1. Hastelloy G-30 muaj npe nrov rau nws cov kev ua lag luam phosphoric acid thiab complex mixed acids. Lub tswv yim tshwj xeeb alloying yog dab tsi-tshwj xeeb yog lub luag haujlwm ntawm Chromium thiab tooj liab-uas muab nws qhov kev ua haujlwm tshwj xeeb, thiab qhov no txawv li cas ntawm C-276 lub tswv yim?
G-30's alloying lub tswv yim yog txhob txwm tawm mus los ntawm "broad-spectrum" mus kom ze ntawm C-276, tsom mus rau qhov ua kom muaj zog tiv thaiv oxidizing acids thiab cov kab mob tshwj xeeb.
Chromium Cov ntsiab lus (~ 29-31%): Qhov no yog qhov siab dua C-276 (~ 15%). Chromium yog lub hauv paus tseem ceeb rau kev tiv thaiv oxidizing media. Nws tsim ib qho ruaj khov, tiv thaiv Cr₂O₃ zaj duab xis passive. Cov ntsiab lus chromium siab no ua rau G-30 tshwj xeeb rau:
Kev lag luam Phosphoric Acid, uas feem ntau kis nrog oxidizing impurities xws li fluorides thiab sulfates.
Nitric Acid (HNO₃), Sulfuric Acid (H₂SO₄) nrog oxidizers (piv txwv li, ferric / cupric ions), thiab lwm yam oxidizing tshuaj kwj.
Cov ntsiab lus tooj liab (~ 1.0-2.4%): Qhov no yog qhov tseem ceeb sib txawv ntawm qhov tsis muaj nyob hauv C-276. Copper ua rau muaj kev tiv thaiv zoo rau cov tsis-oxidizing (txo) sulfuric thiab phosphoric acids. Nws txo qis tus nqi corrosion hauv cov cheeb tsam no, muab qhov sib npaug uas cov ntshiab chromium-molybdenum alloys tsis muaj.
Kev sib piv nrog C-276: C-276 (~ 16% Mo, ~ 4% W) yog ua kom zoo rau kev txo cov kua qaub (xws li HCl) thiab tsis kam mus rau hauv zos chloride nres (pitting / crevice). Nws muaj qis Cr, yog li nws cov kev ua tau zoo hauv oxidizing acids yog qis dua G-30.
Hauv cov ntsiab lus: G-30 siv siab Cr + Cu los ua tswv complex, feem ntau oxidizing, sib xyaw acids. C-276 siv siab Mo + W los ua kom txo qis acids thiab chlorides. G-30 yog tus kws tshaj lij "phosphoric acid thiab oxidizing contaminant".
2. Nyob rau hauv ib tsob nroj phosphoric acid ntau lawm, "cov txheej txheem ntub dej" acid yog hnyav heev nrog cov tshuaj fluorides thiab chlorides. Vim li cas G-30 yeeb nkab yuav raug teev dhau tus qauv 316L stainless hlau lossis txawm tias ib qho super duplex stainless hlau rau qhov kev pabcuam no?
Qhov tshwj xeeb ntawm G-30 yog cov lus teb ncaj qha rau kev sib koom ua ke, muaj kev txhoj puab heev ntawm "cov txheej txheem ntub dej" phosphoric acid ib puag ncig, uas sib txuas ntau yam kev tawm tsam.
316L Stainless Hlau: Yuav ua tsis tau zoo vim:
General Corrosion: Cov pH qis thiab fluorides sai sai ua rau cov zaj duab xis passive.
Pitting/Crevice Corrosion: Cov tshuaj chloride thiab fluoride ntau ntau ua rau muaj kev tawm tsam loj heev.
Stress Corrosion Cracking (SCC): Kev sib xyaw ua ke ntawm chlorides, fluorides, thiab kev ntxhov siab yog ib daim ntawv qhia zoo meej rau SCC.
Super Duplex Stainless Steel (piv txwv li, 2507): Txawm hais tias nyob deb dua 316L, nws tseem muaj qhov tsis zoo:
Fluoride Attack: Cov tshuaj fluoride ions tshwj xeeb yog nruj heev thiab tuaj yeem tawm tsam cov yeeb yaj kiab tsis zoo ntawm cov qib siab - qib stainless hlau, tshwj xeeb tshaj yog nyob rau qhov kub siab thiab qis pH.
Oxidizing Contaminants: Cov kua qaub feem ntau muaj oxidizing hlau ions uas tuaj yeem tsav lub peev xwm corrosion mus rau hauv ib cheeb tsam uas duplex steels yuav raug.
Hastelloy G-30's Superiority: Nws chemistry ncaj qha tawm tsam cov kev hem thawj no:
High Nickel (~ 43%): Muab cov tshuaj tiv thaiv rau chloride SCC.
High Chromium (~ 30%): Khaws ib zaj duab xis uas tsis muaj zog thaum muaj cov fluorides thiab oxidizing cov kab mob.
Molybdenum (~ 5.5%): Muab cov khoom tiv thaiv pitting / crevice corrosion los ntawm chlorides.
Copper (~ 2%): Txhim khu kev tiv thaiv rau sulfuric thiab phosphoric acid matrix nws tus kheej.
G-30 muab kev tiv thaiv dav dav, ntau yam kev tiv thaiv uas cov hlau tsis sib xws tsis tuaj yeem ua tau, ua rau nws txoj kev xaiv txhim khu kev qha rau kev tuav cov txheej txheem ntub dej ntub dej, yog li zam kom tsis txhob raug kaw thiab hloov cov nqi.
3. Vuam G-30 yeeb nkab yuav tsum tau ceev faj muab cov hlau xaiv. Vim li cas kev siv cov khoom sib xyaw ua ke hlau (ERNiCrMo-11) feem ntau poob siab rau cov kev pabcuam tseem ceeb, thiab dab tsi ntau tshaj qhov sib tw muab tub lim hlau feem ntau tau teev tseg kom ntseeg tau tias cov khoom siv welding tsis kam?
Siv cov khoom sib txuam G-30 muab tub lim hlau (ERNiCrMo-11) poob siab vim muaj kev pheej hmoo ntawm microsegregation thiab nyiam vuam hlau corrosion.
Qhov teeb meem: Thaum lub sij hawm weld solidification, cov ntsiab lus zoo li Molybdenum thiab Chromium tuaj yeem cais mus rau hauv cov tub ntxhais ntawm cov qauv dendritic, tawm hauv cov cheeb tsam interdendritic depleted nyob rau hauv cov tseem ceeb corrosion-cov khoom tiv taus. Nyob rau hauv ib puag ncig acid hnyav, cov Mo / Cr- cov cheeb tsam depleted tuaj yeem corrode nyiam, ua rau muaj kev tawm tsam sai ntawm cov hlaws hlaws nws tus kheej.
Txoj kev daws teeb meem: Tshaj -Matching nrog siab dua-Molybdenum Filler Hlau
Tus qauv zoo tshaj plaws yog siv ERNiCrMo-10 (Alloy 622 muab tub lim hlau).
Cov khoom xyaw: ERNiCrMo-10 muaj ntau dua nominal Molybdenum cov ntsiab lus (~ 13-16% vs. G-30's ~ 5.5%) thiab Tungsten (~ 3-4.5%).
Cov txiaj ntsig: Qhov no "dhau-matching" ua kom ntseeg tau tias txawm tias microsegregation tshwm sim thaum lub sij hawm solidification,qis tshajCov ntsiab lus molybdenum nyob rau hauv cov hlau sib cais yog tseem yuav siab dua li ntawm G-30 puag hlau. Qhov no tau lees tias cov hlau hlau tseem nyob hauv cathodic (ntau dua) rau lub hauv paus hlau, tiv thaiv nws los ntawm kev ua tus anode hauv ob peb galvanic. Ib qho kev tawm tsam me me yuav tshwm sim nyob rau hauv cov khoom siv tau, repassivating puag hlau, tsis nyob rau hauv qhov tseem ceeb weld.
Qhov kev coj ua no yog qhov tseem ceeb rau kev khaws cia qhov kev ntseeg ruaj khov ntawm tag nrho cov welded sib koom ua ke hauv G-30 piping systems, ua rau cov vuam zoo li tiv taus, lossis ntau dua, dua li cov yeeb nkab nws tus kheej.
4. Rau cov roj flue desulfurization (FGD) system absorber ntauwd slurry voj, G-30 yeeb nkab yuav raug txiav txim siab. Dab tsi tshwj xeeb kev sib xyaw ua ke ntawm corrosive agents nyob rau hauv qhov chaw no ua si rau G-30 lub zog, thiab nyob rau hauv dab tsi tshwj xeeb kev khiav hauj lwm tej yam kev mob tej zaum yuav ib tug ntau resistant alloy zoo li C-276 yuav tsum tau?
FGD slurry ib puag ncig yog complex "kua zaub" uas ua kom zoo nrog G-30 lub zog.
Cov neeg ua si ua si rau G-30's Strengths:
Sulfuric & Sulfurous Acids: Thawj corrodents. G-30's siab Ni-Cr-Cu cov ntsiab lus muab kev tiv thaiv zoo heev.
Oxidizing Conditions: Lub xub ntiag ntawm huab cua ntau dhau los yog cov pa oxygen hauv cov pa hluav taws xob tsim cov oxidizing ib puag ncig, qhov twg G-30's siab chromium excels.
Chlorides & Fluorides: Tam sim no ua cov kab mob hauv cov thee. G-30 cov ntsiab lus molybdenum muab kev tiv thaiv zoo rau pitting los ntawm cov halides.
Cov xwm txheej xav tau ntau dua cov hlau nplaum (piv txwv li, C-276):
Kev hloov pauv tshwm sim nyob rau hauv kev txo qis, siab -chloride, qis-pH, feem ntau pom hauv:
"Dead Zones" los yog Cheeb Tsam Tsis Txaus: Qhov twg oxygen depleted, ib puag ncig yuav txo tau.
Localized Scale / Deposit Hauv qab: Crevices nyob rau hauv deposits yuav ua acidic thiab txo vim hydrolysis ntawm ntsev.
High Chloride Concentration (>20,000 ppm): Nyob rau hauv xws li txhoj puab heev txo chloride ib puag ncig, lub zos corrosion kuj (pitting / crevice) dhau los ua qhov txwv.
Thaum G-30 muaj cov ntsiab lus Mo zoo, C-276 qhov siab dua Molybdenum (~16%) thiab Tungsten (~4%) cov ntsiab lus muab nws ntau dua Pitting Resistance Equivalent Number (PREN> 70). Qhov no muab qhov kev nyab xeeb loj dua tiv thaiv kev pib ntawm crevice corrosion nyob rau hauv qhov hnyav tshaj plaws, nyob twj ywm, siab-chloride hnab ris ntawm FGD system. Rau qhov tseem ceeb tshaj plaws los yog muaj teeb meem (xws li, slurry nozzles, agitator zones), C-276 tej zaum yuav raug teev.
5. Thaum ua qhov kev ntsuam xyuas tus nqi lifecycle rau cov nroj tsuag tshuaj tshiab, piv rau G-30 piping system mus rau pheej yig dua FRP (Fiberglass Reinforced Plastic) system rau cov kev pabcuam sib xyaw ua kua qaub, peb lub luag haujlwm tseem ceeb thiab kev nyab xeeb yog dab tsi uas ua pov thawj tus nqi pib dua ntawm cov hlau alloy?
Thaum FRP muaj tus nqi qis dua, G-30 muab cov txiaj ntsig zoo tshaj plaws hauv kev ntseeg tau, kev nyab xeeb, thiab tag nrho cov nqi ntawm cov tswv cuab rau kev xav tau kev pabcuam tshuaj.
Mechanical Integrity thiab Fire Safety:
G-30: Nws yog ib qho ductile, siab -lub zog hlau nrog zoo heev cuam tshuam. Nws tsis yog-combustible thiab yuav tsis ua rau hluav taws. Nyob rau hauv ib tsob ntoo hluav taws, nws tswj kev ruaj ntseg ntev dua li yas.
FRP: tuaj yeem nkig thiab raug rau kev puas tsuaj los ntawm kev cuam tshuam lossis thermal shock. Nws yog combustible thiab tuaj yeem tso cov pa luam yeeb thaum hlawv, tsim kom muaj kev nyab xeeb thib ob. Nws cov yam ntxwv zoo degrade ntawm qhov kub thiab txias.
Permeation thiab khoom Purity:
G-30: yog ib qho khoom, impermeable barrier. Nws tiv thaiv kev permeation ntawm cov txheej txheem kua los yog atmospheric gases, kom ntseeg tau cov khoom purity thiab tiv thaiv ib puag ncig paug los yog poob ntawm cov khoom muaj nqis.
FRP: Nws muaj feem cuam tshuam rau permeation, tshwj xeeb tshaj yog los ntawm cov organic molecules me me thiab qee cov kua qaub. Qhov no tuaj yeem ua rau:
Kev kis kab mob ntawm cov txheej txheem ntws.
Maj mam degradation ntawm laminate los ntawm sab hauv.
Emissions rau ib puag ncig.
Ntev -Lub Sijhawm Kev Ntseeg thiab Kev Kho Tus Nqi:
G-30: Muaj pov thawj, lub neej ua haujlwm ntev kaum xyoo hauv qhov chaw nruj heev. Nws yuav tsum tau soj ntsuam tsawg kawg nkaus thiab tsis raug rau qhov zais degradation hom ntawm composites (xws li, resin tawg, zais laminates).
FRP: Yuav tsum muaj kev soj ntsuam nruj thiab tsis tu ncua (piv txwv li, acoustic emission, txim taws) txhawm rau txheeb xyuas qhov tsis zoo thiab delamination. Nws muaj lub neej ua haujlwm tsis muaj kev cia siab ntau dua thiab muaj qhov ua tsis tau sai yog tias kev puas tsuaj mus tsis pom. Kev tu thiab hloov cov nqi tshaj li ntawm 20-xyoo cog lub neej tuaj yeem yooj yim tshaj qhov pib txuag.
Qhov kev txiav txim siab rau G-30 yog kev nqis peev hauv kev nyab xeeb, kev ntseeg tau ntawm kev ua haujlwm, thiab kev kwv yees, kev tu ncua ntev, uas txo qis kev pheej hmoo ntawm kev puas tsuaj loj, kev tsim khoom poob, thiab ib puag ncig xwm txheej.
