Cov pa phem thiab corrosion ntawm electroplated electrodes nyob rau hauv hluav taws xob cua sov raj

Cov pa phem thiab corrosion ntawm electroplated electrodes nyob rau hauv hluav taws xob cua sov raj

Cov pa phem thiab corrosion ntawm electrode 52

521 Cov pa phem

Thaum lub sij hawm kho cov dej khib nyiab, nws yog ib qho inevitable uas muaj cov khoom precipitates los yog txawm colloidal cov khoom tsim los ntawm cov roj stains thiab tshuaj lom neeg cov tshuaj hauv cov dej khib nyiab, uas tuaj yeem yooj yim ua raws li iav zaj duab xis. Lub diffusion ntawm H ntxiv yog cuam tshuam zoo heev, ua rau muaj kev nce ntxiv hauv kev ntsuas qhov yuam kev thiab txawm tias tsis muaj qab hau, ua rau kev txiav txim siab tsis zoo: ntau dhau alkali ntxiv thiab tsis txaus acid ntxiv (tsis nyeem ntawv tsawg). Txawm tias phau ntawv noj tshuaj raws li kev nyeem ntawv tuaj yeem ua rau cov neeg ua haujlwm random muab tshuaj, uas yog qhov phem dua li siv cov ntawv xeem pH rau kev ntsuas.

522 electrode corrosion

(1) fluoride corrosion

Txhua yam tshuaj fluoride tuaj yeem ua rau cov iav hnyav hnyav, thiab cov tshuaj fluoride yog inevitably muaj nyob rau hauv cov dej khib nyiab electroplating, xws li fluorine uas muaj electroplating (fluoroboric acid, fluorosilicate electroplating, siv fluorine uas muaj chromium plating thiab npib tsib xee plating additives, thiab lwm yam), siv fluorine uas muaj cov ntsiab lus rau pre plating ( xws li zinc tuag castings, txhuas qhov chaw ua ntej plating, thiab lwm yam), thiab muaj fluoride nyob rau hauv cov kev kho mob tom qab plating (xws li hexavalent chromium los yog trivalent chromium xiav dawb passivation tov rau zinc plating, thiab lwm yam). Yog li ntawd, nws yog ib qho tseem ceeb rau cov iav electrode membrane kom tsis tu ncua los yog tsis sib xws corrosion los ntawm fluoride thaum kho dej khib nyiab.

(2) Alkali corrosion thiab "alkali txawv"

Raws li paub zoo, cov tshuaj alkaline tuaj yeem corrode iav. Tus nqi pH tswj tau thaum lub sij hawm oxidation ntawm cyanide uas muaj cov dej khib nyiab thiab nag lossis daus ntawm cov hlau hnyav los ntawm cov txheej txheem nag lossis daus yog qhov siab (xws li nag lossis daus ntawm Ni2 ntxiv, qhov tseeb pH yuav tsum ncav cuag 97). Lub iav electrode zaj duab xis nws tus kheej tsuas yog hais txog 02 hli tuab, thiab nws cov kev ua tau zoo yuav hloov tom qab me ntsis corrosion.

In alkaline solutions with pH>9, iav electrodes ua kom cov txheej txheem H ntxiv tau hloov los ntawm alkali hlau nyob rau hauv cov iav zaj duab xis vim qhov kev txiav txim ntawm alkali hlau hauv cov tshuaj. Cov electrode maj mam hloov los ntawm "rov qab rau hydrogen ions" mus rau "rov qab rau alkali hlau ions", ua rau kev ua yuam kev lossis kev laus. Qhov yuam kev no yog hu ua "alkali txawv". Qhov sib txawv alkali tshwm sim los ntawm sodium ions hu ua "sodium sib txawv". Yog tias Li2O siv los hloov Na2O hauv iav, qhov sib txawv sodium me me thiab ntsuas pH tus nqi tuaj yeem ncav cuag 35.

Thaum pH<1, the hydrates of silica in the glass can also exhibit some alkaline characteristics, which can adsorb anions in the solution and cause changes in the physical and chemical properties of the electrode surface.

Yog li ntawd, qhov haum pH ntau rau iav electrodes yog 1-9. Nyob rau ntawm qhov chaw no, qhov yuam kev yuav tshwm sim. Thaum ntsuas qhov tseeb, calibration curves yuav tsum tau rau calibration.

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