Kev tiv thaiv corrosion ntawm stainless hlau feem ntau yog vim qhov sib ntxiv ntawm cov ntsiab lus siab dua ntawm Cr keeb (xws li 316L W (Cr)=16.00 txog 18.00) hauv cov hlau. Cr keeb yog ib qho yooj yim rau oxidize thiab tuaj yeem tsim cov Cr2O3 oxide zaj duab xis ntom ntom ntawm cov hlau. Cov electrode muaj peev xwm ntawm cov hlau thiab corrosion kuj nyob rau hauv nruab nrab oxidizing yog nce sai.
Qhov kev tiv thaiv corrosion ntawm stainless hlau feem ntau yog nyob ntawm qhov tsis tshua muaj nyias (li 1nm) tuab passivation zaj duab xis npog rau ntawm qhov chaw. Qhov no passivation zaj duab xis rho tawm los ntawm corrosive media yog qhov yooj yim barrier rau stainless hlau tiv thaiv.
Yog tias cov yeeb yaj kiab passivation tsis tiav lossis puas los ntawm qhov tsis xws luag, cov hlau tsis muaj steel tseem yuav corroded. Lub lifting, assembling, welding, weld inspection (xws li kev tshuaj xyuas xim, kev ntsuam xyuas siab) thiab cov roj av stains, khawb, xeb, impurities, thiab impurities ntawm stainless hlau chemical tanker Melting point hlau contaminants, xim, vuam slag, spatters, thiab lwm yam. ., cov tshuaj no cuam tshuam rau qhov zoo ntawm cov hlau tsis muaj steel, ua kom lub ntsej muag passivation zaj duab xis, txo cov nplaim corrosion kuj, thiab yooj yim rau kev sib koom nrog corrosive nruab nrab hauv cov tshuaj nqa mus rau yav tom ntej Nws tuaj yeem ua rau pitting corrosion, intergranular corrosion, thiab txawm tias kev nyuaj siab corrosion cracking.
Stainless hlau chemical tankers feem ntau siv dej hiav txwv los ntxuav cov tank hauv kev ua haujlwm. Cov dej hiav txwv yog nplua nuj nyob rau hauv chloride ions, uas muaj ib tug zoo corrosive nyhuv ntawm passivation zaj duab xis. Cov kev ua haujlwm tsis zoo, yog li pickling passivation yog qhov tseem ceeb.
Cov yeeb yaj kiab tsis zoo ntawm cov hlau tsis muaj zog muaj cov yam ntxwv zoo thiab yuav tsum tsis txhob raug suav tias yog qhov ua tiav ntawm kev xeb. Es tsis txhob, nws tsim ib txheej tiv thaiv uas diffuses. Feem ntau nyob rau hauv lub xub ntiag ntawm ib tug txo tus neeg sawv cev (xws li chloride ions), nws nyhav ua kom puas lub passive zaj duab xis. Cua) tuaj yeem tiv thaiv thiab kho cov yeeb yaj kiab passivation thaum nws muaj. Stainless hlau yuav tsim cov oxide zaj duab xis thaum muab tso rau hauv huab cua, tab sis kev tiv thaiv ntawm cov yeeb yaj kiab no tsis zoo tag nrho.
Ib txheej nruab nrab ntawm 10μm tuab ntawm cov hlau stainless yog corroded los ntawm pickling. Cov tshuaj lom neeg ua haujlwm ntawm cov kua qaub ua rau qhov tawg ntawm qhov chaw tsis raug. Nws yog siab dua lwm qhov ntawm qhov chaw, yog li pickling tuaj yeem ua rau tag nrho saum npoo zoo li sib npaug. Qhov tseem ceeb tshaj, los ntawm pickling passivation, hlau thiab hlau oxides yog yaj zoo dua li chromium thiab chromium oxides, thiab cov neeg pluag raug tshem tawm.
Cov txheej chromium enriches nto ntawm stainless hlau nrog chromium, thiab ua kom tiav thiab ruaj khov passivation zaj duab xis nyob rau hauv lub passivation ntawm ib tug oxidant. Lub peev xwm ntawm cov yeeb yaj kiab chromium-nplua nuj passivation tuaj yeem ncav cuag +1.0V (SCE), uas nyob ze rau lub peev xwm ntawm cov hlau tsis muaj zog thiab ua rau muaj kev ruaj ntseg tiv thaiv corrosion.
Pickling thiab passivation txoj kev yog raws li kev ua haujlwm sib txawv. Stainless hlau pickling thiab passivation kev kho mob mas suav nrog 6 txoj kev, nrog rau txoj kev dipping, paste method, txhuam txoj kev, txau txoj kev, txoj kev ncig, electrochemical method, thiab lwm yam. stainless hlau chemical tankers thiab khoom siv.
Pickling passivation txoj kev:
1. Txoj kev dipping:Txoj kev no yog qhov tsim nyog tshaj plaws rau cov kav dej stainless hlau, lub luj tshib, qhov me me, thiab lwm yam, thiab cov nyhuv kho yog qhov zoo tshaj plaws. Vim tias cov khoom kho tau tuaj yeem nkag mus rau hauv cov tshuaj pickling passivation, cov tshuaj tiv thaiv nto tiav thiab cov zaj duab xis passivation yog ntom thiab sib xws. Chuandong Shipyard siv lub rhiav pickling ntawm lub Hoobkas rau pickle" Ninghua 417" stainless hlau pipelines nyob rau hauv batch, thiab ua tiav cov txiaj ntsig zoo. Txoj kev no tsim nyog rau kev ua haujlwm tas mus li, tab sis nws yuav tsum tau ua kom tsis tu ncua nrog cov kua tshiab raws li cov tshuaj tiv thaiv concentration ntawm cov tshuaj txo.
Qhov tsis zoo yog tias nws raug txwv los ntawm cov duab thiab lub peev xwm ntawm cov kua qaub tank, thiab nws tsis haum rau cov khoom siv loj thiab cov kav dej nrog cov duab ntev thiab dav heev; Kev siv mus sij hawm ntev yuav txo tau cov txiaj ntsig vim yog cov volatilization ntawm cov kev daws teeb meem thiab lwm yam laj thawj, xav tau ib qho chaw tshwj xeeb, acid pas dej ua ke thiab cov khoom siv cua sov.
2. Paste method:Stainless hlau pickling passivation muab tshuaj txhuam tau dav siv nyob rau hauv lub teb chaws thiab ib tug series ntawm cov khoom muaj. Cov khoom tseem ceeb yog nitric acid, hydrofluoric acid, corrosion inhibitor, viscous agent, thiab lwm yam. Ntxuav passivation paste" CB / T3595-94 muaj cov cai tshwj xeeb tshuaj xyuas, kev tuav haujlwm, tsim nyog rau kev tsim kho ntawm qhov chaw, vuam seam kev kho mob, vuam discoloration, lawj saum, lub kaum sab xis tuag, rov qab ntawm lub escalator thiab thaj chaw loj hauv lub tank ntawm stainless hlau tshuaj tanker Ob leeg smear passivation muaj feem xyuam.
Qhov zoo ntawm cov txheej txheem muab tshuaj yog tias tsis tas yuav tsum muaj cov cuab yeej tshwj xeeb thiab qhov chaw, tsis muaj cov khoom siv cua sov, hloov tau yooj yim ntawm qhov chaw ua haujlwm, pickling passivation tiav ib zaug, thiab muaj kev ywj pheej muaj zog; passivation paste muaj lub neej txee ntev, thiab passivation paste tshiab yog siv rau txhua daim ntawv thov. Rau kev siv yooj yim, cov tshuaj tiv thaiv yuav tsum nres tom qab passivation ntawm txheej txheej dhau lawm, nws tsis yooj yim rau over-corrosive, thiab nws tsis txwv los ntawm lub sij hawm tom qab ntxuav, thiab cov kev sib txuas tsis muaj zog xws li welds tuaj yeem ntxiv dag zog rau passivation.
Qhov tsis zoo yog tias cov neeg ua haujlwm muaj kev ua haujlwm tsis zoo, kev siv zog ua haujlwm siab, thiab tus nqi siab. Kev kho mob ntawm cov phab ntsa sab hauv ntawm cov kav dej stainless hlau yog me ntsis qis dua, thiab lwm txoj kev yuav tsum tau ua ke.
3. Txau txoj kev:haum rau pickling passivation ntawm ib qho khoom lag luam nrog rau qhov chaw ruaj khov thiab qhov chaw kaw lossis cov khoom siv nrog cov qauv sab hauv yooj yim, xws li cov txheej txheem tshuaj tsuag ntawm cov kab ntau lawm. Rau stainless hlau tshuaj tankers, nws yuav siv tau los acidify lub puab phab ntsa ntawm cov kua cargo tanks. ntxuav. Chuandong Shipyard npaj siv cov tshuaj tsuag rau pickling thiab passivation ntawm cov cargo tso tsheb hlau luam ntawm Sinochem's 3450t stainless hlau tshuaj tanker" Yingchun" nyob rau hauv kev tsim kho.
Qhov zoo dua yog tias kev ua haujlwm tsis tu ncua yog ceev, kev ua haujlwm yog yooj yim, thiab cov nyhuv corrosion ntawm cov neeg ua haujlwm me me. Lub raj xa dej tuaj yeem rov qab tau dua thaum lub sijhawm ua cov raj xa dej. Qhov kev siv tshuaj tov yog siab heev.
Txoj kev no muaj ntau yam kev txwv, xws li:
A.Tag nrho cov scaffolds nyob rau hauv lub tank yuav tsum tau muab tshem tawm, lub tank thiab cov kav dej system yuav tsum tau ntxuav, thiab yuav tsum tsis txhob muaj residues, impurities, thiab lwm yam nyob rau hauv lub pipeline.
B.Tag nrho cov khoom siv ua kua xws li cov twj tso kua dej sib sib zog nqus, cov li qub, thiab lub tshuab ntxhua khaub ncaws yuav tsum tau debugged thiab npaj siv.
C.Yog tias cov kua dej tso rau hauv lub tank ntev dhau lawm, nws yuav hnov mob thiab ua rau cov hlau tsis muaj zog ntau dhau. Yog li ntawd, kev ua haujlwm tas mus li yuav tsum tau ua. Lub nkoj nkoj yuav tsum koom tes nrog ib leeg thiab npaj ntau cov dej ntxuav txhua lub sijhawm. Yog tias muaj hluav taws xob hluav taws xob, dej tawm, kev ua haujlwm nres, thiab lwm yam, nws yuav ua rau muaj teeb meem loj. raws li qhov tshwm sim ntawm.
D. Lub thawv loj yuav tsum tau siv rau cov kua qaub thiab cov dej khib nyiab pov tseg, lossis lub tank yuav tsum tau siv ib ntus, tab sis nws yuav tsum tau nruab nrab thiab tso tawm sai li sai tau kom tsis txhob muaj corrosion ntawm lub tank.
E. Raws li lub sij hawm cov tshuaj tiv thaiv nce thiab impurities nyob rau hauv cov tshuaj nce, cov khoom zoo ntawm cov tshuaj pickling maj mam txo. Qhov concentration ntawm cov tshuaj yuav tsum tau kuaj xyuas txhua lub sijhawm thiab cov tshuaj tshiab yuav tsum tau ntxiv rau lub sijhawm.
F. Lub sij hawm nyob twj ywm ntawm cov kua dej ntawm lub lawj, plaub phab ntsa, cov ces kaum tuag, rov qab ntawm cov escalators, thiab lwm yam yog luv dua, thiab cov nyhuv pickling yog me ntsis phem dua li ntawm cov phaj hauv qab.
