UKUGONA KWEMIKHIQIZO YEZINBAYA

Insimbi engagqwali ingxubevange yensimbi equkethe okungenani 10.5% chromium. Le chromium ivumela ukwakheka kongqimba lwe-oxide oluncane kakhulu endaweni yensimbi, eyaziwa nangokuthi "ungqimba lwe-passive" futhi inikeza insimbi engagqwali ukukhanya kwayo okuhlukile.
Izigqoko eziqinile ezifana nalezi zisiza ukuvimbela ukugqwala kwezindawo zensimbi futhi ngaleyo ndlela zithuthukise ukumelana nokugqwala ngokwandisa inani le-chromium kunsimbi engagqwali. Ngokuhlanganisa izakhi ezifana ne-nickel ne-molybdenum, kungathuthukiswa ama-alloys ensimbi engagqwali ahlukahlukene, okunikeze insimbi izici eziwusizo kakhulu, njengokwakheka okuthuthukisiwe kanye nokumelana nokugqwala okuphezulu.
Imikhiqizo yensimbi engagqwali ekhiqizwa abakhiqizi bamapayipi ensimbi ngeke igxumeke ngaphansi kwezimo "zemvelo" noma ezindaweni zasemanzini, ngakho-ke, ama-cutlery, osinki, ama-countertops, namapani enziwe ngensimbi Insimbi engagqwali yasendlini ivame ukusetshenziswa. Kodwa-ke, kubalulekile ukuqaphela ukuthi le nto "ayinalutho" futhi ayiyona "ibala" ngakho-ke kwezinye izimo kuyokwenzeka ukugqwala.

Yini engabangela insimbi engagqwali igle?
Ukugqwala, encazelweni yayo elula, ukusabela kwamakhemikhali okuthinta ubuqotho bezinsimbi. Uma insimbi ihlangana ne-electrolyte, njengamanzi, umoya-mpilo, ukungcola, noma enye insimbi, lolu hlobo lokusabela kwamakhemikhali lungadalwa.
Izinsimbi zilahlekelwa ama-electron ngemva kokusabela kwamakhemikhali futhi ngaleyo ndlela ziba buthaka. Ibe isingenwa okunye ukusabela kwamakhemikhali okuzayo, okungadala izinto ezifana nokugqwala, ukuqhekeka, nezimbobo zento kuze kube yilapho insimbi iba buthaka.
Ukugqwala nakho kungaba ukuziphilisa, okusho ukuthi uma sekuqalile kungaba nzima ukukumisa. Lokhu kungabangela ukuba insimbi ibe brittle lapho ukugqwala kufinyelele esigabeni esithile futhi kungabhidlika.

IZINHLOBO EZAHLUKENE ZOKUGULA EZINTWINI EZINGAGQI
Ukugqwala Okufanayo
Uhlobo oluvame kakhulu lokugqwala olungathinta insimbi engagqwali nezinye izinsimbi lubizwa ngokuthi i-uniform corrosion. Lokhu ukusabalala "okufanayo" kokugqwala endaweni yonke yezinto.
Kuyathakazelisa ukuthi yaziwa nangokuthi ingenye yezindlela "ezilungile" zokugqwala, nakuba ingamboza izindawo ezinkulu zensimbi. Ngempela, umthelela wayo ekusebenzeni kokubalulekile uyalinganiseka njengoba ingaqinisekiswa kalula.

I-Pitting Corrosion
Ukugqwala kwe-pitting kungase kube nzima ukubikezela, ukuqaphela, nokuhlukanisa, okusho ukuthi ngokuvamile kuthathwa njengenye yezindlela eziyingozi kakhulu zokugqwala.
Lolu uhlobo olusendaweni kakhulu lokugqwala lapho indawo encane yokugqwala kwemigodi yenziwa indawo yendawo ye-anodic noma ye-cathodic. Uma lo mgodi usuqinisiwe, “ingazakhela” kuwo ngokwawo ukuze umgodi omncane wenze kalula imbobo engaba yizimo nobukhulu obuhlukahlukene. Ukugqwala kwemigodi kuvame “ukufuduka” kuye phansi futhi kungaba yingozi ikakhulukazi ngoba uma kuyekwa kungagadiwe, ngisho noma indawo encane ithintekile, kungaholela ekuhlulekeni kwesakhiwo sensimbi.

I-Crevice Corrosion
I-Crevice corrosion iwuhlobo lokugqwala okwenziwe endaweni okubangelwa indawo encane kakhulu lapho izifunda ezimbili zensimbi zinokugxiliswa kwe-ion okuhlukile.
Ezindaweni ezinjengamawasha, amabhawodi, namajoyinti anethrafikhi encane evumela ama-asidi ukuthi angene, le ndlela yokugqwala izokwenzeka. Inani elincishisiwe le-oxygen libangelwa ukuntuleka kokujikeleza, ngakho-ke inqubo ye-passive ingenzeki. Ibhalansi ye-pH yembobo bese iyathinteka futhi ibangele ukungalingani phakathi kwale ndawo nendawo engaphandle. Eqinisweni, lokhu kubangela amazinga aphezulu okugqwala futhi kungase kubhebhethekiswe amazinga okushisa aphansi. Ukusebenzisa umklamo ohlanganyelwe ofanele ukunciphisa ingozi yokuqhekeka kokugqwala kungenye yezindlela zokuvimbela lolu hlobo lokugqwala.

I-Electrochemical Corrosion
Uma icwiliswa esixazululweni esonakalisayo noma esibambayo, izinsimbi ezimbili ezihlukene ngokwe-electrochemically ziyahlangana, zenze ukugeleza kwama-electron phakathi kwazo. Ngenxa yokuthi insimbi enokuqina okuncane iyi-anode, insimbi enokumelana nokugqwala okuncane ivame ukuthinteka kakhulu. Lolu hlobo lokugqwala lubizwa ngokuthi i-galvanic corrosion noma i-bimetallic corrosion.