1: ASTM B725 yog dab tsi, thiab Nickel Alloy UNS N02201 (Nickel 201) ua tau raws li qhov xav tau tshwj xeeb ntawm kev siv cov yeeb nkab welded?
ASTM B725 yog tus qauv kev qhia tshwj xeeb rau Welded Nickel thiab Nickel Alloy Yeeb Nkab, tshwj xeeb tshaj yog npog cov khoom tsim los ntawm tiaj tus -cov ntaub ntawv dov (daim ntawv lossis phaj) tsim thiab welded longitudinally. Thaum ua ntawv thov rau UNS N02201, feem ntau hu ua Nickel 201, tus qauv no tswj hwm kev tsim khoom loj -inch, corrosion-cov kav kav dej. Nickel 201 yog qhov qis-carbon variant ntawm kev lag luam ntshiab npib tsib xee, nrog rau cov ntsiab lus siab tshaj plaws ntawm 0.02%, ua rau nws tshwj xeeb tsim rau welded yeeb nkab fabrication thiab kev pabcuam.
Lub alloy lub zog ua kom zoo kawg nkaus nrog cov kev xav tau ntawm kev siv cov yeeb nkab welded:
Weldability & Structural Integrity: Nickel 201 cov ntsiab lus qis carbon tshem tawm txoj kev pheej hmoo ntawm graphitization- nag lossis daus ntawm cov pa roj carbon monoxide ntawm cov ciam teb thaum lub sij hawm vuam lossis siab - qhov kev pab kub (siab tshaj 315℃/ 600℃F). Qhov no ua kom thaj tsam weld thiab tshav kub- thaj tsam cuam tshuam (HAZ) khaws cov ductility thiab corrosion kuj, uas yog ib qho tseem ceeb rau txoj hlua ntev hauv ASTM B725 yeeb nkab.
Exceptional Corrosion Resistance: Nws muaj kev tiv thaiv zoo rau ntau qhov chaw hnyav, tshwj xeeb tshaj yog kub, muaj zog alkalis (xws li, sodium thiab potassium hydroxide), tsis yog - oxidizing ntsev, thiab ntau cov organic acids. Qhov no ua rau nws yog cov khoom tseem ceeb tshaj plaws rau cov txheej txheem tshuaj piping qhov twg stainless hlau yuav sai sai.
Fabricability los ntawm Phaj: Nyob rau hauv cov kev mob annealed, Nickel 201 phaj muaj zoo heev formability, cia nws yuav dov thiab welded rau hauv loj - txoj kab uas hla kav nrog txheeb ze yooj yim piv rau harder, tsawg ductile alloys.
Thermal Stability: Nws qhov kev ua tau zoo nyob rau hauv siab -kub txo qhov cua thiab tiv thaiv chloride kev nyuaj siab -corrosion cracking (SCC) ua rau nws zoo tagnrho rau cov txheej txheem piping hauv petrochemical thiab refining daim ntaub ntawv.
2: Yuav ua li cas yog ASTM B725 Nickel 201 yeeb nkab tsim, thiab dab tsi tshwj xeeb cov kauj ruam ua kom muaj kev ncaj ncees ntawm txoj kab ntev weld seam?
Kev tsim khoom ntawm ASTM B725 Nickel 201 yeeb nkab yog ntau -theem, tswj txheej txheem tsom rau kev ncaj ncees seam:
Plate Preparation & Testing: Cov txheej txheem pib nrog Nickel 201 phaj, ntawv pov thawj rau ASTM B162. Lub phaj yog kuaj ultrasonically (UT) los xyuas kom meej tias nws tsis muaj laminations los yog inclusions uas yuav cuam tshuam qhov vuam. Nws yog ces beveled thiab txiav mus rau qhov loj me (dav=yeeb nkab ncig, ntev=yeeb nkab seem ntev).
Cold forming: Lub phaj yog tsim los ua ib lub cylindrical siv lub phaj dov tshuab los yog U-O nias (thawj rau hauv U-puab, ces mus rau hauv O-puab). Qhov no yog qhov txias - txheej txheem ua haujlwm rau Nickel 201.
Vuam - Qhov tseem ceeb Longitudinal Seam:
Kev Npaj Ua Ntej: Cov npoo yog qhov sib npaug, feem ntau nrog ib qho -V lossis ob npaug -V bevel npaj.
Vuam txheej txheem: Lub hauv paus longitudinal seam yog welded siv Submerged Arc Vuam (SAW) rau tuab- cov kav dej los yog Gas Tungsten Arc Vuam (GTAW/TIG) rau cov hauv paus hla thiab cov phab ntsa nyias. Filler hlau sib piv cov hlau chemistry (piv txwv li, ENi-1 kev faib tawm) yog siv.
Ntau Daim Ntawv Pov Thawj: Lub vuam tau ua tiav nrog ntau qhov kev sib tw sab hauv thiab sab nrauv kom ntseeg tau tias muaj kev nkag mus rau tag nrho thiab kev sib koom ua ke.
Ncej -Kev Kho Hniav Kub (PWHT): Qhov no yog qhov yuav tsum tau ua thiab cov kauj ruam tseem ceeb rau Nickel 201 yeeb nkab rau ASTM B725. Tag nrho cov yeeb nkab seem yog raug rau tag nrho cov tshuaj anneal (feem ntau cua sov rau 760-870℃/ 1400-1600℃F ua raws li los ntawm ceev ceev). Qhov no ua haujlwm rau:
Homogenize lub vuam hlau thiab HAZ microstructure.
Tshem tag nrho cov kev ntxhov siab seem ntawm kev tsim thiab vuam.
Dissolve ib theem ob thiab kho kom zoo corrosion kuj nyob rau hauv tag nrho cov yeeb nkab, tshwj xeeb tshaj yog nyob rau hauv weld cheeb tsam.
Kev Ua Haujlwm Kawg & Kev Ntsuas: Cov yeeb nkab yog qhov loj me (ntev lossis ntsuas qhov sib npaug), txiav mus rau qhov kawg ntev, thiab dhau qhov kev sim nruj raws li ASTM B725.
3: Dab tsi yog cov ntawv thov tseem ceeb rau loj - txoj kab uas hla ASTM B725 Nickel 201 yeeb nkab, thiab vim li cas feem ntau nws tsuas yog qhov kev xaiv zoo xwb?
ASTM B725 Nickel 201 yeeb nkab tau teev tseg rau cov txheej txheem tseem ceeb uas tsis ua haujlwm yuav ua rau muaj kev puas tsuaj loj, ob qho tib si ntawm kev nyab xeeb thiab nqi. Nws tsis yog ib qho dav dav - lub hom phiaj yeeb nkab tab sis yog ib qho kev daws teeb meem rau kev siv tshuaj lom neeg hnyav tshaj plaws.
Caustic Service hauv Chemical & Petrochemical Plants:
Daim ntawv thov: Thawj cov kab hloov pauv rau cov concentrated (50-73%) sodium hydroxide (caustic soda) ntawm qhov kub siab.
Qhov laj thawj: Stainless hlau thiab feem ntau lwm yam alloys raug kev txom nyem los ntawm caustic cracking thiab siab corrosion nyob rau hauv qhov chaw no. Nickel 201 yog lub cev tiv thaiv kab mob thiab muaj ntau xyoo ntawm kev pabcuam txhim khu kev qha.
Organic Chemical & Fatty Acid Ua:
Daim ntawv thov: Reactor pub thiab tawm kab, distillation kem hloov kab.
Qhov laj thawj: Kev tiv thaiv kom txo cov kua qaub thiab cov kuab tshuaj organic, ua ke nrog cov khoom tsis muaj - paug uas khaws cov khoom purity.
Alumina Production (Bayer Txheej Txheem):
Daim Ntawv Thov: Siab- kub zom thiab slurry hloov kab.
Lub ntsiab lus: Kov kub, caustic aluminate daws qhov twg puas thiab corrosion ua ke. Nws txoj kev weldability tso cai rau kev tsim kho ntawm cov kav dej loj loj.
Nuclear Fuel Processing:
Daim ntawv thov: Piping rau uranium enrichment thiab roj pas nrig fabrication txheej txheem.
Qhov laj thawj: Corrosion resistance nyob rau hauv tej yam fluoride thiab chloride ib puag ncig, ua ke nrog tsawg thermal neutron absorption cross-section.
It becomes the only viable choice when an application requires all of the following: 1) Transport of hot, concentrated caustics or specific aggressive organics, 2) Large diameters (>12 nti) ua seamless yeeb nkab (ASTM B161) txwv tsis pub kim los yog tsis muaj, 3) Ib qho kev xav tau rau kev ntxhov siab tag nrho - nyem thiab homogenization ntawm PWHT, uas yog qhov tseem ceeb rau B725 txoj kev tsim khoom.
4: Cov txheej txheem kuaj thiab tshuaj xyuas dab tsi yog ASTM B725 txoj cai los lav cov yeeb nkab zoo?
ASTM B725 tswj hwm lub roj teeb ntawm kev sim, nrog rau qhov tshwj xeeb tsom rau ntawm qhov vuam seam.
Tsis yog -Kev Tshawb Fawb Kev Puas Tsuaj (NDE) ntawm Weld:
Radiographic Testing (RT): 100% ntawm qhov ntev vuam seam yuav tsum tau radiographed. Qhov no yog tus qauv kub rau kev kuaj pom qhov tsis sib xws hauv ntim xws li slag inclusions, porosity, lossis tsis muaj fusion raws tag nrho qhov ntev ntawm cov seam.
Liquid Penetrant Testing (PT) los yog Sib Nqus Particle Testing (MT): Tag nrho sab nrauv weld nto thiab feem ntau sab hauv (yog siv tau) raug tshuaj xyuas rau saum npoo - tawg tsis xws luag. PT yog siv rau Nickel 201 (tsis yog-magnetic).
Kev Ntsuas Siab: Txhua lub yeeb nkab yuav tsum tau kuaj xyuas hydrostatic ntawm lub siab uas ua rau muaj kev ntxhov siab nyob rau hauv phab ntsa sib npaug li 50% ntawm cov khoom uas tau teev tseg tsawg kawg nkaus yield zog. Qhov no txheeb xyuas tag nrho cov siab ncaj ncees thiab xau- nruj.
Mechanical Tests los ntawm Test Phaj:
Transverse Tension Test: Ib qho qauv txiav hla lub vuam yuav tsum ua tau raws li qhov yuav tsum tau muaj zog tensile yam tsawg kawg nkaus.
Kev taw qhia-Kev Ntsuas Khoov: Ob lub ntsej muag khoov thiab lub hauv paus khoov yuav tsum tau kuaj. Cov qauv welded yog khoov dua ib txoj kab uas hla ntawm mandrel kom pom qhov ductility thiab soundness ntawm weld thiab fusion cheeb tsam. Tsis muaj kab nrib pleb ntau tshaj qhov luaj li cas raug tso cai.
Flattening Test (rau cov kab me me): Rau cov kav dej nyob rau hauv ib qho me me, lub nplhaib qauv yog flattened los xyuas kom meej ductility.
Certification & Traceability: Cov chaw tsim khoom yuav tsum muab Daim Ntawv Qhia Txog Cov Khoom Siv (MTR) uas muab tag nrho traceability los ntawm cov yeeb nkab tiav rov qab mus rau qhov kub ntawm cov phaj qub. MTR yuav tsum tau lees paub cov tshuaj muaj pes tsawg leeg (paub meej UNS N02201 qis-carbon spec), cov txiaj ntsig ntawm kev ntsuas tshuab, cov ntaub ntawv kho cua sov, thiab cov ntsiab lus ntawm tag nrho cov txiaj ntsig NDE.
5: Dab tsi yog qhov tseem ceeb rau kev tsim qauv, vuam, thiab kev teeb tsa ntawm ASTM B725 Nickel 201 yeeb nkab?
Kev tsim kho kom zoo yog qhov tseem ceeb raws li kev tsim zeb.
System Design:
Kev txhawb nqa: Siv dav, tsis yog -cov kev txhawb nqa abrasive (piv txwv li, PTFE pads) los tiv thaiv galling thiab crevice corrosion. Tus account rau Nickel lub thermal expansion ntau dua piv rau carbon steel.
Kev rho tawm: Siv cov khoom siv dielectric rwb thaiv tsev ntawm kev txhawb nqa thiab kev sib txuas rau cov qauv carbon steel los tiv thaiv galvanic corrosion.
Field Welding (Girth Welds):
Kev Tsim Nyog Kev Tsim Nyog: Vuam Cov Txheej Txheem Specifications (WPS) yuav tsum tsim nyog raws li ASME Tshooj IX. Nickel alloys xav tau cov txheej txheem tshwj xeeb.
Kev huv huv: Paramount. Weld aav yuav tsum tau ntxuav tag nrho cov xim, roj, thiab cov kab mob. Siv cov txhuam hniav stainless hlau tshwj xeeb rau cov nickel alloys.
Filler Hlau: Siv cov khoom sib txuam (ERNi-1 rau TIG). Qhov tseem ceeb, tsis txhob siv cov yeeb nkab ntev SAW weld muab tub lim rau GTAW girth welds.
Rov qab Purging: Tsis xav tau. Cov yeeb nkab sab hauv yuav tsum tau purged nrog argon thaum lub sij hawm vuam los tiv thaiv oxidation sab hauv (qab zib) ntawm cov hauv paus hniav, uas yuav ua kom puas corrosion kuj.
Interpass Kub: Tswj nruj kom qis dua 150℃(300℃F).
Installation & Commissioning:
Kev tuav: Siv cov nylon slings. Tiv thaiv polished los yog pickled tiav.
Hydrotest Dej Zoo: Siv demineralized lossis chloride- dej dawb los tiv thaiv pitting corrosion thaum kuaj. Tom qab ziab kom qhuav.
Thaum kawg Passivation: Tom qab tag nrho cov fabrication, tag nrho cov txheej txheem sab hauv yuav tsum tau chemically ntxuav thiab passivated nrog ib tug nitric acid tov kom rov zoo li qub txheej tiv thaiv oxide thiab tshem tawm tej embedded hlau.
Hauv cov ntsiab lus, ASTM B725 Nickel 201 welded yeeb nkab yog ib qho kev daws teeb meem rau kev hloov tshuaj lom neeg. Nws tus nqi yog nyob rau hauv kev sib xyaw ua ke ntawm cov hlau tsis muaj kev tiv thaiv corrosion, cov qauv kev ncaj ncees ntawm cov khoom siv vuam, thiab kev ntxhov siab tag nrho - nyem los ntawm PWHT. Kev vam meej nyob ntawm kev qhia tus qauv kom raug, txheeb xyuas cov ntawv pov thawj zeb, thiab ua tiav kev tsim khoom nrog cov txheej txheem tshwj xeeb uas xav tau rau siab -nickel alloys.
