Crevice corrosion yog ib tug heev zais hauv cheeb tsam corrosion daim ntawv ntawm 316 stainless hlau, uas feem ntau tshwm sim nyob rau hauv me me qhov sib txawv ntawm ob qhov chaw sib cuag. Tsis zoo li pom rusting tag nrho los yog loj - cheeb tsam pitting, crevice corrosion tsim nyob rau hauv nqaim slits thiab yog ib qho nyuaj rau nrhiav tau ntawm qhov muag liab qab. Nws feem ntau ua rau muaj kev nkag mus sai sai thiab tso tawm ntawm cov kav dej cua sov hauv qab kev ua haujlwm zoo li qub, uas yog ib qho ntawm cov teeb meem saum toj kawg nkaus ntawm cov cua sov tsis ua haujlwm.
1. Tsim Mechanism ntawm Crevice Corrosion
Qhov khoob yog tsim los ntawm cov pob qij txha, flange nias qhov chaw, vuam lap seams, scale attachments thiab sediment npog thaj chaw ntawm cov phab ntsa ntawm cov cua sov. Cov kua hauv qhov sib txawv tsis tuaj yeem sib pauv thiab sib pauv nrog cov tshuaj sab nraud. Cov pa oxygen hauv qhov slit yog sai sai los ntawm cov hlau oxidation cov tshuaj tiv thaiv, tsim cov pa oxygen -deficient anodic cheeb tsam, thaum lub sab nraud exposed nto ua lub cathode nrog txaus oxygen mov.
Chloride ions nyob rau hauv nruab nrab tsis tu ncua mus rau hauv qhov sib txawv kom sib npaug cov nqi zoo tsim los ntawm cov hlau tawg. Hydrolysis cov tshuaj tiv thaiv accumulates hydrogen ions nyob rau hauv lub slit, ua rau lub zos ib puag ncig muaj zog acidic. Cov yeeb yaj kiab tsis zoo ntawm 316 stainless hlau yog yaj sai sai nyob rau hauv cov tshuaj chloride siab thiab qis pH tus nqi, thiab corrosion ua rau sab hauv raws qhov sib txawv kom txog thaum cov yeeb nkab phab ntsa perforated. Txawm hais tias tag nrho cov chloride cov ntsiab lus ntawm lub kaw lus yog tsawg, ion enrichment nyob rau hauv qhov sib txawv yuav tsim ib tug loj corrosion microenvironment.
2. Siab -Txoj hauj lwm txaus ntshai ntawm cov cua kub
Xov txuas qhov chaw nruab nrab ntawm cov cua kub raj terminals thiab mounting puag;
Tiv tauj qhov sib txawv ntawm flange sealing nto thiab gaskets;
Lap welds thiab tsis tiav nkag mus weld keeb kwm;
Cov cheeb tsam hauv cheeb tsam npog los ntawm nplai, sludge thiab floating sediment;
Khoov ntu txuas rau sab hauv phab ntsa ntawm lub tank thiab cov ces kaum tuag ua rau cov khoom seem seem.
3. Kev tiv thaiv thiab tswj kev ntsuas
1. Kev tsim qauv tsim kom zoo kom tshem tawm qhov sib txawv
Txais los ntawm welding es tsis txhob lap welding; siv ib qho flanges nrog kev nkag mus rau qhov vuam; zam threaded kev twb kev txuas nyob rau hauv corrosive media, thiab xaiv welded tsau qauv kom ntau li ntau tau. Txo cov txheej txheem sib tshooj sib tshooj uas yooj yim los tsim cov kab sib dhos.
2. Kev kho deg kom txo tau cov nplaum nplaum
Electropolishing los yog txheej txheem passivation kev kho mob yog nqa tawm nyob rau sab nrauv ntawm lub cua sov raj. Lub ultra- du nto zoo heev txo cov adhesion ntawm av thiab sediment, hauv paus tsis txhob tsim cov kev pab them nqi- hom crevice corrosion induced los ntawm scaling.
3. Kev tswj nruab nrab los inhibit ion enrichment
Kev tso tawm tsis tu ncua thiab hloov cov kua circulating kom tsis txhob ntev - lub sij hawm stagnation ntawm qhov nruab nrab; tswj chloride ion cov ntsiab lus thiab pH tus nqi ntawm lub cev; ntxiv qhov tsim nyog corrosion inhibitors kom qeeb anodic dissolution hauv qhov khoob.
4. Kev tu thiab tu tsis tu ncua
Teem lub voj voog descaling ruaj kom tshem tawm cov nplai thiab cov sludge ntawm lub raj nto; rau cov khoom siv uas yuav tsum tau kaw rau standby, ntws cov kua seem nyob rau hauv lub tank es tsis txhob soaking lub cua sov tube nyob rau hauv static nruab nrab rau ib ntev lub sij hawm.
5. Cov khoom siv kho dua tshiab rau kev ua haujlwm hnyav
Rau ib puag ncig uas tsis muaj qhov tsis pom kev thiab cov tshuaj chloride siab, hloov 316 nrog 316L, 2205 duplex steel lossis TA2 titanium hlab los txhim kho qhov tseem ceeb ntawm qhov kub thiab txias ntawm cov khoom nws tus kheej.
4. Qhov sib txawv ntawm Crevice Corrosion thiab Ordinary Pitting Corrosion
Pitting corrosion originates los ntawm me me tsis xws luag ntawm cov hlau nto thiab txhim kho sab nraud los ntawm ib qho taw tes. Crevice corrosion yuav tsum cia siab rau ib puag ncig qhov chaw nqaim kaw, thiab thaj tsam corrosion yog nyob rau tag nrho cov kab sib txuas ntawm qhov sib txawv. Kev nthuav tawm ceev ntawm crevice corrosion feem ntau yog nrawm dua li kev ywj pheej pitting, thiab qhov tsis ua hauj lwm suddenness muaj zog dua.
表格
| Kev Tiv Thaiv Kev Tiv Thaiv | Tshwj xeeb Implementation Effect |
|---|---|
| Tshem tawm qhov tsis sib xws ntawm cov qauv | Txiav tawm thawj yam mob rau crevice corrosion |
| Electropolish nto | Txo cov av txuas qhov tshwm sim ntau dua 70% |
| Tsis txhob ua kua dej ntev ntev | Tiv thaiv kom tsis tu ncua ntawm corrosive ions |
| Txhim kho cov khoom siv alloy | Txhim kho cov khoom tiv thaiv rau qhov sib txawv corrosion |
Xaus
Feem ntau crevice corrosion tsis ua haujlwm yog tshwm sim los ntawm kev tsim qauv tsis tsim nyog thiab tsis saib xyuas txhua hnub es tsis yog cov khoom siv tsis raug. Pib los ntawm kev tshem tawm cov qauv sib txawv thiab txo qhov fouling ntawm qhov chaw, qhov kev pheej hmoo zais ntawm qhov kev tiv thaiv corrosion tuaj yeem tshem tawm tau zoo, txhawm rau ua kom ntev lub voj voog kev nyab xeeb ntawm 316 stainless hlau cua sov raj.
