1: Dab tsi yog Nickel Alloy UNS N02201 (Nickel 201), thiab vim li cas nws thiaj li tsim nyog rau daim ntawv thov steel pickling phaj?
Nickel Alloy UNS N02201, commonly called Nickel 201, is a commercially pure wrought nickel (>99.0% Ni) uas txhob txwm tshaj tawm cov ntsiab lus qis (tsawg dua lossis sib npaug li 0.02%). Qhov kev sib txawv tseem ceeb ntawm nws tus khub, Nickel 200 (C Tsawg dua lossis sib npaug rau 0.15%), ua rau nws qhov kev xaiv zoo tshaj plaws rau kev ua haujlwm siab - kub.
Nyob rau hauv steel pickling kab, kub hydrochloric (HCl) los yog sulfuric (H₂SO₄) acid da dej yog siv los tshem tawm nplai (hlau oxides) los ntawm steel coils. Cov khoom siv xws li cua sov coils, lub tank hauv ob sab phlu, txhawb nqa racks, thiab "phaj ua haujlwm" xws li crane baskets, cassette tuav, thiab acid fume hoods raug rau ib puag ncig tsis zoo:
Kub, Concentrated Acids: Kub feem ntau tshaj 65℃(150℃F), ua kom corrosion.
Oxidizing thiab txo cov xwm txheej: Ib puag ncig tuaj yeem hloov tshuaj lom neeg.
Mechanical Load and Abrasion: Cheebtsam yuav tsum tuav lub luj ntawm steel coils thiab tiv taus lub cev puas los ntawm nplai hais.
Nickel 201 ua tau zoo ntawm no vim nws:
Exceptional Corrosion Resistance: Nws muaj qhov ua tau zoo heev rau txhua qhov kev sib xyaw ntawm hydrochloric acid ntawm ntau qhov kub thiab txias rau sulfuric acid, tshwj xeeb tshaj yog nyob rau hauv tsis yog - aerated tej yam kev mob ntawm pickling da dej.
Resistance to Stress-Corrosion Cracking (SCC): Nws lub ntsej muag-centered cubic qauv thiab cov ntsiab lus nickel siab ua rau nws tiv taus cov tshuaj chloride-induced SCC, ib hom tsis ua hauj lwm rau stainless hlau hauv ib puag ncig no.
Siab -Tub kub ruaj khov: Cov ntsiab lus carbon tsawg tiv thaiv nag lossis daus ntawm graphite grain ciam teb carbides (graphitization) thaum raug kub ntawm 425℃thiab 650℃(800℃F - 1200}℃F), uas tuaj yeem tshwm sim hauv cov khoom cua sov lossis chav bays. Qhov no tuav ductility thiab tiv thaiv embrittlement.
Nws ua ke ntawm txhua yam muaj zog, fabricability, thiab unparalleled corrosion kuj nyob rau hauv kub, tsis yog - oxidizing acids ua rau Nickel 201 cov khoom siv rau qhov tseem ceeb, ntev - lub neej nyob rau hauv pickling kab.
2: Dab tsi yog qhov tseem ceeb ntawm kev tsim thiab kev txiav txim siab thaum siv Nickel 201 phaj rau cov khoom siv pickling?
Ua tiav kev siv Nickel 201 phaj yuav tsum ua raws li cov qauv tsim tshwj xeeb thiab tsim cov txheej txheem los khaws nws cov khoom muaj txiaj ntsig:
Kev txiav txim siab tsim:
Tsis txhob Crevices: Tsim yuav tsum txo qis qhov chaw nyob ruaj khov thiab cov crevices qhov twg cov kua qaub tuaj yeem mloog zoo, ua rau kom nrawm dua hauv cheeb tsam corrosion. Siv cov welds tsis tu ncua es tsis txhob cuam tshuam.
Kev Tiv Thaiv Cathodic: Hauv kev sib xyaw- cov khoom siv, xyuas kom Nickel 201 tsis yog ua tsis tau anodic rau cov ntaub ntawv zoo dua qub, uas yuav ua rau nws qhov corrosion. Kev cais hluav taws xob kom raug yog qhov tseem ceeb.
Thermal Expansion: Nickel muaj cov coefficient ntawm thermal expansion sib txawv ntawm cov hlau. Cov qauv tsim rau cov khoom siv cua sov lossis cov qauv loj yuav tsum suav nrog kev nthuav dav sib txawv kom tsis txhob muaj kev sib tsoo lossis vuam tsis ua haujlwm.
Fabrication Considerations:
Vuam: Siv cov hlau sib txuam (xws li ERNi-1 lossis ENi-1). Ua kom huv si nruj kom tsis txhob muaj cov kab mob sib kis los ntawm cov sulfur, lead, lossis phosphorous, uas tuaj yeem ua rau weld kub tawg. Siv cov khoom siv hluav taws xob tsawg thiab kev tswj xyuas qhov kub kom txaus (feem ntau qis dua 150℃/ 300℃F) txhawm rau tiv thaiv cov qoob loo ntau dhau.
Kev Ua Haujlwm Txias: Nickel 201 ua haujlwm- hardens sai. Kev tsim cov haujlwm xws li dabtsi yog khoov lossis dov yuav tsum muaj lub zog ntau dua li cov pa roj carbon steel thiab yuav tsum muaj cov kauj ruam nruab nrab ntawm cov txheej txheem rau deformations loj los kho cov ductility thiab tiv thaiv kev tawg.
Kev kho cua sov: Kev daws teeb meem annealing (feem ntau 870-980℃/ 1600-1800℃F ua raws li kev quenching ceev) yuav tsum tau tom qab ua haujlwm txias txias los txo cov kev ntxhov siab thiab kho kom zoo dua corrosion. Qhov no yog tshwj xeeb tshaj yog ib qho tseem ceeb rau cov khoom uas yuav pom txhua yam load nyob rau hauv corrosive ib puag ncig.
Deg Contamination: Tiv thaiv cov hlau tsis huv (los ntawm cov cuab yeej, sib tsoo lub log, lossis cov khoom khib nyiab) ntawm cov nickel nto. Embedded hlau yuav xeb hauv kev pabcuam, tsim cov ntsiab lus pib rau pitting. Dedicated, ntxuav cov cuab yeej thiab zaum kawg pickling / passivation ntawm fabricated ib feem nyob rau hauv ib tug nitric acid tov yog qhov tseem ceeb.
3: Yuav ua li cas ua tau zoo thiab tag nrho cov nqi ntawm cov tswv cuab (TCO) ntawm Nickel 201 piv rau lwm cov ntaub ntawv xws li stainless hlau 316L los yog duplex steels rau pickling daim hlau?
Thaum tus nqi pib ntawm cov khoom siv Nickel 201 yog siab dua li cov qauv stainless hlau, nws TCO feem ntau qis dua rau qhov tseem ceeb, siab - coj cov khoom hauv cov kab pickling.
Stainless Hlau 316L: Thaum muab cov kev tiv thaiv zoo dav dav, 316L yog qhov cuam tshuam rau pitting thiab chloride -induced stress corrosion cracking (SCC) nyob rau hauv kub hydrochloric acid ib puag ncig. Tej zaum nws yuav tsim nyog rau cov seem tsis nruj heev (xws li, cov tso tsheb hlau luam yaug) tab sis feem ntau ua tsis tau ntxov ntxov hauv cov kua qaub kub. Lub neej yog ntsuas nyob rau hauv lub hlis mus rau ob peb xyoos, ua rau muaj kev hloov ntau zaus, kev tsim khoom poob qis, thiab cov nqi tu.
Duplex Stainless Steels (piv txwv li, 2205): Muab lub zog zoo dua thiab txhim kho chloride SCC tsis kam piv rau 316L. Txawm li cas los xij, nyob rau hauv kub, concentrated txo cov acids zoo li HCl, lawv cov corrosion kuj tuaj yeem ua tsis tau siab. Lawv zoo dua rau sulfate-raws li los yog tsawg dua cov kab pickling.
Nickel 201: Nws tus nqi corrosion hauv kub HCl yog qhov kev txiav txim siab qis dua li cov khoom siv tsis zoo. Txawm hais tias kim heev, tsim kom zoo thiab tsim cov khoom siv Nickel 201 (piv txwv li, lub coil cassette lossis tank liner) tuaj yeem kav 10-20 xyoo lossis ntau dua nrog kev saib xyuas tsawg. Qhov no drastic txo:
Hloov Cov Nqi: Tsawg dua peev nyiaj rau qhov tshiab.
Cov Nqi Them Nqi: Tsis tshua muaj cov kab ntau lawm nres rau kev hloov khoom siv.
Kev pheej hmoo kis kab mob: Tshem tawm cov khoom kis kab mob los ntawm cov khoom siv hlau ua tsis tiav.
Kev Nyab Xeeb Kev Nyab Xeeb: Txo qhov phom sij ntawm kev puas tsuaj loj thiab cov kua qaub.
Kev suav TCO nyiam Nickel 201 rau cov khoom siv ncaj qha rau cov txheej txheem nruj tshaj plaws, qhov twg cov cuab yeej tsis ua haujlwm yog tus nqi ntau tshaj.
4: Dab tsi yog hom tsis ua haujlwm ntawm Nickel 201 pickling daim hlau, thiab lawv yuav tiv thaiv li cas?
Txawm tias muaj cov khoom siv zoo li Nickel 201, kev ua tsis tiav tuaj yeem tshwm sim, feem ntau yog vim kev siv tsis raug, kev tsim khoom, lossis kev saib xyuas:
Graphitization (tsuas yog siv tsis raug): Qhov no yog hom tsis ua haujlwm rau Nickel 200 (siab dua carbon) hauv siab - kev pabcuam kub. Kev qhia txog Nickel 201 (tsawg carbon) rau ib qho kev tivthaiv pom qhov kub siab tshaj 315℃(600℃F) tag nrho tshem tawm qhov kev pheej hmoo ntawm cov ciam teb embrittlement.
Corrosion Nyob rau hauv Rwb thaiv tsev (CUI): Rau cov rhuab daim hlau los yog tso tsheb hlau luam, yog tias Nickel 201 yog rwb thaiv tsev thiab rwb thaiv tsev yuav ntub nrog chlorides (los ntawm huab cua los yog acid fumes), concentrated chloride daws tuaj yeem tsim thiab ua rau thaj chaw pitting. Kev Tiv Thaiv: Siv cov dej tsis muaj dej, chloride- rwb thaiv tsev pub dawb nrog lub tsho kom zoo. Xav txog kev siv cov txheej tiv thaiv rau cov nickel nto ua ntej insulating.
Galvanic Corrosion: Yog tias Nickel 201 txuas ncaj qha rau cov hlau zoo dua qub (xws li Titanium lossis Graphite) nyob rau hauv cov kua qaub electrolyte, cov npib tsib xee tuaj yeem corrode sacrificially. Kev Tiv Thaiv: Hluav taws xob cais cov khoom siv uas tsis yog- cov pa taws thiab lub tes tsho, lossis tsim nrog txhua yam - npib tsib xee qhov chaw.
Mechanical Failure from Improper Fabrication: Cracking in heat-ffect zones (HAZ) vim kev sib kis kab mob, los yog tawg thaum tsim vim tsis muaj intermediate annealing. Kev Tiv Thaiv: Kev ua raws li cov txheej txheem vuam (AWS DNB2) thiab kev ua haujlwm zoo tshaj plaws raws li tau teev tseg hauv Q2.
Erosion-Corrosion: Nyob rau hauv siab- qhov chaw ntws los yog qhov chaw abrasive scale particles impinge, cov txheej tiv thaiv passive tuaj yeem raug tshem tawm, ua kom cov hlau tsis zoo. Kev Tiv Thaiv: Tsim los rau laminar ntws qhov twg ua tau, siv cov phaj tuab tuab nyob rau hauv siab- thaj chaw puas, lossis xav txog qhov nyuaj- ntsib qhov xwm txheej hnyav.
5: Qhov kev lees paub zoo thiab ntawv pov thawj dab tsi yog qhov tseem ceeb thaum muab Nickel 201 phaj rau daim ntawv thov tseem ceeb no?
Muab qhov kev nyab xeeb thiab nyiaj txiag cuam tshuam ntawm kev ua tsis tiav, kev yuav khoom yuav tsum yog raws li kev txheeb xyuas, tsis yog tus nqi xwb.
Cov ntaub ntawv yuav tsum tau ua: Tus neeg muag khoom yuav tsum muab Daim Ntawv Qhia Tag Nrho Cov Khoom Siv Xeem (MTR) lossis Daim Ntawv Pov Thawj Ua Raws Cai uas tuaj yeem taug qab rau tus lej kub yaj. Qhov MTR no yuav tsum tau lees paub ua raws li cov qauv tsim nyog xws li ASTM B162 (Plate, Sheet, thiab Strip) thiab tshwj xeeb hu rau UNS N02201 qib.
Cov ntaub ntawv tseem ceeb MTR: Daim ntawv tshaj tawm yuav tsum sau:
Chemical Composition: Txheeb xyuas cov pa roj carbon tsawg (tsawg dua lossis sib npaug li 0.02%), cov ntsiab lus nickel siab, thiab txwv tsis pub muaj cov khoom tsis zoo xws li sulfur, tooj liab, hlau, thiab manganese.
Mechanical Properties: Tensile zog, yield zog, thiab elongation ua tau raws li ASTM B162.
Kev kho cua sov: Kev lees paub ntawm qhov kawg annealing mob (feem ntau annealed) kom paub meej corrosion kuj thiab ductility.
Kev Ntsuas Ntxiv (yog tias tau teev): Rau cov khoom tseem ceeb, cov neeg yuav khoom yuav xav tau:
Intergranular Corrosion Test: Xws li ASTM G28 Method A kev sim kom ntseeg tau tias cov khoom nyob rau hauv cov cua sov kom zoo- kho mob thiab tsis muaj teeb meem microstructural theem.
Tsis yog-Kev kuaj kev puas tsuaj (NDE): Ultrasonic kuaj ntawm phaj kom pom cov laminations sab hauv lossis suav nrog.
Kev Tsim Nyog Muaj Peev Xwm: Tau los ntawm cov mills muaj koob npe lossis cov neeg tsim khoom lag luam raug lees paub tshwj xeeb hauv kev ua haujlwm siab - alloys. Lawv yuav tsum muaj kev txawj ntse los pab txhawb daim ntawv thov thiab muab qhov tsim nyog traceability.
Hauv cov ntsiab lus, kev yuav khoom Nickel 201 rau cov khoom siv pickling yog kev nqis peev hauv kev ua haujlwm ntev -, txhim khu kev qha. Kev tsom xam yuav tsum yog ntawm cov ntaub ntawv pov thawj zoo thiab tsim nyog fabrication, raws li tus nqi ntawm qhov tsis ua hauj lwm deb tshaj qhov pib txuag nyiaj los ntawm cov khoom tsis muaj ntawv pov thawj lossis cov khoom tsis zoo.
