Cov yam ntxwv thiab cov qauv ntawm cov creevice corrosion hauv titanium
Aug 12, 2025
Crevice corrosion yog lub zos corrosion tshwm sim uas tshwm sim hauv cov ceg tawv. Crevices tuaj yeem ua qauv (xws li flange lossis gasket surfaces, raj} Thaum pib, nws tau ntseeg tias titanium yuav tsis yauv nyom hauv hiav txwv lossis ntsev tshuaj tsuag. Txawm li cas los xij, kev puas tsuaj corrosion muaj nyob rau hauv he- kub}}} kub}}}} kub}}} kub}
Crevice corrosion hauv titanium yog nyob ntawm ntau yam, suav nrog hom huab cua sov, chloride hom thiab siab, thiab crevice loj thiab geometry. Tsis tas li ntawd, cov cremices ntawm titanium thiab tsis - nws cov ntaub ntawv metallic, xws li solytostre corrosion dua li ntawm titanium thiab titanium.
Raws li kev tshawb fawb thiab kev lag luam kev ua lag luam ob qho tib si thiab thoob ntiaj teb, kev sib koom tes hauv cov yam ntxwv ntawm cov yam ntxwv zoo hauv qab no thiab cov qauv. ① Crevice corrosion muaj lub sijhawm tsim kom loj hlob, xws li cov hom huab cua, xws li cov ntaub ntawv ntsuas kub, cov kua hluav taws xob ph, thiab crevice loj thiab geometry. Rau Titanium hauv cov tshuaj hauv sodium vloride, ntau dua chloride ion siab, thiab qis dua qhov ua kom muaj kev phom sij, qhia tias muaj kev cuam tshuam ntau dua rau kev creevice corrosion.
Dlion Txoj kev daws teeb meem thiab pH nyob rau hauv crevice yog txawv kiag li los ntawm cov nyob rau hauv cov tshuaj. Feem ntau hais lus, thaum cov oxygen concentration hauv cov pob txha yog tsawg thiab cov pH yog qis dua uas ntawm cov tshuaj tua kab), cov pH hauv crevice tuaj yeem poob rau<1, causing the electrode potential in the crevice to become more negative, thus making the titanium in the crevice active. Laboratory electrochemical measurements show that the crevice corrosion potentials of various halide ions follow the order: Cl- < Br- < I-. This indicates that titanium is most susceptible to crevice corrosion in chloride solutions, which is the opposite of titanium's sensitivity to pitting corrosion. ③ Crevice corrosion in titanium typically occurs locally within the crevice surface and generally does not occur throughout the entire crevice surface. After the incubation period, once nucleation has occurred, corrosion rapidly progresses due to autocatalytic mechanisms, ultimately leading to localized perforation and destruction.
④ Crevice corrosion nyob rau hauv titanium feem ntau nrog hydrogen fav, thiab txawm rab koob - Cov tshuaj hydrides tuaj yeem siv lub ntsuas phoo siv lub ntsuas phoo metallographic. Raws li hydrogen haum nce ntxiv, lub saum npoo hydride kev nce qib txuas ntxiv, nrawm nrawm tshaj qhov corrosion. Ib txhij, hydrogen tsis tu ncua txuas ntxiv mus rau hauv cov hlau sab hauv, thiab cov nag xob hauv kev ntxhov siab hauv kev ntxhov siab, ua rau kev tawg ua rau sab nraud kev ntxhov siab.
⑤ Tom qab xyoo kev tshawb fawb, lub cev daim duab ntawm cov txheej txheem corrosion hauv titanium tau dhau los ua kom meej. Tsuas yog muab tso, nws muaj ob theem: lub sijhawm tsim kom loj hlob thiab lub sijhawm ua haujlwm.
Nyob rau hauv thawj lub sij hawm tsim kom loj hlob, tib cov tshuaj tiv thaiv tshwm sim ob sab hauv thiab sab nraum crevice. Lub Cathodic cov tshuaj tiv thaiv noj pa oxygen nyob rau hauv kev daws teeb meem. Thaum lub crevice yuav oxygen {{2} depleted, catodic cov tshuaj tiv thaiv ntawm titanium {}}}} ominates nyob rau hauv crevice. Raws li tus naj npawb ntawm titanium ions nyob rau hauv crevice nce, chloride ions txuas ntxiv mus rau hauv kev tswj hwm kom tswj tau tus nqi zoo thiab tsis zoo ions. Ib txhij, lub titanium ions ntxiv hauv lub crevice thiab yauv ua hydrolysis, ua cov khoom ntsuab du, titanium hydroxide. Lub cev qhuav dej dawb corrosion corrosion tau raug txheeb xyuas li ti2. Cov tshuaj tiv thaiv hydrolysis tsawg tus pH nyob rau hauv crevice, txuas ntxiv cuam tshuam rau Titanium lub passivation. Yog li ntawd, ib zaug tsim kom loj hlob lub sijhawm rau kev ua kom haum crev
⑥ Qhov "geometric yam txheem" ntawm cov ntsiab lus sib xws hauv titanium suav nrog cov ntsiab lus xws li Crevice ntev, kev sib piv ntawm thaj chaw sab hauv thiab sab nraud lub crevice. Cov txiaj ntsig tseem ceeb no feem ntau yuav tsum txiav txim siab kev sim ntawm cov txheej txheem tshwj xeeb thiab tsis tuaj yeem kwv yees tau. Cov kev sim tau qhia tias nqaim crevice corrosion yog ntau yam ntau dua li raug ntau dua li dav dav corrosion, nrog crevice widths feem ntau yog hauv qab 0.5 hli. Txhawm rau txhim kho titanium lub corrosion tsis kam nyob rau hauv kev txo cov acorganic acids thiab txo cov rhiab heev rau cov pob txha caj dab, titanium alloys feem ntau siv. Cov alloys no, xws li ti - pd thiab ti} mo, muaj kev ua lag luam zoo dua piv rau cov lag luam titanium, tshwj xeeb yog ti- pd. Cov kev kho saum npoo xws li xws li palladium oxidation, lossis anodizing tuaj yeem txhim kho titanium kev tiv thaiv mus rau cov corrosion.
Lub tuam txhab khav ua cov khoom lag luam hauv tsev titanium ua ntau lawm, nrog rau:
German -} imported precision titanium raj ntau lawm kab (txhua xyoo tsim muaj peev xwm: 30,000 tons);
Japanese -} technology titanium ntawv ci rolling kab (thinnest rau 6μm);
Qoos motated titanium qws txuas ntxiv mus rau kab extrusion;
Ntse titanium phaj thiab sawb fining;
MES system ua noj digital tswj thiab kev tswj hwm ntawm tag nrho cov txheej txheem ntau lawm, ua tiav cov khoom lag luam seem ntawm ± 0.01M.
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