Corrosion Resistance Ntawm 304 Cov Hlau Stainless Hauv Seawater Desalination Thaum Sib Txawv Sib Txawv

Galvanized steel kav yog ua los ntawm cov dej hiav txwv. Yog li no, steel hlau tsis galvanized hlau feem ntau siv los ua dej ntshiab. Austenitic stainless hlau muaj zoo corrosion kuj, zoo ua rau pitting thiab uniform corrosion, siab zog thiab zoo toughness. Nws yog dav siv nyob rau hauv kev tsim kho, piping thiab li on. Tam sim no, kev coj cwj pwm ntawm cov hlau tsis huv hauv seawater tau tshaj tawm, tab sis nws tsawg dua nyob hauv kev dej hiav txwv ntawm seawater. Nws yog ib qho tseem ceeb ntawm kev kawm txog tus cwj pwm ntawm corrosion ntawm stainless hlau nyob rau hauv kev lim dej ntawm dej hiav txwv dej. Cov dej khov ntawm 304 tsis muaj hlau nyob hauv kev lim dej ntawm seawater tau kawm los ntawm kev siv cov tshuab ua hluav taws xob thiab qeeb nqus npaum li cas thiab SEM kev soj ntsuam, thiab qhov kub nyhiab ntawm qhov corrosion ntawm cov tsis muaj stainless hlau passivation film tau soj ntsuam.

Cov khoom siv yog 304 xim hlau tsis zoo nrog cov tshuaj lom neeg (feem ntau pawg,%): C0.080, Mn2.000, Si1.000, S0.031, P0.027, Ni8.050, Cr17.500, thiab cov nyiaj yog Fe . Qhov luaj li cas ntawm cov hlab ntsha electrochemical yog 10mm * 10mm * 3mm, ib sab yog welded nrog tooj liab hlau thiab encapsulated nrog epoxy cob. Lwm sab yog ua haujlwm ntsej muag. Nws yog grind nrog 600, 800, 1000 xuab zeb ntawv ntsig txog, ces tshuab lo nrog acetone kom tshem tawm roj thiab muab tso rau hauv ib lub tais qhuav. Qhov kev nyuaj siab ntxhov plawv kev nqhis dej no yog dumbbell zoo li tus qauv, 5 hli, thiab qhov ntsuas qhov nruab nrab yog 20 hli ntev.

Qhov nruab nrab yog rov qab osmosis seawater dej kom zoo. Qhov Clement concentration yog 312.5g / m3, tus nqi pH yog 7.8 rau 8.2, tus conductivity yog 0.8mS / cm, qhov kub yog 35, 50, 70 C, feem.

Electrochemical cov kev ntsuam xyuas tau raug siv tawm los ntawm kev siv cov kev tshawb fawb ntawm lub hwjchim Apatied Paratat 2273 electrochemical workstation thiab cov ntaub ntawv los ntawm ZVIEW2. Qhov siv hluav taws xob electrode yog ib qho calorel electrode, tus pab cuam electrode yog graphite electrode, thiab nruab nrab yog kev lim dej seawater. Qhov kub hnyiab tseem ceeb ntawm 304 stainless hlau tau ntsuas los ntawm ASTMG150-1999 (2004). Lub peev xwm ntxiv ntawm kev ntsuam xyuas yog 700mV thiab qhov cua sov tus nqi yog 1 / min.

Kev ntsuam xyuas kev nyuab siab yog tau coj los siv nrog kev sib tw qeeb qeeb los ntawm LETRY qeeb tensile lub tshuab kuaj, tus nqi tensile yog 1 x 10-5s-1, qhov kev xeem nruab nrab yog kev lim dej ntawm seawater, thiab glycerol siv los tswj cov seem. Lub pob zeb ntawm lub tensile qws tau pom los ntawm ZeissUltra555 kuaj electron microscope, thiab cov yam ntxwv ntawm tus cwj pwm tau raug txiav txim. Cov ntawv xeem tau qhia tias:

(1) kub yog qhov tseem ceeb tshaj uas cuam tshuam rau qhov corrosion ntawm 304 stainless hlau hauv dej kom zoo. Thaum twg qhov kub nce ntawm 35 mus rau 70, tus nqi xaib kam thiab cov pitting kev ua lag luam qis dua, cov ntawv tso cai txog kev tiv thaiv muaj peev xwm txo thiab cov pitting rhiab nce. Nyob rau ntawm 35 Eb-Ep, nws tus kheej rov qab muaj peev xwm ntawm kev ua neej tsis tshua muaj neeg pluag, thiab Eb-Ep me dua 70 xyoo. Thaum lub sijhawm ua tsis zoo lawm, nws tus kheej rov muaj zog dua.

(2) qhov kub ntxhov ntawm 304 stainless hlau hauv thawj thim rov qab osmosis dej hiav txwv yog 34.9 C.

(3) Thaum lub ntsuas kub nce siab, qhov lim thiab lub siab tshaj plaws lub zog ntawm 304 stainless hlau maj mam txo, thiab cov pob txha tawg puas yog tsim los ntawm kev rhuav pob txhav rau pob txha tawg, thiab qhov kev ntxhov siab ntawm kev ntxhov siab yog nce.