Pitting corrosion inodaidzwa zvakare kuti small hole corrosion, pitting kana pitting.
Icho chimiro chekukuvadza kwekuora umo vazhinji vepamusoro pesimbi inoitakwete kuonda kana kuita ngura zvishoma, asi makomba ekuora anoonekwa munzvimbo dzemunharaunda uye anokura zvakadzika.Mamwe makomba aripo ari ega, nepo mamwe akabatana uye anotaridzika senzvimbo yakaoma.Etch maburi anogona kunge akakura kana madiki, asi kazhinji madiki, sezvakaratidzwa mumufananidzo unotevera akasiyana makomba makomba akayambuka-chikamu, maererano nehukuru, kudzika kwegomba re etch kunowanzo kuenzana kana kukura kupfuura dhayamita yegomba re etch.Pitting ndeimwe yeakanyanya kukuvadza corrosion maitiro e duplex Stainless simbi.Makomba egomba anowanzova nzvimbo yekutanga yekushushikana kwegora kutsemuka uye ngura kuneta kutsemuka.
Simbi isina ngurasurface passivation firimu nekuda kwekuvapo kwekuremara musimbi isina tsvina, inclusions uye solutes, zvakadai se inhomogeneity, kuitira kuti firimu rekufambisa rive risina kusimba munzvimbo idzi, mune imwe nzira inoparadza inoparadzwa nyore nyore, kuparadzwa kwechikamu cheanode kunova. activated, nzvimbo yakapoteredza inova nzvimbo ye cathode, nharaunda yenharaunda yezviviri iduku zvikuru, iyo anodic current density yakakura kwazvo, basa rekugadzirisa rinokurumidza, uye rinobva rava nhamba yemakomba akafanana netsono.
Simbi isina tsvina, pamwe chete nedzimwe simbi dzinovimba nayopassivationnekuda kwekusaora, mune mhinduro ine anion chaiyo (chloride, bromide, hypochlorite, kana thiosulfate ions).Chero bedzi iyo corrosion inogona (kana iyo inogona kushandiswa panguva yeanodic polarisation) ichipfuura iyo gomba inogona kuitika Eb, pitting inogona kuitika.Iyo meshini yekupinza corrosion ye duplex Stainless simbi yakafanana nemamwe masimbi asina tsvina.
Simbi yakarapwaine oxidising media, chiyero chekuora kwayo pane yekutanga isina kurapwa isati yanyanya kuderera muchiitiko chinozivikanwa sesimbi passivation.Iyo passivation mechanism inogona kunyanya kushandiswa kutsanangura iyo yakaonda firimu dzidziso, kureva,passivationimhaka yebasa resimbi uye oxidising media, basa resimbi yepasi kuti ibudise yakaonda kwazvo, yakakora, yakanaka yekuvhara kuita, inogona kusungirirwa zvakasimba kune simbi pamusoro passivation firimu.Iyi firimu kuita chikamu chakasiyana chiripo, kazhinji oxygen nesimbi makomisheni.Iyo inotamba basa resimbi uye ngura media yakaparadzaniswa zvachose kubva kune basa rekudzivirira simbi uye ngura media mukusangana kwakananga, kuti simbi inomira kunyungudika kuti iite passivated state kudzivirira kuitika kwekuora.
Nguva yekutumira: Zvita-27-2023