Crevice corrosion feem ntau tshwm sim ntawm flanges los yog folds thiab nyob rau hauv crevices nyob ze deposits, thiab nws yuav tsis tshwm sim yog hais tias lub crevice yog heev me me los yog loj heev. Cavitation corrosion yog ib hom corrosion uas tshwm sim hauv qhov qhib, thiab nws yooj yim tshwm sim nyob rau hauv lub xub ntiag ntawm CI-, Br-, thiab I-plasma. Kev nyuaj siab corrosion cracking yog ib yam ntawm corrosion uas tshwm sim thaum lub workpiece los yog cov qauv nyob rau hauv lub ua ke ntawm tensile kev nyuaj siab thiab ib tug corrosive ib puag ncig.
3. Kev puas tsuaj
Daim ntawv corrosion ntawm cov qauv los yog workpiece nyob rau hauv lub corrosive ntws nruab nrab, vim lub mechanical kev txiav txim ntawm cov kua, corrosion yog ceev, vim hais tias cov kua yuav tshem tawm ib feem los yog tag nrho cov khoom corrosion, nthuav tawm qhov chaw tshiab, thiab ceev corrosion.
Dissimilar hlau tiv thaiv corrosion kuj hu ua galvanic corrosion. Nyob rau hauv ib puag ncig corrosive, ob lub hlau lossis cov khoom siv uas muaj peev xwm sib txawv tau muab tso rau. Nyob rau hauv cov ntaub ntawv ntawm ib tug hluav taws xob luv luv Circuit Court, cov hlau uas tsis muaj peev xwm yuav corrode.
4. nqus H2 lossis H2 Crisp
Raws li ib txwm muaj, titanium thiab titanium alloys ib txwm muaj H2. Yog tias H2 tau muab rho tawm los ntawm cov khoom siv, thaum cov nyiaj rho tawm ntau tshaj qhov kev daws teeb meem, nkig hydrides yuav raug tsim, ua rau hydrogen embrittlement.
Nyob rau hauv feem ntau cov xwm txheej, corrosion ntawm titanium thiab titanium alloys yog nyob rau hauv lub zos, thiab nyob rau tib lub sij hawm, lub degree ntawm corrosion ntawm ib tug taw tes yog heev txawv ntawm qhov ntawm lwm yam. Yog li ntawd, qhov kev ntsuam xyuas ntau ntawm corrosion tsuas tuaj yeem ua raws li cov ntaub ntawv txheeb cais ntau, tsis yog cov txiaj ntsig ntawm ob peb cov qauv. Lwm qhov teeb meem loj hauv kev ntsuam xyuas corrosion yog dab tsi yog tus qauv. Kev poob qis yog tsis tshua siv, thiab qib ntawm corrosion feem ntau yog txiav txim raws li lub zog poob, kev hloov pauv ntawm qhov chaw, lossis perforation. Feem ntau, cov txheej txheem corrosion ntawm titanium thiab titanium alloys qeeb. Tshwj tsis yog tias koj tsis tsim nyog rau cov xwm txheej uas koj nyob. Txhawm rau txhawm rau ntsuas qhov ua tau zoo ntawm titanium, nws feem ntau siv sijhawm kaum ob hnub lossis ntau xyoo ntawm kev sim. Nyob rau hauv ntau zaus, titanium thiab titanium alloys corrode sai thaum pib, ces qeeb, thiab tsuas yog tsis muaj zog corrosion feem ntau tshwm sim thaum kawg. Txawm li cas los xij, qee zaum, titanium alloy yuav hloov tom qab lub sijhawm, thiab cov qauv thiab kev ua haujlwm yuav hloov pauv loj heev. Yog li ntawd, kev sim siv sij hawm luv luv tsis yog kev ntseeg siab kiag li. Muaj ntau txoj kev sim siv ceev ceev, tab sis feem ntau, qhov kev sim sai dua, qhov kev ntseeg siab ntawm cov txiaj ntsig tau qis dua.
Titanium yog ib qho ntawm cov thermodynamically tsis ruaj khov hlau. Nws cov txheej txheem electrode muaj peev xwm yog {{0}}.63V, thiab saum npoo yog ib txwm npog nrog nyias thiab tuab TiO2 zaj duab xis. Yog li ntawd, lub peev xwm ruaj khov ntawm titanium thiab titanium alloys zoo li zoo. Piv txwv li, titanium nyob rau hauv qhov ruaj khov muaj peev xwm nyob rau hauv seawater ntawm 25 degree yog hais txog 0.09V. Electrode muaj peev xwm feem ntau yog xam los ntawm cov ntaub ntawv thermodynamic, thiab cov ntaub ntawv sib txawv yuav tshwm sim vim muaj cov ntaub ntawv sib txawv, uas yog qhov qub.
Qhov saum npoo ntawm titanium thiab titanium alloys ib txwm muaj txheej nyias ntawm oxide zaj duab xis uas yog tsim nyob rau hauv huab cua. Nws zoo heev corrosion kuj los ntawm lub hav zoov ntawm ib tug ruaj khov, muaj zog adhesion thiab zoo tiv thaiv oxide zaj duab xis rau saum npoo. . Qhov kev tiv thaiv corrosion ntawm cov yeeb yaj kiab tiv thaiv no tuaj yeem qhia los ntawm P / B piv. Tsuas yog thaum tus nqi P / B ntau dua 1 tuaj yeem tiv thaiv. Txwv tsis pub, qhov corrosion kuj yuav tsawg, tab sis nws yuav tsum tsis txhob siab tshaj 2.5. Yog tias nws ntau dua li tus nqi no, qhov kev ntxhov siab hauv cov oxide zaj duab xis yuav nce, uas yuav yooj yim ua rau cov oxide zaj duab xis tawg thiab corrosion kuj yuav txo. , tus nqi zoo tshaj yog 1 ~ 2.5.
Titanium yuav tam sim ntawd tsim ib zaj duab xis oxide nyob rau hauv cov huab cua los yog aqueous tov. Lub thickness ntawm cov zaj duab xis tsim nyob rau hauv cov huab cua ntawm chav tsev kub yog 1.2nm ~ 1.6nm, thiab nws yuav nce nrog lub sij hawm. Nws yuav nce mus rau 5nm tom qab 70 hnub thiab 8nm ~ 9nm tom qab 545 hnub. . Artificially ntxiv dag zog rau oxidation tej yam kev mob, xws li cua sov, ntxiv oxidants los yog anodic oxidation, thiab lwm yam, tuaj yeem ua kom oxidation, ua kom cov yeeb yaj kiab tuab, thiab txhim kho corrosion kuj.
Cov oxide zaj duab xis nyob rau saum npoo ntawm titanium thiab titanium alloys feem ntau tsis yog ib qho qauv, thiab nws muaj pes tsawg leeg thiab cov qauv muaj feem xyuam rau cov txheej txheem tsim. Feem ntau, qhov sib cuam tshuam ntawm oxide zaj duab xis thiab ib puag ncig feem ntau yog TiO2, thiab qhov sib cuam tshuam ntawm oxide zaj duab xis thiab cov hlau yuav raug tswj hwm los ntawm TiO2, thaum nruab nrab yog txheej hloov pauv ntawm cov xeev sib txawv, lossis txawm tias tsis yog-stoichiometric oxide. , uas txhais tau tias titanium thiab oxide zaj duab xis saum npoo ntawm titanium alloy yog cov txheej txheem ntau txheej. Raws li rau lawv cov txheej txheem tsim, nws tsis tuaj yeem nkag siab yooj yim raws li cov tshuaj tiv thaiv ncaj qha ntawm Ti thiab O2. Qee cov kws tshawb fawb tau tawm tswv yim ntau yam txheej txheem tsim. Cov kws tshawb fawb Lavxias ntseeg tias hydrides tau tsim ua ntej, thiab tom qab ntawd cov yeeb yaj kiab oxide ntshiab yog tsim los ntawm hydrides.
