Lapho kuvela amabala ansundu (amabala) ebusweni bamapayipi ensimbi engagqwali, abantu bamangala kakhulu: “Insimbi engagqwali ayigqwali, futhi uma igqwala, ayiyona insimbi engagqwali, futhi kungase kube nenkinga ngensimbi.”Eqinisweni, lokhu kuwumbono oyiphutha ohlangothini olulodwa mayelana nokuntula ukuqonda kwensimbi engagqwali.Insimbi engagqwali nayo izogqwala ngaphansi kwezimo ezithile.
1. Insimbi engagqwali ayigqwali
Insimbi engagqwali nayo ikhiqiza i-oxide ebusweni.Indlela yokugqwala yazo zonke izinsimbi ezingenasici okwamanje emakethe kungenxa yobukhona besici se-Cr.Imbangela (inqubo) yokumelana nokugqwala kwensimbi engenasici ithiyori yefilimu engenzi lutho.Ifilimu ebizwa ngokuthi i-passivation ifilimu elincanyana elakhiwe ikakhulukazi i-Cr2O3 phezu kwensimbi engagqwali.Ngenxa yobukhona bale filimu, ukugqwala kwe-substrate yensimbi engagqwali emithonjeni ehlukahlukene kuyavinjelwa, futhi lesi simo sibizwa ngokuthi i-passivation.Kunezimo ezimbili zokwakhiwa kwalesi filimu ye-passivation.Enye iwukuthi insimbi engagqwali ngokwayo inamandla okuzithwala, futhi leli khono lokuzibamba liyasheshiswa ngokwanda kokuqukethwe kwe-chromium, ngakho linokumelana nokugqwala;Isimo sokwakheka esibanzi ukuthi insimbi engagqwali yakha ifilimu ye-passivation ohlelweni lokugqwala ezixazululweni ezihlukahlukene ezinamanzi (ama-electrolytes), okuvimbela ukugqwala.Uma ifilimu ye-passivation yonakele, ifilimu entsha ye-passivation ingakhiwa ngokushesha.
Isizathu sokuthi kungani ifilimu ye- passive steel yensimbi engagqwali inamandla okumelana nokugqwala inezici ezintathu: enye ukuthi ugqinsi lwefilimu ye-passive mncane kakhulu, ngokuvamile ama-microns ambalwa kuphela lapho okuqukethwe kwe-chromium> 10.5%;enye amandla adonsela phansi athile efilimu ye-passive inkulu kune-gravity ethize ye-substrate;lezi zici ezimbili zibonisa ukuthi ifilimu ye-passivation yomibili incane futhi iminyene, ngakho-ke kunzima ukuthi ifilimu ye-passive ihlakazwe yi-corrosion medium ukuze idle ngokushesha i-substrate;isici sesithathu ukuthi isilinganiso sokuhlushwa kwe-chromium yefilimu ye-passive I-substrate ingaphezu kokuphindwe kathathu;ngakho-ke, ifilimu ye-passive inokumelana nokugqwala okuphezulu.
2. Ngaphansi kwezimo ezithile, insimbi engagqwali nayo izogqwala
Indawo yokusetshenziswa kwensimbi engagqwali iyinkimbinkimbi kakhulu, futhi ifilimu elula ye-chromium oxide ayikwazi ukuhlangabezana nezidingo zokumelana nokugqwala okuphezulu.Ngakho-ke, izakhi ezifana ne-molybdenum (Mo), ithusi (Cu), ne-nitrogen (N) zidinga ukungezwa ensimbi ngokuvumelana nezimo ezihlukene zokusetshenziswa ukuze kuthuthukiswe ukwakheka kwefilimu ye-passivation kanye nokuthuthukisa ukumelana nokugqwala kwensimbi engagqwali.Ukwengezwa kwe-Mo kukhuthaza kakhulu i-passivation ehlangene ngoba umkhiqizo ogqwalile i-MoO2- useduze ne-substrate futhi uvimbela ukugqwala kwe-substrate;ukungezwa kwe-Cu kwenza ifilimu ye-passive endaweni yensimbi engagqwali iqukethe i-CuCl, ethuthukisa ukusebenza kahle kwefilimu ye-passive ngoba ayihlangani nendawo edlayo.Ukumelana nokugqwala;ukwengeza i-N, ngenxa yokuthi ifilimu ye-passivation inothiswe nge-Cr2N, ukugxila kwe-Cr kufilimu ye-passivation kuyanda, ngaleyo ndlela kuthuthukisa ukumelana nokugqwala kwensimbi engagqwali.
Ukumelana nokugqwala kwensimbi engagqwali kunemibandela.Ibanga lensimbi engagqwali alikwazi ukumelana nokugqwala endaweni ethile, kodwa lingase lonakale kwenye indawo.Ngesikhathi esifanayo, ukumelana nokugqwala kwensimbi engagqwali nakho kuhlobene.Kuze kube manje, ayikho insimbi engagqwali engagqwali nhlobo kuzo zonke izindawo.
Insimbi engagqwali inamandla okumelana ne-oxidation yasemkhathini—okungukuthi, ukumelana nokugqwala, futhi inamandla okugqwala emithonjeni yezindaba equkethe ama-asidi, ama-alkali, nosawoti—okungukuthi, ukumelana nokugqwala.Kodwa-ke, ubukhulu bekhono layo lokulwa nokugqwala bushintshwa ngokubunjwa kwamakhemikhali ensimbi ngokwayo, isimo sokuvikela, izimo zokusetshenziswa kanye nohlobo lwemidiya yemvelo.Isibonelo, ipayipi lensimbi elingu-304 linekhono elihle kakhulu lokulwa nokugqwala endaweni eyomile nehlanzekile, kodwa uma liyiswa endaweni egudle ulwandle, lizogqwala maduzane enkungu yolwandle equkethe usawoti omningi;kuyilapho ipayipi lensimbi le-316 libonisa okuhle.Ngakho-ke, akulona noma yiluphi uhlobo lwensimbi engagqwali olungamelana nokugqwala nokugqwala kunoma iyiphi indawo.
Isikhathi sokuthumela: Sep-23-2022