Corrosion yog ib qho tseem ceeb tshaj plaws uas ua rauvalvekev puas tsuaj. Yog li ntawd, hauvvalvekev tiv thaiv, valve anti-corrosion yog ib qho teeb meem tseem ceeb los xav txog.
Valvecorrosion daim ntawv
Kev xeb ntawm cov hlau feem ntau yog tshwm sim los ntawm cov tshuaj corrosion thiab electrochemical corrosion, thiab corrosion ntawm cov ntaub ntawv uas tsis yog xim hlau feem ntau yog tshwm sim los ntawm cov tshuaj ncaj qha thiab lub cev ua haujlwm.
1. Tshuaj corrosion
Nyob rau hauv cov xwm txheej uas tsis muaj tam sim no raug tsim, qhov nruab nrab ib puag ncig ncaj qha cuam tshuam nrog cov hlau thiab rhuav tshem nws, xws li corrosion ntawm cov hlau los ntawm high-temperature qhuav gas thiab non-electrolytic tov.
2. Galvanic corrosion
Cov hlau yog nyob rau hauv kev sib cuag nrog cov electrolyte, uas ua rau lub ndlwg ntawm electrons, uas ua rau nws tus kheej puas los ntawm electrochemical kev txiav txim, uas yog lub ntsiab ntawm corrosion.
Feem ntau acid-base ntsev tov corrosion, atmospheric corrosion, av corrosion, seawater corrosion, microbial corrosion, pitting corrosion thiab crevice corrosion ntawm stainless hlau, thiab lwm yam, yog tag nrho cov electrochemical corrosion. Electrochemical corrosion tsis tsuas yog tshwm sim ntawm ob yam khoom uas tuaj yeem ua lub luag haujlwm tshuaj, tab sis kuj ua rau muaj qhov sib txawv vim qhov sib txawv ntawm qhov sib txawv ntawm cov tshuaj, qhov sib txawv ntawm cov pa oxygen nyob ib puag ncig, qhov sib txawv me ntsis ntawm cov qauv ntawm cov khoom, thiab lwm yam, thiab tau txais lub zog ntawm corrosion, kom cov hlau tsis tshua muaj peev xwm thiab txoj hauj lwm ntawm lub hnub ci phaj poob.
Valve tus nqi corrosion
Tus nqi ntawm corrosion tuaj yeem muab faib ua rau qib:
(1) Ua tiav corrosion-resistant: tus nqi corrosion yog tsawg dua 0.001 hli / xyoo
(2) Tsis tshua muaj corrosion resistant: corrosion tus nqi 0.001 txog 0.01 hli / xyoo
(3) Corrosion kuj: corrosion tus nqi 0.01 txog 0.1 hli / xyoo
(4) Tseem corrosion resistant: corrosion tus nqi 0.1 txog 1.0 hli / xyoo
(5) Tsis zoo corrosion kuj: corrosion tus nqi 1.0 mus rau 10 hli / xyoo
(6) Tsis muaj corrosion-resistant: tus nqi corrosion yog ntau tshaj 10 hli / xyoo
Cuaj qhov kev tiv thaiv corrosion
1. Xaiv cov khoom siv corrosion-resistant raws li qhov nruab nrab corrosive
Nyob rau hauv qhov tseeb ntau lawm, corrosion ntawm nruab nrab yog heev nyuaj, txawm hais tias cov khoom siv valve siv nyob rau hauv tib qhov nruab nrab yog tib yam, qhov concentration, kub thiab siab ntawm nruab nrab yog txawv, thiab corrosion ntawm nruab nrab rau cov khoom tsis zoo li qub. Rau txhua txhua 10 ° C nce hauv nruab nrab kub, tus nqi corrosion nce li ntawm 1 ~ 3 zaug.
Qhov nruab nrab concentration muaj kev cuam tshuam zoo rau kev xeb ntawm cov khoom siv valve, xws li cov hlau lead yog nyob rau hauv sulfuric acid nrog ib tug me me concentration, corrosion yog heev me me, thiab thaum lub concentration ntau tshaj 96%, corrosion nce sharply. Cov pa roj carbon steel, ntawm qhov tsis sib xws, muaj qhov hnyav tshaj plaws corrosion thaum cov sulfuric acid concentration yog li 50%, thiab thaum cov concentration nce mus rau ntau tshaj 60%, corrosion kuj txo qis. Piv txwv li, txhuas yog corrosive heev nyob rau hauv concentrated nitric acid nrog ib tug concentration ntawm ntau tshaj 80%, tab sis nws yog heev corrosive nyob rau hauv nruab nrab thiab tsawg concentrations ntawm nitric acid, thiab stainless hlau yog heev resistant rau dilute nitric acid, tab sis nws yog aggravated nyob rau hauv ntau tshaj 95% concentrated nitric acid.
Los ntawm cov piv txwv saum toj no, nws tuaj yeem pom tau tias kev xaiv cov khoom siv valve yuav tsum yog raws li qhov xwm txheej tshwj xeeb, tshuaj xyuas ntau yam cuam tshuam rau corrosion, thiab xaiv cov ntaub ntawv raws li cov ntaub ntawv tiv thaiv corrosion.
2. Siv cov khoom tsis yog xim hlau
Non-metallic corrosion kuj yog qhov zoo heev, tsuav yog qhov kub thiab siab ntawm lub valve ua tau raws li qhov yuav tsum tau ua ntawm cov khoom tsis yog xim hlau, nws tuaj yeem tsis tsuas yog daws qhov teeb meem corrosion, tab sis kuj txuag tau cov khoom muaj txiaj ntsig zoo. Lub valve lub cev, lub kaus mom, hauv ob sab phlu, sealing nto thiab lwm yam khoom siv uas tsis yog xim hlau yog tsim.
Cov yas xws li PTFE thiab chlorinated polyether, nrog rau cov roj hmab ntuj, neoprene, nitrile roj hmab thiab lwm yam roj hmab yog siv rau hauv ob sab phlu, thiab lub ntsiab lub cev ntawm lub valve lub cev bonnet yog ua los ntawm cam khwb cia hlau thiab carbon hlau. Nws tsis tsuas yog ua kom lub zog ntawm lub valve, tab sis kuj xyuas kom meej tias lub valve tsis corroded.
Niaj hnub no, ntau thiab ntau cov yas xws li nylon thiab PTFE yog siv, thiab cov roj hmab thiab hluavtaws roj hmab yog siv los ua ntau yam sealing nto thiab sealing rings, uas yog siv rau ntau yam li qub. Cov ntaub ntawv uas tsis yog xim hlau siv los ua sealing nto tsis tsuas yog muaj kev tiv thaiv corrosion zoo xwb, tab sis kuj muaj kev sib khi zoo, uas yog tshwj xeeb tshaj yog siv rau hauv xov xwm nrog cov khoom. Ntawm chav kawm, lawv tsis tshua muaj zog thiab kub resistant, thiab ntau yam kev siv yog txwv.
3. Hlau nto kho
(1) Valve kev twb kev txuas: Lub valve txuas qwj yog feem ntau kho nrog galvanizing, chrome plating, thiab oxidation (xiav) los txhim kho lub peev xwm tiv taus atmospheric thiab nruab nrab corrosion. Ntxiv nrog rau cov txheej txheem saum toj no, lwm cov fasteners kuj tau kho nrog kev kho saum npoo xws li phosphating raws li qhov xwm txheej.
(2) Sealing nto thiab kaw qhov chaw nrog lub cheeb me me: cov txheej txheem saum npoo xws li nitriding thiab boronizing yog siv los txhim kho nws cov corrosion kuj thiab hnav tsis kam.
(3) Kev tiv thaiv corrosion: nitriding, boronization, chrome plating, npib tsib xee plating thiab lwm yam txheej txheem kho saum npoo yog dav siv los txhim kho nws cov corrosion kuj, corrosion kuj thiab puas.
Kev kho deg sib txawv yuav tsum tsim nyog rau cov khoom siv sib txawv thiab qhov chaw ua haujlwm, nyob rau hauv cov huab cua, dej vapor nruab nrab thiab asbestos packing cov qia, tuaj yeem siv tawv chrome plating, roj nitriding txheej txheem (stainless steel yuav tsum tsis txhob siv ion nitriding txheej txheem): nyob rau hauv hydrogen sulfide atmospheric ib puag ncig siv electroplating siab phosphorus npib tsib xee txheej muaj kev tiv thaiv zoo dua. 38CrMOAIA kuj tuaj yeem tiv thaiv corrosion los ntawm ion thiab roj nitriding, tab sis tawv chrome txheej tsis haum rau kev siv; 2Cr13 tuaj yeem tiv taus ammonia corrosion tom qab quenching thiab tempering, thiab cov pa roj carbon steel siv roj nitriding kuj tuaj yeem tiv taus ammonia corrosion, thaum tag nrho cov phosphorus-nickel plating txheej tsis tiv taus ammonia corrosion, thiab cov roj nitriding 38CrMOAIA cov khoom muaj corrosion kuj zoo heev thiab kev ua tau zoo, thiab nws feem ntau yog siv los ua lub valve.
(4) Me-caliber valve lub cev thiab tes log: Nws kuj yog feem ntau chrome-plated los txhim kho nws corrosion kuj thiab kho lub valve.
4. Thermal txau
Thermal spraying yog ib hom txheej txheem txheej txheem los npaj cov txheej txheem, thiab tau dhau los ua ib qho ntawm cov thev naus laus zis tshiab rau cov khoom siv tiv thaiv saum npoo. Nws yog txheej txheem txheej txheem txheej txheem uas siv cov khoom siv hluav taws xob siab ceev (gas combustion nplaim hluav taws xob, hluav taws xob arc, ntshav arc, hluav taws xob cua sov, roj tawg, thiab lwm yam) kom sov thiab yaj hlau lossis cov khoom tsis yog xim hlau, thiab tshuaj tsuag rau hauv cov txheej txheem pretreated nyob rau hauv daim ntawv ntawm atomization los tsim cov tshuaj tsuag txheej, los yog ua kom sov lub sij hawm ntawm qhov chaw ntawm cov txheej txheem dua. substrate los tsim cov txheej txheem saum npoo ntawm cov tshuaj tsuag txheej txheej.
Feem ntau cov hlau thiab lawv cov alloys, hlau oxide ceramics, cermet composites thiab hard hlau compounds tuaj yeem coated ntawm cov hlau los yog cov hlau tsis yog hlau los ntawm ib los yog ob peb thermal spraying txoj kev, uas tuaj yeem txhim kho qhov corrosion kuj, hnav tsis kam, kub tsis kam thiab lwm yam khoom, thiab ua kom lub neej ntev. Thermal spraying tshwj xeeb ua haujlwm txheej, nrog cov rwb thaiv tsev kub, rwb thaiv tsev (los yog hluav taws xob txawv txav), grindable sealing, self-lubrication, thermal tawg, electromagnetic shielding thiab lwm yam khoom tshwj xeeb, kev siv thermal txau tuaj yeem kho qhov chaw.
5. Txau xim
Txheej yog siv dav siv los tiv thaiv corrosion txhais tau tias, thiab nws yog ib qho tseem ceeb los tiv thaiv corrosion thiab cov cim cim ntawm cov khoom valve. Txheej kuj yog cov khoom siv tsis yog xim hlau, uas feem ntau yog ua los ntawm cov khoom siv hluavtaws, roj hmab slurry, roj zaub, hnyav, thiab lwm yam, npog cov hlau nto, cais cov nruab nrab thiab cov cua, thiab ua tiav lub hom phiaj ntawm kev tiv thaiv corrosion.
Cov coatings feem ntau yog siv hauv dej, dej ntsev, dej hiav txwv, huab cua thiab lwm qhov chaw uas tsis muaj corrosive. Cov kab noj hniav sab hauv ntawm lub valve feem ntau yog pleev xim rau cov xim pleev xim los tiv thaiv dej, huab cua thiab lwm yam xov xwm los ntawm corroding lub valve.
6. Ntxiv corrosion inhibitors
Cov txheej txheem los ntawm cov tshuaj tiv thaiv kev tiv thaiv corrosion yog tias nws txhawb cov polarization ntawm lub roj teeb. Corrosion inhibitors feem ntau yog siv hauv kev tshaj tawm thiab muab tub lim. Qhov sib ntxiv ntawm corrosion inhibitors rau qhov nruab nrab tuaj yeem ua rau qeeb qeeb ntawm cov khoom siv thiab cov li qub, xws li chromium-nickel stainless hlau hauv oxygen-dawb sulfuric acid, ib qho loj solubility ntau rau hauv lub xeev cremation, corrosion yog hnyav dua, tab sis ntxiv me me tooj liab sulfate los yog nitric acid thiab lwm yam oxidants, yuav ua rau cov stainless hlau tig mus rau hauv ib tug blunt lub xeev, tiv thaiv qhov chaw ntawm hydrochloric acid. Yog hais tias ib qho me me ntawm oxidant ntxiv, qhov corrosion ntawm titanium tuaj yeem txo.
Kev ntsuas siab valve feem ntau yog siv los ua qhov nruab nrab rau kev ntsuas siab, uas yooj yim ua rau corrosion ntawm cov khoomvalve, thiab ntxiv ib qho me me ntawm sodium nitrite rau hauv dej tuaj yeem tiv thaiv corrosion ntawm lub valve los ntawm dej. Asbestos packing muaj cov tshuaj chloride, uas corrodes lub valve qia zoo heev, thiab cov ntsiab lus chloride tuaj yeem raug txo yog tias siv txoj kev ntxuav dej, tab sis txoj kev no nyuaj heev rau kev siv, thiab tsis tuaj yeem nrov nrov, thiab tsuas yog tsim nyog rau kev xav tau tshwj xeeb.
Txhawm rau tiv thaiv lub pob valve thiab tiv thaiv corrosion ntawm asbestos packing, nyob rau hauv asbestos packing, corrosion inhibitor thiab sacrificial hlau yog coated rau ntawm lub valve qia, corrosion inhibitor yog tsim los ntawm sodium nitrite thiab sodium chromate, uas tuaj yeem tsim cov zaj duab xis passivation ntawm lub valve qia thiab txhim kho cov corrosion kuj ntawm lub valve thiab ua kom lub cev muaj zog. lub luag haujlwm; Qhov tseeb, zinc kuj yog ib qho kev tiv thaiv corrosion, uas tuaj yeem ua ntej ua ke nrog cov tshuaj chloride hauv asbestos, kom cov tshuaj chloride thiab qia hlau sib cuag tau txo qis, thiaj li ua tiav lub hom phiaj ntawm kev tiv thaiv corrosion.
7. Kev tiv thaiv hluav taws xob
Muaj ob hom kev tiv thaiv electrochemical: anodic tiv thaiv thiab cathodic tiv thaiv. Yog tias zinc siv los tiv thaiv hlau, zinc yog corroded, zinc yog hu ua sacrificial hlau, hauv kev xyaum ntau lawm, kev tiv thaiv anode siv tsawg dua, kev tiv thaiv cathodic yog siv ntau dua. Txoj kev tiv thaiv cathodic no yog siv rau qhov loj li qub thiab qhov tseem ceeb, uas yog ib qho kev lag luam, yooj yim thiab siv tau zoo, thiab zinc ntxiv rau cov pob zeb asbestos los tiv thaiv lub valve qia.
8. Tswj qhov chaw corrosive
Qhov chaw hu ua ib puag ncig muaj ob hom kev nkag siab dav thiab nqaim kev nkag siab, qhov dav ntawm ib puag ncig yog hais txog ib puag ncig ib puag ncig ntawm qhov chaw teeb tsa lub valve thiab nws qhov nruab nrab hauv nruab nrab, thiab qhov nqaim ntawm ib puag ncig yog hais txog cov xwm txheej nyob ib puag ncig lub valve installation qhov chaw.
Feem ntau ib puag ncig tsis tuaj yeem tswj tau, thiab cov txheej txheem tsim khoom tsis tuaj yeem hloov pauv tau. Tsuas yog nyob rau hauv rooj plaub uas yuav tsis muaj kev puas tsuaj rau cov khoom thiab cov txheej txheem, cov txheej txheem ntawm kev tswj ib puag ncig tuaj yeem siv tau, xws li deoxygenation ntawm boiler dej, alkali ntxiv rau hauv cov txheej txheem roj refining los kho tus nqi PH, thiab lwm yam. Los ntawm qhov kev pom no, qhov sib ntxiv ntawm corrosion inhibitors thiab electrochemical tiv thaiv tau hais los saum toj no kuj yog ib txoj hauv kev los tswj cov corrosive ib puag ncig.
Cov huab cua yog tag nrho ntawm cov plua plav, dej vapor thiab cov pa luam yeeb, tshwj xeeb tshaj yog nyob rau hauv qhov chaw tsim khoom, xws li cov pa luam yeeb brine, cov pa roj carbon monoxide thiab cov hmoov nplua nuj tawm los ntawm cov khoom siv, uas yuav ua rau muaj kev sib txawv ntawm corrosion mus rau lub valve. Tus neeg teb xov tooj yuav tsum tsis tu ncua ntxuav thiab ntxuav lub valve thiab refuel tsis tu ncua raws li cov kev cai ntawm kev khiav hauj lwm cov txheej txheem, uas yog ib tug zoo ntsuas los tswj ib puag ncig corrosion. Txhim kho lub npog tiv thaiv ntawm lub qia valve, teeb tsa hauv av kom zoo rau hauv av valve, thiab txau cov xim rau ntawm qhov chaw ntawm lub valve yog txhua txoj hauv kev los tiv thaiv cov khoom corrosive los ntawm eroding.valve.
Qhov nce ntawm qhov kub thiab txias ntawm huab cua, tshwj xeeb tshaj yog rau cov khoom siv thiab cov li qub nyob rau hauv ib puag ncig kaw, yuav ua kom lawv cov corrosion, thiab qhib kev cob qhia los yog qhov cua thiab cua txias ntsuas yuav tsum tau siv ntau li ntau tau kom qeeb ib puag ncig corrosion.
9. Txhim kho cov txheej txheem ua haujlwm thiab cov qauv valve
Anti-corrosion tiv thaiv ntawm lubvalveyog ib qho teeb meem uas tau txiav txim siab los ntawm qhov pib ntawm kev tsim, thiab cov khoom siv valve nrog cov qauv tsim tsim nyog thiab cov txheej txheem tsim nyog yuav tsis muaj qhov tsis txaus ntseeg muaj txiaj ntsig zoo ntawm kev ua kom qeeb ntawm corrosion ntawm lub valve. Yog li ntawd, lub tuam txhab tsim thiab tsim khoom yuav tsum txhim kho qhov tsis tsim nyog ntawm cov qauv tsim, tsis raug hauv cov txheej txheem txheej txheem thiab yooj yim ua rau corrosion, thiaj li hloov lawv mus rau qhov yuav tsum tau ntawm ntau yam kev ua haujlwm.
Post lub sij hawm: Jan-22-2025
