321 tšepe e sa hloekang e kopantsoeng ka motsoako oa lik'hemik'hale Thepa ea mochini le boits'oaro ba kutu ea tšepe e sa hloekang ea duplex e nang le eleketrode e ncha.

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Sebopeho sa Lik'hemik'hale tsa Coil Tube ea Stainless Steel 321

Motsoako oa lik'hemik'hale oa li-tubing tsa tšepe tse 321 tse sa hloekang ke tse latelang:
- Khabone: 0.08% max
- Manganese: 2.00% max
Nickel: 9.00% min

Lisebelisoa tsa Mechanical tsa Coil Tube ea Stainless 321

Ho ea ka Stainless Steel 321 Coil Tube Manufacturer, thepa ea mochini ea tšepe e sa hloekang ea 321 coil tubing e thathamisitsoe ka tlase: Tensile Strength (psi) Yield Strength (psi) Elongation (%).

Lits'ebetso le Ts'ebeliso ea Ts'ebetso ea Ts'ebetso ea Ts'epi ea 321 Coil Tube

Lits'ebetsong tse ngata tsa boenjineri, thepa ea mochini le kutu ea meaho e cheselitsoeng ea duplex stainless steel (DSS) ke lintlha tsa bohlokoahali.Boithuto ba hajoale bo batlisitse thepa ea mochini le ho hanyetsa ho bola ha li-welds tsa tšepe tse sa hloekang tse duplex tikolohong e etsisang 3.5% NaCl e sebelisa eleketrode e ncha e entsoeng ka mokhoa o ikhethileng ntle le ho eketsoa ha likarolo tsa motsoako ho lisampole tsa flux.Mefuta e 'meli e fapaneng ea li-fluxes tse nang le index ea motheo ea 2.40 le 0.40 li ne li sebelisoa ho li-electrode E1 le E2 bakeng sa liboto tsa welding DSS, ka ho latellana.Ho tsitsa ha mocheso oa lihlopha tsa flux ho ile ha hlahlojoa ho sebelisoa tlhahlobo ea thermogravimetric.Sebopeho sa lik'hemik'hale hammoho le thepa ea mochine le ea ho bola ea manonyeletso a cheselitsoeng li ile tsa hlahlojoa ho sebelisoa spectroscopy ea emission ho latela maemo a fapaneng a ASTM.X-ray diffraction e sebelisoa ho fumana mekhahlelo e teng ho li-welds tsa DSS, 'me elektronike e hlahlobang ka EDS e sebelisetsoa ho hlahloba microstructure ea li-welds.Matla a tsitsipano a manonyeletso a entsoeng ka li-electrode tsa E1 a ne a le ka hare ho 715-732 MPa, ka li-electrode tsa E2 - 606-687 MPa.Mokhoa oa ho cheseletsa o eketsehile ho tloha ho 90 A ho ea ho 110 A, 'me boima bo boetse bo eketsehile.Linonyello tse cheselitsoeng tse nang le li-electrode tsa E1 tse koahetsoeng ka li-fluxes tsa mantlha li na le thepa e ntle ea mochini.Sebopeho sa tšepe se na le khanyetso e phahameng ea kutu sebakeng sa 3.5% sa NaCl.Sena se tiisa ho sebetsa ha manonyeletso a cheselitsoeng a entsoeng ka li-electrode tse sa tsoa ntlafatsoa.Liphetho li tšohloa mabapi le ho fokotseha ha likarolo tsa alloying tse kang Cr le Mo tse hlokometsoeng ka li-welds tse nang le li-electrode tse koahetsoeng E1 le E2, le ho lokolloa ha Cr2N ka li-welds tse entsoeng ka li-electrode E1 le E2.
Ho latela nalane, polelo ea pele ea semmuso ea duplex stainless steel (DSS) e qalile ka 1927, ha e ne e sebelisetsoa ho etsa lintho tse itseng feela 'me e sa sebelisoe lits'ebetsong tse ngata tsa tekheniki ka lebaka la khabone ea eona e phahameng.Empa ka mor'a moo, lihlahisoa tse tloaelehileng tsa carbon li ile tsa fokotsoa ho ea ho boleng bo phahameng ba 0.03%, 'me litšepe tsena li ile tsa sebelisoa haholo libakeng tse sa tšoaneng2,3.DSS ke lelapa la li-alloys tse nang le litekanyo tse lekanang tsa ferrite le austenite.Lipatlisiso li bontšitse hore karolo ea ferritic ho DSS e fana ka tšireletso e babatsehang khahlanong le chloride-induced stress corrosion cracking (SCC), eo e neng e le taba ea bohlokoa bakeng sa litšepe tse sa hloekang tsa austenitic (ASS) lekholong la bo20 la lilemo.Ka lehlakoreng le leng, liindasteri tse ling tsa boenjiniere le tse ling tlhokahalo ea polokelo ea 4 e ntse e hola ka sekhahla sa ho fihla ho 20% ka selemo.Ts'epe ena e ncha e nang le sebopeho sa mekhahlelo e 'meli ea austenitic-ferritic e ka fumanoa ka khetho e loketseng ea sebopeho, ho hloekisoa ha lik'hemik'hale tsa 'mele le thermomechanical.Ha e bapisoa le tšepe e sa hloekang ea karolo e le 'ngoe, DSS e na le matla a phahameng a lihlahisoa le bokhoni bo phahameng ba ho mamella SCC5, 6, 7, 8. Sebopeho sa duplex se fa litšepe tsena matla a ke keng a lekanngoa, ho tiea le ho eketseha ha kutu libakeng tse mabifi tse nang le li-acids, acid chlorides, metsi a leoatle le lik'hemik'hale tse senyang9.Ka lebaka la ho feto-fetoha ha theko ea selemo le selemo ea li-alloys tsa nickel (Ni) marakeng ka kakaretso, sebopeho sa DSS, haholo-holo mofuta o tlaase oa nickel (lean DSS), o fihletse katleho e mengata e tsotehang ha e bapisoa le face centered cubic (FCC) iron10, 11. The main bothata ba meralo ea ASE ke hore ba tlas'a maemo a fapaneng a thata.Ka hona, mafapha a fapaneng a boenjiniere le lik'hamphani li leka ho ntšetsa pele litšepe tse ling tse tlaase tsa nickel (Ni) tse sebetsang hantle kapa tse molemo ho feta ASS ea setso e nang le weldability e loketseng 'me e sebelisoa lits'ebetsong tsa indasteri tse kang mocheso oa metsi a leoatle le indasteri ea lik'hemik'hale.setshelo sa 13 bakeng sa tikoloho e nang le li-chloride tse ngata.
Khatelo-peleng ea theknoloji ea sejoale-joale, tlhahiso ea welded e phetha karolo ea bohlokoa.Ka tloaelo, litho tsa meralo ea DSS li kopantsoe ke welding ea arc e sirelelitsoeng ka khase kapa welding ea arc e sirelelitsoeng ka khase.The weld e haholo-holo angoa ke ho hlophisoa ha eleketrode sebelisoa bakeng sa tjheseletsa.Li-electrode tsa welding li na le likarolo tse peli: tšepe le flux.Hangata, li-electrode li koahetsoe ke flux, motsoako oa litšepe tseo, ha li senyehile, li lokolla likhase 'me li theha slag e sireletsang ho sireletsa weld ho tloha tšilafalo, ho eketsa botsitso ba arc, le ho eketsa motsoako oa motsoako ho ntlafatsa boleng ba welding14. .Aluminium, tšepe e sa hloekang, tšepe e bonolo, tšepe e matla haholo, koporo, koporo le boronse ke tse ling tsa litšepe tsa li-electrode, athe selulose, phofo ea tšepe le hydrogen ke tse ling tsa lisebelisoa tse sebelisoang.Ka linako tse ling sodium, titanium le potasiamo le tsona li kenyelletsoa motsoako oa flux.
Bafuputsi ba bang ba lekile ho ithuta phello ea tlhophiso ea li-electrode ho ts'epo ea mochini le ho bola ea meaho ea tšepe e cheselitsoeng.Singh le al.15 e ile ea batlisisa phello ea sebopeho sa flux ho bolelele le matla a thata a li-welds tse kolobisitsoeng ka metsi a kolobisitsoeng.Liphetho li bonts'a hore CaF2 le NiO ke tsona tse khethollang matla a ho tiea ha a bapisoa le boteng ba FeMn.Chirag et al.16 ba ile ba batlisisa metsoako ea SMAW ka ho fetola motsoako oa rutile (TiO2) ka motsoako oa electrode flux.Ho ile ha fumanoa hore thepa ea microhardness e eketsehile ka lebaka la keketseho ea peresente le ho falla ha carbon le silicon.Kumar [17] o ile a ithuta moralo le nts'etsopele ea li-fluxes tse kopantsoeng bakeng sa ho tjheseletsa ka tlas'a metsi a lishiti tsa tšepe.Nwigbo le Atuanya18 ba ile ba batlisisa tšebeliso ea li-binders tsa silicate tse nang le potasiamo tse ngata bakeng sa tlhahiso ea li-arc welding fluxes 'me ba fumana li-welds tse nang le matla a phahameng a 430 MPa le sebopeho se amohelehang sa lijo-thollo.Lothongkum et al.19 ba sebelisitse mokhoa oa potentiokinetic ho ithuta karolo ea molumo oa austenite ka duplex tšepe e sa hloekang 28Cr-7Ni-O-0.34N ka tharollo ea NaCl e tletseng moea ka har'a motsoako oa 3.5% wt.tlasa maemo a pH.le 27°C.Ka bobeli litšepe tsa duplex le micro duplex li bonts'a phello e ts'oanang ea naetrojene boitšoarong ba kutu.Nitrojene ha ea ka ea ama bokhoni ba ho bola kapa sekhahla sa pH 7 le 10, leha ho le joalo, monyetla oa ho bola ho pH 10 o ne o le tlase ho pH 7. Ka lehlakoreng le leng, maemong ohle a pH a ithutoang, bokhoni bo ile ba qala ho eketseha ka ho eketseha ha naetrojene. .Lacerda et al.20 e ithutile pitting ea duplex stainless steels UNS S31803 le UNS S32304 ka 3.5% NaCl tharollo sebelisa cyclic potentiodynamic polarization.Ka tharollo ea 3.5 wt.% ea NaCl, matšoao a likoti a fumanoe lipoleiting tse peli tsa tšepe tse batlisisitsoeng.UNS S31803 tšepe e na le matla a holimo a kutu (Ecorr), monyetla oa ho senya (Epit) le ho hanyetsa polarization (Rp) ho feta tšepe ea UNS S32304.UNS S31803 tšepe e na le repassivity e phahameng ho feta tšepe ea UNS S32304.Ho ea ka phuputso e entsoeng ke Jiang et al.[21], tlhōrō ea ho tsosolosa e tsamaellanang le karolo e habeli (austenite le ferrite phase) ea duplex tšepe e sa hloekang e kenyelletsa ho fihla ho 65% ea sebopeho sa ferrite, 'me matla a hona joale a ho tsosolosa ferrite a eketseha ka nako e ntseng e eketseha ea phekolo ea mocheso.Hoa tsebahala hore mekhahlelo ea austenitic le ea ferritic e bonts'a mekhoa e fapaneng ea electrochemical ka mekhoa e fapaneng ea electrochemical21,22,23,24.Abdo et al.25 ba sebelisitse litekanyo tsa potentiodynamic tsa polarization spectroscopy le electrochemical impedance spectroscopy ho ithuta electrochemically induced corrosion ea laser-welded 2205 DSS alloy metsing a maiketsetso a leoatle (3.5% NaCl) tlas'a maemo a fapaneng a acidity le alkalinity.Ho bola ha likoti ho ile ha bonoa libakeng tse pepeneneng tsa mehlala e lekiloeng ea DSS.Ho itšetlehile ka liphuputso tsena, ho ile ha thehoa hore ho na le kamano e leka-lekaneng pakeng tsa pH ea sebaka se qhibilihisang le ho hanyetsa filimi e entsoeng nakong ea ho fetisetsa tefiso, e amang ka ho toba ho thehoa ha pitting le tlhaloso ea eona.Sepheo sa phuputso ena e ne e le ho utloisisa hore na motsoako o sa tsoa ntlafatsoa oa li-electrode oa welding o ama botšepehi ba mochine le bo sa senyeheng ba DSS 2205 e cheselitsoeng tikolohong ea 3.5% ea NaCl.
Liminerale (litsoako) tse sebelisitsoeng ho li-electrode coating formulations e ne e le Calcium Carbonate (CaCO3) e tsoang Seterekeng sa Obajana, seterekeng sa Kogi, Nigeria, Calcium Fluoride (CaF2) e tsoang Profinseng ea Taraba, Nigeria, Silicon Dioxide (SiO2), Talc Powder (Mg3Si4O10 (OH). ) )2) le rutile (TiO2) li ile tsa fumanoa ho Jos, Nigeria, 'me kaolin (Al2 (OH) 4Si2O5) e ile ea fumanoa Kankara, Katsina State, Nigeria.Potassium silicate e sebelisoa e le tlamahano, e fumanoa ho tsoa India.
Joalo ka ha ho bonts'itsoe ho Lethathamo la 1, li-oxide tsa constituent li ne li lekanngoa ka mokhoa o ikemetseng ka tekanyo ea dijithale.Ka nako eo e ne e kopantsoe le potassium silicate binder (23% ka boima ba 'mele) ka motsoako oa motlakase (mohlala: 641-048) ho tloha Indian Steel and Wire Products Ltd. (ISWP) bakeng sa metsotso ea 30 ho fumana pente ea homogeneous semi-solid.Motsoako o motsoako o mongobo o hatelloa ka sebopeho sa cylindrical ho tloha mochine oa briquetting ebe o kenngoa ka kamoreng ea extrusion ka khatello ea 80 ho 100 kg / cm2, 'me ho tloha kamoreng ea phepelo ea terata e kenngoa ka har'a 3.15mm bophara ba terata extruder.The flux e feptjoa ka nozzle / die system mme e kenngoa ka har'a extruder ho ntša li-electrode.Ho ile ha fumanoa karolo ea 1,70 mm, moo ntlha ea tšireletso e hlalosoang e le karo-karolelano ea bophara ba electrode ho bophara ba strand.Ebe li-electrode tse koahetsoeng li omisitsoe moeeng ka lihora tse 24 ebe li calcined ka sebōping sa muffle (mohlala PH-248-0571 / 5448) ka 150-250 ° C \ (-\) bakeng sa lihora tse peli.Sebelisa equation ho bala alkalinity ea phallo.(1) 26;
Ho tsitsa ha mocheso oa lisampole tsa flux tsa lipina E1 le E2 ho ile ha khethoa ho sebelisoa tlhahlobo ea thermogravimetric (TGA).Mohlala oa hoo e ka bang 25.33 mg ea flux e ile ea kenngoa ho TGA bakeng sa tlhahlobo.Liteko li ile tsa etsoa ka mokhoa o sa sebetseng o fumanoang ke phallo e tsoelang pele ea N2 ka tekanyo ea 60 ml / min.Mohlala o ne o futhumetse ho tloha ho 30 ° C ho ea ho 1000 ° C ka mocheso oa mocheso oa 10 ° C / min.Ho latela mekhoa e boletsoeng ke Wang et al.27, Xu et al.28 le Dagwa et al.29, ho senyeha ha mocheso le ho lahleheloa ke boima ba lisampole ka mocheso o itseng ho ile ha hlahlojoa ho tloha merero ea TGA.
Etsa lipoleiti tse peli tsa 300 x 60 x 6 mm DSS ho lokisetsa ho soasoa.V-groove e entsoe ka lekhalo la metso ea 3mm, lesoba la metso ea 2mm le angle ea 60 ° ea groove.Joale poleiti e ne e hlatsuoa ka acetone ho tlosa litšila tse ka bang teng.Weld lipoleiti sebelisa shielded tšepe arc welder (SMAW) le ka ho toba jwale electrode positive polarity (DCEP) sebelisa li-electrode coated (E1 le E2) le eleketrode referense (C) le bophara ba 3.15 limilimithara.Motlakase oa Ts'ebetso ea Motlakase (EDM) (Mohlala: Excetek-V400) e ne e sebelisetsoa ho etsa lisebelisoa tsa tšepe tse cheselitsoeng ka mochine bakeng sa tlhahlobo ea mochine le sebopeho sa kutu.Letlapa la 2 le bonts'a mohlala oa khoutu le tlhaloso, 'me Lethathamo la 3 le bonts'a mefuta e fapaneng ea ts'ebetso ea welding e sebelisoang ho cheselletsa boto ea DSS.Equation (2) e sebelisetsoa ho bala mocheso o lumellanang le oona.
Ho sebelisa Bruker Q8 MAGELLAN optical emission spectrometer (OES) e nang le wavelength ea 110 ho 800 nm le software ea database ea SQL, ho ile ha khethoa lik'hemik'hale tsa metsoako ea weld ea li-electrode E1, E2 le C, hammoho le mehlala ea tšepe ea motheo.e sebelisa lekhalo lipakeng tsa eleketrode le sampole ea tšepe tlas'a teko E hlahisa matla a motlakase ka mokhoa oa tlhase.Mohlala oa likaroloana o entsoe mouoane ebe oa fafatsoa, ​​'me o lateloa ke ho tsosoa ha athomo, ebe ka mor'a moo o ntša mohala o itseng oa spectrum31.Bakeng sa tlhahlobo ea boleng ba sampole, tube ea photomultiplier e lekanya boteng ba spectrum e inehetseng bakeng sa element ka 'ngoe, hammoho le matla a spectrum.Ebe u sebelisa equation ho bala palo e lekanang ea pitting resistance (PREN).(3) Ratio 32 le WRC 1992 state diagram li sebelisoa ho bala chromium le nickel equivalents (Creq le Nieq) ho tsoa ho li-equations.(4) le (5) ke 33 le 34 ka ho latellana;
Hlokomela hore PREN e nka feela tšusumetso e ntle ea likarolo tse tharo tse kholo tsa Cr, Mo le N, ha karolo ea nitrogen x e le ka har'a 16-30.Ka tloaelo, x e khethiloe lethathamong la 16, 20, kapa 30. Phuputsong ea litšepe tse sa hloekang tse duplex, boleng ba bohareng ba 20 bo atisa ho sebelisoa ho bala litekanyetso tsa PREN35,36.
Linonyello tse cheselitsoeng tse entsoeng ka li-electrode tse fapaneng li ile tsa lekoa ka mochine oa tlhahlobo ea bokahohle (Instron 8800 UTM) ka tekanyo ea khatello ea 0.5 mm / min ho latela ASTM E8-21.Tensile strength (UTS), 0.2% shear yield strength (YS), le elongation li ne li baloa ho latela ASTM E8-2137.
Li-wellds tsa DSS 2205 li ne li le fatše pele 'me li bentšitsoe ho sebelisoa boholo bo fapaneng ba grit (120, 220, 320, 400, 600, 800, 1000 le 1200) pele ho tlhahlobo ea boima.Mehlala e cheselitsoeng e entsoe ka li-electrode E1, E2 le C. Ho thatafala ho lekanyetsoa ho lintlha tse leshome (10) ho tloha bohareng ba weld ho ea tšepe ea motheo ka nako ea 1 mm.
X-ray diffractometer (D8 Discover, Bruker, Germany) e hlophisitsoeng ka software ea Bruker XRD Commander bakeng sa pokello ea lintlha le mahlaseli a Fe-filtered Cu-K-α a nang le matla a 8.04 keV a tsamaisanang le wavelength ea 1.5406 Å le sekhahla sa 3 ° Scan range (2θ) min-1 ke 38 ho 103 ° bakeng sa tlhahlobo ea mohato ka li-electrode tsa E1, E2 le C le BM tse teng ho li-welds tsa DSS.Mokhoa oa ntlafatso oa Rietveld o ne o sebelisoa ho bonts'a mekhahlelo ea likhetho ho sebelisoa software ea MAUD e hlalositsoeng ke Lutterotti39.Ho ipapisitsoe le ASTM E1245-03, tlhahlobo e ngata ea metallographic ea litšoantšo tse nyane tsa li-weld tsa li-electrode E1, E2 le C li entsoe ho sebelisoa software ea Image J40.Liphetho tsa ho bala karolo ea molumo oa karolo ea ferrite-austenitic, boleng ba bona bo tloaelehileng le ho kheloha ho fanoe ka Lethathamo.5. Joalokaha ho bontšitsoe ka tlhophiso ea mohlala ho feiga.6d, tlhahlobo ea optical microscopy (OM) e entsoe ka PM le manonyeletso a nang le li-electrode E1 le E2 ho ithuta morphology ea lisampole.Mehlala e ne e bentšitsoe ka 120, 220, 320, 400, 600, 800, 1000, 1200, 1500, le 2000 grit silicon carbide (SiC) sandpaper.Mehlala e ile ea kenngoa ka mokhoa oa electrolytically ka tharollo ea 10% ea aqueous oxalic acid mocheso oa kamore ka mocheso oa 5 V bakeng sa 10 s 'me ea behoa ho LEICA DM 2500 M microscope ea optical bakeng sa morphological characterization.Ho belisoa ho eketsehileng ha sampole ho ile ha etsoa ho sebelisoa pampiri ea 2500 grit silicon carbide (SiC) bakeng sa tlhahlobo ea SEM-BSE.Ho feta moo, manonyeletso a cheselitsoeng a ile a hlahlojoa bakeng sa sebopeho sa microstructure ho sebelisoa mochine oa electron microscope (SEM) (FEI NOVA NANOSEM 430, USA) o nang le EMF.Sample ea 20 × 10 × 6 mm e ile ea siloa ho sebelisoa li-sandpaper tsa SiC tse fapa-fapaneng ho tloha ka boholo ho tloha ho 120 ho ea ho 2500. Mehlala e ne e kenngoa ka electrolytically ka 40 g ea NaOH le 100 ml ea metsi a hloekisitsoeng ka matla a 5 V bakeng sa 15 s, 'me joale. e behiloe holim'a sets'oants'o sa mohlala, se ka kamoreng ea SEM, bakeng sa ho hlahloba lisampole ka mor'a ho hloekisa kamore ka naetrojene.Sekhahla sa elektronike se hlahisoang ke filament ea tungsten e futhumetseng e etsa grating ka sampuli ho hlahisa litšoantšo ka mefuta e sa tšoaneng ea ho hōlisa, 'me liphello tsa EMF li fumanoe ho sebelisoa mekhoa ea Roche et al.41 le Mokobi 42 .
Mokhoa oa polarization oa electrochemical potentiodynamic ho latela ASTM G59-9743 le ASTM G5-1444 e ne e sebelisetsoa ho lekola bokhoni ba ho senyeha ha lipoleiti tsa DSS 2205 tse cheselitsoeng ka li-electrode tsa E1, E2 le C sebakeng sa 3.5% sa NaCl.Liteko tsa electrochemical li ile tsa etsoa ho sebelisoa sesebelisoa sa Potentiostat-Galvanostat/ZRA se laoloang ke k'homphieutha (mohlala: PC4/750, Gamry Instruments, USA).Teko ea electrochemical e entsoe ka tlhahlobo ea li-electrode tse tharo: DSS 2205 e le electrode e sebetsang, saturated calomel electrode (SCE) e le electrode ea referense le molamu oa graphite joalo ka electrode ea counter.Litekanyo li ne li etsoa ho sebelisoa sele ea electrochemical, moo sebaka sa ketso ea tharollo e neng e le sebaka sa electrode e sebetsang 0.78 cm2.Litekanyo li entsoe pakeng tsa -1.0 V ho + 1.6 V bokhoni ba OCP e tsitsitseng pele (e amanang le OCP) ka sekhahla sa 1.0 mV / s.
Liteko tse matla tsa mocheso oa electrochemical pitting li entsoe ka 3.5% NaCl ho lekola khanyetso ea li-pitting ea li-welds tse entsoeng ka li-electrode tsa E1, E2 le C.ka ho hlaka ka bokhoni ba likoti ho PB (pakeng tsa libaka tse sa sebetseng le tse fetisetsoang), le li-welded specimens tse nang le E1, E2, Electrodes C. Ka hona, litekanyo tsa CPT li etsoa ho fumana hantle hore na ho na le monyetla oa ho kenya lisebelisoa tsa welding.Teko ea CPT e entsoe ho latela litlaleho tsa duplex tsa tšepe tse sa hloekang tsa weld45 le ASTM G150-1846.Ho tloha ho e 'ngoe le e' ngoe ea litšepe tse lokelang ho chesetsoa (S-110A, E1-110A, E2-90A), lisampole tse nang le sebaka sa 1 cm2 li ile tsa khaoloa, ho kenyeletsoa libaka tsa motheo, weld le HAZ.Mehlala e ne e bentšitsoe ho sebelisoa sandpaper le 1 µm alumina powder slurry ho latela mekhoa e tloaelehileng ea ho lokisa sampole ea metallographic.Ka mor'a ho polishing, lisampole li ile tsa hloekisoa ka ultrasonically ka acetone bakeng sa 2 min.Tharollo ea 3.5% ea tlhahlobo ea NaCl e ile ea kenngoa seleng ea teko ea CPT 'me mocheso oa pele o ile oa fetoloa ho 25 ° C ho sebelisa thermostat (Neslab RTE-111).Ka mor'a ho fihla mocheso oa pele oa teko ea 25 ° C, Ar gas e ile ea hlajoa ka metsotso ea 15, joale li-sampuli li kenngoa ka seleng, 'me OCF e lekantsoe bakeng sa 15 min.Ka mor'a moo sampuli e ile ea etsoa polarized ka ho sebelisa motlakase oa 0.3 V mocheso oa pele oa 25 ° C, 'me hona joale o ne o lekantsoe bakeng sa 10 min45.Qala ho futhumatsa tharollo ka sekhahla sa 1 °C/min ho isa ho 50 °C.Nakong ea mocheso oa tharollo ea teko, mochine oa mocheso o sebelisetsoa ho tsoela pele ho shebella mocheso oa tharollo le ho boloka nako le data ea mocheso, 'me potentiostat / galvanostat e sebelisetsoa ho lekanya hona joale.Electrode ea graphite e ne e sebelisoa e le electrode ea counter, 'me menyetla eohle e ile ea lekanngoa ho latela electrode ea referense ea Ag/AgCl.Argon purge e ile ea etsoa nakong eohle ea teko.
Ka feiga.1 e bonts'a sebopeho (ka liphesente tse boima) tsa likarolo tsa flux F1 le F2 tse sebelisetsoang ho hlahisa li-electrode tsa alkaline (E1) le acidic (E2), ka ho latellana.The flux basicity index e sebelisoa ho bolela esale pele thepa ea mochini le metallurgic ea manonyeletso a cheselitsoeng.F1 ke karolo ea phallo e sebelisoang ho koahela li-electrode tsa E1, tse bitsoang alkaline flux hobane index ea eona ea mantlha ke> 1.2 (ke hore 2.40), 'me F2 ke phallo e sebelisoang ho koahela li-electrode tsa E2, tse bitsoang acid flux ka lebaka la motheo oa eona. index <0,9 (ke hore 2,40).0.40).Ho hlakile hore li-electrode tse koahetsoeng ka li-fluxes tsa mantlha maemong a mangata li na le thepa e ntle ea mochini ho feta li-electrode tse koahetsoeng ka acidic fluxes.Tšobotsi ena ke ts'ebetso ea ho busa ha oxide ea mantlha tsamaisong ea sebopeho sa flux bakeng sa elektrode E1.Ho fapana le hoo, ho tlosoa ha slag (karohano) le spatter e tlaase e hlokometsoeng ka manonyeletso a nang le li-electrode tsa E2 ke tšobotsi ea li-electrode tse nang le acidic flux coating e nang le litaba tse ngata tsa rutile.Tlhokomelo ena e lumellana le liphuputso tsa Gill47 hore phello ea dikahare tsa rutile ka ho senyeha ha slag le spatter e tlaase ea li-electrode tse koahetsoeng ke acid e tlatsetsa ka potlako ho qhoqhoa ha slag.Kaolin tsamaisong ea phallo e sebelisoang ho koahela li-electrode E1 le E2 e ne e sebelisoa e le setlolo, 'me phofo ea talc e ntlafalitse extrudability ea li-electrode.Li-binders tsa potassium silicate tsamaisong ea flux li kenya letsoho ho ntlafatseng ha arc le botsitso ba ts'ebetso, 'me, ho phaella ho thepa ea bona ea ho khomarela, ho ntlafatsa karohano ea slag lihlahisoa tse cheselitsoeng.Kaha CaCO3 ke letlooa le senya (slag breaker) ka phallo 'me e atisa ho hlahisa mosi o mongata nakong ea ho cheselletsa ka lebaka la ho senyeha ha mocheso ho CaO le hoo e ka bang 44% CO2, TiO2 (e le sehahi sa marang-rang / slag pele) e thusa ho fokotsa chelete eo. ea mosi nakong ea ho cheselletsa .ho cheselletsa 'me kahoo ho ntlafatsa ho senyeha ha slag joalokaha ho khothalelitsoe ke Jing et al.48.Fluorine Flux (CaF2) ke phallo e matla ea lik'hemik'hale e ntlafatsang bohloeki ba solder.Jastrzębska et al.49 e tlalehile phello ea sebopeho sa fluoride ea sebopeho sena sa flux ho thepa ea bohloeki ba weld.Ka tloaelo, flux e eketsoa sebakeng sa weld ho ntlafatsa botsitso ba arc, ho eketsa likarolo tsa alloying, ho haha ​​​​slag, ho eketsa tlhahiso, le ho ntlafatsa boleng ba letamo la weld 50.
Li-curve tsa TGA-DTG tse bontšitsoeng ho Feiga.2a le 2b li bonts'a ho theola boima ba mehato e meraro ha ho futhumatsoa mocheso oa 30-1000°C sebakeng sa naetrojene.Liphetho ho Figure 2a le b li bontša hore bakeng sa lisampole tsa motheo le tse nang le acidic flux, TGA curve e theoha ka ho toba ho fihlela e qetella e tšoana le mocheso oa mocheso, ho pota 866.49 ° C le 849.10 ° C ka ho latellana.Ho lahleheloa ke boima ba 1.30% le 0.81% qalong ea li-curve tsa TGA ho 2a le 2b ka lebaka la mongobo o kenngoa ke likarolo tsa phallo, hammoho le mouoane le ho felloa ke metsi ka holim'a metsi.The decompositions ka sehloohong ea disampole ea flux ka sehloohong ka mekhahlelo ea bobeli le ea boraro ka feiga.2a e etsahetse mefuteng ea mocheso oa 619.45 ° C-766.36 ° C le 766.36 ° C-866.49 ° C, 'me peresente ea tahlehelo ea boima ba bona e ne e le 2.84 le 9.48%., ka ho latellana.Le hoja bakeng sa mehlala ea acidic flux ho 7b, e neng e le mocheso oa mocheso oa 665.23 ° C-745.37 ° C le 745.37 ° C-849.10 ° C, palo ea bona ea boima ba 'mele e ne e le 0.81 le 6.73%, ka ho latellana, e neng e bitsoa ho lahleheloa ke boima ba' mele. ho bola ha mocheso.Kaha likarolo tsa phallo ha li na lintho tse phelang, li-volatile li lekanyelitsoe ho motsoako oa flux.Ka hona, phokotso le oxidation li tšabeha.Sena se lumellana le liphello tsa Balogun et al.51, Kamli et al.52 le Adeleke et al.53.Kakaretso ea tahlehelo ea boima ba sampole ea flux e bonoang feiga.2a le 2b ke 13.26% le 8.43%, ka ho latellana.Tahlehelo e fokolang ea boima ba lisampole tsa flux ho feiga.2b e bakoa ke lintlha tse phahameng tsa ho qhibiliha tsa TiO2 le SiO2 (1843 le 1710 ° C ka ho latellana) e le li-oxide tse ka sehloohong tse etsang motsoako oa flux54,55, ha TiO2 le SiO2 li na le lintlha tse tlaase tsa ho qhibiliha.melting point Primary oxide: CaCO3 (825 °C) ka har'a sampole ea flux feiga.2a56.Liphetoho tsena sebakeng sa ho qhibiliha ha li-oxide tsa mantlha ka har'a metsoako ea flux li tlalehoa hantle ke Shi et al.54, Ringdalen et al.55 le Du et al.56.Ho shebella ho lahleheloa ke boima ba 'mele ho Fig. 2a le 2b, ho ka fihleloa qeto ea hore li-samples tsa flux tse sebelisoang ho li-electrode tsa E1 le E2 li na le ho senyeha ha mohato o le mong, joalokaha ho boletsoe ke Brown57.Mocheso oa mocheso oa ts'ebetso o ka bonoa ho tsoa ho li-curve (wt%) feiga.2a le b.Kaha TGA curve e ke ke ea hlalosa hantle mocheso o itseng oo tsamaiso ea flux e fetohang phetoho ea mohato le crystallization, motsoako oa TGA o sebelisetsoa ho fumana boleng bo nepahetseng ba mocheso oa ntho e 'ngoe le e' ngoe (phetoho ea mohato) e le tlhōrō ea endothermic ho lokisetsa tsamaiso ea flux.
TGA-DTG curves e bontšang ho bola ha mocheso oa (a) alkaline flux bakeng sa ho roala electrode ea E1 le (b) phallo ea acidic bakeng sa ho roala ha electrode ea E2.
Letlapa la 4 le bonts'a liphetho tsa tlhahlobo ea spectrophotometric le tlhahlobo ea SEM-EDS ea tšepe ea motheo ea DSS 2205 le li-welds tse entsoeng ka li-electrode tsa E1, E2 le C.E1 le E2 li bontšitse hore litaba tsa chromium (Cr) li fokotsehile haholo ho 18.94 le 17.04%, 'me litaba tsa molybdenum (Mo) e ne e le 0.06 le 0.08%, ka ho latellana.boleng ba li-welds tse nang le li-electrode E1 le E2 li tlase.Sena se lumellana hanyenyane le boleng bo baliloeng ba PREN bakeng sa mohato oa ferritic-austenitic ho tloha tlhahlobo ea SEM-EDS.Ka hona, ho ka bonoa hore pitting e qala sethaleng ka litekanyetso tse tlaase tsa PREN (li-welds ho tloha ho E1 le E2), ha e le hantle joalokaha ho hlalositsoe ho Lethathamo la 4. Sena se bontša ho fokotseha le ho ka 'na ha e-ba le pula ea alloy ka weld.Kamora moo, phokotso ea litaba tsa Cr le Mo alloying element ka li-welds tse hlahisoang ka li-electrode E1 le E2 le boleng ba tsona bo tlase ba li-pitting (PREN) li bonts'oa ho Lethathamo la 4, le bakang bothata ba ho boloka khanyetso libakeng tse mabifi, haholoholo. libakeng tsa chloride.-e nang le tikoloho.Tekanyo e batlang e le e phahameng ea nickel (Ni) ea 11,14% le moeli o lumelletsoeng oa dikahare tsa manganese ka manonyeletso a cheselitsoeng a li-electrode tsa E1 le E2 e kanna ea ba le phello e ntle ho thepa ea mochini ea li-wellds tse sebelisoang maemong a etsisang metsi a leoatle (setšoan. ).li ile tsa etsoa ho sebelisoa mosebetsi oa Yuan le Oy58 le Jing et al.48 ka phello ea lipina tse phahameng tsa nickel le manganese ho ntlafatsa thepa ea mechine ea mehaho ea DSS e cheselitsoeng tlas'a maemo a thata a ho sebetsa.
Liphetho tsa liteko tsa (a) UTS le 0.2% sag YS le (b) junifomo le bolelele bo felletseng le ho kheloha ha tsona ho tloaelehileng.
Matla a thepa ea motheo (BM) le manonyeletso a entsoeng ka li-electrode tse tsoetseng pele (E1 le E2) le electrode e fumanehang khoebong (C) li ile tsa hlahlojoa ka maqhubu a mabeli a fapaneng a 90 A le 110 A. 3 (a) le (b) bonts'a UTS, YS e nang le 0.2% offset, hammoho le bolelele ba tsona le data e khelohileng e tloaelehileng.Liphetho tsa UTS le YS offset tsa 0.2% tse fumanoeng ho Figs.3a bonts'a litekanyetso tse nepahetseng tsa sampole ea no.1 (BM), mohlala oa no.3 (weld E1), sampole no.5 (weld E2) le sampole no.6 (li-welds tse nang le C) ke 878 le 616 MPa, 732 le 497 MPa, 687 le 461 MPa le 769 le 549 MPa, ka ho latellana, le likhaello tsa tsona tse fapaneng.Ho tloha feiga.110 A) ke disampole tse nang le nomoro ea 1, 2, 3, 6 le 7, ka ho latellana, tse nang le thepa e fokolang e khothalletsoang ho feta 450 MPa tekong ea matla le 620 MPa tekong ea matla e hlahisitsoeng ke Grocki32.The elongation ea tjheseletsa mehlala le li-electrode E1, E2 le C, emeloang ke disampole No. 2, No. 3, No. 4, No. 5, No. 6 le No. 7, ka tjheseletsa maqhubu a 90 A le 110 A, ka ho latellana, e bonahatsa polasetiki le botšepehi.kamano le ditshepe tsa motheo.The elongation ka tlaase o ile a hlalosa ka ho khoneha tjheseletsa mefokolo kapa ho hlophisoa ha eleketrode flux (sa feiga. 3b).Ho ka fihleloa qeto ea hore BM duplex tšepe e sa hloekang le manonyeletso a nang le li-electrode tsa E1, E2 le C ka kakaretso li na le thepa e phahameng haholo ea ho tsitsisa ka lebaka la litaba tsa tsona tse batlang li le holimo (Letlapa la 4), empa thepa ena e ile ea bonoa ka manonyeletso a cheselitsoeng.E2 e sa sebetseng hantle e fumanoa ho sebopeho sa acidic sa flux.Gunn59 e bonts'itse phello ea li-alloys tsa nickel ho ntlafatseng thepa ea mochini oa manonyeletso a cheselitsoeng le ho laola tekano ea karolo le kabo ea lintho.Sena se boetse se tiisa taba ea hore li-electrode tse entsoeng ka lihlopha tsa motheo tsa flux li na le thepa e ntle ea mochine ho feta li-electrode tse entsoeng ka metsoako ea acidic flux, joalokaha ho boletsoe ke Bang et al.60.Ka hona, tlatsetso e kholo e entsoe ho tsebo e teng mabapi le thepa ea motsoako o cheselitsoeng oa electrode e ncha e koahetsoeng (E1) e nang le thepa e ntle ea tensile.
Ka feiga.Lipalo 4a le 4b li bonts'a litšobotsi tsa Vickers microhardness tsa liteko tsa liteko tsa manonyeletso a welded ea li-electrode E1, E2 le C. 4a e bonts'a liphello tse thata tse fumanoang ho tloha ka lehlakoreng le leng la sampuli (ho tloha ho WZ ho ea ho BM), le ho feiga.4b e bonts'a liphetho tsa boima bo fumanoeng mahlakoreng ka bobeli a sampole.Litekanyetso tse thata tse fumanoeng nakong ea ho cheselletsa lisampole No.Keketseho e matla ea boima ba 'mele e ile ea bonoa ka bobeli ho HAZ e mahoashe le HAZ e khahlehang ea lisampole tsohle No. tjheseletsa ka lebaka la disampole tsa chromium-weld di na le mesi e mengata (Cr23C6) .Ha ho bapisoa le lisampole tse ling tsa welding 2, 3, 4 le 5, boleng ba boima ba manonyeletso a cheselitsoeng a sampole No. 6 le 7 ho lifeiga.4a le 4b ka holimo (Lethathamo la 2).Ho ea ka Mohammed et al.61 le Nowacki le Lukoje62, sena se ka 'na sa bakoa ke boleng bo phahameng ba ferrite δ le likhatello tse salang tse bakiloeng ka har'a weld, hammoho le ho fokotseha ha likarolo tsa alloying tse kang Mo le Cr ka har'a weld.Litekanyetso tsa boima ba lisampole tsohle tse nkuoeng tsa liteko sebakeng sa BM li bonahala li tsitsitse.Mokhoa oa liphetho tsa tlhahlobo ea boima ba mehlala e cheselitsoeng e lumellana le liqeto tsa bafuputsi ba bang61,63,64.
Boleng ba ho thatafala ha manonyeletso a cheselitsoeng a mehlala ea DSS (a) karolo ea halofo ea lipapiso tse cheselitsoeng le (b) karolo e felletseng ea manonyeletso a cheselitsoeng.
Mekhahlelo e fapaneng e teng ho DSS 2205 e cheselitsoeng e nang le li-electrode tsa E1, E2 le C li ile tsa fumanoa 'me ponahalo ea XRD bakeng sa diffraction angle 2 \ (\ theta \) e bontšoa setšoantšong sa 5. Litlhōrō tsa austenite (\ (\ gamma \) ) le mekhahlelo ea ferrite (\(\ alpha\)) e ile ea khetholloa ka li-angles tsa diffraction tsa 43 ° le 44 °, ho tiisa ka mokhoa o hlakileng hore sebopeho sa weld ke mekhahlelo e 'meli ea tšepe e sa hloekang ea 65.hore DSS BM e bonts'a mekhahlelo ea austenitic feela (\(\gamma\)) le ferritic (\(\alpha\)), e tiisang liphello tsa microstructural tse hlahisitsoeng ho Figure 1 le 2. 6c, 7c le 9c.Mokhahlelo oa ferritic (\(\ alpha\)) o hlokometsoeng le DSS BM le tlhoro e phahameng ea weld ho electrode C e bonts'a khanyetso ea eona ea kutu, kaha mohato ona o ikemiselitse ho eketsa ho hanyetsa kutu ea tšepe, joalo ka ha Davison le Redmond66 ba na le e boletse, ho ba teng ha lintho tse tsitsitseng tsa ferrite, tse kang Cr le Mo, ka katleho ho tsitsisa filimi e sa sebetseng ea lintho tse bonahalang libakeng tse nang le chloride.Letlapa la 5 le bonts'a karolo ea ferrite-austenitic ka bongata ba metallography.Karo-karolelano ea karolo ea molumo oa karolo ea ferrite-austenitic ka manonyeletso a welded ea electrode C e finyelloa hoo e ka bang (≈1: 1).Sebopeho sa karolo e tlaase ea ferrite (\ (\ alpha \)) ea li-welldments tse sebelisang li-electrode tsa E1 le E2 ka liphello tsa karoloana ea molumo (Letlapa la 5) li bontša hore ho na le kutloisiso e ka khonehang ho tikoloho e senyang, e ileng ea tiisoa ke tlhahlobo ea electrochemical.e tiisitsoe (setšoantšo sa 10a, b)), kaha karolo ea ferrite e fana ka matla a phahameng le tšireletso khahlanong le chloride-induced stress corrosion cracking.Sena se netefatsoa hape ke boleng bo tlase ba boima bo bonoang ho li-welds tsa li-electrode E1 le E2 feiga.4a,b, tse bakoang ke karolo e tlaase ea ferrite mohahong oa tšepe (Letlapa la 5).Ho ba teng ha mekhahlelo e sa leka-lekaneng ea austenitic (\(\ gamma\)) le ferritic (\(\ alpha\)) ka manonyeletso a cheselitsoeng ho sebelisa li-electrode tsa E2 e bonts'a ts'oaetso ea 'nete ea tšepe ho tlhaselo ea kutu e ts'oanang.Ho fapana le hoo, pono ea XPA ea litšepe tse mekhahlelo e 'meli ea manonyeletso a nang le li-electrode tsa E1 le C, hammoho le liphetho tsa BM, hangata li bonts'a boteng ba lintho tse tsitsitseng tsa austenitic le ferritic stabilizing, tse etsang hore thepa e be le thuso ho tsa kaho le indastering ea petrochemical. , hobane o ile a pheha khang Jimenez et al.65;Davidson & Redmond66;Shamant le ba bang67.
Optical micrographs ea manonyeletso a tjheselitsoeng a li-electrode tsa E1 tse nang le lijeometri tse fapaneng tsa weld: (a) HAZ e bonts'ang mohala oa fusion, (b) HAZ e bonts'a mohala oa fusion ka kholo e phahameng, (c) BM bakeng sa mohato oa ferritic-austenitic, (d) weld geometry. , (e) E bonts'a sebaka sa phetoho haufi, (f) HAZ e bonts'a karolo ea ferritic-austenitic ka ho phahamisa holimo, (g) Weld zone e bonts'a ferritic-austenitic phase Tensile phase.
Optical micrographs ea E2 electrode welds at different weld jeometries: (a) HAZ e bonts'ang mohala oa fusion, (b) HAZ e bonts'ang mohala oa fusion ka kholo e phahameng, (c) BM for the ferritic-austenitic bulk phase, (d) weld geometry , (e) ) e bonts'ang sebaka sa phetoho tikolohong, (f) HAZ e bonts'ang karolo ea ferritic-austenitic ka magnification e phahameng, (g) sebaka sa ho cheseletsa se bontšang karolo ea ferritic-austenitic.
Lipalo 6a-c 'me, ho etsa mohlala, li bonts'a sebopeho sa metallographic sa manonyeletso a DSS a cheselitsoeng ho sebelisoa eleketrode ea E1 ho li-geometri tse fapaneng tsa welding (Setšoantšo sa 6d), se bonts'ang moo li-micrograph tsa optical li nkuoe ka magnification a fapaneng.Ka feiga.6a, b, f - libaka tsa phetoho tsa manonyeletso a cheselitsoeng, ho bonts'a sebopeho sa tekano ea karolo ea ferrite-austenite.Lipalo 7a-c le mohlala li boetse li bonts'a OM ea lenonyeletso la DSS le cheselitsoeng ho sebelisoa eleketrode ea E2 ho lijeometri tse fapaneng tsa welding (setšoantšo sa 7d), se emelang lintlha tsa tlhahlobo ea OM ka magnification a fapaneng.Ka feiga.7a,b,f e bonts'a sebaka sa phetoho sa lenonyello le cheselitsoeng ka tekano ea ferritic-austenitic.OM sebakeng sa welding (WZ) e bonts'oa feiga.1 le feiga.2. Li-welds bakeng sa li-electrode E1 le E2 6g le 7g, ka ho latellana.OM ho BM e bontšoa ho Figure 1 le 2. Ho feiga.6c, e le 7c, e bonts'a nyeoe ea manonyeletso a nang le li-electrode E1 le E2, ka ho latellana.Sebaka sa khanya ke karolo ea austenite 'me sebaka se lefifi se letšo ke karolo ea ferrite.Phase e leka-lekaneng sebakeng se amehileng ke mocheso (HAZ) haufi le mohala oa fusion e bontšitse ho thehoa ha li-precipitates tsa Cr2N, joalokaha ho bontšitsoe ho SEM-BSE micrographs ho Feiga.8a,b mme e tiisitsoe ka feiga.9a,b.Ho ba teng ha Cr2N ho bonoa karolong ea ferrite ea lisampole ho Feiga.8a,b 'me e netefalitsoe ke tlhahlobo ea lintlha tsa SEM-EMF le litšoantšo tsa line tsa EMF tsa likarolo tse cheselitsoeng (setšoantšo sa 9a-b), ke ka lebaka la mocheso o phahameng oa mocheso oa mocheso.Ho potoloha ho potlakisa ho kenngoa ha chromium le naetrojene, kaha mocheso o phahameng oa weld o eketsa coefficient ea phallo ea naetrojene.Liphetho tsena li tšehetsa lithuto tsa Ramirez et al.68 le Herenyu et al.69 tse bontšang hore, ho sa tsotellehe hore na ho na le naetrojene e kae, Cr2N e atisa ho behoa lijong tsa ferrite, meeli ea lijo-thollo, le meeli ea α/\(\ gamma\), joalokaha e boetse e hlahisoa ke bafuputsi ba bang.70.71.
(a) letheba SEM-EMF tlhahlobo (1, 2 le 3) ea welded kopanetsweng le E2;
Morpholoji ea holim'a lisampole tse emelang le li-EMF tse tsamaisanang le tsona li bonts'oa ho Feiga.10a–c.Ka feiga.Lipalo 10a le 10b li bonts'a li-micrograph tsa SEM le ponahalo ea tsona ea EMF ea manonyeletso a cheselitsoeng a sebelisa li-electrode E1 le E2 sebakeng sa welding, ka ho latellana, le ka feiga.10c e bonts'a SEM micrographs le EMF spectra ea OM e nang le austenite (\(\gamma\)) le ferrite (\(\alpha\)) mekhahlelo ntle le precipitates.Joalokaha ho bontšitsoe setšoantšong sa EDS setšoantšong sa 10a, peresente ea Cr (21.69 wt.%) le Mo (2.65 wt.%) ha e bapisoa le 6.25 wt.% Ni e fana ka kutloisiso ea tekanyo e lekanang ea karolo ea ferrite-austenitic.Microstructure e nang le phokotseho e phahameng ea dikahare tsa chromium (15.97 wt.%) le molybdenum (1.06 wt.%) ha e bapisoa le litaba tse phahameng tsa nickel (10.08 wt.%) ho microstructure ea motsoako o cheselitsoeng oa electrode E2, e bontšitsoeng ho feie.1. Bapisa.Sekhahla sa EMF 10b.Sebopeho sa acicular se nang le sebopeho sa austenitic se khabane se bonoang ho WZ se bontšitsoeng feiga.10b e tiisa ho fokotseha ho ka khonehang ha likarolo tsa ferritizing (Cr le Mo) ka weld le pula ea chromium nitride (Cr2N) - mohato oa austenitic.Kabo ea likaroloana tsa pula haufi le meeli ea mekhahlelo ea austenitic (\(\ gamma\)) le ferritic (\(\ alpha\)) ea DSS welded joints e tiisa polelo ena72,73,74.Sena se boetse se fella ka ts'ebetso ea eona e mpe ea kutu, kaha Cr e nkoa e le eona ntho e ka sehloohong ea ho etsa filimi e sa sebetseng e ntlafatsang ho hanyetsa ha kutu ea sebaka sa tšepe59,75 joalokaha ho bontšitsoe setšoantšong sa 10b.Ho ka bonoa hore BM ho SEM micrograph setšoantšong sa 10c e bonts'a ntlafatso e matla ea lijo-thollo ha liphello tsa eona tsa EDS spectrum li bontša Cr (23.32 wt%), Mo (3.33 wt%) le Ni (6.32 wt).%) thepa e ntle ea lik'hemik'hale.%) e le ntho ea bohlokoa ea alloying bakeng sa ho hlahloba microstructure ea tekano ea karolo ea ferrite-austenitic ea sebopeho sa DSS76.Liphetho tsa tlhahlobo ea spectroscopic ea EMF ea manonyeletso a cheselitsoeng a elektrode ea E1 e lokafatsa ts'ebeliso ea eona molemong oa kaho le tikolohong e mabifi, kaha li-austenite formers le ferrite stabilizers ka har'a microstructure li latela maemo a DSS AISI 220541.72 bakeng sa manonyeletso a cheselitsoeng, 77.
SEM micrographs ea manonyeletso a marang-rang, moo (a) electrode E1 ea sebaka sa welding se nang le EMF spectrum, (b) electrode E2 ea sebaka sa welding e na le EMF spectrum, (c) OM e na le EMF spectrum.
Ha e le hantle, ho hlokometsoe hore li-welds tsa DSS li tiisa ka mokhoa o feletseng oa ferritic (F-mode), ka li-nuclei tsa austenite tse ka tlas'a mocheso oa ferritic solvus, o itšetlehileng haholo ka karolelano ea chromium ho nickel e lekanang (Creq/Nieq) (> 1.95 e etsa mokhoa F) Bafuputsi ba bang ba hlokometse phello ena ea tšepe ka lebaka la bokhoni bo matla ba ho hasana ba Cr le Mo e le likarolo tse etsang ferrite karolong ea ferrite8078,79.Ho hlakile hore DSS 2205 BM e na le palo e phahameng ea Cr le Mo (e bontšang Creq e phahameng), empa e na le dikahare tse tlaase tsa Ni ho feta li-electrode tsa E1, E2 le C, tse tlatsetsang ho tekanyo e phahameng ea Creq / Nieq.Sena se boetse se totobala thutong ea morao-rao, joalokaha ho bontšitsoe Lethathamong la 4, moo tekanyo ea Creq / Nieq e ileng ea khethoa bakeng sa DSS 2205 BM ka holimo ho 1.95.Ho ka bonoa hore li-welds tse nang le li-electrode E1, E2 le C li thatafala ka mokhoa oa austenitic-ferritic (AF mode), mokhoa oa austenitic (A mode) le mokhoa oa ferritic-austenitic, ka ho latellana, ka lebaka la litaba tse phahameng tsa mokhoa oa bongata (FA mode) .), joalokaha ho bontšitsoe Lethathamong la 4, litaba tsa Ni, Cr le Mo ka weld li fokotsehile, tse bontšang hore karolelano ea Creq / Nieq e ka tlaase ho ea BM.Ferite e ka sehloohong ho li-electrode welds tsa E2 e ne e e-na le morphology ea vermicular ferrite 'me tekanyo ea Creq / Nieq e ikemiselitseng e ne e le 1.20 joalokaha e hlalositsoe ho Lethathamo la 4.
Ka feiga.11a e bontša Open Circuit Potential (OCP) khahlanong le nako bakeng sa mohaho oa tšepe oa AISI DSS 2205 ka tharollo ea 3.5% ea NaCl.Hoa hlokomeleha hore sekhahla sa ORP se fetoha ho ea boemong bo botle haholoanyane, se bontšang ponahalo ea filimi e sa sebetseng holim'a sampuli ea tšepe, ho theoha ha bokhoni ho bontša ho bola ho tloaelehileng, 'me hoo e batlang e le ntho e sa khaotseng ha nako e ntse e feta e bontša filimi e sa sebetseng ka nako., Bokaholimo ba sampuli bo tsitsitse 'me bo na le Sticky 77. Li-curve li bontša likaroloana tsa liteko tlas'a maemo a tsitsitseng bakeng sa mehlala eohle ea electrolyte e nang le tharollo ea 3.5% ea NaCl, ntle le mohlala oa 7 (nonyeletso ea weld e nang le C-electrode), e bontshang ho hloka botsitso hanyane.Ho hloka botsitso hona ho ka bapisoa le boteng ba li-ion tsa chloride (Cl-) ka tharollo, e ka potlakisang karabelo ea kutu, kahoo e eketsa tekanyo ea ho bola.Maikutlo nakong ea ho hlahlojoa ha OCP ntle le matla a sebelisoang a bontšitse hore Cl karabelong e ka ama khanyetso le botsitso ba thermodynamic ba lisampole libakeng tse mabifi.Ma et al.81 le Lotho et al.5 e tiisitse tseko ea hore Cl- e bapala karolo ea ho potlakisa ho senyeha ha lifilimi tse sa sebetseng ho li-substrates, ka hona ho kenya letsoho ho apara ho eketsehileng.
Tlhahlobo ea electrochemical ea lisampole tse ithutoang: (a) ho iphetola ha RSD ho itšetlehile ka nako le (b) polarization ea potentiodynamic ea sampuli ho 3.5% NaCl tharollo.
Ka feiga.11b e fana ka tlhahlobo ea papiso ea potentiodynamic polarization curves (PPC) ea manonyeletso a welded a electrode E1, E2 le C tlas'a tšusumetso ea 3.5% ea tharollo ea NaCl.Mehlala ea BM e cheselitsoeng ho PPC le tharollo ea NaCl ea 3.5% e bonts'itse boits'oaro bo sa sebetseng.Letlapa la 5 le bonts'a litekanyetso tsa tlhahlobo ea electrochemical tsa lisampole tse fumanoeng ho tsoa ho li-curve tsa PPC, joalo ka Ecorr (monyetla oa ho bola) le Epit (monyetla oa ho senyeha ha likoti) le ho kheloha ho amanang le ona.Ha ho bapisoa le disampole tse ling No. 2 le No. 5, welded le li-electrode E1 le E2, disampole No. 1 le No. 7 (BM le welded manonyeletso le eleketrode C) o ile a bontša bokhoni bo phahameng ba pitting kutu ka tharollo NaCl (sa feiga. 11b). ).The phahameng passivating thepa ea pele bapisoa le ea morao-rao ka lebaka la ho leka-lekana ea sebopeho microstructural tsa tšepe (austenitic le ferritic mekhahlelo e) le mahloriso a metsoako motsoako.Ka lebaka la ho ba teng ha mekhahlelo ea ferrite le ea austenitic ho microstructure, Resendea et al.82 e tšehelitse boits'oaro ba DSS mecheng ea litaba e mabifi.Ts'ebetso e tlase ea lisampole tse cheselitsoeng ka li-electrode tsa E1 le E2 li ka amahanngoa le ho fokotseha ha likarolo tsa mantlha tsa alloying, joalo ka Cr le Mo, sebakeng sa welding (WZ), kaha li tsitsisa karolo ea ferrite (Cr le Mo), e sebetsa joalo ka li-passivators Alloys karolong ea austenitic ea litšepe tse nang le oxidized.Phello ea likarolo tsena ho hanyetsa ha pitting e kholo karolong ea austenitic ho feta karolong ea ferritic.Ka lebaka lena, karolo ea ferritic e feta ka potlako ho feta mohato oa austenitic o amanang le sebaka sa pele sa passivation sa polarization curve.Lintho tsena li na le tšusumetso e kholo ho khanyetso ea pitting ea DSS ka lebaka la khanyetso ea tsona e phahameng ea likoti karolong ea austenitic ha e bapisoa le karolo ea ferritic.Ka hona, phallo e potlakileng ea karolo ea ferrite e phahame ka 81% ho feta ea karolo ea austenite.Le hoja tharollo ea Cl-in e na le phello e matla e mpe ho matla a passivating a filimi ea tšepe83.Ka lebaka leo, botsitso ba filimi e fetang ea sampole bo tla fokotseha haholo84.Ho tsoa ho Tafole.6 e boetse e bontša hore bokhoni ba ho bola (Ecorr) ba manonyeletso a cheselitsoeng ka electrode ea E1 bo batla bo sa tsitsa ka tharollo ha bo bapisoa le manonyeletso a cheselitsoeng ka electrode ea E2.Sena se boetse se netefatsoa ke boleng bo tlase ba boima ba li-welds tse sebelisang li-electrode E1 le E2 ka feiga.4a,b, e bakoang ke lintho tse fokolang tsa ferrite (Letlapa la 5) le lintho tse tlaase tsa chromium le molybdenum (Letlapa la 4) mohahong oa tšepe o entsoeng ka.Ho ka fihleloa qeto ea hore khanyetso ea kutu ea litšepe tikolohong e etsisitsoeng ea maoatleng e eketseha ka ho fokotseha ha hona joale le ho fokotseha ka litaba tse tlase tsa Cr le Mo le litaba tse tlase tsa ferrite.Polelo ena e lumellana le phuputso e entsoeng ke Salim et al.85 mabapi le phello ea li-parameter tsa welding tse kang hona joale oa welding holim'a botšepehi ba litšepe tse cheselitsoeng.Ha chloride e kenella ka har'a tšepe ka mekhoa e fapaneng joalo ka ho monya le ho phatlolla ha capillary, likoti (pitting corrosion) tsa sebopeho le botebo bo sa lekaneng lia thehoa.Mochine o fapane haholo le litharollo tse phahameng tsa pH moo lihlopha tse potolohileng (OH-) li khahloang feela ke holim'a tšepe, ho tsitsisa filimi e sa sebetseng le ho fana ka tšireletso e eketsehileng holim'a tšepe25,86.Ntho e ntle ka ho fetisisa ea ho hanyetsa kutu ea sampuli ea No. 1 le No. 7 e bakoa haholo ke ho ba teng ha mohaho oa tšepe oa palo e kholo ea δ-ferrite (Letlapa la 5) le palo e kholo ea Cr le Mo (Letlapa la 4), kaha boemo ba pitting corrosion bo teng haholo-holo ka tšepe, e cheselitsoeng ke mokhoa oa DSS, ka sebopeho sa karolo ea austenitic ea likarolo.Ka hona, motsoako oa lik'hemik'hale oa motsoako o phetha karolo ea makhaola-khang ts'ebetsong ea ho senyeha ha motsoako o ts'oaretsoeng87,88.Ntle le moo, ho ile ha hlokomeloa hore mehlala e cheselitsoeng e sebelisa li-electrode tsa E1 le C thutong ena e bonts'itse boleng bo tlase ba Ecorr ho tsoa ho li-curve tsa PPC ho feta tse cheselitsoeng ho sebelisoa electrode ea E2 ho tsoa li-curve tsa OCP (Letlapa la 5).Ka hona, sebaka sa anode se qala ka matla a tlase.Phetoho ena e bakoa haholo ke ho tsitsisa ha karolo ea "passivation layer" e entsoeng holim'a sampuli le polarization ea cathodic e hlahang pele ho finyelloa botsitso bo feletseng ba OCP89.Ka feiga.12a le b li bonts'a litšoantšo tsa 3D optical profiler tsa mehlala e entsoeng ka liteko tlas'a maemo a fapaneng a ho cheselletsa.Ho ka bonoa hore pitting corrosion size ea disampole e eketseha ka matla a ka tlase a pitting corrosion a hlahisoang ke tjheseletsa e phahameng ea 110 A (sa feiga. 12b), e bapisoang le boholo ba likoti tse fumanoeng bakeng sa li-welds tse nang le karo-karolelano e tlase ea tjheseletsa. 90 A. (Setšoantšo sa 12a).Sena se tiisa boipiletso ba Mohammed90 ba hore lihlopha tsa slip li thehoa holim'a sampuli ho senya filimi ea holim'a passivation ka ho pepesa substrate ho tharollo ea 3.5% ea NaCl e le hore chloride e qale ho hlasela, e etsa hore thepa e qhibilihe.
Tlhahlobo ea SEM-EDS ho Lethathamo la 4 e bonts'a hore litekanyetso tsa PREN tsa karolo e 'ngoe le e' ngoe ea austenitic li phahame ho feta tsa ferrite ho li-welds tsohle le BM.Ho qalisoa ha pitting ho sebopeho sa ferrite/austenite ho potlakisa ho senyeha ha lera le sa sebetseng ka lebaka la inhomogeneity le karohano ea likarolo tse etsahalang libakeng tsena91.Ho fapana le karolo ea austenitic, moo boleng ba pitting resistance e lekanang (PRE) bo phahame, ho qalisoa ha likoti karolong ea ferritic ho bakoa ke boleng bo tlaase ba PRE (Letlapa la 4).Karolo ea austenite e bonahala e na le palo e kholo ea austenite stabilizer (nitrogen solubility), e fanang ka khatello e phahameng ea ntho ena, ka hona, ho hanyetsa ho phahameng ho pitting92.
Ka feiga.Setšoantšo sa 13 se bonts'a likhahla tse mahlonoko tsa mocheso bakeng sa li-welds tsa E1, E2, le C.Ka lebaka la hore boima ba hona joale bo eketsehile ho 100 µA / cm2 ka lebaka la ho pata nakong ea tlhahlobo ea ASTM, ho hlakile hore @ 110A weld e nang le E1 e bonts'a mocheso o fokolang oa mocheso oa 27.5 ° C o lateloa ke E2 @ 90A soldering e bontša CPT ea 40. °C, 'me tabeng ea C@110A CPT e phahameng ka ho fetisisa ke 41°C.Liphetho tse hlokometsoeng li lumellana hantle le liphetho tse hlokometsoeng tsa liteko tsa polarization.
Thepa ea mochini le boits'oaro ba kutu ea li-welds tsa tšepe tse sa hloekang tse duplex li ile tsa fuputsoa ho sebelisoa li-electrode tse ncha tsa E1 le E2.Electrode ea alkaline (E1) le electrode e nang le asiti (E2) e sebelisitsoeng ts'ebetsong ea SMAW e atlehile ho koaheloa ka sebopeho sa flux ka karolelano ea kakaretso ea 1.7 mm le index ea alkaline ea 2.40 le 0.40, ka ho latellana.Ho tsitsa ha mocheso oa li-fluxes tse lokiselitsoeng ho sebelisoa TGA ka mokhoa o sa sebetseng ho hlahlobiloe.Ho ba teng ha litaba tse phahameng tsa TiO2 (%) ka har'a matrix a phallo ho ntlafalitse ho tlosoa ha slag ea li-welds bakeng sa li-electrode tse koahetsoeng ka acidic flux (E2) ha li bapisoa le li-electrode tse koahetsoeng ka mokhoa oa motheo oa flux (E1).Le hoja li-electrode tse peli tse koahetsoeng (E1 le E2) li na le bokhoni bo botle ba ho qala.Maemo a ho tjheseletsa, haholo-holo ho kenya mocheso, hona joale le lebelo, ho phetha karolo ea bohlokoa ho finyella tekanyo ea li-austenite / ferrite ea li-welds tsa DSS 2205 le thepa e babatsehang ea mochine oa weld.The manonyeletso tjheseletsa le eleketrode E1 ile a bontša litšobotsi tse babatsehang tensile (ho kuta 0,2% YS = 497 MPa le UTS = 732 MPa), ho tiisa hore flux coated li-electrode na le index e phahameng ea motheo bapisoa le acid flux coated electrode.Li-electrode li bonts'a thepa e ntle ea mochini e nang le alkalinity e tlase.Ho totobetse hore ka manonyeletso a tjheselitsoeng ea li-electrode tse nang le seaparo se secha (E1 le E2) ha ho na tekano ea karolo ea ferrite-austenitic, e ileng ea senoloa ka ho sebelisa OES le SEM-EDS tlhahlobo ea weld le quantified ka karoloana ea molumo ho. the weld.Metallography e netefalitse thuto ea bona ea SEM.microstructures.Sena se bakoa haholo ke ho fokotseha ha likarolo tsa alloying tse kang Cr le Mo le ho khoneha ho lokolloa ha Cr2N nakong ea welding, e tiisitsoeng ke ho hlahlojoa ha line ea EDS.Sena se boetse se tšehetsoa ke boleng bo tlase ba boima bo bonoang ka li-welds tse nang le li-electrode tsa E1 le E2 ka lebaka la karolo ea tsona e tlase ea ferrite le likarolo tsa alloying mohahong oa tšepe.The Evidence Corrosion Potential (Ecorr) ea li-welds tse sebelisang electrode ea E1 e ipakile e fokola hanyane ho tsoa ho kutu ea tharollo ha e bapisoa le litšepe tse sebelisang eleketrode ea E2.Sena se tiisa katleho ea li-electrode tse ncha tse entsoeng ka li-welds tse lekiloeng sebakeng sa 3.5% sa NaCl ntle le motsoako oa motsoako oa motsoako oa flux.Ho ka fihleloa qeto ea hore khanyetso ea kutu tikolohong e etsisoang ea leoatleng e eketseha ka ho fokotseha ha hona joale.Ka hona, ho theoha ha li-carbides le nitrides le ho fokotseha ho latelang ha ho hanyetsa ha kutu ha manonyeletso a cheselitsoeng ho sebelisa li-electrode tsa E1 le E2 ho ile ha hlalosoa ke ho eketseha ha tjheseletsa hona joale, e leng se ileng sa lebisa ho se leka-lekaneng ho leka-lekana ha karolo ea manonyeletso a cheselitsoeng ho tloha litšepeng tse peli.
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