1. Hastelloy B Seamless Pipe yog dab tsi, thiab nws txhais tau li cas rau cov khoom siv tshuaj thiab cov khoom siv kho tshuab?
Hastelloy B yog npib tsib xee-molybdenum alloy, thiab nws cov yeeb nkab seamless yog tsim los ntawm cov txheej txheem xws li extrusion los yog rotary tho los tsim ib lub raj tsis muaj qhov ntev weld seam. Nws tus yam ntxwv txhais yog nws qhov tshwj xeeb tsis kam tiv thaiv tsis yog -oxidizing ib puag ncig, tshwj xeeb yog hydrochloric acid ntawm txhua qhov siab thiab kub, suav nrog qhov kub kub.
Cov tshuaj muaj pes tsawg leeg yog npib tsib xee (kwv yees . 62-72%) thiab molybdenum (26-}30%), nrog me me ntxiv ntawm hlau, chromium, thiab cobalt. Cov ntsiab lus siab molybdenum yog qhov tseem ceeb rau nws cov corrosion kuj hauv kev txo cov xov xwm. Ib qho kev sib txawv tseem ceeb yog nruab nrab ntawm tus thawj Hastelloy B (UNS N10001) thiab kev txhim kho, feem ntau siv ntau hom Hastelloy B-2 (UNS N10665). B-2 tau tsim los daws teeb meem intergranular corrosion nyob rau hauv tshav kub-cuam tshuam cheeb tsam ntawm welds nyob rau hauv B alloy. Nws ua tiav qhov no los ntawm kev txo qis cov pa roj carbon, silicon, thiab cov ntsiab lus hlau, txo qis kev tsim cov theem cuam tshuam intermetallic.
Cov khoom tseem ceeb ntawm chav tsev kub feem ntau suav nrog lub zog tensile ntau dua lossis sib npaug ntawm 110 ksi (758 MPa), yield zog ntawm Ntau dua lossis sib npaug rau 51 ksi (352 MPa), thiab ductility zoo heev. Nws qhov siab - qhov kub thiab txias yog qhov tseem ceeb. Txawm li cas los xij, qhov kev txwv tseem ceeb yog nws qhov tsis zoo rau oxidizing cov neeg ua haujlwm thiab ib puag ncig uas muaj cov oxidizers me me (xws li ferric lossis cupric ntsev, lossis cov pa yaj), qhov twg cov nqi corrosion tuaj yeem ua tsis tau siab.
2. Hauv cov ntawv thov tshwj xeeb twg yog Hastelloy B Seamless Pipe qhov tseem ceeb tshaj plaws, thiab vim li cas?
Hastelloy B-2 cov kav dej seamless yog qhov tseem ceeb hauv qhov chaw ua tshuaj lom neeg hnyav uas cov khoom siv ncaj ncees yog qhov tseem ceeb. Lawv thawj daim ntawv thov yog tuav kub, concentrated hydrochloric acid (HCl). Qhov no ua rau lawv tseem ceeb hauv kev tsim tshuaj, agrochemicals, thiab organic intermediates qhov twg HCl yog ib qho reagent, by-product, lossis catalyst.
Kev siv loj yog nyob rau hauv Acetic Acid ntau lawm, tshwj xeeb tshaj yog nyob rau hauv cov txheej txheem uas muaj carbonylations (xws li cov txheej txheem Monsanto los yog Cativa). Cov tshuaj tiv thaiv ib puag ncig yog txo qis thiab muaj halide catalysts (iodides) nyob rau hauv qhov kub thiab txias. Hastelloy B-2 kav yog siv rau cov kab noj, reactor internals, thiab hloov kab uas tsis kam mus pitting thiab kev nyuaj siab corrosion cracking yog ib qho tseem ceeb heev. Ib yam li ntawd, hauv kev tuav cov sulfuric acid, B-2 cov kav dej tau teev tseg rau qee qhov kev xav tau thiab qhov kub thiab txias thaum tsis muaj cov kab mob oxidizing.
Lwm daim ntawv thov tseem ceeb yog nyob rau hauv alkylation thiab hydrogenation units nyob rau hauv petrochemical refineries, qhov twg nws lis hydrogen halides thiab organic acids. Kev tsim kho seamless ntawm cov kav dej no tshwj xeeb tshaj yog muaj nuj nqis nyob rau hauv siab - cov tshuab siab, vim nws tshem tawm cov vuam seam raws li txoj kab uas tsis muaj zog rau kev pib corrosion lossis kev ua haujlwm tsis zoo, ua kom muaj kev ntseeg siab ntau dua hauv kev thauj cov kua dej txaus ntshai.
3. Dab tsi yog qhov tseem ceeb fabrication thiab vuam kev txiav txim siab rau Hastelloy B-2 Seamless Pipes?
Fabrication ntawm Hastelloy B-2 yuav tsum tau nruj cov txheej txheem los tswj nws cov corrosion kuj thiab txhua yam khoom. Vim nws cov ntsiab lus tsis tshua muaj carbon, nws muaj feem cuam tshuam rau kev sib kis thiab tsim cov theem tsis zoo yog tias tsis raug cua sov.
Kev kho cua sov: Tom qab-fabrication, ib qho kev daws teeb meem kawg annealing kev kho cua sov ntawm ib ncig ntawm 1065℃(1950℃F) ua raws li cov dej nrawm nrawm yog qhov tseem ceeb. Qhov no dissolves tej teeb meem precipitates (xws li npib tsib xee-molybdenum intermetallic) uas yuav tau tsim thaum lub sij hawm kub ua hauj lwm los yog vuam, kho kom zoo corrosion kuj thiab ductility.
Vuam: Vuam yog ib qho tseem ceeb ua haujlwm. Hastelloy B-2 yog tsim los rau weldable yam tsis muaj kev kho cua sov tom qab vuam, muab cov kev coj ua kom raug. Cov txheej txheem tseem ceeb suav nrog:
Siv cov khoom sib txuam hlau (ERNiMo-7) lossis tungsten inert gas (GTAW / TIG) vuam uas tsis muaj qhov muab tub lim.
Tuav qhov ntsuas kub qis heev (feem ntau qis dua 125℃/ 250℃F) txhawm rau tiv thaiv cov qoob loo ntau dhau thiab nag lossis daus.
Ua kom muaj siab -purity inert backing gas (argon) ntawm cov yeeb nkab sab hauv thaum vuam los tiv thaiv oxidation thiab embrittlement ntawm weld cag.
Ua tib zoo ntxuav txhua qhov chaw kom tshem tawm cov roj, roj, thiab lwm yam khoom siv txawv teb chaws uas tuaj yeem qhia cov pa roj carbon lossis sulfur.
Kev ua haujlwm txias (khoov, dov) tuaj yeem ua tau tab sis yuav tsum tau ua haujlwm tom qab los daws kev ntxhov siab thiab kho cov khoom.
4. Hastelloy B-2 Seamless Pipe piv rau lwm cov nickel alloys zoo li Hastelloy C-276 hauv kev xaiv cov khoom siv li cas?
Kev xaiv ntawm Hastelloy B-2 thiab ib qho hlau zoo li C-276 hinges nkaus ntawm oxidizing lossis txo qhov xwm txheej ntawm cov txheej txheem ib puag ncig.
Hastelloy B-2 (Ni-Mo) ua tau zoo nyob rau hauv qhov chaw txo qis. Nws yog superior rau kub concentrated hydrochloric thiab sulfuric acids uas tsis muaj oxidants. Nws kuj tseem tiv taus ntau dua rau kev ntxhov siab corrosion tawg hauv cov xwm txheej no. Txawm li cas los xij, nws ua haujlwm tsis zoo nyob rau hauv muaj cov oxidants xws li FeCl3, CuCl2, chlorine, los yog yaj oxygen.
Hastelloy C-276 (Ni-Cr-Mo) yog ntau yam, oxidization-resistant alloy. Qhov sib ntxiv ntawm chromium (14.5-16.5%) muab nws zoo heev tiv thaiv oxidizing media, chlorine ntub dej, hypochlorite, thiab sib xyaw acids uas muaj oxidizing ntsev. Nws tuav ob qho tib si txo qis thiab nruab nrab oxidizing tej yam kev mob tab sis tej zaum yuav tsis phim B-2 qhov kev ua tau zoo nyob rau hauv qhov hnyav tshaj plaws, kub txo cov kua qaub uas tsis muaj tus nqi tseem ceeb.
Yog li, txoj cai ntawm tus ntiv tes xoo: Rau kev txo qis, tsis yog - ib puag ncig aerated nrog halides, B-2 yog qhov zoo tshaj plaws, tus nqi - kev xaiv zoo. Rau ib puag ncig uas muaj kev sib xyaw lossis oxidizing, lossis qhov chaw uas muaj oxidizers tuaj yeem ua tau, C-276 yog qhov kev nyab xeeb, ntau yam kev xaiv. Daim ntawv seamless yeeb nkab ntawm ob qho tib si alloys yog xaiv rau high-purity los yog high-pressure kev pab cuam.
5. Dab tsi yog cov kev txwv tseem ceeb thiab kev ua tsis tiav uas yuav tsum xav txog thaum qhia txog Hastelloy B Seamless Pipes?
Kev nkag siab txog cov kev txwv ntawm Hastelloy B/B-2 tseem ceeb npaum li kev paub txog nws lub zog.
1. Kev nkag siab zoo rau Oxidizing Agents: Raws li tau hais tseg, qhov no yog thawj qhov kev txwv. Txawm tias ppm qib ntawm oxidizers hauv qhov txo cov kua qaub tuaj yeem ua rau corrosion sai. Kev txheeb xyuas cov txheej txheem tag nrho yog qhov yuav tsum tau ua.
2. Thermal Instability: Yog tias B-2 tuav hauv lossis maj mam txias los ntawm qhov kub ntawm kwv yees li 550℃txog 1050℃(1020℃F txog 1920℃F), nws tuaj yeem ua rau cov theem intermetallic (Ni4Mo, P-theem). Cov precipitates, uas tuaj yeem tsim thaum tsis raug kev kho cua sov lossis vuam, ua rau kom muaj zog thiab corrosion tsis kam, ua rau embrittlement thiab tsis ua haujlwm. Qhov no ua rau kev daws teeb meem tom qab kev sib tsoo tseem ceeb heev.
3. Stress Corrosion Cracking (SCC): Txawm hais tias muaj zog tiv taus chloride-vim SCC piv rau cov hlau tsis muaj steel, B-2 tuaj yeem raug cuam tshuam los ntawm cov xwm txheej tshwj xeeb, tshwj xeeb tshaj yog nyob rau hauv acidic chloride ib puag ncig ntawm qhov kub siab thaum nyob rau hauv siab tensile kev nyuaj siab (tseem tshuav los ntawm vuam los yog siv).
4. Galvanic Corrosion: Ua npib tsib xee-raws li thiab cathodic, yog tias txuas nrog cov hlau tsis zoo (xws li hlau lossis tooj liab alloys) hauv cov electrolyte conductive, nws tuaj yeem ua kom cov hlau ua kom nrawm dua.
5. Tus nqi pib siab: Cov khoom siv raw thiab kev tsim tshwj xeeb (seamless extrusion, kev kho cua sov zoo) ua rau Hastelloy B-2 kav dej muaj peev txheej loj. Yog li, lawv cov lus qhia tshwj xeeb tsuas yog qhov tsis muaj qis dua - cov nqi hlau (xws li cov hlau tsis muaj steel) tuaj yeem muab cov kev pabcuam tsim nyog rau lub neej, ua kom muaj txiaj ntsig zoo ntawm tag nrho lub neej ntawm cov nroj tsuag.
