Yuav Ua Li Cas Cov Qauv Hluav Taws Xob Hluav Taws Xob (Tam sim no hloov pauv) Los ntawm Titanium Immersion Rhaub Hauv 3% NaCl Ntawm 80℃Hloov Raws Li Metastable Pits Hloov mus rau qhov chaw ruaj khov, thiab yuav siv li cas rau kev ceeb toom ntxov?
Tso lus
Hauv 3% NaCl ntawm 80 degree, titanium nthuav tawm cov yam ntxwv ntawm lub suab nrov electrochemical ua ntej pitting. Metastable pits tsim luv, qis -amplitude tam sim no spikes ntawm 0.1–1 µA nrog lub sijhawm ntawm 0.1–1 thib ob. Cov pits ruaj khov tsim loj, ntev spikes ntawm 5-50 µA nrog lub sijhawm ntev tshaj 1 thib ob thiab tus yam ntxwv nce ntug. Saib xyuas kev hloov pauv ntawm metastable mus rau lub suab nrov ruaj khov muab kev ceeb toom ntxov ntawm pitting, tso cai rau kev cuam tshuam ua ntej perforation. Cov qauv suab nrov hloov pauv los ntawm qhov sib txawv, cais spikes mus rau ntu ntu, siab -amplitude tawg vim qhov pits ruaj khov.
Lub Mechanism ntawm Electrochemical Noise Generation los ntawm Pitting
Thaum lub qhov cub metastable pib, nws loj hlob luv luv thiab tom qab ntawd rov ua dua, ua rau luv luv tam sim no. Thaum lub qhov dej ruaj khov, nws tseem loj tuaj, ua rau lub sijhawm tam sim no ntev dua. Kev hloov pauv tshwm sim thaum lub qhov tob tob tshaj qhov tseem ceeb (feem ntau yog 1-5 µm) qhov twg repassivation ua tsis tau. Lub suab nrov tam sim no yog ntsuas siv xoom-tsis kam ammeter ntawm lub tshuab hluav taws xob ua haujlwm (lub rhaub) thiab lub txee electrode. Cov kev hloov pauv tau txheeb xyuas hauv lub sijhawm.
Quantitative Noise Characteristics as a Function of Pitting Stage
Controlled testing in 3% NaCl at 80°C on Grade 2 titanium has established the following noise characteristics. For metastable pits, the current spike amplitude is 0.1–1 µA, the spike duration is 0.1–1 second, the frequency is 10–100 spikes per hour, and the warning time before perforation is >500 teev. Rau kev hloov pits, qhov amplitude yog 1-5 µA, lub sijhawm yog 0.5-3 vib nas this, zaus yog 50-200 spikes ib teev, thiab lub sijhawm ceeb toom yog 100-500 teev. Rau qhov ruaj khov thaum ntxov, qhov amplitude yog 5-20 µA, lub sijhawm yog 1-10 vib nas this, zaus yog 20-100 spikes ib teev, thiab lub sijhawm ceeb toom yog 50-200 teev. Rau cov pits ruaj khov lig, qhov amplitude yog 20-100 µA, lub sijhawm yog 10-100 vib nas this, zaus yog 5-50 spikes ib teev, thiab lub sijhawm ceeb toom tsawg dua 50 teev.
Noise Pattern Recognition for Early Warning
Cov duab ntawm cov ntsia hlau loj tam sim no kuj hloov. Metastable pits tsim ntse, symmetric spikes. Kev hloov pauv pits tsim asymmetric spikes nrog nce qeeb thiab nrawm nrawm. Cov pits ruaj khov tsim spikes nrog qhov nce qeeb thiab qeeb qeeb, feem ntau nrog cov oscillations thib ob. Tus nqi cumulative (ib feem ntawm tam sim no dhau sij hawm) nce linearly rau cov pits ruaj khov tab sis tseem nyob tas li rau cov pits metastable.
Electrochemical Noise Monitoring Guide for Pitting Detection
Cov lus hauv qab no muab cov lus qhia rau kev txhais cov suab nrov electrochemical los ntawm Qib 2 titanium cua sov hauv 3% NaCl ntawm 80 degree.
| Nthuav Suab nrov | Txhais lus | Pom zoo ua | Cia siab tias yuav muaj sia nyob (1.2 hli phab ntsa) |
|---|---|---|---|
| Qee zaum metastable spikes | Ib txwm passivity | Tsis muaj | >1,000 teev |
| Nquag metastable spikes | Nce qhov pib pib | Nce kev tshuaj ntsuam xyuas | 500-1,000 teev |
| Kev hloov pauv hloov pauv (1-5 µA) | Thawj qhov chaw ruaj khov | Npaj tshuaj xyuas hauv 1 lub hlis | 200-500 teev |
| Stable spikes (5-20 µA) | Pits loj hlob | Tshawb xyuas hauv 1 lub lis piam | 100-200 teev |
| Large stable spikes (>20 µA) | Pitting hnyav | Hloov tam sim ntawd | <100 hours |
Engineering Beyond Noise Monitoring
Qib titanium cuam tshuam rau lub suab nrov. Qib 7 (palladium{2}}stabilized) muaj suab nrov qis dua rau tib lub qhov tob vim qhov rov ua dua sai dua. Phab ntsa thickness tsis cuam tshuam rau lub suab nrov tab sis txiav txim siab lub sij hawm los ntawm kev tshawb pom mus rau perforation. Cov tshuaj chloride concentration cuam tshuam lub suab nrov zaus; Cov tshuaj chloride ntau dua ua rau cov kab mob sib kis. Qhov ntsuas kub cuam tshuam rau lub suab nrov amplitude; kub siab tsub kom lub amplitude. Kev siv hluav taws xob siv hluav taws xob (Ag / AgCl) yuav tsum muaj rau kev ntsuas lub suab nrov ntxiv rau cov suab nrov tam sim no.
Ua ib qho kev qhia tshwj xeeb
Rau qhov tseem ceeb titanium rhaub hauv 3% NaCl ntawm 80 degree, nruab ib lub tshuab hluav taws xob hluav taws xob hluav taws xob nrog lub xoom-tsis kam ammeter thiab platinum counter electrode. Teem lub tswb ntawm qhov hloov pauv hloov pauv amplitude ntawm 2 µA thiab kaw kev cuam tshuam ntawm qhov ruaj khov amplitude ntawm 10 µA. Sau cov suab nrov spectrum tsis tu ncua thiab sib piv cov nqi sib tw. Thaum kuaj pom qhov hloov mus rau qhov ruaj khov pitting, teem caij hloov lub rhaub hauv 30 hnub. Los ntawm kev txheeb xyuas cov qauv suab nrov electrochemical, tus kws ua haujlwm pom qhov kev hloov pauv ntawm metastable mus rau pitting ruaj khov thiab cuam tshuam ua ntej perforation.
