revice corrosion penetration tsis ua hauj lwm yog hais txog nqaim confined gaps tsim ntawm flange sealing nto, ntsia liaj qhov rooj kev sib cuag lub ntsej muag, lap weld pob qij txha, yeeb nkab txhawb kev sib cuag cheeb tsam thiab sediment deposition txheej ntawm 316 stainless hlau cua sov pipelines. Cov kua corrosive yog daig hauv qhov slit nrog cov kua dej tsis zoo. Cov pa oxygen dissolved yog noj sai heev los ntawm cov tshuaj tiv thaiv electrochemical, tsim cov pa oxygen-deficient occluded microenvironment. Chloride ions txuas ntxiv mus rau hauv qhov sib txawv kom tswj tau qhov sib npaug, ua rau lub zos acidification thiab nce siab ntawm corrosive ion concentration. Cov chromium-nplua nuj zaj duab xis nyob rau hauv lub crevice raug puas ntsoog, thiab cov hlau matrix dissolves nyiam raws qhov sib txawv qhov tob mus txog rau thaum cov yeeb nkab phab ntsa nkag mus rau hauv nruab nrab to. Qhov kev tiv thaiv corrosion no tau zais thiab nquag tshwm sim ntawm cov pob qij txha thiab cov kav dej tuag ntawm cov hlau tsis muaj steel tiv thaiv -corrosion cua sov tshuab.
1. Occluded Ion Enrichment thiab Crevice Corrosion Evolution Mechanism
316 stainless hlau cia siab rau ntom chromium oxide passive zaj duab xis los tiv thaiv corrosion hauv ntws dilute corrosive media. Hauv qhov khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob. Qhov sib txawv sab hauv poob cov xwm txheej passivation thiab hloov mus rau hauv ib qho anode rau cov hlau txuas txuas ntxiv, thaum cov pa oxygen sab nraud - nplua nuj nthuav dav ua raws li cathode los tsim cov macroscopic galvanic cell. Txhawm rau kom sib npaug ntawm cov nqi hluav taws xob, halogen ions los ntawm cov tshuaj sab nraud kom diffusing mus rau hauv qhov slit, tsim cov kua qaub acidic uas muaj zog heev uas cuam tshuam tus kheej - kho cov yeeb yaj kiab passive. Sib txawv ntawm tawg pitting corrosion los ntawm ib qho me me cov ntsiab lus, crevice corrosion tsim linearly raws tag nrho txoj kev sib txawv thiab ua rau strip -zoo li tus nkag mus rau corrosion.
2. Tej yam hauj lwm ua rau Crevice Corrosion puas tsuaj
Cov gaskets tsis sib haum thiab khawb flange sealing ntsej muag tsim me me sealing slits;
Lap vuam, sib quas ntus vuam thiab tsis tiav fusion welds tawm hauv qhov seem seem;
Kev sib cuag ncaj nraim ntawm cov kav dej sab nrauv phab ntsa thiab hlau yeeb nkab clamps, brackets thiab hoops;
Kab rov tav cov kav dej hauv qab cov pob zeb uas npog cov phab ntsa sab hauv los tsim cov khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob khoob.
Threaded ceg txuas thiab dig muag tuag- cov kav dej kawg uas cov kua stagnates thiab khaws cov khoom corrosive.
3. Core Inducing Factors Accelerating Crevice Corrosion Failure
Gasket specification tsis sib haum, flange lub ntsej muag deformation thiab khawb tsis tuaj yeem ua tiav lub ntsej muag sealing;
Vuam adopts lap joint qauv es tsis txhob tag nrho nkag mus rau lub taub qab vuam, qhia structural crevices;
Tsis muaj insulating buffer gaskets yog nteg nruab nrab ntawm cov kav dej thiab cov hlau txhawb kom tshem tawm cov kev sib cuag;
Lub kaw lus tsis muaj lub tshuab tsis tu ncua thiab tu, thiab cov av khib nyiab tuaj yeem ua rau cov chaw kaw ntom ntom;
Cov txheej txheem nruab nrab muaj cov chloride ions uas ua rau kom cov ion enrichment thiab acidification hauv qhov khoob.
4. Tag nrho -Txuas Kev Tiv Thaiv thiab Tswj Kev Ntsuas Kev Ntsuas
① Sib phim tus qauv sib xyaw gaskets thiab polish flange sealing nto ua ntej sib dhos
Tshem tawm tsis tu ncua micro qhov sib txawv ntawm mating sealing interface hauv paus.
② Txhim kho vuam tsim kom tau txais kev nkag mus rau lub taub qab vuam thiab kaw tag nrho cov seem weld slits
Tsis txhob muaj qhov sib txawv ntawm cov qauv coj los ntawm cov ntaub ntawv sib txuas tsis tsim nyog.
③ Ntxiv cov uas tsis yog- conductive insulating gaskets ntawm pipeline thiab hlau kho kev txhawb nqa
Txiav tawm qhov sib chwv sib txuas thiab galvanic corrosion coupling tej yam kev mob ib txhij.
④ Teem qis- cov qhov dej ntws tawm thiab siv lub sijhawm ua haujlwm thiab tu npua
Tiv thaiv sediment deposition los ntawm txoj kev kaw corrosive slits.
⑤ Disassemble thiab tshuaj xyuas qhov tseem ceeb flange pob qij txha tsis tu ncua thiab hloov cov laus deformed gaskets
Tshem tawm qhov khoob khoob uas tshwm sim los ntawm gasket aging thiab compression deformation ua ntej.
5. Kev Tiv Thaiv Cov Teeb Meem Sib piv
表格
| Kev sib dhos & Kev tu hom | Crevice Corrosion Risk | Daim ntawv thov tswv yim |
|---|---|---|
| Kev sib tsoo gasket tsis raug + lap vuam + tsis muaj dej phwj pov tseg | Linear slit penetration leakage tshwm sim thaum lub sijhawm ua haujlwm nruab nrab - | Hloov cov qauv vuam, hloov cov qauv gaskets thiab ntxiv cov ntsiab lus ntws ruaj khov |
| Zoo meej sealing haum + tag nrho nkag mus pob tw welding + tsis tu ncua sediment tshem tawm | Ua zoo thaiv ion enrichment thiab txwv tsis pub crevice corrosion pib | Standard siv specification rau 316 stainless hlau cua sov pipeline kev twb kev txuas tsim |
| Tshaj tawm -kev sib dhos seamless passivation + kev tshuaj xyuas peb lub hlis twg + kev tshuaj xyuas online halogen ion | Tsis tshua muaj kev pheej hmoo ntawm qhov sib txawv - hom nkag nkag thiab kaw tsis tau npaj tseg | Cov tswv yim xav tau ntev - voj voog tsis cuam tshuam kev ua haujlwm cua sov yeeb nkab network tej yaam num nrog siab -corrosion media |
Xaus
316 stainless hlau cua sov tube crevice corrosion yog tshwm sim los ntawm cov neeg pluag nruab nrab ncig nyob rau hauv confined gaps, oxygen noj thiab corrosive ion enrichment uas rhuav tshem cov passive zaj duab xis thiab ua rau linear nkag mus rau hauv qhov khoob. Cov kev tiv thaiv tseem ceeb muaj xws li tshem tawm cov kev sib dhos thiab cov qauv sib txawv ntawm cov qauv kev sib khi thiab vuam tsim, cais cov kev sib cuag nrog cov khoom siv txhawb nqa, tshem tawm cov kav dej tsis tu ncua thiab tswj kev ruaj ntseg ntawm cov khoom sib khi. Tag nrho- txheej txheem kaw- kev tswj lub voj voog ntawm cov qauv tsim qauv, kev teeb tsa kev teeb tsa thiab kev saib xyuas niaj hnub tuaj yeem zam qhov nruab nrab thiab cov khoom siv tsis ua haujlwm raug mob tshwm sim los ntawm crevice corrosion ntawm 316 stainless hlau cua kub siab pipelines.
