1. Rau qhov siab - qhov kub thiab txias ntawm cov khoom siv hauv lub qhov cub (xws li lub pob tawb radiant raj), yuav tsum xaiv ntawm Inconel 600 thiab Incoloy 800H phaj. Dab tsi yog qhov tseem ceeb metallurgical yam uas yuav ua rau kev xaiv ntawm Incoloy 800H?
Kev xaiv ntawm Incoloy 800H yog tsav los ntawm nws qhov kev nkag siab zoo tshaj - tawg lub zog ntawm qhov kub siab tshaj 1100℃F (593℃).
Inconel 600 yog ib qho khoom siv -kev daws teeb meem muaj zog nickel-chromium alloy. Nws muaj kev tiv thaiv oxidation zoo tab sis tsuas yog nyob ntawm lub zog ntawm nws cov matrix. Thaum qhov kub thiab txias heev, nws yuav deform yooj yim dua nyob rau hauv tas li load (creep).
Incoloy 800H yog hlau -nickel-chromium alloy. Lub npe "H" txhais tau tias:
Tswj Cov Ntsiab Lus Carbon (0.05-0.10%): Cov pa roj carbon no tso cai rau kev tsim cov carbides ruaj khov nyob rau hauv cov nplej thiab ntawm cov ciam teb thaum lub sij hawm kev pab cuam, uas ntxiv dag zog rau cov qauv tiv thaiv creep deformation.
Tshuaj Annealing rau Coarse Grain Size: Lub phaj yog kho kom muaj ASTM grain loj ntawm 5 los yog coarser. Tsawg tus ciam teb txhais tau hais tias txoj kev ntev dua rau cov kab nrib pleb kom nthuav tawm, ua kom lub neej ntev kev pab cuam nyob rau hauv qhov kub thiab txias.
Rau ib qho kev thauj khoom -cov kabmob zoo li lub pob tawb, lub zog nkag yog cov cuab yeej txhais. Incoloy 800H tau tsim tshwj xeeb rau qhov no, thaum Inconel 600 yog qhov zoo dua rau cov uas tsis yog -load- bearing heat shielding los yog daim ntawv thov uas nws tshwj xeeb corrosion kuj xav tau.
2. Lub nkoj tshuaj reactor yuav tsum muaj ib lub hauv ob sab ntawm nickel alloy phaj los tuav kub, paug sulfuric acid. Vim li cas Hastelloy C-276 yuav yog qhov kev xaiv zoo tshaj Inconel 625 rau qhov kev pabcuam xav tau no?
Txawm hais tias ob qho tib si zoo heev, Hastelloy C-276 feem ntau nyiam rau qhov kev pabcuam no vim nws txoj kev kho kom zoo rau kev txo cov kua qaub thiab ua haujlwm zoo rau hauv cheeb tsam corrosion.
Ib puag ncig: Kub, paug sulfuric acid yog atxokua qaub. Cov kab mob sib kis (xws li chlorides, ferric ions) tuaj yeem ua kom muaj peev xwm oxidizing thiab ua rau muaj kev pheej hmoo ntawm pitting.
Inconel 625: Tau txais lub zog tseem ceeb ntawm niobium thiab molybdenum. Txawm li cas los xij, hauv kev nruj heev txo cov kua qaub, nws cov kev ua tau zoo, thaum zoo, tuaj yeem sib phim lossis dhau los ntawm lwm cov alloys.
Hastelloy C-276:
Siab dua Molybdenum (~ 15-16% vs . 8-10% hauv 625): Molybdenum yog lub hauv paus tseem ceeb rau tiv thaiv cov kua qaub xws li sulfuric thiab hydrochloric. Cov ntsiab lus siab dua hauv C-276 muab kev nyab xeeb ntau dua.
Tungsten Ntxiv (~3-4.5%): Tungsten ntxiv txhim khu kev tiv thaiv kom txo cov kua qaub thiab pitting.
Tsawg Carbon / Silicon: Txo qhov tsim ntawm cov theem teeb meem thaum vuam, txhais tau tias nws ua tau zoo heev xws li -welded corrosion kuj tsis muaj ncej-weld heat treatment. Qhov no yog qhov tseem ceeb rau kev tsim lub nkoj loj.
Rau cov tshuaj lom neeg muaj zog tshaj plaws thiab tsis muaj kev phom sij, tshwj xeeb tshaj yog cov uas cuam tshuam txog kev txo cov kua qaub thiab cov tshuaj chlorides, Hastelloy C-276's balanced chemistry thiab weldability ua rau nws qhov kev xaiv muaj zog thiab txhim khu kev qha.
3. Thaum tsim cov hlab ntsha siab los ntawm Inconel 718 phaj, kev kho cua sov ua ntu zus yog qhov tseem ceeb. Vim li cas thiaj yuav tsum tau cov tshuaj kho mob thiab hnub nyoogtom qabqhov loj vuam thiab kev ua haujlwm tiav?
Inconel 718 yog lub hnub nyoog - hardenable ( nag lossis daus -hardened) alloy. Nws lub zog loj heev tsis yog nyob rau hauv tab sis yog "xauv" los ntawm ib qho tshwj xeeb ob -kev kho cua sov.
Kev Kho Mob: Lub phaj yog rhuab mus rau qhov kub siab (~ 1700 -} 1850℃F / 927-1010 degree) kom yaj tag nrho cov txheej txheem ntxiv zog (feem ntau gamma prime thiab gamma double-prime) rau hauv ib homogeneous khoom tov, ces txias sai. Nyob rau hauv lub xeev no, cov khoom yog mos thiab ductile, zoo tagnrho rau vuam thiab sib sau.
Kev Kho Mob Kev laus: Cov khoom siv yog cua sov kom qis dua (~ 1325-1450℃F / 718-788 degree) thiab tuav rau lub sijhawm meej. Qhov no ua rau cov theem ntxiv dag zog los ua kom zoo, sib npaug ntawm cov khoom sib cais thoob plaws hauv matrix, ua kom muaj zog thiab tawv.
Yog tias koj muaj hnub nyoog - tawv ua ntej thiab tom qab ntawd weld:
Cov cua sov los ntawm vuam yuav dhau -hnub nyoog lub microstructure nyob rau hauv lub tshav kub-Txoj kev cuam tshuam cheeb tsam (HAZ), dissolving cov ua tib zoo tsim precipitates.
Qhov no tsim ib qho "mos thaj tsam" nrog lub zog qis dua thiab cov khoom sib txawv ntawm ib sab ntawm lub vuam, dhau los ua qhov chaw muaj peev xwm rau kev ua tsis tiav hauv siab.
Nws kuj tseem tuaj yeem ua rau muaj kev cuam tshuam loj heev rau strain- hnub nyoog tawg thaum vuam.
Therefore, the correct sequence is: Fabricate (cut, form, weld) in the soft, solution-treated condition ->Ua kev daws teeb meem zaum kawg thiab hnub nyoog ntawm tag nrho cov khoom tiav. Qhov no ua kom muaj qhov sib xws, siab - lub zog microstructure thoob plaws hauv lub nkoj.
4. Rau kev tuav dej hiav txwv, Monel 400 phaj feem ntau tau teev tseg rau cov twj tso kua mis thiab lub valve tseem ceeb. Dab tsi tshwj xeeb cov cuab yeej ua ke ua rau nws zoo dua rau ntau cov hlau tsis muaj steel nyob hauv ib puag ncig no, thiab dab tsi yog nws ib qho tseem ceeb corrosion tsis zoo?
A: Monel 400's superiority nyob rau hauv seawater stems los ntawm nws ua ke ntawm zoo heev corrosion kuj thiab siab zog.
Superior Properties:
Kev Ua Haujlwm Zoo Tshaj Plaws rau Dej Hiav Txwv: Nws tiv taus corrosion thiab, qhov tseem ceeb, kev cuam tshuam thiab cavitation puas zoo dua li cov hlau tsis muaj steel.
High Biofouling Resistance: Cov ntsiab lus tooj liab (~ 31%) muab cov tshuaj toxicity rau cov kab mob hauv hiav txwv, txo cov barnacle thiab mussel txuas.
Kev tiv thaiv rau Chloride Stress Corrosion Cracking (SCC): Nws cov ntsiab lus nickel siab ua rau nws tiv thaiv qhov tsis ua hauj lwm hom rau stainless hlau hauv cov tshuaj chloride sov.
Tseem ceeb Vulnerability:
Thawj qhov tsis zoo ntawm Monel 400 yog nws qhov kev ua haujlwm tsis zoo hauv oxidizing acidic ib puag ncig. Nws yog sai tawm tsam los ntawm:
Nitric Acid
Aerated Hydrochloric thiab sulfuric acids
Cov tshuaj uas muaj ferric (Fe³⁺) los yog cupric (Cu²⁺) ions, uas yog cov muaj zog oxidizers.
Nyob rau hauv cov xwm txheej no, cov zaj duab xis tiv thaiv passive tawg, thiab tus nqi corrosion ua tsis txaus siab. Rau cov kev pabcuam zoo li no, yuav tsum muaj cov hlau zoo dua li Hastelloy C-276 lossis Titanium.
5. Ib tus neeg tsim qauv muaj kev xaiv ntawm Incoloy 800 thiab Inconel 600 phaj rau lub tshav kub exchanger tubing ntawv. Lub plhaub sab yuav pom chav, thiab lub raj sab yuav nqa cov tshuaj chloride - cov kua dej nplua nuj. Dab tsi yog qhov laj thawj tseem ceeb rau kev xaiv Inconel 600 rau cov khoom no?
Qhov laj thawj tseem ceeb yog Inconel 600's kev tiv thaiv rau Chloride Stress Corrosion Cracking (Cl-SCC) los ntawm lub raj - sab dej, ua ke nrog nws lub zog txaus thiab ruaj khov ntawm chav dej.
Lub Cl-SCC Kev Nyuaj Siab: Cov ntawv raj yog ib qho tseem ceeb, tuab tuab tho rau ntau pua lub raj. Kev ua tsis tiav ntawm no yuav muaj kev puas tsuaj loj. Cov tshuaj chloride- cov kua dej nplua nuj nyob rau sab raj tuaj yeem mloog zoo rau hauv cov kab nrib pleb thiab, thaum kub, tsim kom muaj ib puag ncig zoo rau Cl-SCC hauv cov ntaub ntawv raug.
Incoloy 800: Txawm hais tias nws muaj kev tiv thaiv corrosion zoo, nws cov ntsiab lus nickel qis (~ 32%) piv rau Inconel 600 (~ 72%) ua rau nws muaj kev cuam tshuam rau Cl-SCC nyob rau hauv cov xwm txheej hnyav, muaj zog, tshwj xeeb tshaj yog nyob rau hauv lub xeev kev ntxhov siab (kev ntxhov siab los ntawm kev ua haujlwm thiab dov hauv cov raj).
Inconel 600: Nrog nws cov ntsiab lus nickel siab heev, nws muaj kev tiv thaiv zoo rau Cl-SCC. Qhov no muab qhov loj dua thiab txhim khu kev qha kev nyab xeeb rau kev ncaj ncees ntawm tag nrho cov khoom siv hluav taws xob.
Thaum Incoloy 800 yog ib qho khoom siv zoo heev, rau qhov tseem ceeb, tsis yog - cov khoom hloov pauv tau zoo li cov ntawv raj uas raug cov tshuaj chlorides, qhov tseeb Cl-SCC tsis kam ntawm Inconel 600 ua rau nws muaj kev saib xyuas ntau dua thiab kev xaiv zoo los txo qhov kev pheej hmoo ua tsis tiav.
