Incoloy 800 puas tuaj yeem siv rau hauv Marine Environments?

Nws Puas Muaj Seawater Corrosion Resistance?

1. Muaj peev xwm siv tau hauv Marine Environments

Kev 800tuaj yeem siv rau hauv cov xwm txheej tshwj xeeb marine, tab sis nws tsis yog ib qho kev mob siab rau marine corrosion- resistant alloy (xws li super austenitic stainless hlau los yog npib tsib xee-raws li alloys xws li Hastelloy C276). Nws txoj kev siv dej hiav txwv raug txwv rau cov xwm txheej hauv qab no:

Tsawg-kev ntxhov siab, qis- qhov chaw dej hiav txwv ceev ceev: Haum rau qhov zoo li qub lossis qis dua - dej hiav txwv ntws, xws li cov kav dej ntawm ntug dej hiav txwv, cov tshuab hluav taws xob dej tshiab, thiab cov khoom siv hluav taws xob hloov hluav taws xob ua haujlwm ntawm chav tsev kub lossis qis qis.

Atmospheric exposure zones nyob rau hauv ntug hiav txwv dej: Resistant mus rau ntsev tsuag corrosion nyob rau hauv ntug dej hiav txwv muaj chaw, thiab yuav siv tau rau cov qauv kev txhawb nqa, qhov cua ducts, thiab cia tank linings uas tsis ncaj qha mus cuag dej hiav txwv rau lub sij hawm ntev.

Mixed media ib puag ncig: Muaj feem xyuam rau cov kab dej hiav txwv uas cov dej hiav txwv sib xyaw nrog cov dej tsis qab los yog qis dua -chloride media, txo qhov kev pheej hmoo ntawm kev xeb hauv zos.

Txawm li cas los xij, Incoloy 800 yogtsis pom zoo rau cov nram qab no hnyav marine tej yam kev mob:

Siab - thaj chaw dej hiav txwv nrawm nrawm (piv txwv li, nkoj hulls, kiv cua, seawater txias pipelines nrog tus nqi ntws siab), qhov twg yaig-corrosion yog qhov tshwm sim.

Cov dej hiav txwv ib puag ncig uas muaj sulfides, chlorides nyob rau hauv high concentrations, los yog acidic pollutants (xws li, offshore roj thiab roj ntau lawm cov dej khib nyiab).

Cov khoom siv subsea uas yuav tsum tau ua kom ntev - lub sij hawm immersion (ntau tshaj 10 xyoo) yam tsis muaj kev saib xyuas, raws li kev txhim kho hauv cheeb tsam yuav maj mam tshwm sim.

2. Seawater Corrosion Resistance ntawm Incoloy 800

Incoloy 800 qhianruab nrab seawater corrosion kuj, uas yog muab los ntawm nws cov tshuaj muaj pes tsawg leeg (kwv yees . 30% Ni, 21% Cr, tshuav Fe) thiab cov yeeb yaj kiab tiv thaiv oxide tsim rau saum npoo. Nws cov kev ua tau zoo corrosion nyob rau hauv dej hiav txwv yog tus cwj pwm los ntawm cov hauv qab no:

(1) Uniform Corrosion Resistance

Nyob rau hauv tej yam ntuj tso dej hiav txwv nyob rau hauv lub chav tsev kub, lub uniform corrosion tus nqi ntawm annealed Incoloy 800 yog0.01-0.05 hli / xyoo, uas ua tau raws li qhov kev xav tau ntawm kev lag luam uas tsis tshua muaj corrosion (< 0.1 mm/year). This is because the chromium element in the alloy forms a dense Cr₂O₃ passivation film on the surface, effectively isolating the alloy matrix from seawater media.

(2) Localized Corrosion Resistance (Pitting thiab Crevice Corrosion)

Qhov no yog qhovkev txwv tseem ceebntawm Incoloy 800 nyob rau hauv seawater ib puag ncig:

Pitting corrosion: Hauv dej hiav txwv nrog cov tshuaj chloride ntau> 10,000 ppm (cov ntsiab lus ntawm cov dej hiav txwv dej hiav txwv chloride yog 19,000–21,000 ppm), pitting corrosion yuav tshwm sim thaum lub alloy nto kis kab mob, khawb, los yog nyob rau hauv siab - cov pa oxygen. Nws pitting kuj sib npaug tus lej (PREN) yog hais txog25–30, uas yog qis dua li ntawm kev mob siab rau marine alloys (piv txwv li, Hastelloy C276 muaj PREN> 60).

Kev txhim kho corrosion: Nws tuaj yeem tshwm sim hauv thaj chaw crevice xws li kev sib txuas bolt, flange gaskets, thiab cov ntawv kub hloov pauv raj, tshwj xeeb tshaj yog nyob rau hauv cov dej hiav txwv stagnant. Tus nqi corrosion hauv crevices tuaj yeem ncav cuag 0.1-0.3 hli / xyoo, ua rau thaj chaw perforation ntawm cov khoom.

(3) Stress Corrosion Cracking (SCC) Resistance

Incoloy 800 muajzoo tiv thaiv chloride kev nyuaj siab corrosion crackingnyob rau hauv dej hiav txwv ntawm chav tsev kub, uas yog ib qho ntawm nws zoo tshaj austenitic stainless hlau (xws li, 304/316L). Txawm li cas los xij, thaum qhov kub siab tshaj 60℃los yog cov hlau alloy nyob rau hauv qhov txias - ua hauj lwm lub xeev (nrog rau residual stress), qhov kev pheej hmoo ntawm SCC nce ntau.

3. Kev ntsuas los txhim kho Corrosion Resistance hauv Marine Applications

Yog tias Incoloy 800 yuav tsum tau siv nyob rau hauv ib puag ncig marine, cov kev tiv thaiv hauv qab no tuaj yeem siv tau:

Kev kho deg passivation: Tom qab machining, ua kua qaub pickling thiab passivation los kho cov oxide zaj duab xis ntawm qhov chaw thiab txhim kho corrosion kuj.

Cathodic tiv thaiv: Ua ke nrog kev tiv thaiv kev sib tsoo anode (xws li zinc lossis txhuas anodes) kom txo tau qhov kev pheej hmoo ntawm kev xeb hauv zos.

Kev saib xyuas tsis tu ncua: Ib ntus ntxuav lub ntsej muag ntawm cov khoom kom tshem tawm cov khoom siv hauv hiav txwv (xws li barnacles, algae) uas ua rau muaj qhov sib txawv ntawm cov pa oxygen concentration.

Tswj tej yam kev mob: Avoid long-term operation of the alloy in high-temperature (>60 degree) thiab siab -ceev seawater ib puag ncig.

Incoloy 800 tuaj yeem siv rau hauv Marine Environments