1. Lub hauv paus metallurgical muaj pes tsawg leeg ntawm Incoloy 825 round bar yog dab tsi, thiab yuav ua li cas txhua lub hauv paus ua rau nws qhov tshwj xeeb corrosion tsis kam profile?
Incoloy 825 (UNS N08825 / W.Nr. 2.4858) yog npib tsib xee- hlau-chromium alloy uas tau tsim tshwj xeeb rau qhov chaw corrosive hnyav. Nws cov nominal muaj pes tsawg leeg yog kwv yees li 42% Ni, 30% Fe, 21.5% Cr, 3% Mo, 2.3% Cu, thiab 0.9% Ti. Txhua lub hauv paus plays lub luag haujlwm tseem ceeb, sib koom ua ke:
Nickel (Ni): Raws li lub hauv paus ntsiab lus, npib tsib xee muab kev tiv thaiv rau cov tshuaj chloride-ion stress-corrosion cracking (SCC) thiab xyuas kom meej ductility thiab toughness. Nws cov ntsiab lus siab stabilizes austenitic matrix.
Chromium (Cr): Imparts tiv thaiv oxidizing ib puag ncig (xws li, nitric acid, oxidizing ntsev) los ntawm kev tsim ib tug tiv thaiv, passive chromium oxide (Cr₂O₃) zaj duab xis rau saum npoo.
Molybdenum (Mo): Qhov no yog lub hauv paus tseem ceeb rau kev tiv thaiv pitting thiab crevice corrosion nyob rau hauv chloride -cov kev daws teeb meem (xws li dej hiav txwv, dej brackish). Nws ntxiv dag zog rau cov yeeb yaj kiab passive hauv kev txo qis.
Copper (Cu): Ntxiv qhov tseem ceeb tiv thaiv kom tsis txhob muaj cov kua qaub, tshwj xeeb tshaj yog sulfuric thiab phosphoric acid. Copper pab tswj kom tsis txhob muaj corrosion tsawg thoob plaws ntau qhov ntau thiab qhov kub thiab txias hauv cov xov xwm no.
Titanium (Ti): Ua raws li lub stabilizer. Nws ua ke nrog cov pa roj carbon monoxide los tsim titanium carbides, tiv thaiv nag lossis daus ntawm chromium carbides ntawm cov ciam teb nplej thaum vuam lossis siab - kub raug. Qhov no tiv thaiv rhiab heev thiab tom qab intergranular corrosion.
Qhov kev sib npaug ntawm chemistry no ua rau Incoloy 825 puag ncig bar ib qho khoom siv "workhorse" ntau yam rau kev tuav txoj haujlwm, ntau -acid, thiab chloride- cov kab mob sib kis uas tus qauv stainless hlau zoo li 316 yuav sai sai.
2. Hauv cov ntawv thov kev lag luam tshwj xeeb dab tsi yog Incoloy 825 puag ncig bar cov khoom nyiam ntawm kev xaiv, thiab dab tsi yog hom kev ua tsis tiav nws tiv thaiv?
Incoloy 825 round bar yog machined rau hauv qhov tseem ceeb rotating thiab nyob twj ywm Cheebtsam nyob rau hauv kev lag luam uas corrosion yog thawj tsim kev sib tw. Nws cov ntawv thov tseem ceeb suav nrog:
Roj & Roj (Downhole & Nto): Valve stems, twj tso kua mis shafts, mandrels, thiab fasteners nyob rau hauv qaub kev pab cuam (H₂S-muaj) qhov dej thiab kav. Nws tiv taus sulfide stress cracking (SSC) thiab chloride -induced stress corrosion cracking.
Chemical & Petrochemical Processing: Agitator shafts, mixer shafts, thermowells, and tie-rods in reactors and vessels handles sulfuric and phosphoric acid, acid chlorides, and complex process streams.
Kev Tiv Thaiv Kev Ua qias tuaj & Scrubbers: Ntxuam shafts, tshuaj tsuag nozzle caj npab, thiab txhawb nqa rods hauv Flue Gas Desulfurization (FGD) systems, uas muaj chlorides, sulfur compounds, thiab acidic condensates.
Marine & Offshore: Shafts rau seawater twj, cov khoom hauv ballast dej systems, thiab fasteners raug rau ntsev tsuag thiab txaws zones, qhov pitting thiab crevice corrosion yog cov kev txhawj xeeb loj.
Acid Production & Pickling: Cov khoom xyaw hauv cov nroj tsuag tsim cov kua qaub thiab cov khoom siv pickling rau kev sib xyaw cov kua qaub.
Qhov tseem ceeb tsis ua hauj lwm hom nws tiv thaiv yog dav dav corrosion nyob rau hauv sib xyaw acids, localized pitting / crevice nres, kev nyuaj siab corrosion cracking nyob rau hauv chlorides los yog alkalis, thiab intergranular nres tom qab vuam. Los ntawm kev qhia Incoloy 825 puag ncig bar, cov kws tsim khoom ua kom muaj kev ncaj ncees ntawm cov khoom, txo cov sijhawm poob qis, thiab txuas ntxiv lub neej kev pabcuam hauv cov kev pabcuam nruj.
3. Dab tsi yog qhov tseem ceeb ntawm cov tshuab thiab lub cev ntawm Incoloy 825 round bar nyob rau hauv nws cov txheej txheem muab khoom, thiab lawv cuam tshuam li cas ntawm machining thiab fabrication?
Incoloy 825 round bar yog yuav luag universally nkag rau hauv cov tshuaj annealed mob (rhuab mus rau 930-980℃thiab sai txias). Lub xeev no muaj qhov zoo sib npaug ntawm kev tiv thaiv corrosion thiab cov khoom siv kho tshuab, feem ntau ua tau raws li ASTM B425 tus qauv:
Mechanical Properties: Cov yam ntxwv ntawm chav tsev kub muaj xws li Tensile Strength ntawm 586 MPa (85 ksi) min, Yield Strength (0.2% Offset) ntawm 241 MPa (35 ksi) min, thiab Elongation ntawm 30% min. Qhov kev sib xyaw ua ke no muab lub zog siab rau shafting nrog ductility zoo heev los tiv thaiv kev poob siab.
Lub cev muaj zog: Qhov tseem ceeb ntawm lub cev tsis tu ncua yog qhov ceev ntawm 8.14 g / cm³, melting ntau ntawm 1370-1400 degree, thiab thermal expansion coefficient ntawm 14.0 μm / m·℃(20-100 degree). Nws cov thermal conductivity yog tsawg (~ 11 W / m·K), uas yuav tsum tau saib xyuas thaum lub sij hawm vuam thiab machining los tswj cov cua sov.
Machining Considerations: Thaum machinable, Incoloy 825 yog ib qho tawv, gummy alloy uas ua hauj lwm - hardens sai heev. Kev ua tiav machining yuav tsum:
Muaj zog, nruj tshuab teeb tsa los tiv thaiv nws lub zog siab.
Kev siv cov kaum sab xis zoo, cov cuab yeej ntse carbide, thiab tswj kev txau / nrawm los txiav cov khoom siv tsis yog rub nws.
Ua nruj ua tsiv, ua haujlwm zoo ib yam los ua haujlwm hauv qab ntawm kev ua haujlwm- txheej tawv tawv tsim los ntawm kev txiav yav dhau los.
Kev siv ntau ntawm -siab txias txias los tswj cov cua sov thiab ntxuav cov chips.
4. Qhov kev ua tau zoo thiab kev siv ntawm Incoloy 825 round bar txawv li cas ntawm nws cov neeg ua ntej, Incoloy 800 / H / HT, thiab cov alloy siab tshaj, Incoloy 925?
Kev nkag siab txog cov tsev neeg alloy no hierarchy yog qhov tseem ceeb rau kev xaiv cov khoom raug:
vs. Incoloy 800/H/HT: Qhov no yog qhov kev hloov pauv tseem ceeb. Incoloy 800 series yog optimized rau siab -kub lub zog thiab oxidation/carburization kuj (xws li, rauv tubes, kub exchangers). Nws tsis muaj molybdenum lossis tooj liab, yog li nws cov corrosion kuj hauv kev txo cov kua qaub thiab chlorides yog txwv. Incoloy 825 tsis yog qhov kub siab heev; nws niche yog ambient rau nruab nrab siab kub corrosion kuj. Kev siv 825 rau siab - qhov kev pabcuam kub yuav tsis raug thiab raug nqi.
vs. Incoloy 925: Incoloy 925 yog ib qho derivative ntawm 825 tab sis nrog ntxiv ntawm txhuas thiab titanium uas tso cai rau nws muaj hnub nyoog - hardened ( nag lossis daus hardened ). Thaum nws khaws zoo corrosion kuj, nws lub hom phiaj tseem ceeb yog ua kom muaj zog ntau dua (Yield Strength mus txog 758 MPa / 110 ksi). A 925 puag ncig bar yuav raug xaiv ntau dua 825 thaum daim ntawv thov xav tau ob qho tib si corrosion kuj thiab muaj zog dua txhua yam rau hnyav- lub luag haujlwm shafts lossis fasteners.
Nyob rau hauv luv luv: Xaiv 800 series rau cua sov, 825 rau complex corrosion, thiab 925 rau corrosion + siab zog.
5. Dab tsi yog qhov tseem ceeb welding thiab ncej -weld kev coj ua zoo tshaj plaws rau fabricating Cheebtsam los ntawm Incoloy 825 round bar kom khaws nws cov corrosion kuj?
Vuam Incoloy 825 yuav tsum muaj cov txheej txheem uas tswj nws cov metallurgical stability thiab corrosion kev ua tau zoo. Lub hom phiaj tseem ceeb yog kom tsis txhob rhiab heev (chromium carbide nag lossis daus) thiab weld solidification cracking.
Filler Metal Selection: Tus qauv, sib piv cov hlau nplaum yog ERNiFeCr-1 (tseem hu ua Inconel 112 lossis AWS A5.14). Rau qhov siab tshaj plaws tiv thaiv rau pitting thiab crevice corrosion nyob rau hauv lub as-welded mob, tshwj xeeb tshaj yog rau cov kev pab cuam tseem ceeb, ERNiCrMo-3 (Inconel 625 muab tub lim) feem ntau nyiam vim nws cov molybdenum ntau dua thiab niobium cov ntsiab lus, uas muab superior kuj nyob rau hauv lub vuam hlau.
Vuam txheej txheem: Gas Tungsten Arc Vuam (GTAW / TIG) thiab Shielded Hlau Arc Vuam (SMAW / Stick) feem ntau. Gas Hlau Arc Vuam (GMAW/MIG) tuaj yeem siv nrog cov ntsuas kom raug.
Cov kev coj ua zoo tshaj plaws:
Kev huv huv yog qhov tseem ceeb: Tshem tawm tag nrho cov roj, roj, xim, thiab cov cim (tshwj xeeb yog leej faj- muaj) ntawm thaj chaw vuam.
Tswj Cov Cuab Yeej Siv Hluav Taws Xob: Siv cov khoom siv hluav taws xob qis mus rau nruab nrab thiab tsis txhob cuam tshuam ntau heev kom txo tau lub sij hawm cov khoom siv nyob rau hauv qhov kub thiab txias (kwv yees . 550-850℃).
Khaws qhov ntsuas kub qis qis: feem ntau qis dua 150 degree.
Siv Rov Qab Purging: Rau GTAW, siv cov roj inert (argon) tshem tawm ntawm lub nraub qaum ntawm cov vuam los tiv thaiv oxidation (qabzib) thiab poob ntawm kev tiv thaiv corrosion ntawm lub hauv paus sab.
Tom qab- Kev Kho Hniav Kub Kub (PWHT): Rau Incoloy 825, PWHT feem ntau tsis tas yuav tsum tau vim nws cov titanium stabilization, uas tiv thaiv rhiab heev. Txawm li cas los xij, ib qho kev daws teeb meem yuav raug teev tseg rau qhov tshwj xeeb corrosive kev pab cuam kom yaj cov me me precipitates thiab rov zoo corrosion kuj nyob rau tag nrho cov tshav kub- cuam tshuam cheeb tsam (HAZ). Kev daws kev ntxhov siab feem ntau tsis ua.
