1. Cov txheej txheem tsim khoom seamless yog qhov tseem ceeb rau CuNi raj hauv siab - kev siv siab. Dab tsi tshwj xeeb qhov tsis zoo ntawm txoj kev seamless tshem tawm piv rau lub raj welded, thiab cov txheej txheem "pierce thiab kos" yuav ua li cas txhim kho lub raj lub siab -cov kabmob muaj peev xwm?
Cov txheej txheem seamless hauv paus tshem tawm cov longitudinal weld seam, uas yog ib txoj kab uas muaj peev xwm tsis muaj zog hauv lub raj welded.
Vulnerabilities ntawm Welded Tube:
Thaum tshav kub kub-Kev cuam tshuam Cheeb Tsam (HAZ): Cov txheej txheem vuam tsim ib thaj chaw sib txawv ntawm cov hlau uas nyob ib sab ntawm cov vuam nrog cov qauv hloov pauv, uas tuaj yeem yog qhov chaw rau kev nyiam corrosion lossis txo lub zog.
Weld Defects: Cov seam yog qhov cuam tshuam rau kev suav nrog, porosity, lossis tsis muaj fusion, uas ua raws li kev ntxhov siab thiab cov ntsiab lus pib ua rau qaug zog tawg lossis dhau los ntawm - phab ntsa corrosion.
Inhomogeneous Corrosion Resistance: Cov muaj pes tsawg leeg thiab microstructure ntawm cov hlau weld tuaj yeem sib txawv me ntsis ntawm cov niam txiv hlau, uas muaj peev xwm tsim tau lub cell galvanic.
Cov txheej txheem "Pierce thiab Kos" thiab nws cov txiaj ntsig:
Piercing: Ib qho khoom, rhuab CuNi billet yog pierced los ntawm ib tug mandrel los tsim ib tug hollow "plhaub."
Cold Drawing: Lub plhaub no ces rub (kos) los ntawm kev tuag thiab hla mandrels ntawm chav tsev kub. Qhov no yog kev ua haujlwm txias -.
Enhanced Pressure Capability: Cov txheej txheem kos duab txias induces strain hardening, ua kom cov yield thiab tensile lub zog ntawm lub raj piv rau nws lub xeev annealed. Lub raj txias -txoj raj muaj qhov muaj txiaj ntsig ntau dua qhov kev cia siab rau qhov muab phab ntsa tuab.
Superior Surface Finish and Dimensional Control: Cov txheej txheem ua rau muaj qhov sib luag, zoo li sab hauv thiab sab nrauv nrog kev tswj xyuas zoo tshaj ntawm phab ntsa thickness thiab concentricity. Qhov no txo qis kev kub ntxhov thiab yaig - kev pheej hmoo corrosion ntawm tus ID thiab muab qhov chaw zoo sib xws rau kev tsim cov yeeb yaj kiab corrosion.
Lub seamless, txias-kos CuNi raj yog homogeneous, siab- cov khoom muaj zog uas tsis muaj cov ntsiab lus tsis muaj zog hauv cov qauv, ua rau nws tsuas yog xaiv rau siab -cov dej hiav txwv siab, xws li cov uas pom nyob rau hauv naval nkoj thiab offshore platforms.
2. CuNi alloys, tshwj xeeb tshaj yog C70600, yog cov lus dab neeg rau lawv cov dej hiav txwv corrosion. Dab tsi yog qhov tshwj xeeb ntawm kev tiv thaiv zaj duab xis uas tsim, thiab qhov tseem ceeb alloying ntxiv ntawm Nickel thiab Hlau ua rau nws lub siab tawv thiab tus kheej li cas - kho lub peev xwm?
Kev tiv thaiv yog muab los ntawm nyias, complex, thiab adherent passive oxide txheej uas tsim ib txwm muaj thaum raug dej hiav txwv.
Xwm ntawm zaj duab xis: Nws tsis yog ib qho yooj yim teev. Nws yog txheej txheej duplex, feem ntau suav nrog cuprous oxide (Cu₂O), tab sis tau hloov kho los ntawm cov ntsiab lus alloying.
Lub luag haujlwm tseem ceeb ntawm Alloying Elements:
Nickel (10% hauv C70600, 30% hauv C71500): Nickel tau muab tso rau hauv oxide zaj duab xis li NiO, tsim cov tshuaj tov nrog Cu₂O. Cov npib tsib xee - txheej txheej, tshwj xeeb tshaj yog nyob rau hauv cov hlau - oxide interface, muaj kev tiv thaiv ntau dua thiab muaj zog dua li cov oxide ntawm cov tooj liab ntshiab. Nws yog tus yuam sij rau kev tawm tsam impingement nres los ntawm siab - dej nrawm, vim nws tsis tshua muaj kev cuam tshuam los yog kev tshem tawm tshuab.
Hlau (1.0-1.8% hauv C70600, 0.4-1.0% hauv C71500): Hlau yog lub hauv paus tseem ceeb rau kev kho tus kheej lub peev xwm. Nws oxidizes tsim ferric oxide (Fe₂O₃) thiab xav tias yuav muab tso rau hauv sab nrauv ntawm zaj duab xis. Qhov tseem ceeb tshaj, yog tias cov yeeb yaj kiab raug puas tsuaj, cov hlau yaj los ntawm qhov chaw raug oxidizes sai, siv cov pa oxygen thiab pab txhawb cov pH hauv zos. Qhov no tsim cov tshuaj zoo tagnrho rau cov nickel-hloov Cu₂O txheej los hloov kho yuav luag tam sim, kho qhov ua txhaum cai ua ntej muaj kev cuam tshuam loj tuaj yeem tshwm sim.
Qhov kev sib koom ua ke ntawm Ni thiab Fe tsim cov yeeb yaj kiab uas yog ob qho tib si tiv thaiv kev tawg thiab muaj peev xwm rov tsim dua sai, muab CuNi hlab rau lawv xyoo caum- lub neej ua haujlwm ntev hauv dej hiav txwv.
3. Nyob rau hauv lub nkoj lub hauv paus cua txias system, ob lub C70600 thiab C71500 hlab yuav siv tau nyob rau hauv txawv tshav kub exchangers. Cov yam ntxwv tseem ceeb ntawm kev ua haujlwm zoo li cas nrog cov ntsiab lus nickel ntau dua ntawm C71500, thiab nyob rau hauv cov kev pabcuam tshwj xeeb yuav ua rau nws tus nqi siab dua C70600?
Cov yam ntxwv tseem ceeb uas txhim kho nrog cov ntsiab lus ntau dua nickel (C71500) yog tiv thaiv Ammonia -Induced Stress Corrosion Cracking (SCC).
Qhov teeb meem: Hauv qhov chaw kaw lossis hauv qab decomposing organic teeb meem, ammonia (NH₃) tuaj yeem tsim tau. Qhov no yog ib qho zoo -paub corrodent rau tooj liab alloys, thiab nws tuaj yeem ua rau tawg sai, nkig hauv cov khoom hauv qab tensile stress.
Alloy Solution:
C70600 (90-10 CuNi) muaj nruab nrab tsis kam rau ammonia SCC. Nws tuaj yeem raug cuam tshuam rau hauv ib puag ncig uas muaj cov ammonia siab thiab siab residual lossis siv kev ntxhov siab.
C71500 (70-30 CuNi) muaj qhov ua tau zoo tshaj plaws rau ammonia SCC. Cov ntsiab lus ntau dua nickel hloov pauv tus cwj pwm electrochemical ntawm cov hlau thiab qhov xwm txheej ntawm zaj duab xis saum npoo, ua rau nws tsis tshua muaj kev cuam tshuam rau qhov tshwj xeeb kev sib tsoo.
Kev lees paub tus nqi siab dua ntawm C71500:
C71500 yog qhov ncaj ncees hauv cov kev pabcuam uas muaj kev pheej hmoo ntawm ammonia muaj siab thiab qhov tshwm sim ntawm qhov tsis ua haujlwm hnyav. Cov xwm txheej tshwj xeeb suav nrog:
Refinery thiab Chemical Plant Coolers: Qhov twg cov txheej txheem - sab xau tuaj yeem qhia ammonia lossis amines rau hauv dej txias.
Shipboard Lubricant Coolers: Qhov twg cov dej xau hauv lub raj tuaj yeem tso cai rau amine-raws li lubricant additives kom decompose thiab tso ammonia mus rau hauv qhov chaw, kub ntawm lub plhaub sab.
Siab -Kev ntseeg tau ntawm Naval Daim Ntawv Thov: Qhov siab tshaj plaws tiv thaiv tus neeg sawv cev ntawm kev ua tsov rog tshuaj lom neeg lossis kev sib kis tsis zoo yuav tsum tau ua.
Hauv cov xwm txheej no, tus nqi them rau C71500 yog tus nqi - txoj cai pov hwm kev noj qab haus huv zoo tiv thaiv kev puas tsuaj, kev ua tsis tiav.
4. Kev vam meej ntawm lub raj CuNi mus rau CuNi raj ntawv yog ib txoj kev tseem ceeb hauv kev tsim cov khoom siv hluav taws xob. Vim li cas cov hlau muab tub lim yog "dhau- sib luag" hauv cov ntsiab lus npib tsib xee, xws li 70-30 CuNi xaim rau 90-10 CuNi raj, cov qauv kev coj ua, thiab qhov tshwj xeeb no tiv thaiv dab tsi?
Siv ib qho dhau -cov hlau muab tub lim (piv txwv li, ERNiCu-7 rau C70600) yog qhov kev tiv thaiv zoo tiv thaiv cov hlau zoo dua corrosion.
Qhov teeb meem: Microsegregation hauv Weld
Thaum lub sij hawm solidification ntawm ib tug weld puddle, thawj cov hlau rau khov yog nplua nuj nyob rau hauv siab dua - melting- ntsiab lus (Nickel), thaum lub xeem hlau rau khov nyob rau hauv lub interdendritic qhov chaw yog richer nyob rau hauv qis dua - melting- ntsiab lus (Copper). Qhov no tsim lub microscopic "grainy" qauv nrog variations nyob rau hauv muaj pes tsawg leeg.
Galvanic Corrosion Risk:
Hauv ib puag ncig dej hiav txwv corrosive, tooj liab- thaj chaw nplua nuj interdendritic ua anodic rau cov npib tsib xee- nplua nuj dendritic cores. Qhov no teeb tsa lub micro-galvanic cell uas tuaj yeem ua rau xaiv qhov kev tawm tsam thiab nkag mus sai ntawm cov hlau vuam, txawm hais tias cov ntawv niam txiv lub raj thiab cov ntawv raj tiv thaiv corrosion zoo kawg nkaus.
Txoj kev daws teeb meem: Nickel-Tshaj -Matched Filler Hlau
Los ntawm kev siv 70-30 CuNi muab tub lim hlau rau vuam 90-10 CuNi Cheebtsam,tag nrho weld hlauyog richer nyob rau hauv nickel. Qhov no ua kom ntseeg tau tias txawm tias cov tooj liab feem ntau- thaj chaw nplua nuj ntawm cov khoom sib cais tseem muaj txiaj ntsig zoo (cathodic) dua li 90-10 CuNi puag hlau. Ob peb galvanic thim rov qab, thiab txhua qhov kev xaiv me me yuav tshwm sim hauv qhov nkag tau yooj yim, yooj yim repassivated puag hlau nyob ib sab ntawm lub vuam, tsis nyob rau hauv qhov tseem ceeb weld hlau nws tus kheej. Qhov kev coj ua no tau lees paub lub sijhawm ntev corrosion ntawm kev sib koom ua ke.
5. Rau ib thaj av-raws li cov chaw tsim hluav taws xob siv cov dej khib nyiab lossis cov dej khib nyiab kho raws li cov dej txias, lub neej- kev txheeb xyuas tus nqi piv rau CuNi raj rau stainless hlau thiab titanium raj. Dab tsi tshwj xeeb cov cuab yeej ntawm CuNi, dhau ntawm kev tiv thaiv corrosion, muab cov nqi ua haujlwm tseem ceeb tshaj nws cov neeg sib tw?
Cov cuab yeej tseem ceeb yog Intrinsic Biofouling thiab Macro-fouling Resistance.
Cov teeb meem Fouling: Cov dej txias, tshwj xeeb tshaj yog los ntawm cov dej ntws, cov dej ntws, los yog cov dej khib nyiab, yog cov khoom noj muaj txiaj ntsig - nplua nuj thiab muaj kev lom zem nrog lub neej. Cov kab mob xws li mussels, barnacles, algae, thiab tubeworms nrhiav kev colonize submerged nto.
Kev txwv kev sib tw:
Stainless hlau: Tsis muaj kev tiv thaiv biofouling. Nws yuav tsum tau chlorination txuas ntxiv lossis lwm yam biocides kom fouling nyob rau hauv kev tswj, uas ntxiv cov nqi tshuaj tseem ceeb thiab tsim teeb meem ib puag ncig. Yog tias biofouling tshwm sim, nws txo qis kev ua haujlwm ntawm cov cua sov thiab tuaj yeem tsim cov crevices rau hauv qab - deposit corrosion.
Titanium: Tsis tas li ntawd tsis muaj cov khoom siv biocidal. Thaum nws muaj kev tiv thaiv corrosion uas fouling tuaj yeem ua rau cov hlau tsis muaj steel, nws yuav foul li yooj yim, yuav tsum tau siv tib yam khoom siv lossis tshuaj ntxuav tu.
CuNi Kev Ua Haujlwm Zoo:
Tooj-nickel alloys maj mam tso tooj liab ions rau hauv dej. Cov ions no yog cov tshuaj lom rau cov kab mob larval thiab cov theem ntawm cov kab mob fouling. Qhov no tsim ib cheeb tsam "anti-fouling" ntawm lub raj nplaim uas tiv thaiv kev sib haum xeeb thiab kev loj hlob ntawm macro-fouling.
Qhov tshwm sim: CuNi condenser raj feem ntau nyob twj ywm tsis muaj zog fouling.
Kev Txuag Nqi Ua Haujlwm: Qhov no tshem tawm lossis txo qis qhov xav tau rau:
Chlorination (txuag cov nqi tshuaj thiab cov nqi ua raws li ib puag ncig).
Kev tu neeg kho tshuab (txuag rau kev ua haujlwm, khoom siv, thiab kev cog qoob loo).
Kev poob ntawm kev ua haujlwm los ntawm cov raj fouled, uas ncaj qha txhais kom txo cov nqi roj rau tib lub zog tso zis.
Qhov kev tiv thaiv biofouling no muab kev ua haujlwm tsis tu ncua, kev ua haujlwm tsis tu ncua uas txuag tau tias, dhau 30+ xyoo lub neej ntawm lub tshuab fais fab, tuaj yeem tshaj qhov nqi pib ntawm CuNi raj.
