1. Cov tshuaj tseem ceeb ntawm Hastelloy G30 yog dab tsi, thiab nws lub hom phiaj tshwj xeeb ua rau cov phosphoric acid thiab complex mixed acids li cas?
Hastelloy G30 (UNS N06030) yog npib tsib xee -chromium- hlau alloy nrog qhov tseem ceeb ntxiv ntawm molybdenum, tooj liab, thiab tungsten, tshwj xeeb yog tsim los rau kev sib ntaus sib tua cov kua qaub ib puag ncig. Nws cov nominal muaj pes tsawg leeg yog kwv yees li 43% Ni, 30% Cr, 15% Fe, 5.5% Mo, 2.5% W, thiab 1.8% Cu, nrog cov ntsiab lus carbon tsawg heev. Cov txheej txheem no tsim kom muaj kev sib npaug: cov ntsiab lus chromium siab (30%) muab kev tiv thaiv zoo rau oxidizing media xws li nitric acid (HNO₃) thiab oxidizing ntsev (xws li Fe³⁺, Cu²⁺). Lub caij no, cov khoom sib xyaw molybdenum thiab tungsten cov ntsiab lus (tag nrho ~ 8%) imparts robust tsis kam mus rau txo acids xws li hydrochloric (HCl) thiab sulfuric (H₂SO₄) nyob rau hauv uas tsis yog - oxidizing tej yam kev mob. Qhov tseem ceeb ntxiv ntawm tooj liab (~ 1.8%) yog dab tsi pab Hastelloy G30 nws qhov kev ua tau zoo tshwj xeeb hauv cov ntub dej - txheej txheem phosphoric acid, uas yog qhov tsis zoo vim muaj cov kab mob xws li fluoride thiab chloride ions, nrog rau sulfuric acid thiab silicates. Cov tooj liab txhim khu kev tiv thaiv rau ob qho tib si sulfuric thiab phosphoric acids thoob plaws qhov dav dav thiab qhov kub thiab txias. Qhov no ua rau G30 yeeb nkab yog cov khoom siv tseem ceeb tshaj plaws rau cov kav dej, cov khoom siv hluav taws xob, thiab cov khoom siv hluav taws xob hauv kev tsim cov chiv, kev ua phosphate, thiab cov nroj tsuag tshuaj siv tshuaj, feem ntau cov kab mob sib kis, sib xyaw cov kua qaub uas lwm cov qib siab -kev ua tau zoo alloys yuav ua tsis tiav.
2. Hauv cov ntawv thov kev lag luam tshwj xeeb twg yog Hastelloy G30 yeeb nkab suav tias yog cov khoom siv tseem ceeb lossis nyiam ntawm kev tsim kho?
Hastelloy G30 yeeb nkab yog feem ntau teev nyob rau hauv kev lag luam uas cov txheej txheem kwj muaj kev nruj heev, sib tov, thiab feem ntau impure acids. Nws daim ntawv thov yog tsav los ntawm nws lub peev xwm los lis "qhuav" los yog cov kab mob acidic ib puag ncig uas oxidizing thiab txo cov xwm txheej tuaj yeem ua ke.
Phosphoric Acid Production & Fertilizer Industry: Qhov no yog daim ntawv thov tseem ceeb. G30 yog siv dav rau kev tuav ntub dej - txheej txheem phosphoric acid (WPA) ntawm ntau qhov ntau thiab qhov kub thiab txias. Nws tiv thaiv kev tawm tsam los ntawm cov kua qaub nws tus kheej, nrog rau los ntawm corrosive impurities xws li fluoride, chloride, thiab sulfate ions tam sim no hauv pob zeb phosphate. Cov ntawv thov muaj xws li cov hlab ntsha reactor, lub tso tsheb hlau luam hauv plab, cov tshuab lim dej, cov kav dej evaporator, thiab cov kab concentrates.
Kev Pabcuam Sulfuric Acid: Nws qhia tau zoo heev tiv thaiv sulfuric acid nyob rau hauv ib tug dav concentration spectrum, tshwj xeeb tshaj yog nyob rau hauv nruab nrab concentrations thiab siab kub, outperforming ntau stainless steels thiab ib co nickel alloys. Qhov no ua rau nws tsim nyog rau cov nroj tsuag cov kua qaub, cov kab pickling, thiab tshuaj synthesis uas muaj H₂SO₄.
Mixed Acid & Chemical Processing: Cov nroj tsuag tsim los yog siv cov khoom sib xyaw ntawm nitric / hydrofluoric (pickling acids), nitric / sulfuric (nitrating acids), los yog lwm yam nyuaj halogen-muaj cov kua qaub qhia G30 piping rau nws qhov sib npaug ntawm qhov profile. Nws kuj tseem siv tau rau hauv flue gas desulfurization (FGD) systems tuav nruj scrubbing slurries.
Nuclear Roj Reprocessing: Hauv qee theem ntawm kev rov ua dua uas muaj nitric acid nrog fission cov khoom paug, G30 qhov kev tiv thaiv rau oxidizing tej yam kev mob thiab tshwj xeeb ions yog qhov tseem ceeb.
3. Dab tsi yog qhov tseem ceeb ntawm kev tsim thiab vuam cov txheej txheem rau Hastelloy G30 yeeb nkab los tiv thaiv rhiab heev thiab tswj kev ua haujlwm corrosion?
Kev tsim kom zoo yog qhov tseem ceeb los khaws cov kev tiv thaiv corrosion ntawm Hastelloy G30, tshwj xeeb yog kom tsis txhob muaj teeb meem cuam tshuam nrog nws cov ntsiab lus chromium siab.
Thermal Sensitivity thiab "Weld Decay": Zoo ib yam li austenitic stainless hlau, G30 tuaj yeem ua "sensitized" yog tias cua sov hauv qhov kub ntawm kwv yees li 550℃txog 950℃(1020℃F txog 1740℃F). Thaum lub caij txias qeeb lossis isothermal tuav hauv qhov no, chromium-nplua nuj carbides (feem ntau M₂₃C₆) tuaj yeem nag lossis daus ntawm cov ciam teb. Qhov no depletes cov matrix uas nyob ib sab ntawm chromium, tsim ib qho chaw nqaim uas muaj kev cuam tshuam rau intergranular corrosion, tshwj xeeb tshaj yog nyob rau hauv oxidizing acids xws li nitric acid.
Vuam txoj kev zoo tshaj plaws:
Cov txheej txheem: Siv cov txheej txheem hluav taws xob qis xws li Gas Tungsten Arc Vuam (GTAW / TIG) rau cov hauv paus thiab kub dhau, ua raws li Shielded Hlau Arc Vuam (SMAW) lossis GTAW rau sau.
Filler Hlau: Siv cov khoom sib xyaw ua ke - cov hlau muab tub lim (piv txwv li, ERNiCrMo-11 lossis sib npaug sib npaug electrodes) kom muaj tshuaj lom neeg sib luag.
Thaum tshav kub kub Input & Interpass Temperature: Txo cov cua kub tawm thiab tswj kev tswj qhov kub thiab txias, feem ntau qis dua 100℃(212℃F), txwv lub sij hawm nyob rau hauv ntau yam rhiab heev.
Rov qab Purging: Ib txwm siv cov roj inert (argon) rov qab rau sab hauv ntawm cov yeeb nkab kom tiv thaiv oxidation ("qab zib") ntawm cov hauv paus hniav, uas yuav cuam tshuam kev tiv thaiv corrosion.
Tom qab- Weld Heat Treatment (PWHT): Rau qhov siab tshaj plaws tiv thaiv corrosive nres nyob rau hauv vuam cua sov- cuam tshuam cheeb tsam (HAZ), kev kho annealing yog pom zoo. Qhov no suav nrog cua sov tag nrho cov vuam mus rau 1120-1175℃(2050-2150℃F) tom qab quenching sai (dej tsuag los yog immersion). Qhov no dissolves tej precipitated carbides thiab restores ib homogeneous, corrosion-resistant microstructure.
4. Hastelloy G30 sib piv li cas hauv kev ua tau zoo thiab tus nqi rau lwm yam siab -kev ua tau zoo nickel alloys xws li C276 (N10276) thiab 625 (N06625) rau cov ntawv thov yeeb nkab?
Qhov kev xaiv ntawm G30, C276, thiab 625 nyob ntawm qhov tshwj xeeb corrosive ib puag ncig.
Hastelloy C276 (N10276):
Oxidizing Media: Hastelloy G30 zoo dua. Nws cov ntsiab lus 30% Cr muab nws zoo dua rau nitric acid, ferric chloride, thiab lwm yam kev daws teeb meem oxidizing. C276, tsuas yog ~ 16% Cr, tuaj yeem raug mob hnyav.
Txo Media: Hastelloy C276 zoo dua. Nws cov molybdenum siab (~ 16%) cov ntsiab lus ua rau nws nyob deb dua rau cov kub hydrochloric acid thiab txo cov sulfuric acid heev.
Mixed Acids (Phosphoric): G30 tshwj xeeb tshaj yog zoo dua rau cov kab mob ntub dej - txheej txheem phosphoric acid vim nws cov ntsiab lus tooj liab thiab sib npaug chemistry.
Tus nqi: G30 feem ntau tsis tshua kim dua C276 vim qis qis ntawm molybdenum thiab npib tsib xee kim.
vs Alloy 625 (N06625):
Kev sib piv dav dav: Ob leeg muaj cov ntsiab lus siab chromium (~ 21% rau 625) rau oxidation tsis kam . 625 muab lub zog tseem ceeb los ntawm niobium hardening tab sis muaj tsawg molybdenum (~ 9%) thiab tsis muaj tooj liab.
Phosphoric/Sulfuric Acids: G30 feem ntau ua tau zoo tshaj 625 nyob rau hauv kub, concentrated sulfuric thiab phosphoric acid cov kev pab cuam vim nws Cu thiab siab dua Mo + W cov ntsiab lus.
Chloride Pitting / Crevice: 625 muaj Pitting Resistance Equivalent Number (PREN) siab heev thiab feem ntau qhia tau zoo dua rau pitting thiab crevice corrosion hauv chloride brines.
High -Temperature Strength: 625 khaws cov khoom siv zoo tshaj plaws ntawm qhov kub siab.
Kev xaiv Summary: Xaiv G30 rau oxidizing/sib tov acid cov kev pab cuam, tshwj xeeb tshaj yog phosphoric thiab sulfuric. Xaiv C276 kom txo qis acids (HCl) thiab complex chlorides. Xaiv 625 rau siab chloride pitting tsis kam, siab - qhov kub thiab txias, los yog kev pab cuam nitric acid qhov twg G30 dhau - qhia.
5. Dab tsi yog hom kev xeb tsis ua haujlwm rau Hastelloy G30 yeeb nkab, thiab cov kev ua haujlwm zoo li cas pab txo cov kev pheej hmoo no?
Thaum muaj kev tiv thaiv zoo heev, Hastelloy G30 tuaj yeem ua tsis tau raws li qhov tshwj xeeb tawm - qauv tsim.
Intergranular Attack nyob rau hauv Weld HAZ: Raws li tau piav qhia, qhov no yog kev tsim ntau tshaj plaws - cuam tshuam tsis ua haujlwm. Kev tawm tsam tshwm sim nyob rau hauv cov cheeb tsam rhiab heev uas nyob ib sab rau welds thaum raug oxidizing acids. Kev txo qis: Siv cov txheej txheem vuam kom raug thiab siv tom qab-weld solution annealing rau kev pabcuam tseem ceeb.
Pitting thiab Crevice Corrosion nyob rau hauv Stagnant Chlorides: Txawm hais tias resistant rau kev xeb, nyob rau hauv stagnant, aerated, kub chloride daws (xws li, dej txias nrog deposits), G30 tuaj yeem ua rau muaj kev tawm tsam hauv zos. Nws PREN (~50) yog qhov zoo tab sis qis dua super-austenitics lossis C276. Mitigation: Khaws cov dej ntws los tiv thaiv stagnation, xyuas kom zoo piping tsim kom tsis txhob muaj crevices, thiab tswj cov tshuaj chloride thiab kub.
Rapid General Corrosion in Strong Reducing Acids: G30 tsis yog tsim los rau kev pab cuam hauv kub, concentrated hydrochloric acid lossis hnyav txo sulfuric acid (<10% concentration, hot). Exposure will cause high uniform corrosion rates. Mitigation: Strictly adhere to the alloy's corrosion data isocorrosion diagrams. For such services, select a higher-molybdenum alloy like C276 or B-2/B-3.
Galvanic Corrosion: Yog tias txuas nrog cov hlau tsis tshua muaj zog (xws li carbon steel) hauv cov electrolyte conductive, G30 yuav ua raws li cathode thiab ua kom corrosion ntawm lwm cov hlau. Kev txo qis: Siv cov koom haum dielectric insulating los yog xyuas kom cov khoom tsis tshua muaj txiaj ntsig muaj qhov txaus corrosion txaus thiab raug tshuaj xyuas / hloov tsis tu ncua.
Kev yaig-Corrosion: Siab-ceev, abrasive slurries (xws li phosphoric acid nrog cov khib nyiab) tuaj yeem ua rau cov oxide zaj duab xis puas thiab ua rau cov hlau ua kom nrawm dua. Kev txo qis: Tsim kom qis qis hauv cov kab slurry, siv cov kav dej loj dua, thiab xav txog cov phab ntsa tuab ntxiv (qhov nyiaj yaig).
