1.Critical chloride concentration rau SCC ntawm Inconel 625
Tsis muaj ib qho, universally txhais "tseem ceeb chloride concentration" rau kev ntxhov siab corrosion cracking (SCC) ntawm Inconel 625, vim nws nyob ntawm qhov kub thiab txias, pH, theem kev ntxhov siab, tshuaj chemical (xws li, oxygen, sulfide, carbonate), thiab metallurgical mob (kev ua haujlwm txias, kev kho cua sov).
Hauv aerated, ze rau -cov tshuaj chloride nruab nrab, Inconel 625 feem ntau tiv taus cov tshuaj chloride-induced SCC, txawm tias cov tshuaj chloride ntau tshaj 10,000 ppm (1 wt%), muab qhov kub thiab txias tsis dhau.
At elevated temperatures (>~ 150-200℃), tshwj xeeb tshaj yog nyob rau hauv lub xub ntiag ntawm oxygen los yog oxidizing hom, SCC susceptibility yuav nce, tab sis lub ntsiab lus "threshold" concentrations yog feem ntau tshaj tawm raws li> 20,000-100,000 ppm Cl⁻ nyob rau hauv kev ntsuam xyuas ib puag ncig, uas yog ntau tshaj li qhov pib ntawm austenitic stainless hlau.
Nyob rau hauv qaub (sulfide{0}}muaj) ib puag ncig, SCC ntawm Inconel 625 feem ntau txo qis los ntawm nws qhov kev tiv thaiv sulfide kev nyuaj siab tawg (SSC), tab sis kev sib xyaw ua ke ntawm cov tshuaj chlorides, sulfides, thiab kub / siab tuaj yeem nyuaj thiab yuav tsum muaj rooj plaub- kev soj ntsuam tshwj xeeb.
Rau lub hom phiaj engineering, Inconel 625 feem ntau suav hais tias tseem ceeb tiv thaiv cov tshuaj chloride SCC nyob rau hauv feem ntau cov roj av thiab cov txheej txheem tshuaj ib puag ncig uas 300-series stainless hlau yuav ua tsis tiav, thiab "cov ntsiab lus tseem ceeb" feem ntau raug kho raws li qhov ntsuas qhov ntsuas tau txiav txim siab los ntawm kev sim lossis cov qauv kev lag luam (xws li, NACE MR017515/ISO rau kev pabcuam).
2.Corrosion kuj ntawm Inconel 625 vs . 316L nyob rau hauv siab - kub, siab - siab (HTHP) qaub roj thiab roj ib puag ncig
Yog lawm, Inconel 625 feem ntau nthuav tawm qhov kev tiv thaiv corrosion zoo dua li 316L stainless hlau hauv HTHP ib puag ncig, tshwj xeeb tshaj yog nyob rau hauv qaub (H₂S- muaj) cov xwm txheej. Cov laj thawj tseem ceeb suav nrog:
Cov ntsiab lus chromium thiab molybdenum siab dua hauv Inconel 625 (Cr ~ 21-23%, Mo ~ 8-10%) muab kev tiv thaiv zoo rau pitting, crevice corrosion, thiab dav corrosion piv rau 316L (Cr ~ 16-18%, Mo ~ 2-3%).
Inconel 625 muaj zog tiv taus sulfide stress cracking (SSC) thiab chloride-induced stress corrosion cracking (SCC), whereas 316L is susceptible to both in sour, chloride-muaj ib puag ncig, tshwj xeeb tshaj yog nyob rau ntawm qhov kub thiab txias.
Cov npib tsib xee-raws li matrix ntawm Inconel 625 inconel 625 yog qhov ruaj khov dua li cov hlau-raws li matrix ntawm 316L nyob rau hauv lub xub ntiag ntawm H₂S, CO₂, thiab chlorides, txo cov nyiam rau hauv zos corrosion thiab hydrogen embrittlement.
Yog li ntawd, nyob rau hauv HTHP qaub kev pab cuam (xws li, downhole tubulars, li qub, thiab lub taub hau Cheebtsam), Inconel 625 yog feem ntau teev thaum 316L yuav suav hais tias yog tsis tsim nyog vim SSC / SCC thiab pitting kev txhawj xeeb, thiab nws yog dav lees paub tias muaj ntau yam zoo corrosion nyob rau hauv cov mob no.
