Corrosion Resistance ntawm Qib 1 Titanium

1. Tag nrho Corrosion Resistance ntawm Titanium Qib 1

Titanium Qib 1 (UNS R50250) nthuav tawmzoo heev general corrosion kujthoob plaws ntau qhov chaw ib puag ncig, ua rau nws nyiam cov khoom siv hauv kev ua tshuaj lom neeg, marine, thiab kev lag luam. Nws superior corrosion kev ua tau zoo stems los ntawm ob yam tseem ceeb:

A ib txwm tsim, ntom, thiab tus kheej- kho titanium dioxide (TiO₂) zaj duab xis passiventawm nws qhov chaw. Cov zaj duab xis no yog inert rau feem ntau corrosive media thiab sai regenerates yog khawb los yog puas (nyob rau hauv lub xub ntiag ntawm oxygen los yog ya raws), tiv thaiv ntxiv oxidation ntawm lub hauv paus hlau.

Kev ruaj ntseg tshuaj lom neeg siab: Titanium muaj zog affinity rau oxygen ua kom cov zaj duab xis passive tseem nyob twj ywm txawm tias nyob rau hauv cov xwm txheej hnyav, tsis zoo li ntau cov ferrous los yog tsis yog -ferrous alloys uas raug kev txom nyem los ntawm pitting, crevice corrosion, los yog uniform nres.

Hauv ib puag ncig tshwj xeeb, Gr.1 qhia:

Kev tiv thaiv zoo heevrau dej hiav txwv, brines, thiab marine cua (tsis muaj pitting lossis crevice corrosion, txawm nyob rau hauv ntev - immersion).

Zoo tsis kamkom dilute acids (piv txwv li, hydrochloric acid, sulfuric acid) ntawm qhov kub thiab txias (hauv qab 100 degree,<20% concentration for HCl).

Superior kujrau alkalis (piv txwv li, sodium hydroxide, poov tshuaj hydroxide) thoob plaws ntau qhov ntau thiab qhov kub thiab txias (tiv thaiv ob qho tib si corrosion thiab kev ntxhov siab corrosion tawg).

Siab tsis kamrau cov organic acids (piv txwv li, acetic acid, formic acid) thiab chlorine -muaj cov tshuaj (xws li, hypochlorites, chlorinated solvents).

Qhov tseem ceeb, Gr.1 (kev lag luam ntshiab titanium, CP Ti) muaj kev tiv thaiv corrosion zoo dua li siab dua -lub zog titanium alloys (xws li, Gr.5 Ti-6Al-4V) nyob rau hauv feem ntau corrosive ib puag ncig, raws li alloying ntsiab xws li txhuas los yog vanadium yuav txo tau passivity nyob rau hauv tej yam xov xwm.

2. Corrosion Resistance ntawm Titanium Qib 1 hauv Concentrated Nitric Acid (HNO₃)

Titanium Qib 1 qhiazoo heev corrosion kuj nyob rau hauv concentrated nitric acidnyob rau hauv feem ntau kev khiav hauj lwm tej yam kev mob, nrog tsawg heev uniform corrosion thiab tsis pitting / crevice corrosion. Nov yog cov ncauj lus kom ntxaws:

Cov yam ntxwv tseem ceeb ntawm kev ua haujlwm:

Uniform Corrosion Rate: Nyob rau hauv concentrated nitric acid (60–70% ntawm qhov hnyav) ntawm qhov kub thiab txias (20–25 degree), Gr.1 tus nqi corrosion feem ntau yog<0.05 mm/year (2 mils/year)-well below the threshold for "excellent corrosion resistance" (<0.1 mm/year). At elevated temperatures (up to 100°C), the corrosion rate remains low (<0.1 mm/year) for concentrations up to 70%.

Passivity Maintenance: Nitric acid yog ib qho muaj zog oxidizing acid uasTxhim khu kev ruaj ntseg ntawm titanium's TiO₂ passive zaj duab xis(tsis zoo li txo cov kua qaub xws li HCl, uas tuaj yeem ua rau cov yeeb yaj kiab tawg). Lub oxidizing xwm ntawm HNO₃ tiv thaiv zaj duab xis dissolution thiab txhawb kev kho sai, txawm nyob rau hauv siab concentrations.

Tsis kam rau Intergranular Corrosion (IGC): Gr.1 tiv thaiv IGC hauv concentrated HNO₃, raws li nws cov ntsiab lus carbon tsawg (<0.08%) and high purity (≥99.5% Ti) eliminate sensitization to grain boundary attack.

Cov kev txwv ntawm cov xwm txheej heev:

Above 100°C and concentrations >70%, tus nqi corrosion kuj nce me ntsis (rau 0.1-0.3 hli / xyoo) tab sis tseem siv tau rau feem ntau cov ntawv thov kev lag luam.

Presence of impurities (e.g., chloride ions, fluoride ions, or organic contaminants) in concentrated HNO₃ can reduce corrosion resistance. For example, chloride levels >100 ppm tuaj yeem ua rau pitting, siab -purity HNO₃ raug pom zoo.

Sib piv nrog lwm cov ntaub ntawv:

Outperforms stainless steels (e.g., 316L, 304L) in concentrated HNO₃: Stainless steels suffer from severe uniform corrosion and pitting in 60–70% HNO₃ at temperatures >50 degree.

Ua haujlwm zoo nickel-raws li alloys (xws li Inconel 600) raws li tus nqi- ua tau zoo thaum muab piv rau corrosion kuj nyob rau hauv concentrated HNO₃.

Superior rau tooj liab alloys (xws li, C27000 tooj dag, C71500 cupronickel), uas undergo sai dissolution nyob rau hauv concentrated HNO₃ vim oxidation ntawm tooj liab thiab zinc / nickel.

Cov ntawv thov raug:

Gr.1 yog siv dav hauv cov cuab yeej siv los tuav cov concentrated nitric acid, suav nrog:

Cia tank, kav dej, thiab li qub hauv cov nroj tsuag tshuaj.

Reactors thiab kub exchangers rau nitric acid ntau lawm (piv txwv li, Ostwald txheej txheem).

Cov khoom siv hauv chav kuaj thiab cov cuab yeej tshuaj ntsuam xyuas xav tau siab -purity corrosion kuj.

Cov ntsiab lus

General Corrosion Resistance: Titanium Qib 1 yog corrosion kuj heev -tiv taus nyob rau ntau qhov chaw, vim nws ruaj khov TiO₂ passive zaj duab xis thiab tshuaj inertness.

Concentrated Nitric Acid Performance: Gr.1 excels nyob rau hauv concentrated HNO₃ (60–70% HNO₃) ntawm ambient mus rau nruab nrab kub, nrog negligible corrosion tus nqi thiab tsis pitting / crevice corrosion. Nws yog ib qho txhim khu kev qha, tus nqi - cov khoom siv zoo rau kev tuav cov nitric acid, ua haujlwm zoo dua cov hlau tsis muaj steel thiab tooj liab alloys hauv qhov nruab nrab tshwj xeeb.

For critical applications involving extreme temperatures (>100 degree) los yog tsis muaj tseeb concentrated HNO₃, peb pom zoo ua ib qho kev ntsuam xyuas corrosion kom paub meej tias kev ua tau zoo, tab sis Gr.1 tseem yog ib qho kev xaiv sab saum toj rau feem ntau cov concentrated nitric acid.