Txheej txheem cej luam ntawm Duplex Stainless Hlau
Super duplex stainless hlau yog txawv los ntawm cov qauv duplex qib los ntawm nws cov khoom zoo heev corrosion-resistant. Nws yog cov khoom siv alloyed uas muaj qhov siab siab ntawm cov khoom tiv thaiv corrosion xws li chromium (Cr) thiab molybdenum (Mo). Tus thawj super duplex stainless hlau qib, S32750, muaj ntau npaum li 28.0% chromium, 3.5% molybdenum, thiab 8.0% npib tsib xee (Ni). Cov khoom no qhia tshwj xeeb rau cov neeg ua haujlwm corrosive, suav nrog acids, chlorides, thiab caustic daws.
Feem ntau, super duplex stainless hlau tsim los ntawm kev tsim cov txiaj ntsig ntawm duplex qib nrog kev txhim kho tshuaj lom neeg ruaj khov. Qhov no ua rau nws yog qib zoo tshaj plaws rau kev tsim cov khoom tseem ceeb hauv kev lag luam petrochemical, xws li cov khoom siv hluav taws xob, cov boilers, thiab cov khoom siv lub nkoj siab.
Mechanical Properties ntawm Duplex Stainless Hlau
Qib | ASTM A789 Qib S32520 Thaum tshav kub kub kho | ASTM A790 Qib S31803 Thaum tshav kub kub kho | ASTM A790 Qib S32304 Thaum tshav kub kub kho | ASTM A815 Qib S32550 Thaum tshav kub kub kho | ASTM A815 Qib S32205 Thaum tshav kub kub kho |
Elastic Modulus | 200 GPa | 200 GPa | 200 GPa | 200 GPa | 200 GPa |
Elongation | 25% | 25% | 25% | 15% | 20% |
Tensile zog | 770 MPa ua | 620 MPa rau | 600 MPa | 800 MPa | 655 MPa ua |
Brinell hardness | 310 | 290 | 290 | 302 | 290 |
Yield zog | 550 MPa | 450 MPa | 400 MPa | 550 MPa | 450 MPa |
Thermal expansion coefficient | 1E-5 1/K | 1E-5 1/K | 1E-5 1/K | 1E-5 1/K | 1E-5 1/K |
Tshwj xeeb kub muaj peev xwm | 440-502 J / (kg·K) | 440-502 J / (kg·K) | 440-502 J / (kg·K) | 440-502 J / (kg·K) | 440-502 J / (kg·K) |
Thermal conductivity | 13-30 W / (m·K) | 13-30 W / (m·K) | 13-30 W / (m·K) | 13-30 W / (m·K) | 13-30 W / (m·K) |
Classification ntawm Duplex Stainless Hlau
l Thawj hom yog hom tsis tshua muaj alloy, nrog rau qib sawv cev ntawm UNS S32304 (23Cr-4Ni-0.1N). Cov hlau tsis muaj molybdenum, thiab PREN tus nqi yog 24-25. Nws tuaj yeem siv los hloov AISI304 lossis 316 hauv kev ntxhov siab corrosion.
l Hom thib ob belongs rau hom alloy nruab nrab, tus neeg sawv cev hom yog UNS S31803 (22Cr-5Ni-3Mo-0.15N), PREN tus nqi yog 32-33, thiab nws cov corrosion kuj yog nruab nrab ntawm AISI 316L thiab 6% Mo + N austenitic stainless hlau.
l Hom thib peb yog hom alloy siab, uas feem ntau muaj 25% Cr, molybdenum thiab nitrogen, thiab qee qhov kuj muaj tooj liab thiab tungsten. Tus qauv qib UNSS32550 (25Cr-6Ni-3Mo-2Cu-0.2N), PREN tus nqi yog 38-39, thiab corrosion kuj ntawm hom hlau no siab dua li ntawm 22% Cr duplex stainless hlau.
l Hom plaub yog super duplex stainless hlau, uas muaj molybdenum siab thiab nitrogen. Tus qauv qib yog UNS S32750 (25Cr-7Ni-3.7Mo-0.3N), thiab qee qhov kuj muaj tungsten thiab tooj liab. Tus nqi PREN yog ntau dua 40, uas tuaj yeem siv rau qhov hnyav nruab nrab. Nws muaj qhov zoo corrosion kuj thiab txhua yam khoom siv, uas tuaj yeem sib piv nrog super austenitic stainless hlau.
Cov txiaj ntsig ntawm Duplex Stainless Hlau
Raws li tau hais los saum no, Duplex feem ntau ua tau zoo dua li ib tus neeg hlau hom pom nyob rau hauv nws cov microstructure. Zoo dua hais tias, kev sib xyaw ua ke ntawm cov yam ntxwv zoo los ntawm cov ntsiab lus austenite thiab ferrite muab kev daws teeb meem zoo dua rau ntau qhov xwm txheej ntau lawm.
l Anti-corrosive zog - Cov nyhuv ntawm molybdenum, chromium, thiab nitrogen ntawm corrosion kuj ntawm Duplex alloys yog qhov loj heev. Ob peb Duplex alloys tuaj yeem sib tw thiab dhau los tiv thaiv kev ua haujlwm ntawm cov qib austenitic nrov nrog rau 304 thiab 316. Lawv tshwj xeeb tshaj yog tiv thaiv crevice thiab pitting corrosion.
l Stress corrosion cracking - SSC los ntawm ntau yam atmospheric yam - kub thiab av noo yog qhov tseeb tshaj plaws. Tensile kev ntxhov siab tsuas yog ntxiv rau qhov teeb meem. Cov qib austenitic ib txwm muaj qhov cuam tshuam rau kev ntxhov siab corrosion cracking - Duplex stainless hlau tsis yog.
l Toughness - Duplex yog tawv dua li cov hlau ferritic - txawm tias qhov kub qis dua thaum nws tsis ua raws li qhov ua tau zoo ntawm qib austenitic hauv qhov no.
l Lub zog - Duplex alloys tuaj yeem ncav cuag 2 npaug zog dua li ob qho tib si austenitic thiab ferritic qauv. Lub zog siab dua txhais tau tias cov hlau tseem ruaj khov txawm tias txo cov tuab uas yog qhov tseem ceeb tshwj xeeb rau kev txo qhov hnyav.