Nyob rau hauv Titanium Hluav Taws Kub Rhaub rau 20% Zinc Sulfate Electrolyte ntawm 60℃, Yuav Ua Li Cas Tam Sim No Qhov Nthuav Los ntawm Qhov Sib Nqus Plating Busbar (0.5 A / dm² vs . 2 A / dm²) Hloov Kho Cov Txheej Txheem tam sim no -Induced Pitting Pattern?

Nyob rau hauv zinc sulfate electroplating, lub titanium rhaub tuaj yeem polarized los ntawm cov stray tam sim no los ntawm cov busbars nyob ze. Tsawg tam sim no ceev (0.5 A / dm 2) stray tam sim no ua rau cov pits ntiav ntawm 20-50 µm hauv qhov tob. Stray tam sim no ua rau tsim cov pob zeb sib sib zog nqus (100-300 µm) raws li cov kev taw qhia busbar ntawm qhov ceev tam sim no (2 A / dm²). Nrog rau qhov ceev tam sim no, cov qauv pitting hloov pauv los ntawm cov qauv random mus rau cov qauv qhia, vim tias qhov ceev tam sim no ua rau cov hluav taws xob loj dua gradient, thiab yog li concentrates cov stray tam sim no rau qee qhov ntawm lub rhaub.

Mechanism ntawm Pitting nyob rau hauv Stray Currents

Lub titanium rhaub yog immersed nyob rau hauv lub conducting zinc sulfate electrolyte thiab ua raws li ib tug electrode nyob rau hauv lub stray hluav taws xob teb. Lub peev xwm sib txawv ntawm lub rhaub thiab lub busbar tsim ib qho tam sim no los ntawm electrolyte. Ntawm cov ntsiab lus uas tam sim no tawm ntawm lub tshuab cua sov (qhov chaw anodic), titanium nkag mus rau hauv kev daws teeb meem. Ntawm qhov tsis tshua muaj tam sim no qhov chaw anodic raug faib ua ntu zus rau ntawm qhov chaw tsis zoo. Ntawm qhov loj tam sim no densities lub peev xwm gradient yog txaus los kov yeej lub nto heterogeneity thiab tam sim no yog tsom rau cov cheeb tsam geometrically raws li lub busbar. Tus nqi pitting ua raws Faraday txoj cai: qhov tob ∝ tam sim no ceev × lub sij hawm.

Stray Current Pitting Density Quantitative

Kev tswj xyuas ntawm 60℃hauv 20% ZnSO₄ rau 500 teev nrog lub busbar 100 hli los ntawm lub rhaub tau qhia cov hauv qab no rau Qib 2 titanium. Ntawm 0 A / dm² (baseline, tsis muaj stray tam sim no) qhov ntom ntom yog 0 pits / cm², qhov siab tshaj plaws qhov tob yog 0 µm thiab pitting qauv tsis muaj. Qhov siab tshaj qhov tob yog 20-50 µm, qhov ntom ntom yog 5-20 pits ib cm² thiab cov qauv tawg ntawm 0.5 A / dm². Ntawm 1.0 A / dm 2, qhov ntom ntom yog 20-60 pits / cm 2, lub qhov tob yog 50-150 µm, thiab cov qauv yog nruab nrab nrog lub busbar. Qhov ntom ntom: 50-150 pits / cm2 Qhov tob: 100-250 µm Qauv: dlhos 1.5 A / dm2 Ntawm 2.0 A / dm 2 lub qhov ntom ntom yog 100-300 pits / cm 2, lub qhov tob tob yog 150 µbar thiab cov qauv kev taw qhia.

Kev cuam tshuam ntawm Busbar Sib cais thiab Kev Taw Qhia ntawm Stray Current Density

Qhov ceev ceev tam sim no ntawm lub tshuab cua sov txo qis raws li qhov square ntawm qhov deb ntawm lub busbar. Qhov ceev ceev tam sim no ntawm qhov deb ntawm 50 mm los ntawm busbar yog 2.0-3.0 A / dm2, thiab pitting yog hnyav heev. Qhov ceev 1.0-1.5 A / dm², pitting yog nruab nrab ntawm 100 mm. Ntawm 200 mm qhov ceev yog 0.3-0.5 A / dm2 thiab pitting yog tsawg. Ntawm 500mm, qhov ceev yog $0.05-0.1$ A/dm$^2$ thiab pitting tsis tseem ceeb. Cov kev taw qhia ntawm lub rhaub nrog rau lub busbar kuj tseem ceeb heev: lub rhaub thaum uas tig mus rau lub busbar yuav ntsib loj stray tam sim no tshaj lub rhaub perpendicular rau nws.

Mitigation ntawm Stray Currents thiab Tiv Thaiv Pitting

Cov lus hauv qab no qhia txog cov lus qhia rau kev tiv thaiv kev tsis sib haum xeeb tam sim no ntawm Qib 2 titanium rhaub hauv 20% zinc sulfate ntawm 60 degree.

Heater Stray Current Density (A/dm²) Severity of Pitting Expected Maximum Pit Depth (µm/xyoo) Pom Zoo Ua<0.3 None <20 None 0.3–0.8 Low 20–80Plastic mesh shield heater
0.8-1.5 Moderate 50-150Move heater >300 mm deb ntawm busbar
1.5-2.5 High 150-300 Install > Electrical isolation2.5 Severe >300 Hloov lub tank layout
Engineering Beyond Stray Current Controls

Lub pitting kuj nyob ntawm qib titanium. Qib 7 (palladium{2}}stabilized) muaj 2-3 npaug ntawm qhov tsis kam mus rau stray tam sim no pitting, yog li tuaj yeem ua haujlwm ntawm 1.0-1.5 A / dm2 nrog rau cov nqi pitting. Qib 12 yog kev txhim kho nruab nrab. Phab ntsa thickness muab lub qhov nkag nkag; phab ntsa ntawm 2.0 hli tuab nrog pits ntawm 150 µm txhua xyoo yuav kav mus txog 13 xyoo. Cov stray tam sim no raug txo los ntawm 70-80% los ntawm perforated yas ntaub thaiv npog (PTFE los yog polypropylene, 5 hli qhov, 50% qhib cheeb tsam) nyob ib ncig ntawm lub rhaub. Lub tshuab cua sov yuav tsum tau muab hluav taws xob sib cais los ntawm lub tank hauv av kom tsis txhob muaj kev cuam tshuam tam sim no los ntawm kev nrhiav txoj hauv kev rov qab los.

Ua ib qho kev kwv yees

Rau lub tshuab hluav taws xob titanium hauv 20% zinc sulfate ntawm 60 degree, tso lub rhaub tsawg kawg 300 hli los ntawm qhov ze tshaj plaws kom tsis txhob muaj qhov ceev tam sim no hauv qab 0.5 A / dm². Yog tias qhov chaw nruj, tsim kom muaj qhov thaiv cov yas perforated nyob ib puag ncig lub rhaub thiab tau txais qib 7 titanium. Shield los yog hloov lub tso cua sov rau cov cua sov uas twb muaj lawm nrog stray tam sim no pitting. Hauv kev pabcuam tshuaj xyuas lub rhaub rau cov qhov sib txawv sib txawv. Yog tias pitting tob dua 0.2 hli, hloov lub rhaub. Nyob rau hauv zinc sulfate electroplating kev pab cuam tus engineer tswj stray tam sim no ceev los ntawm kev nyob deb thiab shielding kom tsis txhob loj pitting.