1. Metallurgical Stability: Nyob rau hauv tuab -section phaj fabrication, yog vim li cas yog Hastelloy B-3 teev nyob rau hauv thawj B-2 los tiv thaiv tshav kub-cuam tshuam cheeb tsam tawg thaum vuam?
Q: Peb tab tom tsim cov khoom hnyav- cov phab ntsa reactor siv 50mm tuab Hastelloy phaj. Peb cov lus qhia qub tau hu rau B-2, tab sis qhov kev hloov kho tshiab tau txiav txim siab B-3. Peb tau ntsib teeb meem tawg nrog B-2 yav dhau los. Dab tsi hloov metallurgically hauv B-3 phaj uas tiv thaiv cov kab nrib pleb?
A: Kev hloov ntawm Hastelloy B-2 mus rau B-3 nyob rau hauv tuab-section phaj fabrication yog ib qho kev txhim kho tseem ceeb tshaj plaws hauv nickel alloy metallurgy. Qhov tawg uas koj tau ntsib nrog B-2 yog qhov yuav tsis yog tus neeg ua haujlwm yuam kev-nws yog ib qho tseem ceeb ntawm cov hlau tsis muaj zog uas B-3 tau tsim tshwj xeeb los daws.
B-2 Vulnerability:
Nyob rau hauv daim hlau tuab (dhau 12 hli), qhov cua sov- cuam tshuam cheeb tsam (HAZ) nyob ib sab ntawm lub vuam txias ntawm tus nqi nruab nrab. Hastelloy B-2 yog nquag rau ob yam tshwm sim:
Luv -Range Ordering: Nyob rau hauv qhov kub ntawm 550-850℃F (290-455 degree), cov atoms hauv B-2 rearrange rau hauv cov qauv txiav txim. Qhov no ua rau cov khoom tsis tshua muaj zog thiab nkig.
Carbide Precipitation: B-2 yooj yim precipitates carbides thiab intermetallic theem (Mu theem) ntawm grain ciam teb nyob rau hauv lub HAZ thaum lub sij hawm vuam.
Qhov tshwm sim yog HAZ uas poob tag nrho cov ductility. Raws li cov hlau vuam txias thiab sib cog lus, nws rub tawm tsam HAZ nkig no, thiab cov kab nrib pleb nthuav tawm raws li cov ciam teb cov qoob loo- feem ntau pom tsis pom ntawm qhov muag liab qab tab sis pom tau los ntawm NDT.
B-3 Solution (Chemistry Control):
Hastelloy B-3 khaws zoo tib yam corrosion kuj zoo li B-2 tab sis hloov cov chemistry (nrog kev tswj ntxiv ntawm cov hlau thiab chromium, thiab tswj nruj dua ntawm carbon thiab silicon) kom qeeb lub kinetics ntawm kev txiav txim thiab nag los ntawm ib qho ntawm ze li ntawm 100.
Tswv yim Implication rau Phaj Fabrication:
Nrog B-3 phaj, HAZ tseem ductile thaum txias. Lub weld tuaj yeem cog lus yam tsis tau rhuav tshem lub hauv paus hlau uas nyob ib sab. Qhov no txhais tau tias:
Tsis muaj qhov yuav tsum tau tshaj tawm -weld heat treatment (PWHT) yog yuav tsum tau los kho ductility.
Ntau- hla vuam ntawm cov ntu tuab muaj kev nyab xeeb; lub thermal cycling los ntawm kev hla tom ntej tsis embrittle cov dhau dhau los.
Cov phaj tuaj yeem siv tau raws li -welded mob hauv cov kev pabcuam mus txog qhov kub thiab txias yam tsis muaj kev pheej hmoo ntawm - kev pabcuam embrittlement.
2. Hydrochloric Acid Service: Nyob rau hauv azeotropic HCl reactors, yuav ua li cas corrosion npaum li cas los ntawm Hastelloy B-3 phaj, thiab yuav ua li cas thickness tsim kom haum raws li lub ntiaj teb no acid impurities?
Q: Peb tab tom tsim lub reactor los tuav azeotropic hydrochloric acid (kwv yees . 20% HCl) ntawm 150℃. Peb tau xaiv 25 hli tuab Hastelloy B-3 phaj. Peb yuav tsum siv tus nqi corrosion li cas rau peb lub neej kev suav, thiab yuav ua li cas yog tias kab ferric ions (Fe+3) tshwm hauv cov kua qaub?
A: Hauv cov ntshiab azeotropic HCl ntawm 150 degree, Hastelloy B-3 muaj kev ua tau zoo tshwj xeeb. Txawm li cas los xij, koj cov lus nug txog impurities yog qhov tseem ceeb vim tias B-3 muaj qhov tsis zoo uas yuav tsum tau nkag siab hauv cov txheej txheem tshuaj lom neeg tiag tiag.
Lub hauv paus Corrosion Rate:
Nyob rau hauv ntshiab, oxygen -dawb hydrochloric acid ntawm 150℃, Hastelloy B-3 feem ntau nthuav tawm corrosion tus nqi tsawg dua 0.1 hli ib xyoo (4 mpy). Qhov no tso cai rau cov txheej txheem corrosion kuj zoo dua li 20 xyoo tsim lub neej. Cov ntsiab lus molybdenum siab (28-30%) muab qhov kev tiv thaiv no los ntawm kev tsim cov yeeb yaj kiab tiv thaiv hauv qhov txo qis acidic ib puag ncig.
Ferric Ion Threat (Lub "Oxidizing Ion" Nraug):
Qhov no yog ib qho tseem ceeb tshaj plaws kev xav txog kev ua haujlwm rau B-3 cov cuab yeej.
Mechanism: Hastelloy B-3 yog tsim los rautxokua qaub. Nws muaj cov ntsiab lus chromium tsawg (1-3%) tshwj xeeb vim tias chromium muaj kev puas tsuaj hauv HCl ntshiab. Txawm li cas los xij, yog tias cov txheej txheem kwj tuaj yeem kis kab mob oxidizing hom-feem ntau ferric ions (Fe+3) los ntawm cov dej ntws tawm, cov ions cupric (Cu+2), lossis cov pa oxygen yaj-cov txheej txheem corrosion hloov tag nrho.
Hom Tsis Ua Haujlwm: Cov yeeb yaj kiab tsis zoo ntawm B-3 tsis tuaj yeem tiv taus oxidizing tej yam kev mob. Nyob rau hauv lub xub ntiag ntawm Fe+3, tus nqi corrosion tuaj yeem skyrocket los ntawm<0.1 mm/year to >5mm / xyoo. Qhov no feem ntau pom yog "riam-kab" lossis nrawm dav dav.
Design Mitigation:
Corrosion Allowance: Thaum 0.1 hli / xyoo yog lub hauv paus, cov neeg tsim khoom paub txog feem ntau ntxiv 3 hli "tsis paub txog qhov tseem ceeb" ntxiv rau tus account rau cov txheej txheem kev ntxhov siab uas qhia txog oxidizing hom.
Cov Txheej Txheem Tswjhwm: Kev tiv thaiv tiag tiag rau B-3 phaj yog kev tswj xyuas sab saud-ua kom cov kua qaub nyob twj ywm tsis muaj kab mob hlau thiab cov pa oxygen nkag mus.
Kev soj ntsuam: suav nrog kev soj ntsuam xyuas corrosion nyob rau hauv lub reactor txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txheeb xyuas cov kab mob oxidizing tau nkag mus rau hauv lub cev.
3. Kev tsim & Fabrication: Dab tsi yog qhov kev txwv rau kev ua txias txias Hastelloy B-3 phaj, thiab thaum twg yog qhov kub sib sau yuav tsum tau tiv thaiv kev tawg?
Q: Peb yuav tsum tsim 40mm tuab Hastelloy B-3 phaj rau hauv lub taub hau hemispherical rau lub nkoj siab. Peb lub khw feem ntau txias cov ntaub ntawv stainless hlau. Peb puas tuaj yeem txias daim B-3, lossis peb puas xav tau daim ntawv kub? Dab tsi yog qhov txaus ntshai?
A: Kev tsim lub 40mm tuab Hastelloy B-3 phaj rau hauv hemisphere yog kev ua haujlwm hnyav. Ntawm no thickness thiab nrog no alloy, kub sib sau yog xav kom pom zoo, yog tsis yuav tsum tau. Sim ua kom txias txias yuav ua rau muaj kev tawg tam sim lossis ncua kev ua tsis tiav.
Qhov Kev Ua Haujlwm Hardening Challenge:
Hastelloy B-3 muaj kev ua haujlwm siab heev- hardening rate-ntau dua li austenitic stainless hlau. Thaum koj txias daim ntawv phaj, nws sai sai yuav muaj zog tab sis kuj poob ductility. Rau qhov sib sib zog nqus nqus zoo li lub taub hau hemispherical, cov kab mob ntawm lub pob taws yog qhov hnyav heev.
Quantifying qhov txwv:
Stainless Hlau: Feem ntau tuaj yeem zam 20-25% txias txo ua ntej yuav tsum tau annealing.
Hastelloy B-3: Cov txheej txheem ua kom txias txias yog feem ntau 10-15% strain siab tshaj plaws. Lub taub hau hemispherical los ntawm lub phaj tiaj tus yuav nyob hauv zos tshaj qhov no, tshwj xeeb tshaj yog nyob rau ntawm lub voj voog hloov.
Kub forming Parameters:
Yog tias koj daim ntawv kub, qhov tseeb yog qhov tseem ceeb:
Qhov Kub Kub: Qhov zoo tshaj plaws kub tsim ntau rau B-3 yog 1000℃txog 1200℃(1830℃F txog 2190℃F).
Thaj Chaw Txaus Ntshai: Koj yuav tsum zam qhov embrittlement ntau ntawm 550℃txog 850℃(1020℃F txog 1560℃F). Yog hais tias lub phaj txias maj mam los ntawm qhov ntau ntawm no thaum lub sij hawm tsim, kev txiav txim thiab embrittlement tuaj yeem tshwm sim.
Tom qab-Kev Kho Kub Kub: Tom qab kub sib sau, lub taub hau yuav tsum tau rov ua dua - cov tshuaj annealed (rhuab siab tshaj 1060℃thiab sai quenched) kom rov zoo li qub, mos, corrosion-resistant microstructure. Cov txheej txheem tsim, txawm tias kub, tuaj yeem tsim cov khoom tsis yog -ib txwm lis.
Qhov Txias Forming Exception:
Yog tias koj tab tom tsim nyias phaj (<6mm) into simple bends (e.g., for a duct), cold forming is possible. However, even then, the formed area will be work-hardened. If the component will be used in a corrosive environment, the cold-formed area (now stressed and harder) may corrode preferentially. A full solution anneal after forming is always the safest practice.
4. ASME Txoj Cai Ua Raws Cai: Cov qauv kev ntxhov siab dab tsi siv rau Hastelloy B-3 phaj nyob rau hauv ASME Tshooj VIII, Division 1, thiab cov vuam cuam tshuam li cas rau cov kev ntxhov siab?
Q: Peb tab tom tsim lub nkoj siab rau ASME Tshooj VIII, Div 1 siv Hastelloy B-3 phaj. Peb welding cov seams. Tus nqi siab tshaj plaws uas peb tuaj yeem siv rau lub phaj yog dab tsi, thiab qhov kev sib koom ua ke ntawm kev sib koom ua haujlwm puas txo tus nqi no?
A: Hastelloy B-3 phaj yog tus yam ntxwv zoo hauv ASME Boiler thiab Pressure Vessel Code. Kev nkag siab txog kev sib cuam tshuam ntawm lub hauv paus hlau kev ntxhov siab qhov tseem ceeb thiab kev sib koom ua ke ntawm kev sib koom tes yog qhov tseem ceeb rau kev tsim qauv zoo thiab kev lag luam.
Khoom Specification:
Hastelloy B-3 phaj feem ntau yog tsim los rau ASTM B333 (Nickel-Molybdenum Alloy Phaj). Qhov kev qhia tshwj xeeb no tau txais los ntawm ASME Tshooj II, Ntu A, thiab cov kev ntxhov siab tso cai tau teev tseg hauv ASME Tshooj II, Ntu D.
Tso cai Stress Values:
Lub zog tensile tso cai rau B-3 phaj ntawm chav tsev kub yog feem ntau nyob ib ncig ntawm 180-190 MPa (26-27.5 ksi), nyob ntawm seb cov khoom tshwj xeeb thiab kev kho cua sov. Cov txiaj ntsig no tau muab los ntawm lub zog tensile faib los ntawm 4, lossis lub zog tawm los muab faib los ntawm 1.5, qhov twg qis dua.
Weld Joint Efficiency Factor (E):
Qhov no yog qhov uas tus tsim engineers yuav tsum tau ceev faj. Qhov kev ntxhov siab uas tau tso cai los ntawm Tshooj II, Ntu D yog siv raupuag hlau. Thaum koj qhia txog lub vuam seam, koj yuav tsum muab qhov kev ntxhov siab ntawm lub hauv paus hlau los ntawm kev sib koom ua haujlwm zoo (E) rau UG-27 thiab UW-12.
Hom 1 (Tag Nrho RT): Yog tias koj ua 100% kev kuaj hluav taws xob ntawm txhua Qeb A thiab B welds, koj tuaj yeem siv Joint Efficiency E=1.0. Qhov no txhais tau hais tias cov vuam raug suav tias yog 100% zoo li cov hlau hauv paus, thiab koj tuaj yeem siv tag nrho cov txiaj ntsig kev ntxhov siab hauv koj cov thickness xam.
Hom 2 (Spot RT): Yog tias koj ua tsuas yog qhov chaw radiography, qhov ua tau zoo poob rau E=0.85.
Hom 3 (Tsis muaj RT): Yog tias koj tsis ua cov duab hluav taws xob, qhov ua tau zoo yog feem ntau E=0.70 rau Qeb A welds (ntev ntev seams hauv plhaub).
Tswv yim siv:
Rau lub tshuab hluav taws xob tseem ceeb, koj yuav luag yuav luag 100% hluav taws xob hluav taws xob (E=1.0) kom ua kom qhov siab txaus siab thiab txo cov phab ntsa tuab. Txawm li cas los xij, cov txheej txheem vuam thiab vuam yuav tsum tsim nyog rau ASME Tshooj IX, thiab cov hlau muab tub lim (feem ntau ERNiMo-7 lossis ERNiMo-10) yuav tsum sib haum.
Derating rau Temperature:
Nco ntsoov tias qhov tso cai rau kev ntxhov siab txo qis thaum tsim qhov kub thiab txias. Koj yuav tsum sab laj cov lus hauv ASME Tshooj II, Ntu D rau qhov tshwj xeeb ntawm koj daim ntawv thov (piv txwv li, 150 degree, 200 degree, thiab lwm yam).
5. Kho Vuam: Yog tias muaj qhov tsis xws luag hauv Hastelloy B-3 phaj thaum tsim khoom, txoj kev kho vuam vuam tsis muaj kev cuam tshuam corrosion yog dab tsi?
Q: Thaum lub sij hawm NDT ntawm peb lub nkoj B-3 fabricated, peb pom ib tug ntiav nto defect (lub puab tsaig los yog inclusion) nyob rau hauv niam txiv phaj. Peb yuav tsum zom nws tawm thiab weld kho nws. Cov txheej txheem tshwj xeeb yog dab tsi los xyuas kom meej qhov chaw kho kom zoo ib yam li cov phaj qub?
A: Kho vuam ntawm Hastelloy B-3 phaj yog tso cai, tab sis nws yuav tsum tau ua tib zoo saib xyuas kom meej. Kev kho tsis zoo tuaj yeem tsim "qhov chaw nyuaj" lossis thaj chaw tshuaj lom neeg sib cais uas corrodes nyiam hauv kev pabcuam. Ntawm no yog cov kauj ruam -ib-kauj ruam raws tu qauv rau kev kho lub suab metallurgically.
Kauj Ruam 1: Kev tshem tawm qhov tsis xws luag thiab pov thawj:
Kev Sib Tsoo: Siv aluminium oxide lossis silicon carbide logmob siab rau tsuas yog cov nickel alloys. Tsis txhob siv lub log uas tau siv hlau lossis hlau, vim tias cov khoom siv hlau yuav ua rau xeb thiab pitting.
NDT Kev Tshawb Fawb: Tom qab sib tsoo, ua cov tshuaj dye penetrant (PT) kom paub meej tias qhov tsis xws luag raug tshem tawm tag nrho. Cov kab noj hniav yuav tsum du -contoured tsis muaj cov ces kaum ntse (ib lub vojvoog yog qhov tseem ceeb los tiv thaiv kev ntxhov siab).
Kauj Ruam 2: Filler Hlau Xaiv:
Siv cov hlau muab tub lim kom raug: ERNiMo-7 (rau B-2) lossis ERNiMo-10 (feem ntau pom zoo rau B-3 kom phim cov chemistry ruaj khov). Siv lub hom phiaj dav dav nickel muab tub lim yuav tsim ib qho chaw dilution nrog cov yam ntxwv sib txawv.
Kauj Ruam 3: Vuam Parameters (Control Vaj Huam Sib Luag):
Low Heat Input: Siv cov txheej txheem GTAW (TIG) nrog qis amperage. Lub hom phiaj yog txhawm rau tso cov hlau muab tub lim yam tsis tau yaj lub hauv paus hlau ntau dhau. High dilution ntawm lub hauv paus hlau rau hauv lub pas dej ua ke tuaj yeem tsim molybdenum- thaj chaw depleted uas muaj kev cuam tshuam rau kev tawm tsam.
Interpass Temperature: nruj me ntsis tswj interpass kub. Khaws nws hauv qab 100℃(212℃F). Kev tsim cov cua sov ntau dhau tuaj yeem txhawb nqa kev xaj lossis carbide nag lossis daus hauv tshav kub- cuam tshuam thaj chaw kho.
Stringer Beads: Siv cov hlaws me me, stringer hlaws ntau dua li cov hlaws dav dav. Weaving ua rau kom muaj cua sov nkag thiab qhov dav ntawm cov cua sov- thaj tsam cuam tshuam.
Kauj Ruam 4: Tshaj tawm -Kev kho Weld (Theem tseem ceeb):
Rau kev kho ntawm lub phaj tuab, cua sov los ntawm vuam tsim ib qho me me HAZ. Thaum B-3 tiv taus kev txiav txim, thaj chaw kho yuav muaj kev ntxhov siab seem thiab qhov sib txawv me ntsis.
Yog tias tag nrho cov hlab ntsha twb tau muab tshuaj annealed: Ib qho chaw hauv zos -weld kho cua sov (PWHT) ntawm thaj chaw kho yog qhov txaus ntshai. B-3 tsis tas yuav muaj kev ntxhov siab, thiab sim ua kom cua sov hauv zos tuaj yeem tsim kom muaj cua sov gradient thiab tsis xav tau kev ntxhov siab.
Qhov Zoo Tshaj Plaws: Qhov xwm txheej zoo tshaj plaws yog ua kom tiav tag nrho cov kev khoua ntejqhov kawg daws anneal ntawm lub nkoj. Yog tias lub nkoj loj dhau los rov ua dua-anneal, kev kho yuav tsum tau ua nrog cov cua kub qis uas HAZ tsawg, thiab thaj chaw tau txais nyob rau hauv raws li -welded condition- muab cov hlau muab tub lim sib tw rau corrosion kuj.
Kauj Ruam 5: Kev Tshawb Fawb Kawg:
Tom qab welding, grind lub kho flush thiab smooth.
Ua ib qho kev kuaj PT tshiab kom ntseeg tau tias qhov kho tau zoo.
Yog tias ua tau, ua qhov kev sim Feritscope (txawm tias B-3 yuav tsum tsis yog-magnetic; ib qho lus teb sib nqus qhia tias muaj kab mob lossis tsis raug microstructure).
