Pitting corrosion kuj hu ua qhov me me corrosion, pitting los yog pitting.
Nws yog ib daim ntawv ntawm corrosion puas nyob rau hauv uas feem ntau ntawm cov nto ntawm lubhlau uatsis corrode los yog corrodes me ntsis, tab sis corrosion qhov tshwm sim nyob rau hauv cov chaw hauv zos thiab loj hlob tob.Qee qhov pits muaj nyob rau hauv kev sib cais, thaum lwm tus yog compactly txuas thiab zoo li ib tug ntxhib nto.Etch qhov tuaj yeem loj lossis me, tab sis feem ntau me me, raws li qhia hauv daim duab hauv qab no sib txawv pitting pits cross-section, raws li qhov loj me, qhov tob ntawm qhov etch yog feem ntau sib npaug los yog ntau dua li txoj kab uas hla ntawm lub qhov etch.Pitting yog ib qho ntawm cov teeb meem corrosion tshaj plaws ntawm duplex stainless hlau.Pitting qhov feem ntau yog qhov chaw pib ntawm kev ntxhov siab corrosion tawg thiab corrosion qaug zog tawg.
Stainless hlaunto passivation zaj duab xis vim muaj cov tsis xws luag nyob rau hauv stainless hlau, inclusions thiab solutes, xws li inhomogeneity, thiaj li hais tias cov passivation zaj duab xis yog yooj yim dua nyob rau hauv cov chaw no, nyob rau hauv ib tug tshwj xeeb corrosive tov yog yooj yim puas, kev puas tsuaj ntawm ib feem ntawm lub anode ua. Siv zog, thaj chaw ib puag ncig dhau los ua qhov chaw ua haujlwm, thaj tsam ntawm ob qho tseem ceeb heev, qhov kev ua ntawm kev ua kom nrawm, thiab tom qab ntawd dhau los ua lub qhov uas zoo li.
Stainless hlau, nrog rau lwm yam hlau uas tso siab raupassivationrau corrosion kuj, nyob rau hauv ib tug tov uas muaj ib tug tshwj xeeb anion (chloride, bromide, hypochlorite, los yog thiosulfate ions).Ntev npaum li qhov muaj peev xwm corrosion (los yog lub peev xwm siv thaum lub sij hawm anodic polarisation) tshaj qhov pitting muaj peev xwm Eb, pitting tuaj yeem tshwm sim.Lub mechanism ntawm pitting corrosion ntawm duplex stainless hlau yog tib yam li lwm yam stainless hlau.
Hlau khonrog oxidising xov xwm, nws tus nqi corrosion tshaj qhov qub tsis kho ua ntej qhov kev txo qis hauv qhov tshwm sim hu ua hlau passivation.Cov txheej txheem passivation tuaj yeem siv los piav qhia cov kev xav ntawm zaj duab xis nyias, uas yog,passivationyog vim lub luag hauj lwm ntawm hlau thiab oxidising xov xwm, lub luag hauj lwm ntawm cov hlau nto los tsim ib tug heev nyias, ntom, zoo kev pab them nqi, tuaj yeem ruaj khov txuas rau cov hlau nto passivation zaj duab xis.Cov yeeb yaj kiab no mus rau hauv ib theem sib cais, feem ntau yog cov pa oxygen thiab hlau sib txuas.Nws plays lub luag hauj lwm ntawm cov hlau thiab corrosion media tag nrho sib cais los ntawm lub luag hauj lwm ntawm kev tiv thaiv cov hlau thiab corrosion media nyob rau hauv kev sib cuag ncaj qha, yog li ntawd cov hlau yeej tsis dissolving los tsim ib tug passivated lub xeev los tiv thaiv cov nyhuv ntawm corrosion.
Post lub sij hawm: Dec-27-2023