Yuav Ua Li Cas Stainless Hlau Reactors Kuaj Cov Tshuaj Corrosive?

Stainless hlau reactors, tshwj xeeb tshaj yog siv SS reactors, yog engineered los lis corrosive chemicals los ntawm ib tug ua ke ntawm kev tsim tshiab thiab cov khoom siv. Cov reactors no siv cov qib high-qib stainless hlau alloys uas tsim cov txheej txheem tiv thaiv chromium oxide ntawm lawv qhov chaw, tiv thaiv cov hlau hauv qab los ntawm kev tawm tsam tshuaj lom neeg. Cov zaj duab xis passive tsis tu ncua regenerates thaum puas, muab kev tiv thaiv ntev. Tsis tas li ntawd, siv SS reactors feem ntau suav nrog cov txheej tshwj xeeb lossis cov hauv ob sab phlu los txhim kho lawv cov kev tiv thaiv corrosion ntxiv. Lub tshuab hluav taws xob tsim cov yam ntxwv, xws li cov npoo sab hauv du, cov kua dej kom zoo, thiab ua tib zoo xaiv cov gaskets thiab cov ntsaws ruaj ruaj, kuj tseem ua lub luag haujlwm tseem ceeb hauv kev txo qis cov tshuaj lom neeg thiab cov ntsiab lus corrosion. Tsis tas li ntawd, cov tuam txhab lag luam feem ntau siv cov txheej txheem kev tsim khoom, xws li electropolishing lossis passivation, txhawm rau txhim kho lub reactor qhov kawg thiab corrosion kuj. Los ntawm cov txheej txheem ntau yam no, cov hlau tsis muaj steel reactors tuaj yeem tswj hwm lawv txoj kev ncaj ncees thiab kev ua haujlwm txawm tias raug cov tshuaj corrosive heev, ua rau lawv tsis tuaj yeem nyob hauv ntau qhov kev lag luam uas hnyav hnyav hnyav ib puag ncig.

Peb muab SS reactors, thov xa mus rau lub vev xaib hauv qab no kom paub meej cov lus qhia thiab cov ntaub ntawv khoom.
Khoom siv:https://www.achievechem.com/chemical-equipment/ss-reactor.html

 

 

Kev Tshawb Fawb Tom Qab Stainless Hlau Corrosion Resistance

Stainless hlau lub peev xwm zoo tshaj plaws los tiv thaiv corrosion nyob rau hauv hnyav tshuaj ib puag ncig stems los ntawm nws cov cim muaj pes tsawg leeg thiab cov qauv molecular. Hauv plawv ntawm qhov kev tiv thaiv no yog muaj cov chromium, uas tsim ib txheej nyias, pom tsis pom ntawm chromium oxide ntawm cov hlau saum npoo thaum raug oxygen. Cov zaj duab xis passive no ua ib qho thaiv, tiv thaiv cov khoom corrosive los ntawm kev tawm tsam cov hlau hauv qab. Cov ntsiab lus chromium hauv stainless hlau, feem ntau yog li ntawm 10.5% mus rau 30%, txiav txim siab qhov ua tau zoo ntawm cov txheej txheem tiv thaiv no. Ntau dua chromium concentrations feem ntau ua rau superior corrosion kuj.

Ntxiv mus, qhov sib ntxiv ntawm lwm yam alloying ntsiab xws li npib tsib xee, molybdenum, thiab nitrogen ntxiv txhim khu cov hlau muaj peev xwm tiv thaiv corrosive tawm tsam. Cov ntsiab lus no ua rau muaj kev ruaj ntseg ntawm cov txheej txheem passive thiab txhim kho nws cov khoom siv rov ua dua tshiab. Thaum cov zaj duab xis passive puas lawm, nws hloov kho sai sai thaum muaj cov pa oxygen, ua kom muaj kev tiv thaiv tsis tu ncua. Qhov kev kho tus kheej tus yam ntxwv no yog qhov tseem ceeb rau kev tswj xyuas qhov corrosion mus sij hawm ntev hauv sivSS reactorsraug rau cov tshuaj phem heev.

Electrochemical Properties thiab lawv lub luag haujlwm hauv kev tiv thaiv corrosion

Cov khoom siv electrochemical ntawm stainless hlau ua lub luag haujlwm tseem ceeb hauv nws txoj kev tiv thaiv corrosion. Cov zaj duab xis passive tsim kom muaj hluav taws xob ua haujlwm siab ntawm cov hlau nto thiab ib puag ncig ib puag ncig, txo cov nqi hluav taws xob hloov hluav taws xob tsim nyog rau kev tiv thaiv corrosion tshwm sim. Qhov kev tiv thaiv electrochemical no ua rau qeeb qeeb lossis tiv thaiv cov txheej txheem oxidation uas ua rau corrosion.

Tsis tas li ntawd, cov ntsiab lus alloying hauv stainless hlau tuaj yeem hloov kho nws cov peev txheej electrochemical, ua rau nws muaj txiaj ntsig zoo thiab tsis tshua muaj kev cuam tshuam rau galvanic corrosion thaum sib cuag nrog lwm cov hlau. Qhov no yog qhov tseem ceeb tshwj xeeb hauv cov tshuab reactor complex uas muaj cov khoom sib txawv. Lub electrochemical stability ntawm stainless hlau kuj pab txhawb rau nws tiv thaiv pitting thiab crevice corrosion, uas yog localized cov ntaub ntawv ntawm corrosion uas yuav ua tau tshwj xeeb yog detrimental nyob rau hauv chemical ua ib puag ncig.

 

 

Austenitic Stainless Hlau: Ua Haujlwm ntawm Corrosion Resistance

Austenitic stainless hlau, tshwj xeeb tshaj yog 300 series, yog dav suav hais tias yog qhov kev xaiv zoo tshaj plaws rau cov reactors tuav cov tshuaj corrosive. Cov qib 316 thiab 316L tshwj xeeb tshaj yog nrov vim lawv zoo heev corrosion kuj thiab txhua yam khoom. Cov alloys no muaj qib siab dua ntawm chromium (16-18%) thiab npib tsib xee (10-14%), nrog ntxiv ntawm molybdenum (2-3%) rau kev txhim kho pitting thiab crevice corrosion kuj. Qhov "L" hauv 316L qhia txog cov ntsiab lus qis dua, uas txo qhov kev pheej hmoo ntawm kev sib tsoo ntawm qhov chaw welded.

Rau qhov xav tau ntau dua ib puag ncig, super austenitic stainless hlau zoo li 904L lossis 6% Mo qib muab kev tiv thaiv zoo rau cov xov xwm corrosive heev. Cov alloys no muaj ntau theem ntawm chromium, npib tsib xee, thiab molybdenum, nrog rau qhov sib ntxiv ntawm nitrogen, muab tshwj xeeb tsis kam rau chloride-induced pitting thiab kev nyuaj siab corrosion cracking. Txawm tias kim dua, cov khoom siv siab heev tuaj yeem txuas ntxiv lub neej ntawm cov reactors nyob rau hauv ib puag ncig tshuaj lom neeg hnyav heev.

Duplex thiab Super Duplex Stainless Steels: Lub zog ua tau raws li kev tiv thaiv corrosion

Duplex stainless hlau, xws li 2205 thiab 2507, muaj kev sib xyaw tshwj xeeb ntawm lub zog siab thiab zoo heev corrosion kuj. Cov alloys muaj ib qho microstructure uas muaj qhov sib npaug ntawm austenite thiab ferrite, ua rau cov khoom siv kho kom zoo dua qub piv rau qib austenitic. Duplex stainless hlau yog tshwj xeeb tshaj yog haum rau reactors uas yuav tsum tau ob qho tib si corrosion kuj thiab kub siab los yog kub muaj peev xwm.

Super duplex qib, zoo li S32750 thiab S32760, thawb lub hnab ntawv ntxiv nrog cov ntsiab lus ntau dua alloying. Cov ntaub ntawv no nthuav tawm tshwj xeeb rau pitting, crevice corrosion, thiab kev ntxhov siab corrosion tawg nyob rau hauv ib puag ncig uas muaj chloride. Lawv lub zog-rau-qhov hnyav piv kuj tso cai rau cov phab ntsa reactor thinner, uas yuav txo tau cov nqi ntawm cov khoom siv thiab kev txhim kho kev hloov hluav taws xob. Txawm tias tsawg dua li qib austenitic, duplex thiab super duplex stainless hlau tau txais kev muaj koob npe hauv cov ntawv tshwj xeeb uas lawv cov khoom tshwj xeeb muaj qhov zoo.

 

 

Tsim kev txiav txim siab rau Txhim Kho Corrosion Resistance

Siv SS reactorstswj lawv cov kav ntev thaum raug cov tshuaj corrosive los ntawm kev ua tib zoo tsim kev txiav txim siab uas txo cov ntsiab lus tsis muaj zog thiab txhim kho tag nrho cov kev tiv thaiv corrosion. Ib qho tseem ceeb yog qhov kev tshem tawm cov crevices thiab qhov chaw tuag uas cov xov xwm corrosive tuaj yeem sib sau. Reactor designers siv cov khoom sib npaug, sib npaug hauv qhov chaw thiab txhim kho cov qauv ntawm cov kua dej kom zoo los tiv thaiv thaj chaw tsis ruaj. Tsis tas li ntawd, kev xaiv cov gaskets uas tsim nyog thiab cov ntsaws ruaj ruaj yog qhov tseem ceeb, vim tias cov khoom no yuav tsum tiv taus qhov chaw corrosive thaum tuav lub foob nruj.

Lwm qhov kev tsim qauv tseem ceeb yog kev xaiv cov txheej txheem vuam thiab kev kho tom qab vuam. Welded pob qij txha tuaj yeem yog cov ntsiab lus tsis muaj zog hauv kev tiv thaiv corrosion, yog li cov tuam txhab feem ntau siv cov txheej txheem vuam tshwj xeeb thiab ua cov kev kho cua sov tom qab vuam kom ntseeg tau tias muaj kev ncaj ncees ntawm cov txheej txheem dhau ntawm tag nrho cov reactor nto. Tsis tas li ntawd, kev koom ua ke ntawm cov yam ntxwv zoo li kev txi anodes lossis cathodic tiv thaiv kab ke tuaj yeem muab cov txheej txheem ntxiv ntawm kev tiv thaiv corrosion nyob rau hauv tshwj xeeb aggression ib puag ncig.

Kev kho deg thiab txheej txheej rau kev tiv thaiv zoo dua

Kev kho deg ua si lub luag haujlwm tseem ceeb hauv kev txhim kho corrosion kuj ntawmsiv SS reactors. Electropolishing, piv txwv li, tshem tawm qhov tsis zoo ntawm qhov chaw thiab tsim kom muaj kev ua tiav zoo kawg nkaus uas txo qhov peev xwm rau kev pib corrosion. Cov txheej txheem no tseem ua kom lub ntsej muag zoo nrog chromium, ntxiv kev txhim kho cov txheej txheem ua haujlwm zoo. Kev kho mob Passivation, uas koom nrog kev nthuav tawm cov hlau tsis huv rau oxidizing acids, kuj tuaj yeem ua haujlwm los txhim kho qhov tsim ntawm cov txheej txheem tiv thaiv oxide.

Qee zaum, cov coatings ntxiv lossis cov ntaub hauv ob sab phlu tuaj yeem siv rau cov khoom siv SS reactors los muab kev thaiv ntxiv rau cov khoom corrosive. Fluoropolymer coatings, xws li PTFE lossis PFA, muaj cov tshuaj tiv thaiv zoo heev thiab tuaj yeem siv los ua kab reactor interiors. Rau cov xwm txheej hnyav dua, cov iav tshwj xeeb lossis cov ntaub nplaum nplaum tuaj yeem ua haujlwm. Cov txheej no tsis tsuas yog txhim kho corrosion kuj tab sis kuj tuaj yeem txhim kho kev huv thiab tiv thaiv cov khoom sib kis. Kev xaiv cov kev kho kom zoo thiab txheej txheej yog nyob ntawm qhov chaw tshwj xeeb tshuaj thiab kev ua haujlwm ntawm lub reactor.

 

ASTM A240/A240M-18, Txuj Specification rau Chromium thiab Chromium-Nickel Stainless Hlau Phaj, Sheet, thiab Sawb rau Cov Vev Xaib Siab thiab rau Kev Siv Dav Hlau.

Frank, DH, & Southwick, WR (2004). Corrosion Resistance ntawm Stainless Steels nyob rau hauv Chemical thiab Petrochemical ib puag ncig.Corrosion Engineering, Science thiab Technology, 39(3), 200-211.

Vignarooban, K., & Sivakumar, V. (2013). Corrosion cwj pwm ntawm stainless hlau nyob rau hauv ib puag ncig tshuaj.Phau ntawv Journal of Materials Science thiab Technology, 29(5), 443-452.

Fontana, MG (1986). Corrosion Engineering, 3rd Edition. McGraw-Hill Education.