Corrosion ntawm titanium thiab titanium alloys

Uniform corrosion tshwm sim nyob rau saum npoo ntawm titanium cov qauv lossis cov khoom ua haujlwm, tsim cov txheej txheem ntawm cov khoom siv corrosion nrog cov tuab tuab uas ua rau ze rau ntawm titanium nto thiab feem ntau tsis nthuav sab hauv lub sijhawm, tab sis muaj kev zam. Hauv ntau cov xov xwm corrosive, titanium qhov kev ua haujlwm corrosion zoo li zoo lossis zoo dua li lwm cov hlau nrog cov txheej tiv thaiv, xws li txhuas. Qhov corrosion ntawm titanium feem ntau yog electrolytic hauv qhov, yog li muaj qee qhov kev sib raug zoo ntawm corrosion thiab electrode peev xwm thiab electrodynamic tam sim no. Anodic thiab cathodic polarization kuj muaj zog cuam tshuam rau corrosion mechanisms thiab tus nqi. Lub peev xwm hluav taws xob ntawm titanium feem ntau nyob ntawm cov khoom insulating ntawm oxide zaj duab xis. Yog li ntawd, cov yam ntxwv ntawm titanium nto oxide zaj duab xis ua lub luag haujlwm txiav txim siab hauv nws qhov kev tiv thaiv corrosion. Txhua yam uas tuaj yeem txhim kho qhov ntom, tuab, thiab rwb thaiv tsev ntawm oxide zaj duab xis yuav pab txhim kho corrosion kuj. Ntawm qhov tsis sib xws, txhua yam uas txo qhov muaj peev xwm tiv thaiv zoo ntawm cov yeeb yaj kiab oxide, txawm tias siv tshuab lossis tshuaj lom neeg, yuav ua rau corrosion kuj ntawm titanium poob qis heev.

Feem ntau corrosion ntawm titanium yog nyob rau hauv qhov xwm txheej, nrog rau qhov corrosion ntawm ib tug taw tes yog ho txawv dua li ntawm corrosion ntawm lwm qhov chaw. Crevice corrosion, kab noj hniav corrosion, kev nyuaj siab corrosion cracking, thiab lwm yam. yog tag nrho cov localized corrosion. Crevice corrosion feem ntau tshwm sim ntawm flanges lossis folds thiab nruab nrab ntawm qhov khoob ze ntawm kev tsim. Qhov no yuav tsis tshwm sim yog tias qhov sib txawv me dhau lossis loj dhau. Cavitation corrosion yog ib hom kev xeb uas tshwm sim hauv qhov qhib. Hom corrosion no tuaj yeem yooj yim tshwm sim nyob rau hauv lub xub ntiag ntawm CI-, Br-, I-plasma. Kev ntxhov siab corrosion cracking yog ib hom kev xeb uas tshwm sim hauv cov khoom ua haujlwm lossis cov qauv hauv qab kev sib xyaw ua ke ntawm tensile kev nyuaj siab thiab corrosive ib puag ncig.

Daim ntawv ntawm corrosion ntawm cov qauv los yog workpieces nyob rau hauv corrosive flowing media yog ceev los ntawm cov neeg kho tshuab kev txiav txim ntawm cov kua, vim hais tias cov kua yuav tshem tawm ib co 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, tso ob lub hlau lossis cov khoom siv nrog cov khoom siv hluav taws xob sib txawv. Yog tias qhov hluav taws xob luv luv tshwm sim, cov hlau uas muaj peev xwm qis dua yuav corrode.

Suck 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, brittle hydrides yuav tsim thaum cov nyiaj rho tawm ntau tshaj qhov kev daws teeb meem, ua rau hydrogen embrittlement.

Feem ntau, corrosion ntawm titanium thiab titanium alloys yog nyob rau hauv lub zos, thiab cov degree ntawm corrosion ntawm ib tug taw tes yog heev txawv los ntawm cov degree ntawm corrosion ntawm lwm lub ntsiab lus. Yog li ntawd, kev ntsuam xyuas ntau ntawm corrosion tsuas tuaj yeem ua raws li cov khoom siv txheeb cais ntau ntau dua li cov txiaj ntsig ntawm ob peb cov qauv. Lwm qhov teeb meem loj hauv kev ntsuam xyuas corrosion yog dab tsi siv los ua tus qauv. Kev poob qis yog tsis tshua muaj siv, thiab qib ntawm corrosion feem ntau yog txiav txim raws li lub zog poob, kev hloov ntawm qhov tsos, los yog perforations. Feem ntau hais lus, titanium thiab titanium alloys corrode maj mam. Tshwj tsis yog tias koj tsis haum rau cov xwm txheej. Txhawm rau ntsuas qhov ua tau zoo ntawm titanium, kev ntsuas feem ntau tau ua ntau ntau hnub lossis ntau xyoo. Feem ntau, titanium thiab titanium alloys corrode sai thaum xub thawj, ces qeeb, thiab thaum kawg tsuas yog tsis muaj zog corrosion feem ntau tshwm sim. Tab sis qee zaum, titanium alloys yuav hloov pauv tom qab lub sijhawm, thiab cov qauv thiab cov khoom yuav hloov pauv ntau. Yog li ntawd, kev sim siv sij hawm luv luv tsis yog kev ntseeg siab tag nrho. Muaj ntau ntau txoj kev sim sai, tab sis feem ntau hais lus, qhov kev sim sai dua, qhov kev ntseeg tau tsawg dua.

Titanium yog ib qho ntawm cov thermodynamically tsis ruaj tsis khov hlau. Nws tus qauv electrode peev xwm yog {{0}}.63V. Qhov 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, qhov ruaj khov muaj peev xwm ntawm titanium hauv dej hiav txwv ntawm 25 degree yog txog 0.09V. Lub peev xwm electrode feem ntau yog xam raws li cov ntaub ntawv thermodynamic. Vim muaj cov ntaub ntawv sib txawv, cov ntaub ntawv sib txawv yuav tshwm sim, uas yog qhov qub.

Muaj ib txwm muaj nyias oxide zaj duab xis nyob rau saum npoo ntawm titanium thiab titanium alloys, uas yog ib txwm tsim nyob rau hauv huab cua. Nws zoo heev corrosion kuj los ntawm qhov ruaj khov, muaj zog adhesion thiab zoo tiv thaiv oxide zaj duab xis uas ib txwm muaj nyob rau ntawm nws qhov chaw. Kev tiv thaiv corrosion ntawm cov yeeb yaj kiab tiv thaiv yog qhia los ntawm P / B piv. Tsuas yog thaum tus nqi P / B ntau dua 1 nws muaj kev tiv thaiv. Txwv tsis pub, qhov kev tiv thaiv corrosion yuav qis, tab sis nws tsis tuaj yeem siab dua 2.5. Yog tias nws ntau dua li tus nqi no, qhov kev ntxhov siab hauv cov yeeb yaj kiab oxide nce, uas tuaj yeem ua rau cov oxide zaj duab xis tawg tau yooj yim thiab txo qhov kev tiv thaiv corrosion. Qhov zoo tshaj tus nqi yog 1 ~ 2.5.

Titanium yuav tam sim ntawd tsim oxide zaj duab xis nyob rau hauv cov huab cua los yog aqueous tov. Lub thickness ntawm zaj duab xis tsim nyob rau hauv qhov chaw ntawm chav tsev kub yog 1.2nm ~ 1.6nm, thiab loj hlob nrog lub sij hawm. Nws yuav nce mus rau 5nm tom qab 70 hnub thiab tuaj yeem thickened mus rau 8nm ~ 9nm tom qab 545 hnub. . Artificially ntxiv dag zog rau oxidation tej yam kev mob, xws li cua sov, ntxiv oxidants los yog anodizing, muaj peev xwm ua kom oxidation, nce zaj duab xis thickness, 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, thaum qhov sib cuam tshuam ntawm oxide zaj duab xis thiab cov hlau feem ntau yog TiO2, nrog cov txheej txheem hloov pauv ntawm cov xeev sib txawv lossis txawm tias tsis yog-stoichiometric oxides hauv nruab nrab. Qhov no txhais tau hais tias qhov chaw oxide zaj duab xis ntawm titanium thiab titanium alloys muaj ntau txheej txheej 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. Ntau tus kws tshawb fawb tau tawm tswv yim ntau yam kev tsim kho. Cov kws tshawb fawb Lavxias ntseeg tias hydride yog tsim ua ntej, thiab tom qab ntawd cov yeeb yaj kiab oxide ntshiab yog tsim rau ntawm hydride.