Stainless hlau welded kav yog hu ua stainless hlau welded kav vim lawv siab tsis kam mus corrosion thiab corrosive xwm ntawm lawv ib puag ncig. Muaj ntau txoj kev xav los piav qhia qhov passivation ntawm stainless hlau welded yeeb nkab.
Kev piav qhia los ntawm chemical theory
Vim yog qhov kev txiav txim nrog qhov nruab nrab, yuav muaj txheej txheej ntawm Cr20-raws li zaj duab xis rau saum npoo, uas yog, clocking zaj duab xis, thiaj li hais tias stainless hlau huang raj raug suav hais tias muaj corrosion kuj. Hom zaj duab xis no yog tus cwj pwm los ntawm nyias, feem ntau tsuas yog ob peb microns, cov ntsiab lus chromium ntau dua 10.5%, qhov tshwj xeeb lub ntiajteb txawj nqus ntawm hom zaj duab xis yog ntau dua li qhov tshwj xeeb lub ntiajteb txawj nqus ntawm cov hlau matrix, qhia tias zaj duab xis yog tuab heev. Qhov no tuaj yeem tiv thaiv cov hlau matrix los ntawm kev xeb, vim tias cov yeeb yaj kiab zoo li no nyuaj heev los ua corrosive nruab nrab puas tsuaj. Electronic Theory Explanation.
Nws ntseeg tau tias lub xeev bellicose ntawm cov hlau muaj feem xyuam rau cov txheej txheem electron uas tsis tau sau. Cov hlau-chromium alloy stainless hlau humongous raj yog passivated vim chromium sim nqus electrons thiab hlau (Fe) atoms poob electrons. Qee cov kws tshawb fawb ntseeg tias thaum cov ntsiab lus chromium nyob rau hauv cov tshuaj ferrochromium alloy khoom ncav cuag 1/8 (piv txwv li, 12.5%), lub peev xwm electrode tuaj yeem dhia ntawm 0.56 V mus rau +0.2 V. nce hauv electrode muaj peev xwm ua rau cov hlau hauv electrolyte ruaj khov, uas yog, tsis tshua muaj corrosion. Cov kev xav saum toj no yog ua raws li lub luag haujlwm ntawm kev coj tus kheej hauv siab. Qhov tseeb, vim muaj ntau haiv neeg thiab tsis yooj yim ntawm cov khoom ib puag ncig, txhawm rau txhim kho thiab sib sau ua ke ntawm cov khoom siv corrosion, nws yog ib qho tsim nyog yuav tsum tau ntxiv lwm cov ntsiab lus alloying nyob rau hauv tej yam kev mob. Piv txwv li, qhov sib ntxiv ntawm nitrogen (N) cov ntsiab lus yuav ua rau cov khoom corrosive M002 ze rau lub hauv paus so, los txhawb lub passivation ntawm lub substrate; qhov sib ntxiv ntawm cov neeg, N) cov ntsiab lus yuav ua rau cov hlau tsis muaj steel raj nto ntawm cov yeeb yaj kiab tshuaj muaj u0, tsis yog corrosive nruab nrab theem, yog li txhim kho corrosion kuj ntawm cov khoom; Qhov sib ntxiv ntawm cov neeg nitrogen (N) cov ntsiab lus yuav ua rau cov khoom siv corrosion kuj, vim tias cov zaj duab xis passivation yog nplua nuj nyob rau hauv Cr2N, yog li ua kom cov concentration ntawm chromium nyob rau hauv passivation zaj duab xis.
