Ob peb lub zos Corrosion yam ntxwv ntawm titanium cov ntaub ntawv

1.1 crevice corrosion Titanium crevice corrosion kuj yog tshwj xeeb tshaj yog muaj zog, tsuas yog nyob rau hauv ob peb chemical media crevice corrosion. Titanium crevice corrosion thiab kub, chloride concentration, pH tus nqi thiab qhov loj ntawm qhov crevice muaj kev sib raug zoo. Raws li cov ntaub ntawv tseem ceeb, cov chlorine ntub dej kub siab tshaj 85 degree yog ib qho yooj yim los tsim crevice corrosion. Piv txwv li, qee cov nroj tsuag nyob rau hauv lub txias txias ua ntej lub packed ntauwd ncaj qha txias kom cov ntub dej chlorine kub mus rau 65 ~ 70 degree, thiab ces mus rau hauv lub titanium txias txias los txhim kho kev tiv thaiv rau crevice corrosion, cov nyhuv kuj tseem ceeb heev. Kev xyaum tau ua pov thawj: txo qhov kub yog los tiv thaiv crevice corrosion yog ib txoj hauv kev zoo, nyob rau hauv qhov kub thiab txias sodium chloride tov kuj tau tshwm sim hauv titanium crevice corrosion. Nyob rau hauv luv luv, kom yooj yim los tsim crevice corrosion ntawm cov khoom thiab cov khoom, xws li sealing nto, raj phaj thiab raj expansion qhov chaw, phaj kub exchanger, ntauwd phaj thiab ntauwd tiv tauj qhov chaw nrog rau ntauwd fasteners yuav tsum tau siv Ti-0 .2Pd thiab lwm yam titanium alloys, nyob rau hauv tus tsim yuav tsum tau zam kom tsis txhob muaj cov tsos ntawm crevices thiab stagnant ntws cheeb tsam. Xws li ntauwd fasteners yuav tsum tsis txhob siv cov ntsia hlau txuas. Cov yeeb nkab phaj thiab raj nrog nthuav dav thiab sealing vuam qauv yog zoo dua li yooj yim expansion, rau lub flange sealing nto, yuav tsum tsis txhob siv asbestos gasket, yuav tsum tau siv Teflon zaj duab xis qhwv asbestos gasket.

1.2 Kub kub corrosion

Titanium corrosion kuj ntawm qhov kub thiab txias, nyob ntawm seb cov yam ntxwv ntawm qhov nruab nrab thiab kev ua haujlwm ntawm lawv tus kheej nto oxide zaj duab xis. Titanium nyob rau hauv cov huab cua los yog oxidizing huab cua, raws li ib tug structural khoom siv tau rau 426 degree, tab sis nyob rau ntawm txog 250 degree, titanium pib nqus hydrogen heev, nyob rau hauv ib tug tag nrho hydrogen cua, thaum kub nce mus rau 316 degree los yog ntau tshaj, titanium hydrogen. nkaws. Yog li ntawd, thaum tsis muaj kev sim dav dav, titanium yuav tsum tsis txhob siab tshaj 330 degree C rau kev siv cov khoom siv tshuaj, los ntawm kev nqus ntawm hydrogen thiab mechanical zog thiab lwm yam kev xav, kev siv tag nrho titanium siab txog ntsha kub yuav tsum tsis pub tshaj 250 degree. C, tshav kub exchanger titanium raj nrog kev siv lub sab sauv txwv ntawm qhov kub ntawm 316 degree C.
1.3 Kev nyuaj siab corrosion

Ntxiv rau ob peb hom kev tshaj tawm, kev lag luam titanium kev nyuaj siab corrosion kuj zoo heev, qhov tshwm sim ntawm kev ntxhov siab corrosion tshwm sim los ntawm titanium khoom puas tsuaj tseem tsawg. Muaj blunt titanium nkaus xwb nyob rau hauv fuming nitric acid, ib co methanol tov los yog ib co hydrochloric acid tov, high-temperature hypochlorite, qhov kub ntawm 300 ~ 450 degree ntawm molten ntsev los yog NaCl -muaj huab cua, carbon disulfide, n-hexane thiab qhuav chlorine gas thiab lwm yam xov xwm los tsim kev ntxhov siab corrosion. Titanium nyob rau hauv nitric acid nrog qhov nce ntawm NO2 cov ntsiab lus thiab txo cov ntsiab lus ntawm cov dej, qhov kev xav ntawm kev ntxhov siab corrosion rupture maj mam nce. Hauv anhydrous nitric acid uas muaj 20% dawb NO2 titanium kev nyuaj siab corrosion nyiam mus txog loj. Nyob rau hauv cov concentrated nitric acid uas muaj ntau tshaj 6.0% NO2 thiab tsawg dua 0.7% H2O, txawm nyob rau hauv chav tsev kub, muaj ntshiab titanium yuav tshwm sim kev nyuaj siab corrosion rupture. Tuam Tshoj nyob rau hauv 98% concentrated nitric acid nyob rau hauv kev siv cov titanium cov khoom tau tshwm sim nyob rau hauv loj kev nyuaj siab corrosion thiab tawg. Muaj cov ntshiab titanium hauv 10% hydrochloric acid tov, muaj kev ntxhov siab corrosion rupture rhiab heev, nyob rau hauv muaj 0.4% hydrochloric acid ntxiv rau methanol tov ntawm titanium kev nyuaj siab corrosion.