Sab nraud atmospheric pitting corrosion tsis ua hauj lwm yog hais txog sab nrauv ntawm 316 stainless hlau cua sov cov raj raug nthuav tawm rau cov huab cua ntub dej, ntsev pos huab, dew condensation thiab plua plav deposition ntev. Cov chloride ions nyob rau hauv ib puag ncig sib sau ua ke hauv cov dej me me uas txuas nrog cov yeeb nkab phab ntsa, rhuav tshem cov yeeb yaj kiab tsis zoo ntawm cov hlau nto. Localized me me corrosion pits maj mam tsim rau ntawm phab ntsa sab nrauv, uas txuas ntxiv mus rau sab hauv raws phab ntsa thickness kev taw qhia thiab thaum kawg nkag mus rau hauv cov yeeb nkab lub cev ua rau nruab nrab to. Hom kev puas tsuaj no feem ntau tshwm sim hauv cov kav dej sab nraum zoov, cov kav dej ntawm ntug hiav txwv ntsev tsuag ib puag ncig cov kav dej thiab cov kav dej rhiav ua rau cov dej khib nyiab thiab tshuaj lom neeg cov plua plav sib sau ua ke, yog cov khoom siv hauv zos sab nraud electrochemical corrosion.
1. Pitting Initiation thiab Penetration Mechanism
316 stainless hlau cia siab rau nyias chromium-nplua nuj passive zaj duab xis los tiv thaiv corrosion nyob rau hauv atmospheric ib puag ncig. Thaum cov tshuaj chloride ions yog enriched nyob rau hauv lub nyias kua zaj duab xis condensed nyob rau hauv cov yeeb nkab phab ntsa, cov ions yuav adsorb thiab rhuav tshem lub zos passive oxide txheej, tsim ib tug me me anode cheeb tsam uas cov hlau matrix dissolves nyiam. Cov yeeb yaj kiab uas nyob ib puag ncig tsis zoo ua raws li thaj chaw cathode loj, ua kom cov tshuaj tiv thaiv anode corrosion hauv lub qhov. Cov khoom siv corrosion nyob rau hauv lub qhov dej thaiv qhov qhib, tsim cov microenvironment occluded nrog nce acidity thiab tsis tu ncua chloride concentration. Lub qhov dej nthuav dav vertically sab hauv sai sai yam tsis muaj qhov pom tseeb corrosion nyob rau sab nrauv ntawm lub raj xa dej nyob rau theem pib. Sib txawv ntawm sab hauv hauv qab - deposit corrosion tshwm sim los ntawm nruab nrab scale, qhov tsis ua hauj lwm no tshwm sim los ntawm sab nraud ib puag ncig yaig es tsis yog sab hauv nruab nrab erosion.
2. Cov hauj lwm zoo tshaj plaws rau sab nrauv Pitting Corrosion
Hauv qab ntawm cov kav dej uas muaj dej ntws pov tseg uas cov dej lwg thiab cov dej nag tau yooj yim khaws thiab khaws cia;
Cov kav dej nyob ze ntawm ntug dej hiav txwv thiab cov chaw tso dej phwj tuaj nrog cov ntsev ion ntau hauv huab cua;
Qhov sib txawv ntawm cov yeeb nkab clamps thiab cov yeeb nkab sab nrauv phab ntsa uas muaj plua plav thiab dej zaj duab xis tau daig rau lub sijhawm ntev;
Weld tshav kub- thaj chaw cuam tshuam nrog cov yeeb yaj kiab tsis ruaj khov thiab tsis muaj zog corrosion;
Cov kav dej uas muaj kev puas tsuaj sab nrauv los tiv thaiv- xeb txheej thiab liab qab hlau ncaj qha mus rau qhov chaw.
3. Core Inducing Factors Accelerating Pitting Damage
Cov txheej tiv thaiv sab nrauv -corrosion txheej ntawm cov kav dej poob tawm, tawg los yog tsis txau tag nrho thaum tsim kho;
Qhov chaw ua haujlwm muaj cov tshuaj chloride siab, sulfur- muaj cov pa khib nyiab thiab corrosive plua plav;
Lub raj xa dej thermal rwb thaiv tsev txheej yog puas, dej nkag mus rau hauv lub interlayer thiab tsim ib tug ntev - lub sij hawm humid kaw ib puag ncig;
Nto khawb thiab cov neeg kho tshuab puas tsuaj ua rau cov yeeb yaj kiab tsis zoo thiab ua kom nyiam cov ntsiab lus pib corrosion;
Kev soj ntsuam ntev - lub sij hawm tsis tuaj yeem saib xyuas yam tsis tau ntxuav cov av thiab cov dej seem ntawm cov yeeb nkab.
4. Tag nrho -Txuas Kev Tiv Thaiv thiab Tswj Kev Ntsuas Kev Ntsuas
① Ua tiav txheej txheej sandblasting thiab tiv thaiv - xeb txheej txau tom qab kev teeb tsa cov kav dej
Tsim ib txheej kev sib cais txuas ntxiv kom cais cov hlau substrate los ntawm atmospheric corrosive nruab nrab.
② qhwv ua tiav waterproof thermal rwb thaiv tsev txheej rau sab nraum zoov thiab seaside nteg pipelines
Tsis txhob dej nag thiab ntsev pos huab los ntawm kev sib cuag ncaj qha rau cov yeeb nkab phab ntsa.
③ Tsis tu ncua ntxuav cov plua plav, cov khib nyiab thiab cov khib nyiab seem ntawm cov kav dej sab nrauv
Tshem tawm cov txheej txheem ntxiv ntawm chloride ion dej zaj duab xis los ntawm qhov chaw.
④ Kho cov txheej txheej puas thiab rwb thaiv tsev nyob rau lub sijhawm kom tsis txhob muaj cov hlau liab liab
Thaiv thawj channel ntawm kev puas tsuaj zaj duab xis passive.
⑤ Ua raws li kev ntsuas thickness tsis tu ncua thiab kev tshuaj xyuas tam sim no ntawm cov yeeb nkab raug
Tshawb nrhiav zais qhov corrosion ua ntej nkag mus thiab to.
5. Kev Tiv Thaiv Cov Teeb Meem Sib piv
表格
| Kev Tiv Thaiv & Kev Tu Hom | Sab nrauv Pitting Corrosion Risk | Daim ntawv thov tswv yim |
|---|---|---|
| Txheej tsis tiav + rwb thaiv tsev puas + ntev -lub sij hawm tsis tu | Perforation to tshwm sim nyob rau hauv 1 mus rau 2 xyoo kev pab cuam | Tshem tawm cov txheej txheem qub thiab rwb thaiv tsev, rov ua dua tshiab los tiv thaiv - corrosion thiab tiv thaiv dej tsis zoo |
| Integral tiv thaiv-corrosion txheej + tsis muaj dej tsis zoo rwb thaiv tsev + tu lub sijhawm | Zoo inhibit qhov tsim thiab nthuav ntawm sab nraud pitting pits | Txuj kev tiv thaiv -corrosion tsim tshwj xeeb rau sab nraum zoov stainless hlau cua sov kav |
| Multi-txheej txheej los tiv thaiv-corrosion system + tiag-lub sij hawm ib puag ncig corrosion saib xyuas + txhua xyoo qhov tsis zoo | Tsis tshua muaj sab nrauv phab ntsa perforation zais txaus ntshai | Cov tswv yim nyiam rau cov chaw cog qoob loo ntawm ntug dej hiav txwv thiab siab -kev ua qias tuaj rau cua sov pipeline engineering |
Xaus
Sab nraud atmospheric pitting perforation tsis ua hauj lwm ntawm 316 stainless hlau cua sov raj yog tshwm sim los ntawm ib puag ncig chloride ion rhuav tshem cov zaj duab xis nto thiab tsim occluded corrosion pits uas nkag mus rau hauv cov yeeb nkab phab ntsa. Cov kev tiv thaiv tseem ceeb suav nrog kev ua kom zoo rau sab nrauv phab ntsa tiv thaiv - kev tiv thaiv kev tiv thaiv corrosion, txhim kho kev sib khi ua haujlwm ntawm cov txheej txheem thermal rwb thaiv tsev, tu cov kav dej tsis tu ncua, kho cov txheej txheem puas tsuaj raws sijhawm thiab teeb tsa lub sijhawm tsis ua haujlwm - kev puas tsuaj. Tag nrho - txheej txheem tswj cov kav raj xa dej los tiv thaiv- kev txhim kho corrosion, kev tiv thaiv ib puag ncig txhua hnub thiab kev tshuaj xyuas niaj hnub tuaj yeem tiv thaiv cov pa nruab nrab thiab cov khoom siv kaw qhov xwm txheej tshwm sim los ntawm sab nraud atmospheric pitting corrosion ntawm cov cua sov raj.
