I-pitting corrosion ibizwa nangokuthi ukugqwala kwemigodi encane, i-pitting noma i-pitting.
Kuwuhlobo lomonakalo wokugqwala lapho iningi lobuso beinsimbi yenzaayigqwali noma ingagqwali kancane, kodwa izimbobo zokugqwala ziyavela ezindaweni zendawo futhi zikhule zijule.Eminye imigodi ikhona yodwa, kuyilapho eminye ixhumene futhi ibukeka njengendawo emagebhugebhu.Izimbobo ze-etch zingaba zinkulu noma zibe zincane, kodwa ngokuvamile zibe zincane, njengoba kukhonjisiwe emfanekisweni olandelayo imigodi yemigodi ehlukene ingxenye enqamulayo, ngokosayizi, ukujula kwembobo ye-etch ngokuvamile kuyalingana noma kukhulu kunobubanzi bembobo ye-etch.I-Pitting ingenye yamaphethini okugqwala ayingozi kakhulu ensimbi engagqwali eyi-duplex.Izimbobo zokubhoboza ngokuvamile ziyisizinda sokuqala semifantu yokugqwala kwengcindezi kanye nokuqhekeka kokukhathala.
Insimbi engagqwaliifilimu ye-surface passivation ngenxa yokuba khona kweziphambeko ensimbi engagqwali, inclusions kanye ne-solutes, njenge-inhomogeneity, ukuze ifilimu ye-passivation ibe ntekenteke kakhulu kulezi zindawo, kusixazululo esithile esigqwalayo sibhujiswa kalula, ukubhujiswa kwengxenye ye-anode kuba. icushiwe, indawo ezungezile iba indawo ye-cathode, isilinganiso sendawo salokhu okubili sincane kakhulu, ukuminyana kwamanje kwe-anodic kukhulu kakhulu, umsebenzi wokuxazulula uyashesha, bese kuba inombolo yezimbobo ezifana nenaliti.
Insimbi engagqwali, kanye nezinye izinsimbi ezithembele kuzoukuthathekaukumelana nokugqwala, esixazululweni esiqukethe i-anion ethile (i-chloride, i-bromide, i-hypochlorite, noma i-ion thiosulfate).Inqobo nje uma amandla okugqwala (noma amandla asetshenziswa phakathi ne-anodic polarisation) edlula i-Eb engase ibe khona, umgodi ungenzeka.Indlela yokugqwala kwe-pitting yensimbi engagqwali eyi-duplex iyafana nezinye izinsimbi ezingenasici.
Ukwelashwa kwensimbingemidiya ekhipha i-oxidising, izinga lokugqwala kwalo kunelokuqala elingelashwanga ngaphambi kokwehla okukhulu kwento eyaziwa ngokuthi i-metal passivation.I-passivation mechanism ingasetshenziswa ikakhulukazi ukuchaza ithiyori yefilimu emincane, okungukuthi,ukuthathekakungenxa yendima yensimbi kanye nemidiya ye-oxidising, indima yendawo yensimbi ukuze ikhiqize ukusebenza okuncane kakhulu, okuminyene, okuhle kokumbozwa, kungenziwa ngokuqinile enamathiselwe kwifilimu yensimbi ye-surface passivation.Le filimu ibe yisigaba esihlukile ikhona, ngokuvamile i-oxygen ne-metal compounds.Idlala indima yemidiya yensimbi nokugqwala ehlukaniswe ngokuphelele nendima yokuvimbela imidiya yensimbi nokugqwala ukuthintana okuqondile, ukuze insimbi ngokuyisisekelo iyeke ukuncibilika ukuze yakhe isimo esidlulile ukuvimbela umphumela wokugqwala.
Isikhathi sokuthumela: Dec-27-2023