316 stainless hlau tau ntev tau suav tias yog ntau yam los tiv thaiv- cov khoom siv hluav taws xob cua sov thiab siv dav hauv kev lag luam. Txawm li cas los xij, nws muaj cov kev txwv tsis pub siv thiab muaj qhov tsis zoo uas tsis tuaj yeem tsis quav ntsej. Qhov muag tsis pom kev xaiv 316 yam tsis tau soj ntsuam cov kev ua haujlwm feem ntau ua rau cov khoom siv tsis ua haujlwm ntxov, hloov tsis tu ncua thiab nce kev siv nyiaj tag nrho. Qhia meej txog nws qhov kev siv tau thiab qhov tsis muaj zog pab cov engineers txiav txim siab xaiv cov khoom tsim nyog.
Thawj qhov kev txwv tseem ceeb yog nyob rau hauv kev ua haujlwm tsis zoo rau siab -chaw chloride ib puag ncig. Lub molybdenum keeb nyob rau hauv 316 txhim khu nws pitting kuj piv nrog zoo tib yam 304 stainless hlau, tsis tau nws passive oxide zaj duab xis tseem yuav punctured los ntawm chloride ions saum toj no ib co concentration thiab kub pib. Thaum cov ntsiab lus chloride ion ntau tshaj 200 ppm thiab qhov kub siab tshaj 60 degree, pitting corrosion thiab crevice corrosion zoo li sai. Nyob rau hauv dej hiav txwv, saturated brine thiab desalination circulating systems, 316 cua kub raj feem ntau tsis nyob rau hauv 1 mus rau 3 xyoo, deb tshaj lub neej kev pab cuam ntawm titanium los yog duplex stainless hlau lwm.
Thib ob, 316 ua haujlwm tsis zoo hauv kev txo cov kua qaub. Hydrochloric acid, dilute sulfuric acid nrog kev txo cov impurities thiab hydrofluoric acid tuaj yeem ncaj qha rau cov yeeb yaj kiab tiv thaiv ntawm 316. Txawm tias qis -concentration hydrochloric acid yuav ua rau pom tseeb corrosion thiab hauv zos perforation nyob rau hauv ib lub sij hawm luv luv. Tsis zoo li PFA- cov cua kub cua sov uas sib haum nrog yuav luag tag nrho cov inorganic acids, 316 tsis tsim nyog rau lub sij hawm ntev - cua sov ntawm pickling kev daws teeb meem uas muaj hydrochloric acid.
Thib peb, 316 austenitic stainless hlau yog raug rau kev ntxhov siab corrosion cracking (SCC). Thaum tensile residual kev nyuaj siab los ntawm dabtsi yog khoov thiab vuam coexist nrog chloride - muaj siab - kub nruab nrab, ceg tawg yuav propagate sai yam tsis pom tseeb ua ntej - tsis deformation. Xws li kev tawg tam sim ntawd yuav ua rau nruab nrab to thiab txawm tias muaj kev nyab xeeb hauv cov khoom siv tshuaj tiv thaiv kaw. Duplex stainless hlau thiab muaj titanium muaj zog tiv thaiv -SCC muaj peev xwm nyob rau hauv zoo tib yam corrosive tej yam kev mob.
Plaub, intergranular corrosion muaj nyob rau hauv welded 316 khoom. Thaum lub sij hawm welding thermal cycles ntawm 450℃thiab 850 degree, chromium carbides precipitate nyob rau hauv grain ciam teb, depleting chromium ze ntawm grain ciam teb thiab tsis muaj zog corrosion kuj. Txawm hais tias 316L qis- qib carbon txo qhov tsis xws luag, nws tsis tuaj yeem tshem tawm qhov kev pheej hmoo tag nrho nyob rau lub sijhawm ntev - kev pabcuam kub.
Ntxiv rau qhov tsis xws luag corrosion, 316 kuj muaj qhov tsis zoo ntawm kev siv lub cev thiab kev siv. Nws cov thermal conductivity yog tsawg, uas ua rau qeeb tshav kub hloov efficiency piv nrog carbon steel thiab tooj liab. Tsis tas li ntawd, qhov saum npoo yog yooj yim rau scale thiab organic adhesion thaum ua kua cua sov. Scaling khaubncaws sab nraud povtseg ntxiv txo thermal efficiency thiab tsim crevice ib puag ncig uas ua kom lub zos corrosion, yuav tsum tau siv tshuaj ntxuav tu uas qhia txog kev ua hauj lwm ntxiv.
Table 1 Cov xwm txheej ua haujlwm tsis siv tau thiab cov khoom siv hloov pauv tau pom zoo rau 316 Cov Tub Hluav Taws Xob
表格
| Kev ua haujlwm tsis zoo | Core Failure Risk | Pom zoo hloov khoom siv |
|---|---|---|
| High chloride brine & dej hiav txwv | Pitting & perforation | TA2 ntshiab titanium / 2205 duplex steel |
| Hydrochloric acid / tov kua qaub pickling | Ceev ceev uniform corrosion | PFA coated rhaub |
| Kub kub + chloride + vuam residual stress | Kev nyuaj siab corrosion cracking | 254SMO / titanium alloy |
| Lub sijhawm ntev - kev pabcuam tom qab rov ua dua | Intergranular corrosion kuj | 316L nrog ncej-weld annealing |
| Nquag scaling & nyuaj-rau- huv nruab nrab | Thaum tshav kub kub poob & crevice corrosion | Electropolished 316 los yog PFA rhaub |
Paub txog qhov kev ua tau zoo thiab qhov tsis zoo ntawm 316 stainless hlau zam dhau - kev cia siab rau cov khoom siv ib leeg no thiab ua rau lub sijhawm ntev - ruaj khov thiab kev lag luam ntawm cov khoom siv cua sov.
