1: Dab tsi yog qhov sib txawv ntawm Hastelloy C-276 thiab Hastelloy C-22, thiab qhov sib txawv no cuam tshuam li cas rau lawv cov kev ua tau zoo hauv kev siv cov kav dej?
Hastelloy C-276 thiab C-22 yog ob qho tib si npib tsib xee-chromium-molybdenum alloys los ntawm Haynes International tsev neeg, muaj npe nrov rau lawv qhov tshwj xeeb corrosion kuj. Lawv qhov sib txawv tseem ceeb yog nyob rau hauv lawv cov muaj pes tsawg leeg, uas dictates lawv lub hnab ntawv ua haujlwm.
Hastelloy C-276 (UNS N10276) muaj kwv yees li 57% Ni, 16% Cr, 16% Mo, 4% W, thiab ib qho me me, tswj cov hlau. Nws lub ntsiab lus txhais yog nws cov pa roj carbon tsawg heev thiab silicon cov ntsiab lus, txo qhov tsim ntawm grain ciam precipitates thaum vuam. Qhov no ua rau nws zoo heev li -welded corrosion kuj tsis muaj kev kho cua sov tom qab vuam.
Hastelloy C-22 (UNS N06022) muaj qhov sib npaug ntawm li 56% Ni, 22% Cr, 13% Mo, thiab 3% W. Cov ntsiab lus chromium siab dua muab kev tiv thaiv zoo tshaj rau oxidizing corrosive media, xws li cov uas muaj chlorates, ferric ions, lossis hypochlorite. Qhov me ntsis qis molybdenum yog them los ntawm kev nce chromium thiab tungsten, muab tag nrho pitting zoo heev thiab crevice corrosion kuj.
Kev cuam tshuam rau Piping Performance:
Rau cov kav dej, qhov no txhais tau tias:
C-276 Cov kav dej feem ntau yog thawj qhov kev xaiv rau kev tuav cov cheeb tsam loj heev (piv txwv li, kub hydrochloric thiab sulfuric acids) thiab qhov twg cov kav dej yuav tsum tau siv dav, complex fabrication thiab vuam ntawm - qhov chaw, raws li nws khaws cov corrosion kuj nyob rau hauv lub vuam kub-tsim cheeb tsam.
C-22 Cov kav dej ua tau zoo nyob rau hauv ib puag ncig uas muaj cov kua qaub sib xyaw lossis oxidizing tej yam kev mob, muaj nyob rau hauv flue gas desulfurization (FGD) systems, bleach nroj tsuag, thiab pov tseg incineration. Lawv tshwj xeeb tshaj yog tiv taus pitting thiab kev ntxhov siab corrosion tawg hauv cov tshuaj chloride-cov kabmob. Thaum tseem muaj qhov zoo weldability, nws qhov kev ua kom zoo muaj pes tsawg leeg ua rau nws sib cav ntau yam "sib npaug" alloy rau ntau yam kev siv tshuaj lom neeg kev lag luam (CPI).
2: Hauv cov kev lag luam tshwj xeeb thiab cov ntawv thov twg yog Hastelloy C-276 thiab C-22 cov kav dej suav tias yog qhov tseem ceeb, thiab vim li cas?
Cov alloys no tau teev tseg tias qhov tsis ua haujlwm ntawm cov kav dej yuav ua rau muaj kev nyab xeeb loj, ib puag ncig, lossis kev ua haujlwm poob qis. Lawv cov ntawv thov tseem ceeb suav nrog:
Kev Lag Luam Kev Lag Luam Tshuaj (CPI): Rau reactor pub kab, effluent kab, thiab tshav kub exchanger tubing tuav aggressive intermediates, halogenated hydrocarbons, acetic acid, thiab catalyst kwj. Lawv tiv thaiv ob qho tib si cov txheej txheem kua thiab tsis sib haum xeeb.
Pollution Control & Flue Gas Desulfurization (FGD): C-22, tshwj xeeb, yog tus qauv kub rau ducting, dampers, thiab tshuaj tsuag cov kav dej ntub dej. Nws tiv taus cov corrosive condensates uas muaj chlorides, fluorides, thiab sulfuric / sulfurous acids ntawm qhov kub thiab pH sib txawv.
Pharmaceutical & Fine Chemical: Rau siab - purity txheej txheem piping (feem ntau electropolished) qhov khoom purity yog qhov tseem ceeb, thiab cov khoom siv corrosion tsis tuaj yeem zam. Lawv tsis kam mus rau qhov dav dav ntawm cov kua qaub thiab chlorides yog qhov tseem ceeb.
Khib nyiab Incineration & Wastewater Treatment: Cov kav dej tuav cov dej kub, cov dej khib nyiab, cov khib nyiab chlorinated, thiab cov txheej txheem oxidative thermal kho cov txheej txheem cia siab rau cov hlau no los tswj cov kub kub thiab cov tshuaj lom neeg.
Marine & Offshore: Rau ib puag ncig saline heev, tshwj xeeb tshaj yog nyob rau hauv cov txheej txheem ntawm kev txhaj tshuaj hauv dej hiav txwv, cov kav dej sab saum toj hauv cov kev pabcuam hauv ntug dej hiav txwv, thiab cov khoom cuam tshuam rau marine atmospheric corrosion.
Nuclear Fuel Reprocessing: C-276 yog keeb kwm siv rau cov kav dej thiab cov cuab yeej siv cov tshuaj hydrochloric acid thiab chlorine-muaj cov xov xwm hauv cov nroj tsuag reprocessing.
3: Dab tsi yog qhov tseem ceeb fabrication thiab vuam kev txiav txim siab thaum txhim kho Hastelloy alloy piping system?
A3: Fabrication ntawm cov siab -kev ua tau zoo alloys yuav tsum tau nruj cov txheej txheem los khaws lawv corrosion kuj.
Kev Tiv Thaiv Kev Tiv Thaiv Kab Mob: Cov cuab yeej tshwj xeeb, cov hlau tsis xeb hlau txhuam, thiab cov chaw ua haujlwm huv yog yuav tsum tau tiv thaiv cov hlau tsis huv (los ntawm cov cuab yeej carbon steel) los yog hla - sib kis nrog lwm cov hlau (xws li tooj liab lossis txhuas), uas tuaj yeem tsim cov galvanic hlwb thiab txo cov corrosion kuj.
Ua haujlwm txias & kho cua sov: Cov hlau no ua haujlwm- tawv sai. Cov yeeb nkab dabtsi yog khoov thiab sib sau yuav tsum muaj lub zog ntau dua thiab yuav tsum muaj qhov nruab nrab annealing. Txawm li cas los xij, annealing yuav tsum tau ua nyob rau hauv kev tswj xyuas (ceev quenching los ntawm qhov kub siab) kom tsis txhob nag lossis daus ntawm cov teeb meem intermetallic theem.
Vuam - Kev Ua Haujlwm Tseem Ceeb: Gas Tungsten Arc Vuam (GTAW/TIG) yog thawj txoj hauv kev.
Filler Hlau: Yuav tsum sib phim lossis tshaj qhov alloy qhov corrosion kuj. ERNiCrMo-4 rau C-276 thiab ERNiCrMo-10 rau C-22 yog tus qauv. Rau C-22, ERNiCrMo-14 (rau C-2000) yog qee zaum siv rau kev txhim kho cov khoom.
Thaum tshav kub kub input: yuav tsum tau tswj thiab khaws cia kom tsawg li tsawg tau. Kev siv hluav taws xob siab lossis cua txias qeeb tuaj yeem ua rau microsegregation ntawm molybdenum thiab tungsten, thiab muaj peev xwm ua rau muaj kev kub ntxhov hauv cov vuam thiab cua sov- thaj chaw cuam tshuam (HAZ), tsim cov cheeb tsam hauv cheeb tsam uas muaj kev cuam tshuam rau kev tawm tsam.
Interpass Temperature: nruj me ntsis tswj qis dua 125℃(250℃F) kom tsis txhob muaj cua sov ntau dhau.
Back Purging: Qhov tseem ceeb rau cov hauv paus hla. Kev siv cov roj inert argon rov qab yog tsis yog -kev sib tham los tiv thaiv oxidation thiab "qab zib" (tsim cov ntxeem tau, oxidized hlaws) nyob rau sab hauv ntawm cov yeeb nkab weld, uas yuav yog qhov chaw pib corrosion loj heev.
Tshaj tawm -Kev Kho Hniav Kub Kub (PWHT): Feem ntau tsis tas yuav tsum tau lossis pom zoo rau cov qib no, vim nws tuaj yeem txhawb nqa nag lossis daus. Cov alloys yog tsim los rau kev pabcuam raws li -welded condition.
4: Yuav ua li cas lub zos corrosion kuj, tshwj xeeb tshaj yog tiv thaiv pitting thiab crevice corrosion, ntawm no alloys pom zoo rau lawv siv tshaj tus qauv stainless hlau hauv piping?
Standard stainless hlau (xws li, 316L) cia siab rau ib tug nyias, passive chromium oxide txheej rau kev tiv thaiv. Nyob rau hauv ib puag ncig uas muaj chlorides, tshwj xeeb tshaj yog nyob rau ntawm qhov kub siab, zaj duab xis no tuaj yeem tawg hauv zos, ua rau muaj kev puas tsuaj rau pitting lossis crevice corrosion.
Hastelloy C-276 thiab C-22 tawm tsam qhov no los ntawm kev sib koom ua ke, ntau lub ntsiab lus:
Nickel (Ni): Lub hauv paus matrix muab kev ruaj ntseg ntawm cov hlau tsis muaj zog thiab tiv thaiv chloride stress corrosion cracking (SCC), ib hom tsis ua hauj lwm rau austenitic stainless hlau.
Chromium (Cr): Tsim cov yeeb yaj kiab thawj zaug (Cr₂O₃). Qhov siab dua Cr hauv C-22 (22% vs . 16% hauv C-276) ua rau muaj kev tiv thaiv zoo rauoxidizingcov xwm txheej uas tuaj yeem rhuav tshem zaj duab xis no.
Molybdenum (Mo): Lub ntsiab tseem ceeb rau kev tawm tsamtxotej yam kev mob thiab chloride-induced localized attack. Mo enriches nyob rau hauv cov zaj duab xis passive thiab blocks active dissolution chaw. Nws ua rau qhov tseem ceeb ntawm qhov kub thiab txias (CPT) thiab Critical Crevice Temperature (CCT). Ob leeg muaj cov ntsiab lus Mo siab heev (13-16%), ua rau lawv tiv taus pitting txawm nyob rau hauv kub, concentrated chloride brines.
Tungsten (W): Ua haujlwm sib koom ua ke nrog molybdenum txhawm rau txhim kho kev tiv thaiv hauv zos corrosion hauv acidic chloride media.
Rau cov yeeb nkab, uas muaj qhov sib txawv ntawm cov flanges, hauv qab gaskets, thiab ntawm cov welding rov qab rings, thiab uas tej zaum yuav muaj qhov kub thiab txias gradients thiab deposits, qhov no superior tiv thaiv rau localized nres yog ib qho tseem ceeb rau cov khoom siv ntau dua. Nws ua kom ntev - lub sij hawm, txhim khu kev qha kev pab cuam qhov twg stainless hlau kav yuav ua tsis tau ntxov ntxov.
5: Dab tsi yog qhov tseem ceeb ntawm ASTM / ASME cov qauv tswj hwm qhov tshwj xeeb thiab kev sim ntawm Hastelloy C-276 thiab C-22 yeeb nkab rau kev lag luam?
Cov ntaub ntawv pov thawj kom raug thiab ua raws li cov qauv yog qhov tseem ceeb rau kev lees paub zoo.
Khoom Specifications:
Seamless & Welded Yeeb Nkab: ASTM B622 / ASME SB622 npogseamlessyeeb nkab thiab raj ntawm nickel{0}} alloy (xws li C-276 thiab C-22). ASTM B619 / ASME SB619 npogweldedcev. Cov qauv no qhia txog cov tshuaj muaj pes tsawg leeg, cov khoom siv kho tshuab (lub zog tensile, lub zog tawm los), kev kho cua sov, thiab cov kev ntsuas uas tsis muaj kev puas tsuaj.
Fittings: ASTM B366 / ASME SB366 npog Hoobkas - ua npib tsib xee- alloy fittings (lub luj tshib, tees, kaus mom).
Kev xeem thiab ntawv pov thawj:
Kev Tshuaj Ntsuam Xyuas Tshuaj: Yuav tsum ua raws li cov kev txwv hauv cov qauv xws li ASTM B574 (rau bar) lossis cov khoom sib xyaw uas tau teev tseg hauv B622. Mill test reports (MTRs) yog qhov yuav tsum tau ua.
Kev kuaj Corrosion: Txawm hais tias tsis yog ib qho kev xeem xa khoom niaj hnub, ASTM cov qauv zoo li G28 Txoj Kev A (rau kev kuaj xyuas qhov cuam tshuam rau kev sib tsoo) thiab G48 Txoj Kev A & C (rau pitting thiab crevice corrosion testing hauv ferric chloride) feem ntau yog siv rau kev tsim nyog lossis hauv - pov thawj hauv tsev.
Nondestructive Examination (NDE): ASTM B622 mandates hydrostatic or pneumatic testing of each pipe. Eddy kev kuaj tam sim no muaj rau cov raj. Rau cov kev pabcuam tseem ceeb, NDE ntxiv xws li dye penetrant testing (PT) ntawm welds lossis puv -lub cev ultrasonic kuaj (UT) yuav raug teev.
Dimensional Standards: Cov yeeb nkab qhov ntev feem ntau ua raws li ASME B36.19M (rau stainless thiab npib tsib xee-alloy yeeb nkab).
Kev qhia qhov tseeb ASTM / ASME tus qauv ntawm cov ntaub ntawv yuav khoom ua kom cov yeeb nkab xa khoom ua tau raws li qhov tsawg kawg nkaus uas yuav tsum tau muaj tshuaj lom neeg, tshuab, thiab cov qauv zoo rau kev nyab xeeb thiab txhim khu kev qha hauv kev pabcuam nruj.
