Kev tshawb fawb qab story stainless hlau passivation: li cas cov zaj duab xis tiv thaiv cov hlau ua tau

Lub hauv paus rau phau ntawv

Stainless hlau yog dav paub rau nws cov zoo heev corrosion tsis kam, durability, thiab huv si. Txawm li cas los xij, muaj pes tsawg tus neeg tsis paub yog tiasStainless hlau tsis yog inherently corrosion - ntawv pov thawjCov. Qhov tseeb, yam tsis muaj kev kho kom zoo, stainless hlau tuaj yeem zoo li cov roj carbon hlau {}}}}} maj mam maj mam. Qhov tseeb vim li cas stainless hlau tiv taus xeb dag nyob rau hauv ib qho tshwj xeeb, microscopically nyias txheej uas hu ua tusPassive Zaj Duab Xis.

Zaj yeeb yaj kiab no tsis tas mus li. Nws tuaj yeem puas los ntawm kev hnav kho tshuab, tshuaj lom neeg tawm tsam, lossis kev sib kis ib puag ncig. Tom qab txiav txim siab, cov hlau hauv qab ua kom yooj yim. Qhov no yog qhov twgpassivationdhau los ua ib qho tseem ceeb. Passivation restores, ntxiv dag zog, thiab tso cov txheej tiv thaiv oxide los tswj cov hlau stainless new-}} lub sij hawm kev ua tau zoo.

Cov ntawv no tshawb txog cov ntsiab cai muaj keeb kwm kev tshawb fawb tom qab passivation, vim li cas cov kev ua yeeb yaj kiab passive, thiab ib txwm muaj ib puag ncig cuam tshuam nws ruaj khov.

1. Lub passive zaj duab xis:Stainless hlau's zais cov ntaub thaiv

Tus Hlau Stainless muajTsawg kawg yog 10.5% chromium, uas yog tus tseem ceeb ua lub luag haujlwm rau kev tsim cov txheej passive. Thaum Chromium reacts nrog oxygen - Txawm hais tias muaj tsawg tsawg tsawg- nws cov ntaub ntawv:

Chromium (III) Oxide - b₂o₃ (lub passive zaj duab xis)

No ultra - cov yeeb yaj kiab nyias nyias (tsuas yog 1-5 nanometers tuab):

Cov qauv spontaneously hauv cov pa oxygen

Yog nruj nreem rau cov hlau nto

Yog chemically ruaj khov

Tus kheej -} kev kho thaum kos

Ua raws li kev thaiv kev tawm tsam cov neeg sawv cev hauv cov neeg sawv cev

Txawm hais tias nws yog microscopic, zaj duab xis no yog qhov sib txawv ntawmXyoo caum ntawm kev pabcuam lub neejthiabsai sai corrosion tsis ua hauj lwm.

2. Yuav ua li cas cov lus zaj duab xis passive

2.1 Ntuj passivation

Thaum stainless hlau tau raug rau cov pa oxygen hauv huab cua lossis dej, chromium migrates mus rau saum npoo, rov qab los ua cr₂o₃.

Cov txheej txheem ntuj no yog qhov ua tau zoo tab sis qeeb, thiab hauv cov chaw muaj kev muaj, txheej oxide tuaj yeem tsim cov nyom, tawm ntawm cov hnab ris ntawm qhov tsis muaj zog.

2.2|Artificial Passivation

Tshuaj lom neeg hla kev nrawm nrawm thiab txhim kho cov txheej txheej passive siv cov oxidizing cov kua qaub xws li:

Nitric Acid

Citric acid mixtures

Cov qauv oxidizing

Cov zaub mov hla hle tau tshem tawm cov paug, thiab hlau dawb, tsim cov kev cai zoo tshaj plaws rau cov chromium oxide los ua cov uniformly.

3. Dab tsi ua rau kev puas tsuaj zaj yeeb yaj kiab?

Zaj duab xis passive tuaj yeem tsis muaj zog lossis rhuav tshem los ntawm ntau yam:

Thaum zaj duab xis puas, kev xeb pib ntawm qib me me thiab kis tau.

4. Yuav ua li cas cov tshuaj passivation rov kho dua cov txheej passive

4.1 Kauj Ruam 1 - npoo tu

Ua ntej kev caij nkoj tuaj yeem tshwm sim, txhua tus paug yuav tsum raug tshem tawm:

Roj

Roj

NplEEM

Hlau Hais Los Ntawm Machining

Weld Oxides

Yog tsis muaj kev tu kom zoo, cov zaj duab xis passive tsis tuaj yeem ua rau tsis zoo.

4.2 Kauj Ruam 2 - ecidizing da dej

TusStainless hlauyog raus hauv cov kev daws teeb meem passivation tshwj xeeb uas:

Tshem tawm cov hlau dawb

Dissolve Hlau Oxides

Txhawb chomium txhawb nqa ntawm qhov chaw

Tso cai rau lub ntshiab chromium oxide zaj duab xis los ua

4.3 kauj ruam {3 - rinsing thiab ziab

Cov dej huv yaug tso tseg cov tshuaj tiv thaiv thiab tso cai rau cov pa oxygen kom hnov ​​cov tshuaj chromium.

4.4 Kauj Ruam 4 -}} Cov Yeeb Yam Zaj Duab Xis Passive

Tsis pub dhau cov sij hawm, ib qho ruaj khov cr₂o₃ txheej, txhim kho:

Corrosion Kuj

Tshuaj Muaj Peev Xwm

Zoo nkauj heev

Qhov Kev Pab Nyiaj Li

5. Lub chemistry of passivation

Thaum lub sijhawm dhau los, ntau yam kev tawm tsam tshwm sim:

Oxidation ntawm chromium

4Cr +3}} → 2Cr2o34cr {}} → → 2cr {}} o2} → 2cr2 o3

Tshem tawm cov hlau dawb
Hlau reacts nrog nitric acid los tsim solubble hlau nitrate.

Saum npoo chromium txhawb nqa
The acidic environment removes iron more readily than chromium, increasing chromium-to-iron ratio at the surface.

Tsim ntawm chromium oxide zaj duab xis
Cov ntawv tso pa oxygenation ib qho ruaj khov, tsis sib thooj zaj yeeb yaj kiab.

6. Corrosion tus cwj pwm ua ntej thiab tom qab passivation

Passivation txhim kho kev ua tau zoo los ntawm kev ua kom muaj kev tiv thaiv tsis zoo.

7. Cov txheej txheem passivation cov txheej txheem

7.1 nitric acid passivation

Tus neeg sawv cev muaj zog heev

Zoo heev rau Aerospace thiab muaj stainless hlau

Tuaj yeem tshem tawm cov hlau hnyav

Tsis yog ib puag ncig tus phooj ywg

7.2 Citric Acid Passivation

Eco - tus phooj ywg thiab nyab xeeb

Zoo heev rau cov khoom noj thiab cov khoom noj

Tsim ruaj khov ua yeeb yaj kiab

Maj mam rau ntawm cov khoom siv me

7.3 electrochemical passivation

Siv Voltage kom nrawm zaj duab xis tsim kev tsim

Qhov zoo tagnrho rau cov geometries lossis siab -} purity chaw

8. Qhov ntau yam cuam tshuam rau passivation zoo

9. Cov ntawv thov uas muaj zog passivation yog qhov tseem ceeb

Cov Khoom Siv Kho Mob

Khoom Noj Khoom Haus thiab Dej Haus Raug

Tshuaj Lom Ua Tshuab

Marine Hardware

Cov Hluav Taws Xob Tshav Kub Kub

Kws Tsim Kho

Aerospace Cheebtsam

Roj Thiab Roj Pipelines

Hauv cov lag luam no, ua tsis tau passivate tuaj yeem ua rau:

Kev sib kis hlau

Cov qauv muaj zog

Khoom tsis ua hauj lwm

Kev cai tsis yog - ua raws

Nyeem ntxiv:Cov txheej txheem passivation, cov qauv, thiab kev coj ua zoo tshaj plaws rau kev lag luam stainless hlau

10. Xaus

Passivation tsis yog xaiv tau - nws yog qhov tseem ceeb yuav tsum tau ua kom muaj kev ua tau ntev rau kev ua kom zoo nkauj stainless hlau ntev thiab corrosion tsis kam. Los ntawm kev sib sau thiab kev tswj hwm lub siab tawv passcomium oxide txheej ruaj khov, nyab xeeb, thiab txhim khu kev nyab xeeb txawm tias muaj ib puag ncig cov nyom.

Yog tsis muaj cov neeg ua hauj lwm kom tsim nyog, stainless hlau poob nws lub tshuab tiv thaiv thawj zaug, ua rau cov teeb meem zais, thiab ua ntej ntxov.

Passivation yog li ntawdib qho ntawm cov txheej txheem tseem ceeb tshaj plaws hauv cov hlau tsis xeb, tsim khoom, thiab txij nkawm.