|
Super Duplex 2507 (UNS S32750, PREN kwv yees li 42-45) tiv taus pitting thiab crevice corrosion nyob rau hauv siab -chloride thiab seawater kev pab cuam deb zoo dua Duplex 2205 (UNS S32205, PREN kwv yees li 35), thiab nws kuj muab roughly 20% zog dua. Duplex 2205 tseem yog qhov kev xaiv pheej yig dua rau nruab nrab -chloride chemical processing, desalination, thiab cov kav dej dav dav. Xaiv 2507 thaum chloride concentration, kub, lossis crevice geometry thawb yav dhau los 2205 lub hnab ntawv pov thawj kev pabcuam - feem ntau yog offshore, subsea, thiab high-salinity seawater systems. |
PREN yog dab tsi?
PREN (Pitting Resistance Equivalent Number) yog ib qho kev ntsuas tus lej zoo tshaj plaws ntawm kev ua kom tsis muaj zog lossis duplex alloy yuav tiv taus qhov chaw nyob hauv ib puag ncig chloride. Super Duplex 2507 tau qhab nia kwv yees li 25% siab dua tus qauv Duplex 2205, uas yog tag nrho vim li cas ob qib muaj nyob hauv tsev neeg cov khoom sib cais ntau dua li ib qho.
PREN yog xam los ntawm cov hlau alloy cov tshuaj muaj pes tsawg leeg siv cov mis PREN=%Cr + 3.3 x (%Mo + 0.5 x %W) + 16 x %N. Chromium tsim cov txheej txheem oxide passive, molybdenum stabilizes txheej hauv chloride-nplua nuj tej yam kev mob, thiab nitrogen ntxiv dag zog rau ob lub passive zaj duab xis thiab lub austenite theem. Qhov qhab nia PREN ntau dua txhais tau hais tias cov hlau tsis muaj zog pitting pib ntawm cov tshuaj chloride ntau dua thiab kub dua.
|
Alloying Element |
Lub luag haujlwm hauv Corrosion Resistance |
PREN Qhov Ntsuas Qhov Ntsuas |
|
Chromium (Cr) |
Ua tus passive chromium - oxide zaj duab xis |
1x |
|
Molybdenum (hli) |
Stabilizes zaj duab xis passive tiv thaiv chloride nres |
3.3x |
|
Nitrogen (N) |
Strongthe passive zaj duab xis thiab austenite theem |
16x |
|
Tungsten (W) |
Ntxiv cov nyhuv molybdenum (tsis tshua muaj hauv cov qib no) |
1.65x (0.5 x 3.3) |
Kev lag luam convention faib duplex stainless hlau los ntawm PREN cov qhab nia: tus qauv duplex qib poob ntawm 30 thiab 40, thiab super duplex qib siab tshaj 40. Qhov 40-point threshold no tsis yog arbitrary - nws sib haum mus rau ib tug ntsuas dhia nyob rau hauv qhov tseem ceeb pitting kub uas engineers siv ncaj qha rau hauv cov ntaub ntawv xaiv cov qauv xws li MAST-60 NORS.
Yuav Ua Li Cas PREN Cov qhab nia ntawm 2205 thiab 2507 Tiag tiag?
2507 ua 2nqa PREN ntawm kwv yees li 42-45 piv rau 2205 qhov kwv yees li 35, qhov sib txawv uas tau tsav los ntawm ntau dua molybdenum thiab nitrogen cov ntsiab lus - thiab qhov sib txawv yog dab tsi cais tus qauv duplex qib los ntawm qib super duplex.
|
Khoom |
Duplex 2205 (UNS S32205) |
Super Duplex 2507 (UNS S32750) |
|
Hom PREN |
~35 |
~42-45 |
|
PREN kev faib tawm |
Standard duplex (30-40) |
Super duplex (>40) |
|
Chromium cov ntsiab lus |
22.0-23.0% |
24.0-26.0% |
|
Cov ntsiab lus molybdenum |
3.0-3.5% |
3.0-5.0% |
|
Nitrogen cov ntsiab lus |
0.14-0.20% |
0.24-0.32% |
Qhov sib txawv ntawm PREN ntawm kwv yees li 7-10 cov ntsiab lus yuav zoo li me me ntawm daim ntawv, tab sis nws sib raug rau lub qhov rais uas muaj kev nyab xeeb ntau dua hauv kev pabcuam chloride. Hauv cov ntsiab lus, qhov no yog qhov sib txawv ntawm cov yeeb nkab uas yuav tsum tau soj ntsuam ntawm lub sijhawm luv luv hauv kev pabcuam dej hiav txwv thiab ib qho uas tuaj yeem teev tau nrog kev ntseeg siab rau kev ua haujlwm tsis tu ncua.
Dab tsi yog tag nrho cov tshuaj lom neeg sib txawv?
Tshaj li PREN-cov ntsiab lus tseem ceeb, 2507 tseem nqa cov ntsiab lus nickel siab dua kom sib npaug nws cov ferrite- austenite theem piv, uas ntxiv tus nqi tab sis txhim kho toughness ntawm qib siab alloying.
|
Lub ntsiab |
Duplex 2205 (wt%) |
Super Duplex 2507 (wt%) |
|
Chromium (Cr) |
22.0 - 23.0 |
24.0 - 26.0 |
|
Nickel (Ni) |
4.5 - 6.5 |
6.0 - 8.0 |
|
Molybdenum (hli) |
3.0 - 3.5 |
3.0 - 5.0 |
|
Nitrogen (N) |
0.14 - 0.20 |
0.24 - 0.32 |
|
Manganese (Mn) |
2.0 max |
1.2 max |
|
Cov pa roj carbon (C) |
0.030 max |
0.030 max |
|
Hlau (Fe) |
Tshuav |
Tshuav |
Ob qib tswj hwm kwv yees li 50/50 ferrite- rau- austenite theem sib npaug, uas yog qhov ua rau duplex stainless hlau lawv cov kev sib xyaw ua ke ntawm lub zog siab thiab zoo toughness. 2507 cov ntsiab lus ntawm cov alloy siab dua yuav tsum nruj dua tswj thaum lub sij hawm tshuaj annealing los tiv thaiv qhov sib npaug, uas yog ib qho laj thawj 2507 commands tus nqi tsim khoom tshaj li raw khoom.
Qib twg muab cov cuab yeej siv zog siab dua?
Super Duplex 2507 muab kwv yees li ntawm 20-25% siab dua qhov qis tshaj tawm lub zog tshajTIAB SA 2205, uas cia cov engineers txo cov phab ntsa tuab thiab cov khoom hnyav hauv siab - khaws daim ntawv thov -- feem ntau offsetting ib feem ntawm nws cov nqi siab dua ib kilogram.
|
Mechanical Property |
TIAB SA 2205 |
Super Duplex 2507 |
|
Yam tsawg kawg nkaus yield zog (0.2% offset) |
450 MPa (65 ksi) |
550 MPa (80 ksi) |
|
Tsawg kawg tensile zog |
620 MPa (90 ksi) |
795-800 MPa (116 ksi) |
|
Elongation thaum so |
25% yam tsawg kawg nkaus |
15% yam tsawg kawg nkaus |
|
Hom hardness |
290 HB max |
310 HB max |
|
Impact toughness (Charpy, -46 degree) |
Zoo |
Zoo, me ntsis qis paj |
Lub zog kom zoo dua ntawm 2507 yog qhov tseem ceeb tshaj plaws nyob rau hauv siab - siab piping, subsea manifolds, thiab structural Cheebtsam uas txo cov phab ntsa thickness ncaj qha txo qhov hnyav thiab cov khoom nqi ib 'meter' yeeb nkab - ib feem them rau nws cov nqi siab dua.
Lawv ua li cas hauv chloride-Cov chaw nplua nuj thiab dej hiav txwv?
2507 tiv taus ntau dua chloride concentration thiab kub ua ntej pitting los yog crevice corrosion pib, ua rau nws tus qauv xaiv rau seawater thiab subsea kev pab cuam, thaum 2205 tseem ntseeg tau tsuas yog nyob rau hauv nruab nrab - chloride tej yam kev mob xws li dej brackish thiab cov txheej txheem dej.
|
Corrosion Metric |
TIAB SA 2205 |
Super Duplex 2507 |
|
Critical Pitting Kub (CPT, ASTM G48A) |
20-25 ° C |
+ 35-40 ° C |
|
Critical Crevice Kub (CCT, ASTM G48B) |
~ 15-20 ° C |
~ 30-35 degree |
|
Cov kev pabcuam siab tshaj plaws chloride |
Nruab nrab (dej brackish, txheej txheem me ntsis) |
Siab (seawater, subsea, siab -salinity brine) |
|
Chloride stress corrosion cracking kuj |
Zoo, zoo dua austenitic 316L |
Zoo heev |
Ob qib ua tau zoo tshaj tus qauv austenitic stainless hlau xws li 316L hauv kev pabcuam chloride vim tias cov duplex microstructure tiv thaiv kev ntxhov siab corrosion tawg zoo dua li cov qauv austenitic tag nrho. Tab sis ntawm ob qib duplex, CPT qhov sib txawv ntawm kwv yees li 15℃yog qhov txiav txim siab seb cov hlau puas tuaj yeem raug teev rau cov kav dej hiav txwv tsis muaj dej tsis muaj kev tiv thaiv corrosion lossis kev tiv thaiv cathodic ntxiv.
Tus nqi sib txawv ntawm 2205 thiab 2507 yog dab tsi?
Super Duplex 2507 feem ntau raug nqi 20-35% ntau dua Duplex 2205 ib kilogram, uas tau tsav los ntawm nws cov molybdenum siab dua thiab cov ntsiab lus npib tsib xee ntxiv rau kev tswj xyuas nruj dua - yog li kev qhia 2507 tsuas yog ua rau kev lag luam thaum daim ntawv thov tiag tiag xav tau nws qhov kev tiv thaiv corrosion ntxiv lossis lub zog.
Molybdenum yog tus tseem ceeb tus nqi tsav tsheb: 2507 nqa mus txog 5% Mo tawm tsam 2205's 3.5% qab nthab, thiab molybdenum yog ib qho ntawm cov khoom siv hluav taws xob ntau dua thiab kim alloying nyob rau hauv npib tsib xee- cov saw hlau hlau. Nickel cov ntsiab lus, kev ua tiav ntau dua thaum lub sij hawm kev daws teeb meem, thiab qis dua zeb dhau los rau super duplex heats ntxiv cov nqi ntxiv.
Kev them nyiaj yug lifecycle:Nyob rau hauv dej hiav txwv los yog subsea kev pab cuam qhov twg 2205 yuav xav tau ib tug corrosion pub, cathodic tiv thaiv, los yog ib tug luv luv lub sij hawm soj ntsuam, tus nqi siab dua ntawm 2507 yog nquag rov qab los ntawm kev txo cov txij nkawm, tsawg shutdowns, thiab ntev kev pab cuam lub neej. Txawm li cas los xij, rau nruab nrab - cov ntawv thov chloride, 2205 feem ntau xa tus nqi qis dua ntawm cov tswv cuab.
Cov kev lag luam twg thiab cov ntawv thov haum rau txhua qib?
Duplex 2205 dominates chemical processing, pulp thiab paper, and desalination, hos Super Duplex 2507 is the default options for offshore oil and gas, subsea, and high -salinity seawater systems.
|
Daim ntawv thov |
Pom zoo Qib |
Yog vim li cas |
|
General chemical processing piping |
2205 |
Cov tshuaj chloride tsawg; tus nqi- zoo |
|
Pulp thiab ntawv khoom siv |
2205 |
Zoo tiv thaiv chloride thiab organic acids |
|
Desalination (RO/MSF) systems |
2205 los yog 2507 |
2507 rau siab -salinity pub lossis brine concentrate |
|
Offshore platform piping |
2507 |
Ncaj qha dej hiav txwv thiab ntsev - tsuag tsuag |
|
Subsea manifolds thiab risers |
2507 |
Nruam siab -chloride, siab - kev pabcuam siab |
|
Hluav taws kub thiab dej hiav txwv ring mains |
2507 |
Cov dej hiav txwv stagnant txhawb kev crevice corrosion |
|
Architectural structural cov tswv cuab |
2205 |
Tus nqi - lub zog zoo rau kev siv tsis yog - raus siv |
Vuam thiab Fabrication Requirements txawv li cas?
2507 xav tau kev tswj xyuas cov cua sov kom nruj dua thiab nruj dua tiv thaiv kev siv roj ntau dua li 2205 vim tias nws cov ntsiab lus alloy siab dua ua rau nws yooj yim dua rau theem tsis sib xws thiab nag lossis daus thaum lub sij hawm vuam.
Ob qib xav tau nitrogen-enriched shielding gas kom khaws nitrogen cov ntsiab lus nyob rau hauv weld thiab tshav kub- thaj tsam cuam tshuam.
2507 yuav tsum muaj kev tswj xyuas qhov kub ntawm qhov sib cuam tshuam (feem ntau hauv qab 150 degree) kom tsis txhob muaj nag lossis daus xws li theem sigma, uas txo cov tawv thiab corrosion kuj.
2507 cov txheej txheem weld feem ntau hu rau ntau tshaj -alloyed muab tub lim hlau los them rau qhov kev pheej hmoo siab dua ntawm ferrite / austenite imbalance nyob rau hauv fusion zone.
Tom qab- kev tshuaj xyuas vuam rau 2507 yuav tsum suav nrog cov ntsiab lus ferrite pov thawj, vim tias qhov pom tau zoo ntawm ferrite qhov rais yog nqaim dua li 2205.
Rau ob qib, cov txheej txheem vuam tsim nyog rau ASME Tshooj IX thiab tom qab- vuam corrosion testing ib ASTM A923 (rau kev kuaj xyuas cov theem tsis zoo intermetallic) yog cov qauv kev coj ua ntawm cov kav dej tseem ceeb.
Duplex 2205 lossis Super Duplex 2507 -- Koj Yuav Tsum Xaiv Qhov twg?
Xaiv 2205 thaum cov tshuaj chloride raug nruab nrab thiab nyiaj txiag teeb meem; xaiv 2507 thaum daim ntawv thov cuam tshuam nrog dej hiav txwv, subsea tej yam kev mob, lossis cov tshuaj chloride uas thawb dhau 2205 lub hnab ntawv pov thawj.
|
Kev txiav txim Factor |
Zoo 2205 |
Zoo 2507 |
|
Chloride concentration |
Tsawg rau nruab nrab |
High (seawater thiab saum toj no) |
|
Ua haujlwm kub |
Hauv qab ~ 25℃hauv kev pabcuam chloride |
Qhov kub siab nrog cov chlorides tam sim no |
|
Nyiaj txiag rhiab heev |
Qhov tseem ceeb tshaj |
Secondary rau kev ntseeg |
|
Phab ntsa thickness / qhov hnyav txo cov hom phiaj |
Tsis tseem ceeb |
Qhov tseem ceeb (siab zog tso cai rau cov phab ntsa nyias) |
|
Immersion lossis subsea lub luag haujlwm |
Tsis muaj |
Yog lawm |
|
Kev saib xyuas kev nkag |
Kev nkag mus tsis tu ncua muaj |
Kev nkag tau yooj yim lossis kim kim (subsea, faus) |
Rau cov haujlwm nyob ze ntawm ciam teb ntawm ob qhov profile no, ib qhov project -kev ntsuam xyuas corrosion tshwj xeeb xa mus rau qhov tseeb chloride concentration, kub, thiab crevice geometry yog lub hauv paus zoo tshaj plaws rau kev xaiv qib kawg. EETA pab pawg engineering tuaj yeem tshuaj xyuas cov kev ntsuas no tiv thaiv cov ntaub ntawv ntawm qhov kev thov.
Cov lus nug nquag
Q: PREN sawv cev rau dab tsi?
A: PREN sawv cev rau Pitting Resistance Equivalent Number. Nws yog cov qhab nia suav raws li chromium, molybdenum, thiab nitrogen cov ntsiab lus uas kwv yees tias cov hlau tsis muaj stainless lossis duplex alloy tiv thaiv thaj tsam pitting corrosion hauv chloride ib puag ncig.
Q: Puas yog Super Duplex 2507 ib txwm zoo dua Duplex 2205?
A: Tsis yog . 2507 muaj kev tiv thaiv corrosion zoo dua thiab muaj zog dua, tab sis ntawm 20-35% tus nqi them nqi. Rau nruab nrab -chloride, tsis yog - daim ntawv thov rau immersed, 2205 feem ntau yog tus nqi ntau dua thiab kev xaiv txaus.
Q: Dab tsi yog PREN kev txiav tawm ntawm qib duplex thiab super duplex?
A: Tus qhab nia PREN siab tshaj 40 feem ntau faib cov hlau nplaum ua super duplex. Duplex 2205 tau qhab nia kwv yees li 35, muab tso rau hauv cov txheej txheem duplex; Super Duplex 2507 tau qhab nia kwv yees li 42-45, muab nws ruaj khov rau hauv qeb super duplex.
Q: Duplex 2205 puas tuaj yeem siv rau hauv kev pabcuam dej hiav txwv?
A: 2205 tuaj yeem siv rau hauv cov dej hiav txwv nyob rau hauv cov xwm txheej tsis tshua muaj, feem ntau nrog kev tiv thaiv cathodic ntxiv, ntws - ntxias tus kheej - ntxuav, lossis qhov chaw nyob ruaj khov, kev sib tshuam - zam qhov xwm txheej tsis zoo. Rau kev nruam los yog tsis muaj dej hiav txwv raug, 2507 yog qhov kev xaiv ntau dua.
Q: Vim li cas 2507 nqi ntau dua 2205?
A: 2507 muaj ntau dua molybdenum, npib tsib xee, thiab nitrogen, tag nrho cov uas nce nqi raw khoom. Nws tseem yuav tsum tau nruj dua kev tswj xyuas thaum lub sij hawm melting, kev daws annealing, thiab vuam, uas ntxiv cov nqi tsim khoom ntxiv.
Q: Puas yog 2205 thiab 2507 xav tau cov txheej txheem vuam sib txawv?
A: Yog. 2507 yuav tsum tau nruj dua interpass kub tswj thiab feem ntau tshaj -alloyed muab tub lim hlau kom tsis txhob intermetallic theem tsim, uas yog feem ntau yuav tshwm sim vim nws cov ntsiab lus alloy siab dua.
