Raws li peb txhua tus paub, cov khoom hlau nrog hlau raws li lub ntsiab tivthaiv feem ntau xeb yog tias tsis muaj kev tiv thaiv zoo (tshwj tsis yog hlau). Qhov no yog vim tias cov hlau atoms ntawm cov hlau saum npoo sib txuas nrog oxygen rau saum huab cua los tsim cov hlau oxide. Hlau oxide tshwm xim xim av, uas yog ib qho xeb ntau, raws li qhia hauv daim duab hauv qab no.
Qhov laj thawj yog vim li cas stainless hlau tsis xeb yog tias nws cov tshuaj lom neeg muaj tsawg dua 10.5% chromium. Thaum stainless hlau nthuav tawm rau huab cua lossis dej chromium yuav hnov mob txheej txheem ua ntej hlau thiab tsim cov hlau stainless matrix los ntawm oxidation ntxiv thiab corrosion.
Qhov tseeb, txhuas yog tib yam li hlau. Aluminium thiab nws cov aluminium tseem yuav muaj kev cuam tshuam nrog txhuas atoms ntawm lawv cov npoo thiab oxygen rau cov pa tawm txhuas oxide, tab sis xim grey lossis tsaus xim, tsis xeb, tsis xeb, tsis xeb, tsis xeb, tsis xeb. Txawm li cas los xij, qhov no txhuas oxide ua yeeb yam ib yam li txheej txheem tiv thaiv kab hlau los tiv thaiv kev tiv thaiv hlau, raws li pom hauv daim duab hauv qab no.
Hauv kev coj ua, peb tau pom qee qhov steel qhov xeb tshwj xeeb, thiab qee qhov txawm xeb los ntawm, raws li pom nyob hauv daim duab hauv qab no, thaum txhuas yog qhov tsawg. Kuv xav tias koj muaj lus nug nyob ntawm no: Vim li cas cov tshuaj oxide thiab chromium oxide, tab sis hlau oxide tsis tau?
Qhov tseeb, qhov tseem ceeb ntawm no yog seb cov txheej oxide tsim olide yog tuab lossis tsis yog. Yog tias txheej oxide yog ntom heev, nws yog qhov nyuaj rau cov kab corrosive sab nraud (xws li corrorides, thiab lwm yam) yuav tsum tsis tshwm sim. Daim duab hauv qab no yog qhov sib piv ntawm txhuas thiab hlau oxides. Hlau oxide yog xoob thiab ntxeem tau, thiab nws yooj yim rau tev tawm, thaum lub sij hawm txhuas oxide yog ntom thiab haum nruj me ntsis rau lub substrate.
Tom qab ntawd cov lus nug tshwm sim dua, vim li cas yog hlau oxide tsis ntom thiab tsis haum? Qhov no yuav tsum muaj kev paub ntau txog kev paub tob thiab physics los piav. Vim tias qhov nyuaj ntawm lub hauv paus ntsiab lus ntawm xeb, nws tsis yog qhov tseeb hauv ib lossis ob kab lus, tab sis peb tuaj yeem tsuas piav nws:
Qhov tseeb, yog tias huab cua qhuav qhuav (tsis muaj noo noo kiag li (tsis muaj noo noo lawm (seb puas yog FE3O4) tseem yog qhov ruaj khov uas yuav tsis ua rau cov xim ruaj khov uas yuav tsis ua rau cov xim av thiab corrosion txuas ntxiv. Qhov tseeb vim li cas rau qhov xeb kom poob tawm thiab corrode sab hauv yog cov hydrated hlau oxide Fe2o3o thiab hlau (HYO (HYO (OH)) Tom qab cov hydrated hlau hydroleside sib xyaw ua ke nrog cov hlau, nws nthuav dav hauv ntim thiab yooj yim rau kev hu thiab tawg. Ntawm qhov tod tes, nws tseem ua rau nws tsis tuaj yeem ua kom zoo rau cov hlau matrix thiab yog yooj yim rau tev tawm. Thaum cov iav qhia tawm cov hlau tshiab hauv qab, nws yuav oxidize thiab xeb rov qab los txog thaum txhua cov hlau yog xeb thiab corroded.
Nyob rau hauv ib txwm mob, txhuas oxide yuav tsis hnov mob nrog dej thiab yuav tsis "xeb" xws li hlau, tab sis nws yuav corrode nyob rau qee qhov xwm txheej. Piv txwv li, nyob rau hauv cov muaj zog acid lossis muaj zog alkali txiav txim siab ntawm Oxide Txheej rau saum npoo yuav siab dua nws tus nqi tiam. Txhawm rau kom zam dhau qhov xwm txheej no, Txhuas tsis muaj kev kho deg ua ke yuav tsum tau siv nyob rau hauv cov PHOT ntawm 4.5 txog 8.5.
Lwm qhov ua rau muaj cov corrosion aluminium yog electrochemical corrosion. Thaum ob cov hlau sib txawv tau raus hauv dej roj teeb lossis hluav taws xob tsis muaj zog lossis hluav taws xob. Qhov no ua rau cov hluav taws xob ntws los ntawm cov hlau, depleting ntau ntxiv Electrochemically nquag ntawm ob qho hlau. Aluminium muaj ntau dua electrochemical muaj peev xwm tshaj li lwm cov hlau, raws li qhia hauv daim duab hauv qab no. Yog li ntawd, yog tias lub voj voos yog tsim ntawm txhuas thiab cov hlau lossis hlau me me lossis hlau tsis yooj yim.
Duab los ntawm kev tiv thaiv corrosion thiab corrosion tiv thaiv phau ntawv qhia
Yog li ntawd, nws tsis txhais tau tias txhuas tsis yog ib qho uas xeb thiab xeb, thiab tsis muaj qhov saum npoo tiv thaiv corrosion corrosion. Thaum Aluminium yog qhov pheej hmoo ntawm corrosion, tsim nyog kev kho yog tseem tsim nyog, xws li anodizing, hmoov txheej, rwb thaiv tsev kev sib cais, thiab lwm yam.(文章来源: Imchanics 机械)
