Nyias patina txheej (<5 μm, immature formation stage)
Lub patina thinner tshaj 5 μm yog nyob rau hauv lub sij hawm tsim thaum ntxov, nrog ib tug xoob, tsis tiav microstructure thiab tsis zoo adhesion rau steel substrate. Nws tsis tuaj yeem tsim lub cev tsis tu ncua- tshuaj tiv thaiv, yog li ya raws, oxygen, thiab cov xov xwm corrosive me me (xws li, plua plav, qis- cov pa phem) tuaj yeem nkag mus tau yooj yim hauv txheej kom ncav cuag cov hlau nto, ua rau cov khoom siv hluav taws xob tsis tu ncua. Nyob rau theem no, cov hlau tseem muaj qhov siab corrosion, thiab patina xav tau lub sijhawm loj hlob thiab ntom ntom kom tiv thaiv kev tiv thaiv.
Optimal thickness ntau (5-15 μm, tag nrho stabilized theem)
Qhov no yog qhov paub tab, ruaj khov ntawm SPA-H's natural patina. Cov txheej yog ntom, zoo -grained, thiab nruj nreem khi rau lub substrate, nrog ib tug uniform qauv enriched nyob rau hauv Cu, Cr, Ni alloy oxides. Nws tuaj yeem thaiv kev nkag mus ntawm cov xov xwm corrosive, txo cov hlau nto ntawm electrochemical kev ua, thiab txawm tias nws tus kheej me ntsis - kho muaj peev xwm rau kev puas tsuaj me. Nyob rau hauv no thickness ntau, lub patina ua tiav covqhov zoo tshaj plaws sib npaug ntawm qhov ntom ntom thiab kev ua haujlwm tsis zoo, txo tus nqi corrosion ntawm SPA-H mus rau qib qis heev (deb qis dua li cov pa roj carbon zoo tib yam) thiab muab kev tiv thaiv ntev - lub sij hawm txhim khu kev qha rau cov hlau substrate.
Excessively thick patina layer (>15 μm, overgrown / laus theem)
Lub patina tuab dua 15 μm feem ntau yog tshwm sim los ntawm qhov ntev - raug rau qhov chaw hnyav (piv txwv li, cov av noo siab, tshuaj tsuag ntsev me me) lossis tsim tsis sib xws. The overgrown layer will lose its dense microstructure, becoming loose, porous, and even prone to cracking or peeling from the substrate. Cov kev tsis xws li no tsim cov channel rau corrosive media kom nkag mus rau hauv txheej sab hauv thiab ncav cuag cov hlau nto, thiab cov xoob patina tuaj yeem khaws cov dej noo, ua kom cov kab mob hauv zos (xws li crevice corrosion) hauv qab txheej. Tsis tas li ntawd, cov txheej txheej tuab heev muaj qhov tsis zoo, thiab ib nrab flaking yuav nthuav tawm cov hlau substrate, ua rau cov xeb tshiab tsim thiab txo tag nrho corrosion kuj.
