Thaum Lub Titanium Sheath rhaub yog siv los Boil A 5% Sodium Tartrate Solution ntawm 103 degree, Vim li cas Lub Tartrate Ion Complex Titanium Ions Thiab Tiv Thaiv Repassivation, Ua rau Uniform Corrosion Ntawm 0.2 mm Ib Xyoo?
Tso lus
Hauv 5% sodium tartrate ntawm 103℃(boiling), tartrate ion (C₄H₄O₆²⁻) yog ib qho muaj zog chelating tus neeg sawv cev rau titanium. Tsis zoo li chloride lossis fluoride uas ua rau pitting, tartrate forms soluble titanium-tartrate complexes: Ti⁴⁺ + 3C₄H₄O₆²⁻ → [Ti(C₄H₄O₆)₃]⁴⁻. Qhov complexation no tshem tawm Ti⁴⁺ ions los ntawm qhov chaw raws li lawv tau tsim, tiv thaiv kev tsim ntawm cov yeeb yaj kiab ruaj khov. Yog tsis muaj kev tiv thaiv zaj duab xis, titanium corrodes uniformly ntawm tus nqi tsis tu ncua ntawm 0.15-0.25 hli hauv ib xyoos, tsis muaj pitting hauv zos. Tus nqi corrosion yog ywj siab ntawm lub sijhawm tom qab pib lub sijhawm hloov pauv.
Lub Mechanism ntawm Tartrate-Induced Uniform Corrosion
Tartrate ions muaj ntau pawg hydroxyl thiab carboxyl uas tsim muaj tsib - koom nrog chelate rings nrog Ti⁴⁺. Qhov tsim tsis tu ncua rau Ti-tartrate complex yog siab heev (log K ≈ 20). Qhov no txhais tau hais tias ib qho Ti⁴⁺ tso tawm ntawm cov hlau nto yog tam sim ntawd complexed thiab muab tshem tawm mus rau hauv kev daws. Cov zaj duab xis passive tsis tuaj yeem tsim tau vim tias cov khoom solubility ntawm TiO₂ tsuas yog dhau ntawm Ti⁴⁺ hauv zos siab heev. Lub corrosion ua tiav los ntawm kev sib cais ncaj qha ntawm cov hlau: Ti → Ti⁴⁺ + 4e⁻, ua raws li cov complexation ceev. Cov txheej txheem tsis sib xws vim tias tsis muaj zaj duab xis passive kom tawg hauv zos.
Quantitative Corrosion Rate raws li Kev Ua Haujlwm ntawm Tartrate Concentration
Kev tswj xyuas hauv cov kev daws teeb meem ntawm boiling sodium tartrate (103 degree) dhau 500 teev tau tsim cov hauv qab no rau Qib 2 titanium. Ntawm 0% tartrate (dej ntshiab), tus nqi corrosion yog 0.005-0.010 hli ib xyoo, qhov saum npoo yog ci, thiab cov txheej txheem yog passive. Ntawm 1% tartrate, tus nqi yog 0.03-0.06 hli ib xyoo, qhov saum npoo qhia pom lub teeb etching, thiab cov txheej txheem sib xyaw. Ntawm 3% tartrate, tus nqi yog 0.08-0.15 hli hauv ib xyoos, qhov saum npoo muaj qhov sib txawv ntawm qhov sib txawv, thiab cov complexation dominates. Ntawm 5% tartrate, tus nqi yog 0.15-0.25 hli nyob rau ib xyoos, qhov chaw muaj ib tug zoo matte tiav, thiab lub mechanism yog complexation{19}}dominant. Ntawm 10% tartrate, tus nqi yog 0.20-0.35 hli hauv ib xyoos, qhov saum npoo yog uniformly matte, thiab cov txheej txheem yog complexion loj.
Kev cuam tshuam ntawm pH thiab qhov kub thiab txias ntawm Complexation Rate
Tus nqi complexation thiab corrosion yog nyob ntawm pH thiab kub. Ntawm 60℃thiab pH 7 nrog 5% tartrate, tus nqi corrosion yog 0.04-0.08 hli ib xyoo. Ntawm 80℃thiab pH 7, tus nqi yog 0.08-0.15 hli hauv ib xyoos. Ntawm 100℃thiab pH 7, tus nqi yog 0.15-0.25 hli hauv ib xyoos. Ntawm 100℃thiab pH 9, tus nqi yog 0.10-0.18 hli hauv ib xyoos (pH siab dua slows corrosion). Nyob rau ntawm 100℃thiab pH 5, tus nqi yog 0.20-0.35 hli ib xyoo (qis pH accelerates corrosion). Lub zog ua kom muaj zog yog kwv yees li 50 kJ / mol.
Tartrate Concentration thiab pH Control Guide rau Titanium rhaub
Cov lus hauv qab no muab cov lus pom zoo rau kev ua haujlwm rau Qib 2 thiab Qib 7 titanium rhaub hauv sodium tartrate daws.
| Sodium Tartrate Concentration (%) | Kub (degree) | pH | Qib 2 Corrosion Rate (mm/xyoo) | Qib 7 Corrosion Rate (mm/xyoo) | Kev pom zoo |
|---|---|---|---|---|---|
| <1 | 100 | 7 | 0.03–0.06 | 0.02–0.04 | Txais tau |
| 1–3 | 80 | 7 | 0.05–0.10 | 0.03–0.06 | Txais tau |
| 3–5 | 80 | 7 | 0.08–0.15 | 0.05–0.10 | Siv qib 7 |
| 3–5 | 100 | 7 | 0.15–0.25 | 0.10–0.18 | Siv Qib 7 + tuab phab ntsa |
| 5–10 | 100 | 9 | 0.10–0.18 | 0.06–0.12 | Nce pH |
| >10 | Ib qho | Ib qho | >0.20 | >0.12 | Tsis pom zoo |
Engineering Beyond Tartrate Concentration Control
Qib titanium cuam tshuam rau tus nqi complexation. Qib 7 (palladium-stabilized) muaj 30-50% qis dua corrosion dua Qib 2 hauv tartrate cov ntsiab lus vim tias palladium pab tswj cov yeeb yaj kiab nyias nyias txawm tias nyob rau hauv cov xwm txheej nyuaj. Qib 12 muaj kev txhim kho nruab nrab. Phab ntsa thickness muab kev tiv thaiv corrosion; ib lub 2.0 hli phab ntsa nrog 0.15 hli nyob rau hauv ib lub xyoo uniform corrosion kav 13 xyoo. Qhov saum npoo tiav tsis muaj qhov cuam tshuam tseem ceeb rau kev xeb tsis sib xws. Ua kom pH mus rau 9 los ntawm kev ntxiv sodium hydroxide txo tus nqi corrosion los ntawm 30-40%. Txo qhov kub ntawm 100℃mus rau 80℃txo tus nqi los ntawm 50%.
Ua ib qho kev qhia tshwj xeeb
Rau lub titanium sheath rhaub nyob rau hauv 5% sodium tartrate ntawm 103 degree, txais zoo corrosion raws li tus tseem ceeb mechanism. Qhia rau qib 7 titanium kom txo qhov corrosion ntawm 0.10-0.18 hli ib xyoos. Siv phab ntsa tuab ntawm 2.0 hli los muab lub neej ua haujlwm 10-15 xyoo. Yog tias ua tau, nce pH mus rau 9 los ntawm kev ntxiv sodium hydroxide lossis txo qhov kub ntawm 80 degree. Thaum lub sijhawm ua haujlwm, saib xyuas lub ntsuas kub txhua xyoo los ntawm kev ntsuas ultrasonic; Thaum cov phab ntsa thickness nce mus txog 0.5 hli, hloov lub rhaub. Los ntawm kev nkag siab tias tartrate ions complex titanium ions thiab tiv thaiv repassivation, tus engineer xaiv cov qib tsim nyog thiab cov phab ntsa thickness rau kev kwv yees tsis zoo corrosion.
