1. Kev ntxhov siab corrosion: Stainless hlau yeeb nkab fittings tsim kev ntxhov siab corrosion nyob rau hauv nruab nrab corrosive ib puag ncig uas muaj oxygen thiab chloride ions. Qhov feem pua ntawm kev ntxhov siab corrosion tsis ua haujlwm yog siab li 45 feem pua.
Kev tiv thaiv ib puag ncig: Kev xaiv cov khoom tsim nyog thiab cov khoom siv tiv thaiv kev ntxhov siab feem ntau suav nrog high-purity austenitic chromium-nickel steel, high-silicon austenitic chromium-nickel steel, high-chromium ferritic steel thiab ferritic-austenitic dual-theem steel. Ntawm lawv, ferrite-austenite dual-theem steel muaj qhov zoo tshaj plaws kev ntxhov siab corrosion kuj. Kev tswj kev ntxhov siab: Thaum lub sij hawm sib dhos, sim txo qis kev ntxhov siab, thiab ua kom qhov sib txuas nrog qhov nruab nrab muaj qhov tsawg kawg nkaus kev ntxhov siab, tiv thaiv pob thiab khawb, thiab ua raws li cov txheej txheem vuam nruj me ntsis.
Ua raws li cov txheej txheem kev khiav hauj lwm: nruj me ntsis tswj cov txheej txheem ntsuas xws li raw khoom muaj pes tsawg leeg, txaus tus nqi, nruab nrab kub, siab, thiab pH nqi. Ntxiv corrosion inhibitor nyob rau hauv qhov ntau tau tso cai los ntawm cov txheej txheem txheej txheem. Thaum chromium-nickel stainless hlau yeeb nkab fittings siv rau hauv cov pa oxygen chloride yaj, cov feem ntawm cov pa oxygen yuav tsum raug txo kom qis dua 1. 0 × 10 - 6 . Kev xyaum tau ua pov thawj tias hauv dej muaj 5{{5}0. 0 × 10 - 6 pawg feem ntawm chloride ions, nws tsuas yog yuav tsum tau ntxiv ib qho kev sib xyaw ntawm nitrate nrog ib pawg loj ntawm 150. 0 × 10 - 6 thiab sodium sulfite nrog ib pawg loj ntawm 0. . 5 × 10 - 6 , Koj tuaj yeem tau txais txiaj ntsig zoo.
2. Pitting corrosion tsis ua hauj lwm thiab kev tiv thaiv kev ntsuas
Qhov me me corrosion feem ntau yooj yim tshwm sim hauv cov xov xwm zoo li qub. Corrosion pits feem ntau txhim kho raws qhov kev taw qhia ntawm lub ntiajteb txawj nqus lossis transverse kev taw qhia, thiab thaum lub pitting corrosion yog tsim, nws yuav cia li ceev mus rau qhov tob. , oxide zaj duab xis nyob rau saum npoo ntawm stainless hlau yeeb nkab fittings yog yaj nyob rau hauv cov aqueous tov uas muaj chloride ions. Yog li ntawd, cov pits me me uas muaj qhov pore loj ntawm 20 μm mus rau 30 μm yog tsim los ntawm cov hlau puag. Cov pits me me no yog pitting nuclei. Ntev npaum li qhov nruab nrab muaj qee qhov nyiaj ntawm chloride ions, corrosion nuclei tuaj yeem tsim rau hauv qhov corrosion.