Corrosion Resistance ntawm ntau yam hluav taws xob cua sov raj

Thaum xaiv cov khoom siv rau cov hlau hluav taws xob cua sov, qhov kev tiv thaiv corrosion ntawm cov qib sib txawv ntawm stainless hlau feem ntau yog qhov tseem ceeb tshaj plaws. Niaj hnub no, peb yuav tham txog ntau yam ntawm stainless hlau uas feem ntau siv nyob rau hauv hluav taws xob cua sov raj thiab yuav tiv thaiv corrosion.

Hluav taws xob cua sov raj tuaj yeem muab kev tiv thaiv corrosion zoo hauv ntau qhov chaw muaj. Raws li qhov tiag -kev paub hauv ntiaj teb, stainless hlau tuaj yeem corrode ntau txoj hauv kev ntxiv rau kev ua haujlwm tsis zoo. Ib txoj hauv kev tseem ceeb uas cov hlau tsis muaj hlau tuaj yeem corrode yog los ntawm kev xeb hauv zos, uas suav nrog kev ntxhov siab corrosion tawg, pitting corrosion, intergranular corrosion, corrosion qaug zog, thiab crevice corrosion. Localized corrosion hom yog lub luag hauj lwm rau ntau tshaj ib nrab ntawm tag nrho cov tsis ua hauj lwm. Hauv kev muaj tiag, xaiv cov khoom siv zoo tuaj yeem pab tiv thaiv ntau qhov kev ua tsis tiav. Vim li no, stainless hlau lub peev xwm los tiv thaiv corrosion yog qhov tseem ceeb heev rau cov cua sov siv hauv kev lag luam.


Kev ntxhov siab Corrosion Cracking (SCC)
Kev ntxhov siab corrosion cracking yog ib lo lus dav rau kev tawg ntawm cov hlau nplaum uas tshwm sim thaum cov kab nrib pleb sib kis hauv qhov chaw corrosive. Nws muaj cov pob txha tawg, txawm tias nws tuaj yeem tshwm sim hauv cov ntaub ntawv uas muaj zog heev. nro corrosion cracking tsuas yog tshwm sim thaum muaj tensile nro (xws li residual stress, thov kev nyuaj siab, los yog ob qho tib si) thiab ib co corrosive xov xwm. Cracks pib thiab kis mus rau hauv ib txoj kev uas roughly perpendicular mus rau cov kev taw qhia ntawm tensile nro. Cov qib kev ntxhov siab uas ua rau muaj kev ntxhov siab corrosion tawg yog qhov qis dua qhov uas yuav ua rau cov khoom tawg yam tsis muaj corrosive media.

Transgranular tawg yog cov uas dhau los ntawm cov nplej, hos cov kab nrib pleb intergranular yog cov uas mus raws li cov ciam teb. Thaum kev ntxhov siab corrosion tawg mus txog qhov tob tob (qhov twg qhov kev ntxhov siab ntawm cov khoom thauj khoom hla- ntu nce mus txog nws qhov kev ntxhov siab tawg hauv huab cua), cov khoom tawg los ntawm kev sib tsoo ib txwm nthuav tawm (hauv cov ntaub ntawv tawv, feem ntau yog los ntawm kev sib koom ua ke ntawm micro- tsis xws luag). Yog li ntawd, qhov tawg ntawm cov khoom uas ua tsis tiav vim kev ntxhov siab corrosion cracking nta ib qho chaw tshwj xeeb ntawm kev ntxhov siab corrosion cracking thiab thaj tsam "dimple" txuas rau kev sib koom ua ke ntawm micro- tsis xws luag.

Corrosion nruab nrab ntawm cov nplej
Cov ciam teb nplej yog thaj chaw nruab nrab ntawm cov nplej uas tsis muaj cov qauv qhia meej thiab muaj ntau yam crystallographic orientations. Qhov no ua rau lawv qhov chaw zoo rau cov ntsiab lus sib txawv kom sib cais los yog rau cov khoom siv hlau (xws li carbides thiab δ-theem) rau hauv cov hlau. Yog li, nws tsis yog qhov xav tsis thoob tias cov ciam teb ntawm cov qoob loo yuav muaj feem cuam tshuam rau qee qhov chaw corrosive. Intergranular corrosion yog ib hom corrosion uas tuaj yeem tshwm sim rau feem ntau cov hlau thiab alloys thaum lawv nkag mus rau hauv qee yam corrosive.

Corrosion nyob rau hauv Crevices
Crevice corrosion yog ib hom kev txhim kho hauv zos uas tuaj yeem tshwm sim nyob rau hauv stagnant crevices lossis ntawm qhov chaw uas tiv thaiv los ntawm kev daws teeb meem. Crevices zoo li no tuaj yeem tshwm sim qhov twg cov hlau ntsib hlau lossis hlau ntsib lwm yam, xws li rivets, bolts, gaskets, valve seats, loose de deposits, or marine life.

Corrosion feem ntau
General corrosion yog ib kab lus rau hom corrosion uas tshwm sim heev tusyees thoob plaws tag nrho cov nto ntawm ib tug alloy. Corrosion tshwm sim thaum cov khoom maj mam tau thinner thiab tej zaum yuav tawg tag nrho. Cov kua qaub thiab alkalis muaj zog tuaj yeem ua rau muaj kev xeb ntau hauv stainless hlau. Kev ua tsis tiav vim kev xeb tsis zoo tsis yog qhov ceeb tshwj xeeb, vim tias daim ntawv ntawm corrosion no feem ntau yuav xav tias siv cov kev sim ncaj nraim los yog los ntawm kev xa mus rau corrosion- cov ntaub ntawv ntsig txog.