Q1: Dab tsi yog qhov sib txawv ntawm Alloy 200 Pipe thiab Alloy 201 Pipe, thiab qhov kev sib txawv no cuam tshuam li cas rau kev yuav khoom thiab kev qhia tshwj xeeb rau qhov kub siab -kab kab?
A: Txawm hais tias ob qho tib si Alloy 200 (UNS N02200) thiab Alloy 201 (UNS N02201) yog cov khoom lag luam ntshiab wrought npib tsib xee, qhov sib txawv nyob hauv lawv cov ntsiab lus carbon, uas hais txog lawv qhov kev nyab xeeb ntawm kev ua haujlwm kub. Rau cov kav dej engineers, qhia qhov tsis ncaj ncees lawm rau txoj kab hluav taws xob tuaj yeem ua rau muaj kev puas tsuaj loj heev.
Alloy 200 Pipe feem ntau muaj cov ntsiab lus carbon txog li 0.15%. Cov hlau no yog tus qauv rau cov khoom ua haujlwm qis dua 315℃(600℃F).
Alloy 201 Pipe yog qhov qis -carbon derivative, nrog cov ntsiab lus siab tshaj plaws ntawm 0.02%.
Nyob rau hauv qhov siab -kub kab ua haujlwm siab tshaj 315 degree, qhia txog Alloy 200 yog qhov txaus ntshai. Ntawm qhov kub siab no, cov pa roj carbon nyob rau hauv Alloy 200 tuaj yeem tso tawm ntawm cov kua dej thiab tsim cov graphite films ntawm cov ciam teb nplej -ib qho tshwm sim hu ua graphitization. Cov txheej txheem no ua tau zoo hloov cov yeeb nkab phab ntsa mus rau hauv cov qauv nkig, ua rau nws muaj kev cuam tshuam los ntawm kev kub ntxhov los yog kev kub ntxhov.
Yog li ntawd, rau tej chav lossis txheej txheem kab ua haujlwm siab tshaj 315 degree, qhov kev qhia tshwj xeeb yuav tsum tau ua kom pom tseeb ntawm Alloy 201. Txawm li cas los xij, rau ambient kub caustic hloov kab, Alloy 200 feem ntau yog qhov kev xaiv pheej yig dua. Ib txwm txheeb xyuas qhov ntsuas kub siab tshaj plaws ntawm P&ID ua ntej yuav khoom.
Q2: Nyob rau hauv ib tug caustic soda hloov kab, yuav ua li cas corrosion mechanism ntawm Alloy 200 yeeb nkab txawv ntawm cov hlau stainless, thiab vim li cas nws thiaj li yog qhov kev xaiv txawm tias tus nqi pib ntau dua?
A: Qhov kev nyiam rau Alloy 200 yeeb nkab hauv kev pab cuam caustic yog qhov xwm txheej ntawm lub neej- voj voog tus nqi tshaj qhov kev siv nyiaj ua ntej. Qhov sib txawv yog nyob rau hauv qhov xwm ntawm corrosion nres.
Stainless hlau (piv txwv li, 304 / L lossis 316 / L):
Kev pheej hmoo: Nyob rau hauv ib puag ncig caustic, stainless hlau cia siab rau lawv cov chromium oxide passive txheej rau kev tiv thaiv. Txawm li cas los xij, ntawm qhov siab thiab qhov kub thiab txias, caustic soda tawm tsam cov txheej txheem no.
Hom Tsis Ua Haujlwm: Qhov kev pheej hmoo tseem ceeb yog Caustic Stress Corrosion Cracking (Caustic SCC). Qhov no yog ib qho insidious tsis ua hauj lwm qhov twg cov yeeb nkab tawg nyob rau hauv kev ua ke ntawm tensile kev nyuaj siab (los ntawm lub siab los yog residual vuam kev nyuaj siab) thiab ib tug corrosive caustic ib puag ncig. Cov kab nrib pleb tuaj yeem nthuav tawm sai sai yam tsis muaj qhov poob ntawm phab ntsa tuab, ua rau kom sai sai.
Alloy 200:
Lub Mechanism: Raws li ib tug ntshiab nickel alloy, Alloy 200 tsis cia siab rau ib tug chromium oxide txheej. Es tsis txhob, nws tsim ib tug ruaj khov, tenacious nickel oxide / hydroxide zaj duab xis uas yog inherently ruaj khov nyob rau hauv caustic ib puag ncig.
Hom Tsis Ua Haujlwm: Corrosion ntawm Alloy 200 hauv cov kev pabcuam caustic feem ntau yog cov qauv corrosion. Cov phab ntsa tuab txo qis ntawm qhov qeeb, kwv yees, thiab ntsuas tau (feem ntau tsawg dua 0.05 hli / xyoo hauv kev pabcuam tsim nyog).
Kev Lag Luam Logic: Txawm hais tias cov yeeb nkab steel hlau yuav raug nqi tsawg dua, nws lub sijhawm tsis ua haujlwm tsis txaus ntseeg (SCC) yuav tsum tau tshuaj xyuas ntau zaus thiab muaj kev pheej hmoo siab ntawm kev poob qis. Alloy 200 tso cai rau cov kws ua haujlwm los suav cov nyiaj pub dawb rau kev txhim kho corrosion thiab teem sijhawm saib xyuas kom zoo, ua kom muaj kev nyab xeeb thiab ua kom lub sijhawm cog qoob loo.
Q3: Peb tab tom txhim kho Alloy 200 pipeline tshiab. Dab tsi yog qhov nruj "kub txoj cai" rau vuam cov khoom no kom tsis txhob muaj qhov tsis xws luag xws li porosity thiab kub tawg?
A: Vuam Alloy 200 yuav tsum muaj kev qhuab qhia los ze zog rau vuam reactive hlau zoo li titanium dua vuam stainless hlau. Tus yeeb ncuab tseem ceeb yog kev sib kis. Nov yog cov kev cai golden rau kev vam meej weld:
1. Txoj Cai "Kev Kho Mob Kev Kho Mob":
Qhov no tsis yog -negotiable. Alloy 200 yog rhiab heev rau impurities xws li sulfur, lead, phosphorus, thiab roj.
Kev Ua: Cov yeeb nkab saum npoo yuav tsum yog hauv av lossis machined rov qab rau cov hlau ci kom tsawg kawg 1-2 ntiv tes los ntawm ntug vuam. Tom qab ntawd qhov chaw yuav tsum tau muab ntxuav nrog cov ntaub so ntswg huv, lint -dawb daim ntaub saturated nrog cov kuab tshuaj tsis muaj halogen (xws li acetone). Tsis txhob siv lub khw rags uas tej zaum yuav tau siv ntawm carbon steel.
2. Txoj Cai Dedicated Tooling:
Kev Ua: Koj yuav tsum siv cov hlau tsis muaj hlau txhuam, cov khoom sib tsoo, thiab cov ntaub ntawv uas tau mob siab rau cov nickel alloys nkaus xwb. Yog tias lub cuab yeej tau siv los ntawm cov hlau, nws yuav embed hlau hais rau hauv qhov chaw ntawm Alloy 200. Cov hlau hais no dhau los ua qhov chaw rau galvanic corrosion thiab tuaj yeem ua rau tawg hauv qhov vuam.
3. Txoj Cai Tswj Kub Kub:
Kev Ua: Siv cov txheej txheem vuam qis qis (feem ntau GTAW / TIG). Khaws qhov kub ntawm qhov sib cuam tshuam (feem ntau qis dua 150℃F / 65℃). Tsis txhob siv cov txheej txheem weaving; siv ib tug stringer hlaws dai. Cov tswv yim kub kub ua rau cov qoob loo loj hlob thiab tuaj yeem ua rau kub tawg thaum solidification.
4. Txoj Cai Filler Hlau:
Kev Ua: Siv ERNi-1 muab tub lim hlau. Qhov tshwj xeeb muab tub lim no muaj cov deoxidizers (Titanium thiab Aluminium) tsim los tiv thaiv porosity hauv cov ntshiab nickel matrix. Tsis txhob sim welding nws nrog stainless hlau muab tub lim los yog tsis muaj muab tub lim tshwj tsis yog tias tus tsim tso cai rau autogenous vuam ntawm nyias phab ntsa tubing.
Q4: Ib qho qub Alloy 200 pipeline tau ua haujlwm tau 20 xyoo. Thaum lub sijhawm tshuaj xyuas tsis ntev los no, peb pom thaj chaw uas muaj "graphitic nto" thiab tawg. Puas yog tus qauv hnav thiab tsim kua muag, lossis qhov tshwj xeeb metallurgical tsis ua haujlwm?
A: Qhov koj tab tom piav txog lub suab zoo li cov ntaub ntawv classic ntawm Graphitization, ib qho tshwj xeeb metallurgical degradation mechanism uas yog thawj qhov ntev - lub sij hawm tsis ua hauj lwm hom rau Alloy 200.
Raws li tau hais hauv Q1, qhov no tshwm sim thaum cov yeeb nkab tau ua haujlwm ntawm qhov kub siab (feem ntau siab dua 315 degree) rau lub sijhawm ntev. Cov pa roj carbon, uas yog nyob rau hauv ib tug metastable khoom tov nyob rau hauv cov npib tsib xee, precipitates tawm mus ua nodules los yog films ntawm graphite.
Vim li cas qhov no tseem ceeb?
Poob lub zog: Lub graphite tsis muaj lub zog muaj zog. Cov hlau matrix zoo tau hloov los ntawm lub zog tsis muaj zog, nkig.
Embrittlement: Lub graphite ntawm cov ciam teb ua rau lub ductility ntawm cov yeeb nkab. Yog tias koj yuav tsum coj tus qauv, nws yuav tawg thaum khoov, coj zoo li cam khwb cia hlau es tsis muaj nickel ductile.
Kev daws teeb meem:
Yog tias koj pom graphitization, koj tsis tuaj yeem "kho" nws ntawm kev kho cua sov. Cov qauv metallurgical puas lawm.
Yog tias nws yog qhov graphitization nkaus xwb: Koj tuaj yeem zom nws tawm yog tias phab ntsa tuab txaus.
Yog tias nws dhau los ntawm - phab ntsa lossis ntawm cov ciam teb nplej: Qhov cuam tshuam ntawm Alloy 200 yeeb nkab yuav tsum raug txiav tawm thiab hloov pauv. Qhov tseem ceeb, qhov hloov spool yuav tsum tau tsim los ntawm Alloy 201 los tiv thaiv qhov teeb meem ntawm qhov kub thiab txias.
Q5: Peb tab tom tawm tsam nrog qhov ntev ntev ntawm qhov kev txiav txim loj ntawm seamless Alloy 200 yeeb nkab. Sab nraud txoj kab uas hla (OD) zoo li txawv dua li peb pom nrog stainless hlau. Qhov no puas yog qhov chaw tsim khoom yuam kev, lossis yog nws muaj nyob rau hauv cov khoom?
A: Qhov no yog ib qho kev sib tw hauv kev yuav khoom thiab feem ntau yog los ntawm kev tsim cov txheej txheem ntawm nickel alloys es tsis yog qhov chaw tsim khoom yuam kev.
Qhov "Stiffness" Factor:
Alloy 200 yog qhov "stiffer" thiab ua hauj lwm- hardens sai dua austenitic stainless hlau zoo li 304 los yog 316. Thaum tsim seamless yeeb nkab los ntawm cov txheej txheem tho thiab dov (piv txwv li, Mannesmann txheej txheem), cov khoom yog nyuaj npaum li cas ntawm cov cuab yeej.
Lub txim:
Tool Wear: Lub hardness ntxiv ua rau hnav sai dua ntawm cov thom khwm thiab dov tuag.
Caij nplooj ntoos hlav-Rov qab: Nickel alloys muaj qhov sib txawv elastic rov zoo li qub. Tom qab cov yeeb nkab dhau los ntawm lub sizing zeb, nws yuav "caij nplooj ntoos hlav rov qab" txawv dua li cov hlau, ua rau nws nyuaj rau tuav nruj OD tolerances.
Ua Haujlwm Hardening: Raws li cov yeeb nkab ua haujlwm, nws hardens. Yog tias lub zeb sim ua kom zoo, cov khoom yuav tiv thaiv deformation, ua rau me me variations.
Cov Tswv Yim Muag Khoom:
Qhia kom meej tus qauv: Xyuas kom meej tias koj tau xa mus rau qhov tseeb ASTM tus qauv (xws li ASTM B161 rau Seamless Nickel Pipe). Cov txheej txheem no txhais tau tias kev kam rau siab, uas rau cov nickel alloys qee zaum yuav dav me ntsis dua rau cov hlau tsis muaj steel nyob ntawm qhov loj thiab lub sijhawm.
Tshuab Tshuag Nyiaj: Yog hais tias cov yeeb nkab yog destined rau ib feem uas yuav tsum tau machining meej (xws li ib tug flange los yog ib tug valve lub cev), nws yog tsim nyog los txiav txim cov yeeb nkab nrog ib tug hnyav phab ntsa thickness (ntxiv Tshuag) kom tso cai rau ib tug huv si - nce machining pass kom tiav qhov kawg meej qhov ntev.
Kev sib txuas lus: Sib tham txog koj qhov yuav tsum tau ua siab ntev nrog lub zeb lossis tus xa khoom ua ntej. Yog tias koj xav tau "kev zam tshwj xeeb" nruj dua li ASTM tus qauv, lawv tuaj yeem sib tham, txawm tias lawv yuav ua rau tus nqi nce ntxiv thiab lub sijhawm ua haujlwm.
