Q1: Hauv cov ntawv thov kev lag luam, Nickel 200 thiab Nickel 201 zoo li yuav luag zoo ib yam. Dab tsi yog qhov tseem ceeb tshaj plaws metallurgical sib txawv uas yuam cov engineers xaiv ib qho ntawm lwm qhov, tshwj xeeb tshaj yog nyob rau hauv qhov kub siab - ib puag ncig?
A: Txawm hais tias ob qho tib si Nickel 200 (UNS N02200) thiab Nickel 201 (UNS N02201) yog cov khoom lag luam ntshiab wrought npib tsib xee alloys nrog corrosion kuj zoo heev, cov ntsiab lus carbon yog qhov sib txawv uas txiav txim siab lawv daim ntawv thov, tshwj xeeb tshaj yog hais txog qhov kub thiab txias.
Nickel 200 muaj cov ntsiab lus carbon txog li 0.15%.
Nickel 201 yog qhov "qis-carbon" version, nrog cov ntsiab lus siab tshaj plaws ntawm 0.02%.
Qhov sib txawv no yuav zoo li me me ntawm daim ntawv, tab sis nws yog qhov tseem ceeb hauv kev coj ua vim muaj qhov tshwm sim hu ua graphitization.
Ntawm qhov kub siab (feem ntau siab dua 315℃lossis 600℃F), cov pa roj carbon tam sim no hauv Nickel 200 yuav tsis ruaj khov. Sij hawm dhau mus, nws tuaj yeem tso tawm ntawm cov kua dej thiab tsim cov graphite films ntawm cov ciam teb. Cov txheej txheem no, hu ua graphitization, embrits cov khoom. Ib qho kev tivthaiv uas yog ib zaug ductile thiab muaj zog tuaj yeem tawg tam sim ntawd los yog poob rau hauv kev ntxhov siab vim tias cov ciam teb tau zoo "glued" sib nrug los ntawm brittle graphite.
Nickel 201, nrog rau nws cov ntsiab lus txo cov pa roj carbon ntau, zoo tshem tawm txoj kev pheej hmoo ntawm graphitization. Yog li ntawd, txoj cai kev lag luam ntawm tus ntiv tes xoo yog qhov tseeb:
Siv Nickel 200 rau cov ntawv thov hauv qab 315℃(xws li, caustic evaporators ntawm qhov kub nruab nrab, cov khoom siv ua zaub mov).
Nco ntsoov qhia Nickel 201 rau txhua daim ntawv thov uas cuam tshuam rau qhov kub siab tshaj 315 degree. Qhov no ua rau Ni 201 tus qauv kev xaiv rau cov khoom xws li tshuaj reactor hlab ntsha, superheater raj, thiab spargers nyob rau hauv siab -kub caustic ib puag ncig.
Tsis tas li ntawd, cov ntsiab lus tsis tshua muaj carbon no muab Ni 201 superior tiv thaiv rau intergranular nres (sensitization) nyob rau hauv tej yam welding scenarios, ua rau nws ib tug ntau zam txim rau fabrication.
Q2: Peb tab tom tsim cov dej qab zib caustic (sodium hydroxide) evaporator system. Ib puag ncig muaj qhov siab - concentration NaOH ntawm qhov kub siab. Vim li cas Nickel 201 yog cov khoom siv ntsuas rau daim ntawv thov tshwj xeeb no, thiab qhov twg nws poob?
A: Nickel 201 yog dav suav hais tias yog cov khoom siv tseem ceeb ntawm kev tsim kho rau kev tuav cov dej qab zib caustic, tshwj xeeb tshaj yog hauv kev tsim cov dej qab zib caustic nws tus kheej (chlor-alkali kev lag luam). Nws qhov kev ua tau zoo tshaj plaws hauv daim teb no yog vim muaj kev sib xyaw ua ke tshwj xeeb:
Kev tiv thaiv rau Caustic Stress Corrosion Cracking (SCC): Stainless hlau, tshwj xeeb tshaj yog cov qib austenitic xws li 304 thiab 316, muaj kev cuam tshuam rau caustic SCC ntawm qhov kub thiab txias. Nickel 201, ua cov nickel dawb huv, tsis muaj hlau ua nws cov khoom tseem ceeb thiab muaj lub ntsej muag -centered cubic qauv uas yog inherently resistant rau hom kev tawg.
Tsim Cov Txheej Txheem Tiv Thaiv Oxide: Nickel tsim ib txheej nyias, siab tawv, thiab tiv thaiv txheej ntawm nickel oxide ntawm nws qhov chaw. Nyob rau hauv ib puag ncig caustic, txheej txheej no ruaj khov thiab tiv thaiv kev xeb ntxiv sai, ua rau qis heev, kwv yees corrosion tus nqi.
Siab -Kev Sib Raug Zoo Kub: Raws li tau tham hauv nqe lus nug dhau los, cov ntsiab lus carbon tsawg ntawm Ni 201 ua kom nws nyob twj ywm thiab tiv taus embrittlement ntawm qhov kub siab (feem ntau 150-200℃lossis siab dua) siv rau hauv caustic evaporation kom nce concentration.
Qhov twg nws "ua tsis tiav" lossis yuav tsum tau ceev faj?
Qhov corrosion kuj ntawm Ni 201 yog nyob ntawm qhov chaw nyobdawb huvcaustic.
Muaj cov Oxidizers: Yog tias cov kwj deg muaj cov kab mob oxidizing muaj zog xws li chlorates, hypochlorites, lossis hnyav hlau ions (piv txwv li, tooj liab, hlau), txheej tiv thaiv oxide tuaj yeem tawg, ua rau kom nrawm thiab hnyav hauv cheeb tsam corrosion.
Polythionic Acids: Txawm hais tias tsis muaj nyob rau hauv cov kev pabcuam dawb huv, yog tias muaj cov tshuaj sulfur, Ni 201 tuaj yeem raug kev txom nyem.
Aeration: Thaum feem ntau zoo, cov pa aerated siab (oxygen-saturated) caustic solutions tuaj yeem ua rau cov nqi corrosion ntau dua piv rau de- aerated ones.
Hauv cov ntsiab lus, rau cov ntshiab lossis siab -purity caustic ib puag ncig ntawm qhov kub thiab txias, Nickel 201 muaj kev sib xyaw ua ke ntawm kev tiv thaiv corrosion thiab kev ua haujlwm zoo.
Q3: Peb yog ib tug fabricator tshiab rau welding Nickel 201. Peb twb hnov nws yog "touchy" piv rau stainless hlau. Dab tsi yog qhov teeb meem feem ntau hauv vuam Ni 201, thiab cov txheej txheem tshwj xeeb dab tsi lav lub suab, corrosion-resistant weld?
A: Koj hais yog lawm; Vuam Nickel 201 yuav tsum muaj kev qhuab qhia txawv dua li vuam stainless hlau. Nws tsis yog qhov nyuaj dua, tab sis nws yog tsawg dua kev zam txim ntawm kev coj tsis zoo. Lub hom phiaj tseem ceeb yog tswj cov khoom siv purity thiab corrosion kuj, tsis txhob muaj kab mob uas tuaj yeem ua rau tawg lossis embrittlement.
Ntawm no yog cov feem ntau pitfalls thiab cov txheej txheem los lav ib tug zoo weld:
Common Pitfalls:
Porosity: Nickel muaj lub siab solubility rau cov pa roj hauv lub xeev molten, tab sis raws li nws solidifies, qhov solubility poob qis heev. Yog tias kev tiv thaiv tsis txaus, cov pa roj (tshwj xeeb tshaj yog oxygen, nitrogen, thiab hydrogen) raug kaw, tsim porosity.
Kub Cracking: Nickel alloys raug kub kub tawg (solidification cracking) yog impurities xws li sulfur, phosphorus, lead, los yog tsawg- melting- taw tes hlau muaj nyob.
Loss of Ductility: Cov pa paug los ntawm cov pa roj carbon (xws li, los ntawm cov roj los yog roj) tuaj yeem ua rau carbide nag lossis daus hauv tshav kub- thaj tsam cuam tshuam, txo cov corrosion kuj thiab ductility.
Cov txheej txheem vuam tseem ceeb (Cov "Cov Cai"):
Kev tu kom zoo (Txoj Cai # 1): Qhov chaw vuam thiab cov hlau muab tub lim yuav tsum raug phais kom huv. Tshem tawm tag nrho cov roj, roj, xim, av, thiab kos tus cwj mem siv halogen-cov kuab tshuaj dawb (xws li acetone). Cov khaubncaws sab nraud povtseg yuav tsum tau muab tshem tawm los ntawm kev siv tshuab (stainless steel hlau txhuammob siab rau nickel nkaus xwblos yog sib tsoo) tam sim ntawd ua ntej vuam.
Kev sib cais ntawm cov khoom nruj me ntsis: Siv cov cuab yeej ( txhuam hniav, grinders) uas tsis tau siv rau ntawm cov hlau. Hlau thiab steel hais tuaj yeem paug cov nickel nto thiab ua rau muaj teeb meem corrosion.
Kev Tiv Thaiv Gas Zoo: Siv 100% Argon lossis Argon-Helium sib tov. Xyuas kom muaj roj txaus txaus thiab siv lub lens roj los txhim kho kev pab. Trailing shields tej zaum yuav tsim nyog rau complex geometries los yog cov ntawv thov tseem ceeb los tiv thaiv cov cua txias thiab cua sov- thaj tsam cuam tshuam los ntawm oxidation.
Filler Hlau Xaiv: Cov hlau muab tub lim yog feem ntau ERNi-1. Qhov muab tub lim no tshwj xeeb tsim los rau vuam Nickel 200 thiab 201 thiab muaj cov deoxidizers (xws li Titanium thiab Aluminium) los tawm tsam porosity.
Thaum tshav kub kub input Control: Siv lub tshav kub input. Ib qho "stringer hlaws" txheej txheem nrog tsawg weaving yog nyiam. Cov cua kub ntau dhau tuaj yeem ua rau cov qoob loo loj hlob, kub tawg, thiab cua sov dav dua - thaj tsam cuam tshuam. Interpass kub yuav tsum tau khaws cia qis (hauv qab 150℃F / 65 degree).
Arc Initiation: Siv lub siab - zaus pib lossis khawb pib ntawm kev khiav- tawm tab. Tsis txhob ntaus ib qho arc rau ntawm niam txiv cov ntaub ntawv saum npoo, vim qhov no tsim ib qho chaw me me, uas tuaj yeem ua qhov chaw rau qhov pib tawg.
Los ntawm kev kho Ni 201 nrog kev hwm nws xav tau-tshwj xeeb txog kev huv huv-fabricators tuaj yeem tsim cov welds uas muaj zog thiab corrosion- tiv taus zoo li lub hauv paus hlau.
Q4: Tshaj li cov txheej txheem tshuaj lom neeg kev lag luam, lwm yam kev lag luam siab - thev naus laus zis lossis kev lag luam tshwj xeeb yog Nickel 201 qhov tseem ceeb, thiab vim li cas nws cov cuab yeej profile tshwj xeeb tsim nyog rau lawv?
A: Txawm hais tias kev lag luam caustic yog nws daim ntawv thov nto moo tshaj plaws, Nickel 201 qhov tshwj xeeb ua ke ntawm cov khoom siv - siab purity, tswj thermal expansion, sib nqus cov yam ntxwv, thiab corrosion resistance- ua rau nws tseem ceeb nyob rau hauv ob peb lwm high -tech sectors.
Electronics thiab Aerospace:
Daim Ntawv Thov: Cov khoom siv hauv cov khoom siv hluav taws xob, xws li cov roj teeb rau qhov chaw thiab satellite, thiab cov khoom siv rau lub foob pob hluav taws thiab cov thrusters.
Vim li cas Ni 201? Nws tuaj yeem tsim tau yooj yim thiab sib sib zog nqus - kos rau hauv cov duab nyuaj. Nws tswj coefficient ntawm thermal expansion pab tswj thermal stresses thaum koom nrog lwm yam ntaub ntawv xws li ceramics los yog iav nyob rau hauv hluav taws xob feedthroughs thiab hermetically kaw Cheebtsam. Nws lub peev xwm los tswj cov ductility ntawm qhov kub thiab txias kuj yog ib qho cuab yeej cuab tam loj rau cov tshuab roj aerospace.
Soda-Kev tsim cov iav iav (Platinum Hloov):
Daim ntawv thov: Stirrers, thermocouple tiv thaiv raj, thiab tuav cov khoom siv rau molten soda-lime iav.
Vim li cas Ni 201? Molten iav yog corrosive heev rau feem ntau cov hlau. Nickel 201 nthuav tawm zoo heev tiv thaiv corrosion los ntawm molten soda- txiv qaub iav, feem ntau vim tias nws tsis yooj yim tsim oxides uas yuav paug cov iav (tsis zoo li hlau- raws li cov alloys uas tuaj yeem ua rau muaj xim). Nws yog tus nqi -txoj kev zoo rau platinum nyob rau hauv ntau yam tsis yog - iav tiv tauj daim ntawv thov.
Synthetic Fiber ntau lawm (Spinnerets):
Daim ntawv thov: Spinnerets thiab lwm yam khoom siv rau extruding hluavtaws fibers zoo li rayon.
Vim li cas Ni 201? Cov txheej txheem viscose rau kev ua rayon suav nrog cov tshuaj lom neeg. Ni 201 muaj qhov tsim nyog corrosion kuj. Tsis tas li ntawd, nws cov qauv zoo ib yam thiab tsis yog -reactive nto tso cai rau kev tsim cov fibers nrog txoj kab uas hla zoo ib yam thiab nto tiav, uas yog qhov tseem ceeb rau textile zoo.
Hauv cov ntawv thov no, nws tsis yog hais txog "tsis xeb"; nws yog hais txog purity (tsis txhob muaj cov khoom paug), formability, thiab kwv yees lub cev muaj zog nyob rau hauv huab mob.
Q5: Ib tus kws tshaj lij tau teev npe Nickel 201 rau ib feem ua haujlwm ntawm 350℃(660℃F). Dab tsi yog qhov tseem ceeb ntawm cov cuab yeej cuab yeej cuab tam uas lawv yuav tsum suav rau hauv lawv qhov tsim, vim tias cov khoom no txawv ntawm chav tsev kub?
A: Kev tsim qauv rau qhov kev pabcuam kub siab yuav tsum muaj kev hloov pauv ntawm kev xav los ntawm kev tsim qhov kub thiab txias. Ntawm 350 degree, cov khoom ntawm Nickel 201 tau hloov pauv ntau, thiab kev tsim qauv raws li chav - cov ntaub ntawv kub tuaj yeem ua rau ua tsis tiav ntxov.
Nov yog cov kev txiav txim siab tseem ceeb rau ib feem ua haujlwm ntawm 350 degree:
Txo cov tawm los thiab Tensile zog: Zoo li feem ntau cov hlau, Nickel 201 poob lub zog thaum kub nce. Qhov kev tsim tsim kev ntxhov siab (qhov kev ntxhov siab ntawm cov khoom tuaj yeem ua tau zoo) yuav tsum tau derated. Tus engineer yuav tsum sab laj nrog ASME Boiler thiab Pressure Vessel Code (los yog cov qauv hauv zos) rau qhov siab tshaj plaws kev ntxhov siab ntawm 350 degree. Cov nqi no yog qhov qis dua ntawm chav tsev kub.
Creep thiab Stress-Rupture: Qhov no yog tej zaum qhov tseem ceeb tshaj qhov xav txog. Ntawm 350℃, Nickel 201 yog nyob rau hauv qhov kub thiab txias qhov twg nws tuaj yeem nkag mus tau -ib lub sij hawm- nyob ntawm cov yas deformation nyob rau hauv tas li load, txawm tias qhov kev ntxhov siab yog qis dua cov khoom siv zog.
Tus engineer yuav tsum tsis tsuas yog xav txog qhov kev ntxhov siab tam sim ntawd tab sis kuj yog qhov kev nyuaj siab uas yuav sib sau ua ke ntawm cov khoom tsim lub neej. Piv txwv li, ib tug bolted sib koom ua ke yuav poob nws preload lub sij hawm vim creep so.
Tus qauv tsim yuav tsum yog raws li kev ntxhov siab- cov ntaub ntawv tawg, uas qhia koj txog qib kev ntxhov siab uas yuav ua rau tsis ua haujlwm tom qab muaj pes tsawg teev ntawm qhov kub thiab txias (xws li, 100,000-teev rupture zog).
Thermal Expansion: Nickel 201 muaj cov coefficient siab ntawm thermal expansion. Hauv kev ua haujlwm ntawm 350 degree, thermal expansion thiab contraction thaum pib-nce thiab kaw- voj voog tuaj yeem tsim kev ntxhov siab loj. Kev tsim qauv yuav tsum ua raws li qhov kev txav no los ntawm:
Kev teeb tsa kom zoo ntawm cov kav dej nrog kev nthuav dav loops lossis bellows.
Ua tib zoo tsim cov flanged pob qij txha thiab cov cuab yeej txhawb nqa kom tso cai rau kev loj hlob thermal yam tsis dhau - txwv tsis pub cov khoom.
Oxidation: Thaum Ni 201 muaj kev tiv thaiv oxidation zoo, ntawm 350℃hauv huab cua, nws yuav maj mam tsim cov nplai oxide. Rau cov ntu nyias lossis cov khoom siv nrog kev ua siab ntev (xws li cov khoom siv ntsuas), qhov kev ntsuas qeeb no yuav tsum tau txiav txim siab dhau lub neej ua haujlwm ntev.
Hauv luv luv, tsim nrog Ni 201 ntawm 350℃yog lub sijhawm - nyob ntawm qhov teeb meem tsim. Tus kws tshaj lij yuav tsum txav los ntawm kev suav yooj yim lub zog mus rau kev txheeb xyuas nrog rau tus nqi nkag, kev ntxhov siab- lub neej tawg, thiab thermal qaug zog kom ntseeg tau ntev - lub sijhawm, kev ua haujlwm nyab xeeb.
