1. Rau ib tug loj - txoj kab uas hla combustion pa duct los yog hloov piece nyob rau hauv ib tug industrial gas turbine (IGT), yog vim li cas yuavwelded Hastelloy X raj yuav tsum tau teev nyob rau hauv ntau fabricable, qis dua -tus nqi stainless hlau zoo li 309 los yog 310?
Qhov kev xaiv no yog tsav los ntawm peb qhov kev hem thawj ntawm qhov kub thiab txias, oxidation, thiab thermal cycling tshaj qhov muaj peev xwm ntawm cov cua sov-cov hlau tsis muaj zog.
Kev txwv kev ua haujlwm ntawm 309/310 Stainless:
Kub Ceiling: Thaum zoo mus txog ~ 1900℃F (1040 degree) rau kev pabcuam cuam tshuam, lawv lub zog creep poob sai dua 1800℃F (980 degree). Qhov loj - txoj kab uas hla hauv qab nws qhov hnyav ntawm 2000℃F + yuav muaj kev pheej hmoo siab ntawm sagging, distortion, thiab creep rupture.
Oxidation / Scale Resistance: Lawv tsim cov chromium oxide nplai uas tuaj yeem ua tsis ruaj khov thiab ua rau muaj kev sib kis (flaking tawm) nyob rau hauv lub caij ntuj sov hnyav, ua rau cov phab ntsa thinning thiab qhov tshwm sim tshwm sim.
Thermal Fatigue Cracking: Tsawg pob txha toughness thiab siab dua thermal expansion coefficient piv rau HX tuaj yeem ua rau luv luv thermal qaug zog lub neej ntawm kev ntxhov siab concentrators xws li welds.
Qhov zoo ntawm Hastelloy X Welded Tube:
Superior High -Tsub Muaj Zog: Nws muaj zog- kev daws teeb meem ntxiv zog (Mo, Cr, Co) muab kev nkag tau zoo heev- tawg lub zog ntawm 2000-}2200℃F (1095-1205 degree), tso cai rau kev tsim cov kev txhawb nqa tus kheej, loj.-dia
Exceptional Oxidation Resistance: Lub 22% Chromium ua ke nrog Lanthanum (La) ntxiv txhawb kev tsim ntawm ib qho adherent heev, qeeb - loj hlob, thiab spallation - tiv taus oxide nplai. Qhov no yog qhov tseem ceeb rau kev ua haujlwm ntev - lub neej ua haujlwm hauv lub luag haujlwm cyclic.
Kev Ua Haujlwm Zoo Thermal Fatigue Resistance: Tuav cov ductility thiab toughness tom qab raug, tso cai rau nws kom haum raws li cov kev ntxhov siab los ntawm rov pib dua -up/shutdown cycles.
Kev Ncaj Ncees Kev Ncaj Ncees: Txawm hais tias cov khoom siv thiab cov nqi tsim khoom ntawm Hastelloy X welded raj yog qhov siab dua, nws yog qhov tsim nyog los ntawm kev zam ntawm qhov tsis tau npaj tseg los ntawm cov kav dej tsis ua haujlwm. Hloov qhov tsis ua tiav qhov hloov pauv ntawm cov kav dej hauv IGT tuaj yeem xav tau lub limtiam ntawm kev poob qis, raug nqi ntau lab hauv kev tsim hluav taws xob poob. Cov khoom siv hwm zoo ua kom ntseeg tau ntau xyoo ntawm kev pabcuam txhim khu kev qha hauv qhov chaw tseem ceeb ntawm cov pa roj kub qhov chaw.
2. Vuam Hastelloy X nthuav qhia cov kev cov nyom tshwj xeeb los khaws nws cov khoom kub siab -. Dab tsi yog cov hlau muab tub lim kom raug rau qhov ntev seam vuam ntawm HX raj, thiab qhov tseem ceeb tshaj plaws ntawm kev kho cua sov (PWHT) yog dab tsi, tshwj xeeb tshaj yog rau cov tuab- cov phab ntsa?
Weldment yog qhov txuas tsis muaj zog; nws cov khoom yuav tsum tau rov qab los kom phim lub hauv paus hlau.
Kho Filler Hlau:
Tus qauv thiab kev xaiv raug yog ERNiCrMo-2 (AWS A5.14) lossis nws cov electrode coated sib npaug ENiCrCoMo-1 (AWS A5.11). Cov fillers no tau tsim tshwj xeeb kom haum rau Hastelloy X cov ntsiab lus, suav nrog nws cov ntsiab lus Cobalt (Co), uas yog qhov tseem ceeb rau qhov kub thiab txias zog.
Vim Li Cas Tsis Muaj Cov Filler Zoo li ERNiCr-3? Siv cov muab tub lim yam tsis muaj Mo thiab Co yuav tsim cov hlau vuam uas tsis muaj siab tshaj - qhov kub thiab txias tsis kam oxidation, ua rau nws lub neej txwv ntawm kev sib dhos.
Qhov tseem ceeb tshaj plaws -Weld Heat Treatment (PWHT):
Rau nyias-walled tube (< ~0.125" / 3mm) in non-critical service, it may be used in the as-welded condition after proper pickling.
Rau cov tuab- cov phab ntsa phab ntsa lossis cov ntawv thov cov txheej txheem tseem ceeb, PWHT yog qhov yuav tsum tau ua. Qhov kev kho mob uas yuav tsum tau muaj yog Kev Nyuaj Siab Kev Nyuaj Siab Anneal.
Kub: 1800℃F (980 degree) yam tsawg kawg nkaus.
Soak Sijhawm: Feem ntau 1 teev ib nti ntawm tuab.
Cua txias: Tswj cua txias yog qhov siv tau.
Lub hom phiaj ntawm Kev Ruaj Ntseg:
Relaxes welding residual stresses uas yuav ua rau distortion los yog kev nyuaj siab corrosion cracking nyob rau hauv kev pab cuam.
Homogenizes qhov vuam thiab txhawb nqa qee cov qoob loo loj hlob hauv HAZ, txhim kho siab -kub ductility.
Nws yog kev kho mob tsis txaus siab- nws tsis muab tag nrho cov tshuaj anneal (uas yuav yog ntawm ~ 2150℃F / 1175℃thiab ua rau cov qoob loo loj hlob ntau dhau) tab sis txaus los xyuas kom meej weld kev ncaj ncees rau feem ntau qhov siab -kub cov qauv siv.
3. Nyob rau hauv siab, siab - kub exchanger designs (piv txwv li, rau syngas coolers los yog reformer effluent), dab tsi yog qhov tshwj xeeb tsim thiab fabrication xav txog kev siv Hastelloy X welded raj, tshwj xeeb tshaj yog hais txog thermal expansion thiab kev txhawb nqa?
Tsim nrog HX raj ntawm qhov kub thiab txias yuav tsum muaj engineering uas haum rau nws tus cwj pwm ntawm lub cev.
Thermal Expansion Management:
Hastelloy X muaj cov coefficient ntawm thermal expansion (CTE), zoo ib yam li lwm cov nickel alloys (~ 8.5 µin/in·℃F ntawm 1000℃F).
Kev Tsim Nyog: Hauv qhov ruaj khov -tubesheet heat exchanger nrog HX raj thiab carbon steel plhaub, qhov sib txawv ntawm qhov sib txawv yuav loj heev, ua rau muaj kev puas tsuaj loj.
Kev daws: Siv lub raj xa dej ntab lossis U- raj pob tsim los tso cai rau cov raj kom nthuav dav / cog lus ntawm nws tus kheej. Rau ncaj- raj tsim, cov ncauj lus kom ntxaws thermal stress tsom xam yuav tsum tau.
Fabrication rau Heat Exchanger Service:
Tube-rau-Tubesheet Joining: Qhov no yog qhov sib koom ua ke tseem ceeb. Cov txheej txheem muaj xws li:
Kev nthuav dav (Rolling): Yuav tsum tau ua tib zoo ua kom tsis txhob dhau - ua haujlwm thiab ua haujlwm - ua kom lub raj xau. Lub teeb lub zog vuam tuaj yeem raug ntxiv tom qab nthuav dav rau kev ruaj ntseg.
Vuam: Siv ERNiCrMo-2 muab tub lim. Lub vuam yuav tsum tau kho tom qab vuam cua sov (hauv zos lossis nrog tag nrho cov pob) kom txo tau kev ntxhov siab.
Internal Cleanliness: Rau cov kev pab cuam roj, lub raj ID yuav tsum tsis muaj vuam splatter, nplai, thiab khib nyiab los tiv thaiv qhov kub thiab fouling. Passivation los yog pickling ntawm lub raj ua tiav yog tus qauv.
Kev them nyiaj yug & vibration:
Ntev, siab - cov raj kub yog qhov ua rau muaj kev ntws tawm -vim kev co (FIV). Baffle spacing thiab kev txhawb nqa tsim yuav tsum tau ua tib zoo xam.
Kev txhawb nqa / baffles yuav tsum tau ua los ntawm cov khoom siv nrog CTE zoo sib xws (piv txwv li, Hastelloy X lossis RA 330) kom tiv thaiv kev khi lossis fretting hnav.
4. Dab tsi yog qhov tseem ceeb ntev - lub sij hawm tsis ua hauj lwm mechanisms rau Hastelloy X welded hlab nyob rau hauv tas li siab - kub kev pab cuam, thiab dab tsi nyob rau hauv - kev soj ntsuam kev pab cuam (ISI) cov tswv yim zoo tshaj rau kev saib xyuas lawv kev noj qab haus huv?
Txawm tias Hastelloy X degrades lub sijhawm. Kev tshuaj ntsuam xyuas yog qhov tseem ceeb rau kev kwv yees ua tsis tiav.
Dominant Failure Mechanisms:
Creep Damage: Lub neej tseem ceeb -txoj kev txwv. Nyob rau hauv qhov kev ntxhov siab tas li (los ntawm lub siab, qhov hnyav tuag) ntawm qhov kub thiab txias, cov khoom maj mam deforms, ua rau bulging, ovality, thiab qhov tshwm sim rupture. Welds, tshwj xeeb tshaj yog nyob rau hauv - kho, tuaj yeem yog qhov chaw nyiam tshaj plaws rau creep cavitation.
Thermal Fatigue Cracking: Los ntawm kev rov ua dua thermal, pib ntawm geometric stress concentrators (nozzle welds, kev txhawb nqa txuas).
Oxidation & Scale Spallation: Thaum zoo heev, oxide nplai yuav nws thiaj li degrade. Cyclic spallation ua rau phab ntsa thinning.
Microstructural Degradation: Formation of detrimental secondary phases (sigma phase, carbides) after very long exposure (>10,000 teev), uas tuaj yeem ua rau cov khoom siv.
Siv tau zoo hauv -Kev Tshawb Fawb Kev Pabcuam (ISI) Cov Txheej Txheem:
Visual & Dimensional: Kev kuaj xyuas tsis tu ncua rau kev cuam tshuam, kev hneev taw, thiab qhov poob loj.
Kev Ntsuas Ultrasonic (UT): Cov cuab yeej tseem ceeb rau kev ntsuas phab ntsa tuab thiab kuaj pom kev puas tsuaj sab hauv. Advanced UT tuaj yeem pom cov phab ntsa nyias nyias thiab txawm tias pom cov kab mob nkag mus.
Replication Metallography: Cov txheej txheem tsis yog -kev puas tsuaj. Ib qho chaw polished ntawm lub raj (feem ntau ntawm lub vuam HAZ) yog etched, thiab muab cov yas replica. Kev ntsuam xyuas hauv lub tshuab kuaj kab mob tuaj yeem qhia tau tias:
Grain ciam cavitation (thaum ntxov-theem creep puas).
Microcracking.
Degradation ntawm subsurface microstructure.
Kev Ntsuas Hardness: tuaj yeem qhia dhau -aging lossis embrittlement los ntawm theem tsim.
5. Thaum muab welded Hastelloy X raj rau ASTM B619/B626 rau ib qhov project tseem ceeb, dab tsi ntxiv kev pov thawj zoo tshaj li tus qauv hydrotest thiab kev tshuaj xyuas qhov muag yuav tsum tau teev kom ntseeg tau tias weld kev ncaj ncees rau siab - kub kev pab cuam?
Rau qhov kev pabcuam tseem ceeb, qhov kev xeem "mill run" tsis txaus. Cov txheej txheem kev yuav khoom yuav tsum ua kom muaj kev pov thawj zoo dua.
Qhov Tseem Ceeb Ntxiv QA Yuav Tsum Tau:
100% Radiographic Test (RT) ntawm Longitudinal Welds: Ib ASTM E94/E1032. Qhov no tsis yog -kev sib tham tau rau kev kuaj xyuas qhov tsis xws luag xws li tsis muaj fusion, porosity, thiab tawg hauv qhov vuam seam. Qhia meej txog kev lees txais (piv txwv li, hauv ASME BPVC Sec. VIII, UW-51).
Tshaj tawm- Daim ntawv pov thawj Weld Heat Treatment: Yuav tsum tau ntsuas kub tsis tu ncua los ntawm kev ntxhov siab anneal (xws li, ntawm 1850℃F / 1010℃) ua pov thawj tag nrho cov raj ntev tau kho.
Hardness Traverse ntawm Weld Daim Coupon: Xav kom tus neeg muag khoom los muab daim ntawv ntsuam xyuas hardness (Rockwell los yog Vickers) hla cov qauv vuam ntau lawm (puag hlau, HAZ, weld hlau). Qhov no ua pov thawj tias thaj chaw weld tsis tau embrittled thiab tias PWHT ua haujlwm tau zoo.
Tshuaj ntsuam xyuas ntawm Weld Hlau: Rau kev ncaj ncees siab tshaj plaws, qhia cov khoom lag luam tsom los ntawm cov vuam seam kom paub meej tias cov hlau muab tub lim yog qhov tseeb thiab tsis muaj paug.
Grain Size Report: Daim ntawv pov thawj ntawm lub hauv paus hlau grain loj (ASTM No.) los xyuas kom meej cov tshuaj pib annealing.
Rau Kev Pabcuam Huab Cua (Aerospace, Nuclear):
Kev Ntsuas Penetrant (PT): Ntawm txhua qhov chaw vuam.
Kev ntsuas kub siab: Tej zaum yuav xav tau kev ntxhov siab- kuaj kev puas tsuaj ntawm cov qauv los ntawm cov khoom siv vuam.
Thib peb-Kev Tshawb Fawb Tus Neeg Pom Zoo: Txoj cai rau tus neeg yuav khoom tus neeg soj ntsuam ua pov thawj txhua yam tseem ceeb ntawm kev tsim khoom thiab kev sim cov kauj ruam ntawm lub zeb.
Procurement Specification Piv txwv:
*"Welded Hastelloy X (UNS N06002) Tube rau ASTM B619. Tag nrho cov longitudinal seams yuav tsum 100% Radiographically Examined per ASTM E94, txais ib ASME Sec. VIII, UW-51. Tubes kom muaj kev ntxhov siab nyem annealed ntawm 1850℃CM F mine daim ntawv qhia, nrog rau cov ntawv qhia txog F min. Cov kab kos kev kho mob, thiab kev soj ntsuam hardness hla ib qho qauv weld. "*
Hauv cov ntsiab lus, Hastelloy X welded raj yog cov kev daws teeb meem loj rau - nplai, siab - qhov kub thiab txias, oxidizing, thiab cov txheej txheem xav tau kev siv qhov twg tawm - lub - txee seamless raj tsis muaj los yog raug nqi - txwv tsis pub. Nws qhov kev ua tiav zoo yog qhov kev tswj hwm nruj ntawm vuam thiab tom qab-weld heat treatment, ntse tsim rau kev tswj thermal, thiab kev tswj xyuas nruj thiab kev soj ntsuam uas ua rau muaj kev ncaj ncees ntawm cov khoom tsim.
