Stainless hlau yog cov hlau uas tsis yooj yim xeb. Lub ntsiab alloying hauv stainless hlau yog Cr (chromium). Thaum cov ntsiab lus Cr tau nce mus txog ib qho txiaj ntsig, cov hlau muaj tshuaj tiv thaiv corrosion, thiab cov hlau stainless feem ntau muaj cov ntsiab lus Cr tsawg kawg yog 10.5%.
Lub tshuab ntawm kev txhim kho ntawm kev txhim kho ntawm stainless hlau yog qhov kev xav ntawm passivation zaj duab xis, uas yog, nws saum npoo yog tsim nrog ntau heev thiab muaj zog thiab ruaj khov Cr-nplua nuj passivation zaj duab xis kom tiv thaiv oxygen atoms los txuas ntxiv rau kev cuam tshuam thiab mus ntxiv oxidize, yog li ua tiav lub peev xwm los tiv thaiv xeb.
Kev txhim kho corrosion mechanism ntawm stainless hlau yog qhov kev xav ntawm passivation zaj duab xis, uas yog, tib neeg xav tias" stainless hlau tsis xeb, thiabrusty tsis yog hlau stainless. Qhov tseeb, qhov no yog qhov muaj kev nkag siab ib-sab uas stainless hlau tsis muaj kev nkag siab. Cov hlau tsis xeb yuav xeb hauv qee yam. Yog tias peb tuaj yeem to taub cov ntau hom kev xeb ntawm cov hlau tsis huv, nyob rau hauv lub ntsej muag ntawm kev xeb ntawm steel hlau tuaj yeem muaj cov kev ntsuas coj los txo kom poob. Cov ntsiab lus hauv qab no qhia txog hom kev xeb ntawm cov xeb ntawm stainless hlau ua ke nrog cov xwm txheej tiag tiag ntawm qhov project, qhia luv luv txog qhov cuam tshuam tiv thaiv kev tiv thaiv, thiab tsom rau cov laj thawj ntawm stainless hlau kev ntxhov siab xeb thiab tiv thaiv thiab ntsuas kev ntsuas.
Qhov kev puas tsuaj ntawm xeb puas tsuaj nyob rau hauv cov hlau xeb yog feem ntau hauv zos ua kev puas tsuaj, feem ntau ua kev cuam tshuam corrosion (9%), pitting corrosion (23%) thiab kev nyuaj siab (49%).
Pitting yog qhov phom sij txaus ntshai heev nyob hauv qhov chaw uas tshwm sim thaum cov qhov me me tshwm sim thiab tom qab ntawd corrodes sai. Nyob rau hauv cov mob hnyav, perforation tuaj yeem tshwm sim. Lub hauv paus tseem ceeb uas cuam tshuam pitting yog:
1. Cuam Tshuam ntawm Cl-, Cl- ua rau muaj kev puas tsuaj ib feem ntawm zaj duab xis passivation ntawm stainless hlau, uas ua rau muaj kev xeb ua haujlwm ntawm feem;
2, cawv ntawm qhov kub, cov cua kub ntau dua, kev cuam tshuam sai dua;
3, nplaim nplaum nplaum rau ntawm cov pa paug txhawm rau txhawm rau tiv thaiv cov pa ntawm cov pa.
Piv txwv, pitting corrosion feem ntau tshwm sim hauv steel hlau (feem ntau 201 lossis 304 stainless hlau) dab dej hauv lub neej txhua hnub. Yog tias qee cov tshuaj acidic lossis salty tau muab tso rau hauv lub taub dej thiab tsis kho kom tsis raws sij hawm, pitting ntawm lub thoob ntawm cov hlau tsis huv yuav tshwm sim.
Cov kev tiv thaiv kev tiv thaiv yog li nram qab no:
1, txhawm rau tiv thaiv Cl-nplaum;
2, kev kho kom zoo saum npoo av, qhov tsim ntawm zaj duab xis ruaj khov passive;
3. Xaiv cov ntaub ntawv uas tiv taus Cl-corrosion (xws li 316L stainless hlau nrog Mo.
