Duplex Stainless Steels Luv Taw Qhia
Duplex Stainless hlauyog ib tsev neeg ntawm cov hlau tsis muaj steel uas sib txuas cov khoom zoo ntawm ob qho tib siausteniticthiabferritic stainless hlau. Qhov kev sib xyaw tshwj xeeb no ua rau cov khoom siv uas nthuav tawm tshwj xeeb corrosion kuj, siab zog, thiab zoo weldability. Lub ntsiab lus ntawm duplex alloys yog lawv ob-theem microstructure, muaj ob qho tib si austenitic (lub ntsej muag-centered cubic) thiab ferritic (lub cev-centered cubic) theem nyob rau hauv roughly sib npaug proportions.
Duplex Stainless Steel Composition Thiab Qib
Duplex stainless hlau yeeb nkabmuaj Cr cov ntsiab lus ntawm 22% -25% nrog ntxiv ntawm Mo, W thiab N (ASM International, 2001a). Lub microstructure muaj austenite theem thiab ferrite theem. Qhov zoo tshaj plaws piv ntawm austenite theem rau ferrite theem yog 1: 1 (ASM International, 2001a; Tuck li al., 1994). Txawm hais tias duplex stainless hlau muaj SCC siab tsis kam, nws muaj siab dua SSC rhiab heev vim muaj cov theem ferrite. Duplex stainless hlau yog npaj rau kev pabcuam kub ntawm 300 degree lossis qis dua. Lub zog tuaj yeem nce mus rau 65 ksi lossis siab dua los ntawm kev kho kev daws teeb meem thiab mus rau 160 ksi los ntawm kev ua haujlwm txias. Hom duplex stainless hlau hom yogS31803, S32205, S32507, S32760, S39274 and U-50M (NACE, 2000b, 2004b).
Ib nyuag Keeb Kwm Ntawm Duplex Stainless Steel
Lub tswv yim ntawm duplex stainless hlau tau tham thaum ntxov li xyoo 1920. Txawm li cas los xij, kev tsim cov thawj duplex alloys tsis tau pib txog thaum xyoo 1930s. Cov duplex thaum ntxov tshaj plaws no feem ntau txwv rau kev tsim cov cam khwb cia thiab kev siv tshwj xeeb vim lawv muaj cov pa roj carbon ntau. Txawm li cas los xij, thaum kawg ntawm xyoo 1960, decarburization tso cai rau cov hlau tsim los tsim cov pa roj carbon tsawg nrog cov ntsiab lus siab chromium thiab npib tsib xee thaum ntxiv ntsuas cov qauv ferrite thiab austenite.
Cov noduplex stainless hlauqhia ntau yam zoo sib xws nrog cov alloys niaj hnub hauv kev tsim khoom niaj hnub no -- tshwj xeeb,TIAB SA 2205(UNS S31803/32205). Tsim nyob rau hauv nruab nrab-1970s, cov hlau no tseem nrov niaj hnub no muab kev tiv thaiv corrosion zoo tshaj rau cov qib austenitic stainless hlau, xws li 304 (UNS S30400), 316 (UNS S31600), thiab 317 (UNS S31700).
Cov khoom tseem ceeb ntawm Duplex Stainless Steels Qhov txawv ntawm lawv hauv B2b daim ntawv thov:
1. Corrosion Resistance: Duplex alloys muaj kev tiv thaiv zoo rau ntau qhov chaw corrosive, nrog rau cov kua qaub, chlorides, thiab dej hiav txwv. Qhov no ua rau lawv tshwj xeeb tshaj yog tsim rau kev lag luam xws li kev ua tshuaj lom neeg, roj thiab roj, thiab kev lag luam marine.
2. Siab zog:Cov qauv dual-theem muab lub zog siab rau Duplex Stainless Steels, tso cai rau txo cov khoom tuab thiab qhov hnyav hauv cov khoom siv. Qhov no yog qhov tseem ceeb tshaj plaws hauv kev siv uas ob qho tib si lub zog thiab qhov hnyav yog qhov tseem ceeb rau kev txiav txim siab.
3. Weldability zoo heev: Duplex alloys nthuav tawm qhuas weldability, yooj yim ntawm fabrication thiab sib dhos.
4. Tus nqi-zoo: Kev sib xyaw ua ke ntawm lub zog siab thiab kev tiv thaiv corrosion txhais ua cov nqi tsim nyog rau ntau yam kev lag luam. Duplex Stainless Steels feem ntau muab kev lag luam ntau dua piv rau cov khoom siv ib txwm muaj, pab txhawb kev ua haujlwm tag nrho.
5. Versatility: Duplex alloys nrhiav kev siv thoob plaws ib qho kev lag luam, suav nrog kev ua tshuaj lom neeg, kev tshawb nrhiav roj thiab roj, kev desalination, thiab kev tsim cov ntaub ntawv thiab ntawv.
