Rau cov engineers, project cov thawj tswj hwm, thiab kev xaiv tshwj xeeb hauv kev xav tau kev lag luam, cov khoom siv yog qhov kev txiav txim siab tseem ceeb uas muaj kev ua tau zoo thiab tus nqi sib tshuam. Thaum txiav txim siab titanium rau kev thov koom nrog cov xov xwm corrosive, feem ntau slows mus rau ob qhov kev lag luam hauv cov qib: Qib 2 (uns uns uns400) thiabQeb 7(Tsis yog R52400). Thaum qib 2 muaj ib lub baseline ntawm kev ua tau zoo corrosion thiab yog siv dav dav, nqi {{{{}} kub sab nraud nthuav qhia kev sib tw tseem ceeb. Nov yog qhov xwm txheej zoo nkauj uas yog ib daim ntawv teev npe rau cov ntawv sau tseg, tsis yog cov khoom siv hloov tshiab. Qhov kev txiav txim siab nqis peev rau ntawm palladium - alloyedGr7 Titanium SheetPob khawm rau kev nkag siab zoo ntawm nws cov kev ua tau zoo tshaj plaws, thiab lub sijhawm ntev ntawm kev pheej hmoo ua rau cov khoom siv tsis ua tiav.
Lub txiav txim siab qhov tseem ceeb: Palladium qhov cuam tshuam ntawm electrochemical ruaj khov
Ib nrais muag, cov cuab yeej siv cov neeg kho mob ntawm qib 7 titanium yuav luag zoo ib yam li cov qib alpha, muab ib qho kev sib piv sib piv, muaj zog} weldability, thiab zoo dua cov ntawv muaj peev xwm. Qhov kev sib cav uas muaj qhov tseem ceeb, thiab cov khoom ntawm qib 7 qhov kev ua tau tshwj xeeb, lus dag hauv tus menyuam yaus tab sis muaj zog ntxiv rau nws cov tshuaj lom neeg: Palladium (PD).
Raws li cov ASTM B265 qauv, qib 7 titanium muaj cov tswj kev tswj ntawm 0.12% rau 0.25% palladium. Lub caij no ua raws li tus neeg sawv cev muaj zog uas ua rau muaj kev txhim kho corrosically ntawm cov chaw nyob qhov twg uas qib 2 yuav yog kev cuam tshuam sai sai.
Tus kws kho tshuab tom qab txoj kev txhim kho no yog enctrochemical. Titanium cov nyiaj tau los ntawm kev ruaj khov, tenacious, thiab tus kheej-}} kev kho oxide txheej (tseem ceeb ntawm nws cov nplaim. Hauv oxidizing lossis nruab nrab ib puag ncig, cov txheej txheej no yog qhov muaj zog. Txawm li cas los xij, hauv kev txo cov kua qaub (xws li hydrochloric acid los yog nyob rau hauv tej yam uas crevice corrosion tuaj yeem pib ua tiav, cov oxide oxide no tuaj yeem tawg.
Palladium, ua lub noble hlau, muaj ntau dua cov muaj peev xwm txuas ntxiv dua titanium. Thaum txuam nrog titanium, lub palladium ua raws li lub vev xaib Cathodic ntawm cov khoom seem. Nyob rau hauv qhov kev tshwm sim ntawm ib cheeb tsam ib cheeb tsam ntawm passive oxide zaj duab xis nyob rau ib puag ncig kev tawm tsam (hydrogen evoling), uas nyob rau hauv lem polarizing evanium rau ib tug neeg muaj peev xwm ntxiv. Qhov no rov ua kom zoo rau saum npoo av, ua tau zoo thiab tam sim ntawd kho cov txheej oxide thiab tiv thaiv kev xeb ntxiv. Qeb 2, tsis muaj lub ntsiab lus catalytic no, tsis tuaj yeem rov qab ua rau muaj kev txhoj puab heev, ua rau kev ua tsis tau xeb thiab cov khoom tsis muaj kev ua tsis tiav.
Quantitive Performance: Corrosion tus nqi sib piv nrog kev tawm tsam
Cov lus piav qhia theoretical yog qhov muaj txiaj ntsig, tab sis cov ntaub ntawv tseeb, tab sis cov ntaub ntawv qhia tau txiav txim siab rau cov khoom siv tshwj xeeb. Kev tshuaj ntsuam ntawm cov ntaub ntawv corrosion cov ntaub ntawv kom pom meej txog kev ua tau zoo ntawm qib 2 thiab qib 7 titanium hauv cov chaw sib tw ib puag ncig. Tus nqi corrosion yog feem ntau ntsuas hauv millimeters ib xyoos (hli / xyoo / Mil) lossis Mil) lossis MBY); Tus nqi qis dua 0.13 hli / xyoo (5 MPY) feem ntau suav tias yog qhov lees txais rau cov ntawv thov feem ntau.
PERFOSION Corrosion nyob rau hauv kev txo cov kua qaub (cov ntaub ntawv tau los ntawm ASM Phau Ntawv thiab Kev Lag Luam Kev Lag Luam)
| Ib puag ncig (thaum npau npau taws) | Titanium Qib 2 Corrosion tus nqi (hli / yr) | Gr7 Titanium Sheet Corrosion Tus Nqi (MM / YR) | Kev Ntsuam Xyuas Kev Ua Yeeb Yam |
| 1% hydrochloric acid (HCl) | > 1.27 | < 0.02 | Qeb 7 yog neeg tiv taus; Qib 2 yog qhov tsis haum. |
| 5% hydrochloric acid (HCl) | Sai tau tawm tsam | ~0.40 | Qeb 7 qhia ntsuas kev ntsuas tab sis tseem ceeb qis dua. |
| 0.5% sulfuric acid (hso₄) | ~0.50 | < 0.02 | Qeb 7 muaj kev tiv thaiv zoo heev; Qib 2 yog ciam teb. |
| 2% sulfuric acid (hatso₄) | > 1.30 | < 0.13 | Qib 7 tseem haum haum; Qeb 2 tsis tau ua tiav. |
Cov ntaub ntawv tsis sib xws qhia tau tias hauv kev txo cov kua qaub, txawm tias muaj cov tshuaj qis, qib 2 tus nqi kho kom nrawm dua li siv tau. Hauv kev sib piv, qib 7 tswj lub xeev passive, nthuav qhia cov nqi tsis saib xyuas cov nqi uas feem ntau ntawm qhov qis dua.
Tsis tas li ntawd, kev pheej hmoo ntawm cov chlorice corrosion hauv cov tshuaj kub (piv txwv li kev txhawj xeeb zoo li plhaub li plhaub thiab} Qib 2 tau paub tias yuav raug rau cov cevice corrosion nyob rau hauv cov mob no. Palladium nyob rau hauv qib 7 tseem txhawb nqa nws kev tiv thaiv kev yeem, ua nws cov khoom siv kub thiab lwm yam tshuaj yuav txhawb microenvirirments.
Tus Nqi Ntsuam Xyuas: Thawj zaug kev nqis peev thiab tag nrho tus nqi ntawm cov tswv cuab (TCO)
Tsis muaj qhov tsis meej xwm tias cov ntawv sau ua ke ntawm qib 7 titanium daim ntawv yog siab tshaj qhov qib 2 siab dua los ntawm tus nqi lag luam ntawm palladium. Qhov kev ua tiav thawj zaug tau sib txawv tuaj yeem yog ib qho kev xav ntawm Hesitation tsom rau cov chaw ua haujlwm tsom mus rau cov peev txheej tam sim ntawd. Txawm li cas los xij, kev soj ntsuam lub sib hloov tsis huv yog luv luv thiab tsis ua raws li qhov ntev- sij hawm kev ua haujlwm ntawm cov khoom tsis muaj txiaj ntsig.
Tus nqi tag nrho ntawm cov tswv cuab (TCO) tsom xam cov kev xav tau nyiaj ntau dua. Xav txog cov hauv qab no:
- Cuab tam simset ntev:Nyob rau hauv kev pab cuam corrosive corrosive uas qib 2-3 xyoos, qib 7 tivthaiv ntev li 15-20 xyoos lossis ntau dua. Thawj tus nqi them tus nqi yog amortized tshaj li ntau npaum li cas siv sijhawm ntev dua.
- Txo cov nqi txij nkawm:Siv cov khoom seem ua ntu zus tsim nyog siv sijhawm ntau, kev kho tshiab, thiab kev hloov pauv ntawm cov nqi hluav taws xob thiab cov nqi khoom siv. Qib 7 txoj kev cia siab rau cov sijhawm teem sijhawm no thiab tsis muaj kev tswj hwm.
- Kev tiv thaiv ntawm downtime:Qhov tseem ceeb tshaj plaws muaj feem cuam tshuam nrog cov khoom tsis ua haujlwm yog feem ntau ntau lawm downtime. Hauv kev siv tshuaj lom neeg ua haujlwm lossis lub vaj tse muaj zog, ib hnub ntawm ploj ntau lawm tuaj yeem ua rau muaj kev poob nyiaj ntawm thawj qib 2 dhau qib 7.
- Kev nyab xeeb thiab ib puag ncig kev pheej hmoo:Cov cuab yeej tsis ua hauj lwm vim yog corrosion tuaj yeem ua rau muaj kev phom sij lom zem, tsim kev nyab xeeb rau cov neeg ua haujlwm puas tsuaj thiab muaj peev xwm ua lub luag haujlwm.
Thaum saib los ntawm lub lens ntawm TCO, qhov siab dua thawj zaug hauv qib 7 tsis yog tus nqi pov hwm tawm tsam kev puas tsuaj, ua haujlwm tsis muaj zog, thiab ntev}}}}}}}}}}}}}}}}}}}}}}} thibility kev pheej hmoo nyiaj txiag.
Cov Lus Qhia Kev Xaiv: Gr7 vs. Gr2
Ua cov kev xaiv kom raug yuav tsum tau nkag siab meej txog cov haujlwm tshwj xeeb. Siv cov lus qhia hauv qab no los txiav txim siab thaum kev nqis peev hauv Qib 7 yog kev ncaj ncees thiab thaum qeb 2 yog qhov kev xaiv zoo meej thiab kev lag luam zoo kawg nkaus.
Qhia rau qib 2 Titanium ntawv thaum:
- Thawj ib puag ncig yog oxidizing (piv txwv li, nitric acid, cov tshuaj xhlorine ntub dej).
- Daim ntawv thov cuam tshuam nrog seawater, brine, lossis lwm txoj kev daws teeb meem chloride ntawm qhov kub tsis tu ncua 80℃(176℃f).
- Cov txheej txheem dej yog nruab nrab lossis tsuas yog txo me me.
- Muaj kev pheej hmoo tsawg kawg ntawm kev tsim cov kab ke, lossis tus qauv tsim tuaj yeem tsim cov khoom siv rau txo nws.
- Daim ntawv thov yog tus nqi -} rhiab thiab cov txheej txheem mob poob zoo nyob rau hauv cov tsim kev ua haujlwm ntawm qib 2.
Qhia kom meej Gr7 Titanium ntawv thaum:
- Cov txheej txheem cuam tshuam cov roj qaub txo, txawm tias muaj kev sib zog. Qhov no suav nrog hydrochloric acid (hcl), sulfuric acid (hso₄), phosphoric acid (h acidpephor acid (h acid₃₄), thiab lwm tus qhov twg nyob qib 2 tau paub kom nquag plias.
- There is a high risk of crevice corrosion. This is critical in applications with gaskets, flanges, tube-to-tubesheet joints, and areas under deposits, especially in hot chloride solutions (>80 degree).
- Cov txheej txheem dej kev siv tshuab kuj hloov tau cov txheej txheem lossis tsis paub txog, nrog lub peev xwm rau cov neeg sawv cev lossis cov kev qhia txog kev txo cov neeg sawv cev. Qib 7 muab cov npoo kev nyab xeeb.
- Cov cuab yeej ntseeg tau thiab ntev yog qhov tseem ceeb, thiab tus nqi kho mob, lossis tsis ua haujlwm zoo rau cov tshuaj tiv thaiv cov tshuaj txias, lossis lub zog nuclear cog txias).
- Daim ntawv thov yuav tsum tau muaj qib siab tshaj plaws ntawm corrosion resistance muaj nyob rau hauv ib qib kev lag luam titanium tau.
Tag
Kev txiav txim siab ntawm qib 2 thiab qib 7 titanium tsis yog ib qho kev xaiv ntawm ob cov khoom, tab sis kev txheeb xyuas cov tswv yim ntawm kev pheej hmoo, kev ua tau zoo, thiab ntev} lub txiaj ntsig. Thaum qib 2 ua haujlwm ua cov haujlwm ua haujlwm ruaj khov thiab txhim khu kev qha rau cov kev siv ntau heev, nws tau txhais tau meej meej txog kev txwv. Thaum twg cov txheej txheem cov neeg tuaj yeem mus rau hauv thaj chaw ntawm kev txo cov kua qaub lossis siab - kub chlorides, cia siab rau qib 2 yog qhov tsis tsim nyog. Qhov kev suav nrog Palladium hloov cov khoom, tsim covGr7 Titanium Sheet- Ib qho tshwj xeeb alloy corineered los tswj nws txoj kev ncaj ncees nyob rau hauv cov chaw uas lwm tus yuav swb. Los ntawm kev nqis peev hauv nws cov kev ua haujlwm zoo tshaj, engeters tsis yog tsuas yog yuav cov khoom; Lawv yog qhov ua kom tiav kev ua haujlwm, kev nyab xeeb, thiab ntev- TSHEM NYIAJ TXHAWB RAU lawv cov khoom tseem ceeb tshaj plaws.
Tiv Tauj Peb
Los tham txog koj cov kev thov tshwj xeeb, ntsuam xyuas cov ntawv txheeb cov ntaub ntawv, lossis muab cov ntawv pov thawj qib 7 titanium los xij, thov hu rau peb cov kws tshaj lij cov kws tshaj lij. Peb npaj tau los pab koj ua qhov kev txiav txim siab tshaj plaws rau koj txoj haujlwm tiav.
Xa email peb pab neeg ntawm:andy@ytitanium.com
Ntawv Sawv cev
- Astm International. (2019). ASTM B265-19: Cov qauv qhia tshwj xeeb rau cov titanium thiab titanium alloy sawb, ntawv, thiab phaj. West Conshockocken, PA: Astm International.
- Schutz, RW (1996). Ib qho kev xav 50-xyoo ntawm kev txhim kho ntawm titanium alloys rau kev pabcuam corrosive. JOM, 48 (10), 24-29.
- Davis, JR (Ed.). (2000). Corrosion ntawm titanium thiab titanium alloys. Hauv phau ntawv kawm ASM, ntim 13B: corrosion: cov ntaub ntawv. ASM International.
- Thomas, De, & yuav kawm tiav. (1983). Cov cwj pwm corrosion ntawm palladium -} alloyed titanium. Titanium thiab titanium alloys: kev tshawb fawb thiab thev naus laus zis, 2, 11454.
- Nace thoob ntiaj teb. (2005). Corrosion cov ntaub ntawv tshawb fawb - cov hlau seem, 6th tsab. Houston, tx: nace xovxwm.