321 ishubhu ehlanganisiwe yensimbi engagqwali eyakhiwe ngamakhemikhali Izakhiwo zikagesi kanye nokuziphatha kokugqwala kwe-duplex stainless steel weld ene-electrode entsha

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I-Stainless Steel 321 Coil Tube Chemical Composition

Ukwakhiwa kwamakhemikhali we-321 stainless steel coil tubing imi kanje:
- Ikhabhoni: 0.08% ubuningi
I-Manganese: 2.00% ubuningi
I-Nickel: 9.00% min

I-Stainless Steel 321 I-Coil Tube Mechanical Properties

NgokoMkhiqizi we-Stainless Steel 321 Coil Tube, izakhiwo zemishini yeshubhu yekhoyili yensimbi engagqwali engu-321 zidwetshwe ngezansi: Amandla Aqinile (psi) Amandla Okukhiqiza (psi) Ukwelulwa (%)

Izicelo kanye nokusetshenziswa kwe-Stainless Steel 321 Coil Tube

Ezinhlelweni eziningi zobunjiniyela, izakhiwo zokumakhenikha nokugqwala kwezakhiwo ezishiselwe i-duplex stainless steel (DSS) yizinto ezibaluleke kakhulu.Ucwaningo lwamanje luphenye izakhiwo zemishini kanye nokumelana nokugqwala kwamashisela ensimbi engagqwali ayi-duplex endaweni elingisa i-3.5% NaCl kusetshenziswa i-electrode entsha eklanywe ngokukhethekile ngaphandle kokwengezwa kwezinto ezixutshwayo kumasampuli agelezayo.Izinhlobo ezimbili ezihlukene zokuguquguquka ezinenkomba eyisisekelo engu-2.40 no-0.40 zisetshenziswe kuma-electrode E1 no-E2 wokushisela amabhodi e-DSS, ngokulandelana.Ukuzinza kokushisa kwezingxube ze-flux kwahlolwa kusetshenziswa ukuhlaziywa kwe-thermogravimetric.Ukwakheka kwamakhemikhali kanye nezakhiwo zemishini nokugqwala kwamajoyinti ashiselwe kuye kwahlolwa kusetshenziswa i-emission spectroscopy ngokuvumelana namazinga ahlukahlukene e-ASTM.I-X-ray diffraction isetshenziselwa ukunquma izigaba ezikhona kumashisela e-DSS, futhi i-electron yokuskena nge-EDS isetshenziselwa ukuhlola ukwakheka okuncane kokushisela.Amandla aqinile wamajoyinti ashiselwe enziwe ama-electrode e-E1 ayengaphakathi kuka-715-732 MPa, ngama-electrodes E2 - 606-687 MPa.I-welding current inyusiwe isuka ku-90 A yaya ku-110 A, kanti nobulukhuni bunyusiwe.Amajoyinti ashiselwe anama-electrode e-E1 ambozwe ngama-fluxes ayisisekelo anezakhiwo ezingcono zemishini.Isakhiwo sensimbi sinokumelana nokugqwala okuphezulu endaweni engu-3.5% ye-NaCl.Lokhu kuqinisekisa ukusebenza kwamajoyinti ashiselwe enziwe ngama-electrode asanda kuthuthukiswa.Imiphumela kuxoxwa ngayo ngokuncishiswa kwezakhi ze-alloying ezifana ne-Cr ne-Mo ezibhekwa kuma-welds anama-electrode ahlanganisiwe E1 no-E2, kanye nokukhululwa kwe-Cr2N kuma-welds enziwe kusetshenziswa ama-electrode E1 no-E2.
Ngokomlando, ukukhuluma kokuqala okusemthethweni kwe-duplex stainless steel (DSS) kuhlehlela emuva ku-1927, lapho yayisetshenziselwa ukulingisa okuthile futhi ingasetshenziswa ezinhlelweni eziningi zobuchwepheshe ngenxa yokuqukethwe kwayo okuphezulu kwekhabhoni1.Kodwa kamuva, okuqukethwe kwekhabhoni evamile kwancishiswa kwaba yinani eliphakeme lika-0.03%, futhi lezi zinsimbi zasetshenziswa kabanzi emikhakheni ehlukahlukene2,3.I-DSS iwumndeni wama-alloys anamanani cishe alinganayo e-ferrite ne-austenite.Ucwaningo luye lwabonisa ukuthi isigaba se-ferritic ku-DSS sinikeza isivikelo esihle kakhulu ekuqhekekeni kwe-chloride-induced stress corrosion cracking (SCC), okwakuyinkinga ebalulekile ye-austenitic stainless steels (ASS) ekhulwini lama-20.Ngakolunye uhlangothi, kwezinye izimboni kanye nezinye izimboni4 isidingo sokugcina sikhula ngesilinganiso esingafika ku-20% ngonyaka.Le nsimbi emisha enezigaba ezimbili ze-austenitic-ferritic ingatholwa ngokukhetha ukwakheka okufanelekile, ukucwengwa kwamakhemikhali ngokomzimba kanye ne-thermomechanical.Uma kuqhathaniswa nesigaba esisodwa sensimbi engagqwali, i-DSS inamandla esivuno esiphezulu namandla aphakeme okumelana ne-SCC5, 6, 7, 8. Isakhiwo esiyi-duplex sinikeza lezi zinsimbi amandla angenakuqhathaniswa, ukuqina kanye nokwanda kokubola kokugqwala ezindaweni ezinolaka eziqukethe ama-asidi, ama-acid chloride, amanzi olwandle namakhemikhali adlayo9.Ngenxa yokuguquguquka kwentengo yonyaka yama-alloys e-nickel (Ni) emakethe evamile, isakhiwo se-DSS, ikakhulukazi uhlobo lwe-nickel ephansi (i-lean DSS), sizuze izimpumelelo eziningi ezivelele uma kuqhathaniswa ne-face centered cubic (FCC) iron10, 11. Okuyinhloko Inkinga yemiklamo ye-ASE iwukuthi ingaphansi kwezimo ezihlukahlukene ezinzima.Ngakho-ke, iminyango ehlukahlukene yobunjiniyela kanye nezinkampani zizama ukukhuthaza ezinye izinsimbi ezingenasici ze-nickel (Ni) ezisebenza kahle noma ezingcono kune-ASS yendabuko ezinokushisela okufanele futhi ezisetshenziswa ezimbonini ezifana nezishintshisi zokushisa kwamanzi olwandle kanye nemboni yamakhemikhali.isitsha 13 sezindawo ezine-chloride ephezulu.
Enqubekelaphambili yesimanje yezobuchwepheshe, ukukhiqizwa okushiselwe kudlala indima ebalulekile.Imvamisa, amalungu esakhiwo se-DSS ajoyinwa nge-arc evikelwe ngegesi noma i-arc evikelwe ngegesi.I-weld ithinteka kakhulu ekubunjweni kwe-electrode esetshenziselwa ukushisela.Ama-electrode welding aqukethe izingxenye ezimbili: insimbi kanye ne-flux.Ngokuvamile, ama-electrode ahlanganiswe ne-flux, ingxube yezinsimbi okuthi, lapho ebolile, akhulule amagesi futhi enze i-slag evikelayo ukuze avikele i-weld ekungcoleni, akhulise ukuzinza kwe-arc, futhi engeza ingxenye ye-alloying ukuthuthukisa ikhwalithi ye-welding14. .I-cast iron, i-aluminium, insimbi engagqwali, insimbi emnene, insimbi enamandla kakhulu, ithusi, ithusi, nethusi ezinye zezinsimbi ze-electrode ezishiselayo, kuyilapho i-cellulose, i-iron powder, ne-hydrogen kungezinye zezinto ezisetshenziswayo.Ngezinye izikhathi i-sodium, i-titanium ne-potassium nayo yengezwa engxube ye-flux.
Abanye abacwaningi bazamile ukutadisha umphumela wokucushwa kwe-electrode kubuqotho bemishini nokugqwala kwezakhiwo zensimbi ezishiselwe.Singh et al.15 yaphenya umthelela wokwakheka kwe-flux kubude namandla aqinile wama-weld ashiselwe ngokushisela i-arc engaphansi kwamanzi.Imiphumela ibonisa ukuthi i-CaF2 ne-NiO yizona ezinquma amandla okuqinile uma kuqhathaniswa nokuba khona kwe-FeMn.U-Chirag et al.16 uphenye izinhlanganisela ze-SMAW ngokushintshanisa ukugxila kwe-rutile (TiO2) kungxube ye-electrode flux.Kwatholakala ukuthi izakhiwo ze-microhardness zanda ngenxa yokwanda kwamaphesenti kanye nokufuduka kwekhabhoni ne-silicon.U-Kumar [17] ufunde ukwakheka nokuthuthukiswa kwama-agglomerated fluxes we-arc welding engaphansi kwamashidi ensimbi.U-Nwigbo no-Atuanya18 baphenye ukusetshenziswa kwezibophezelo ze-sodium silicate ezicebile nge-potassium ukuze kukhiqizwe ama-arc welding fluxes futhi bathola ama-welds anamandla aphezulu we-430 MPa kanye nesakhiwo sokusanhlamvu esamukelekayo.U-Lothongkum et al.19 wasebenzisa indlela ye-potentiokinetic ukuze atadishe ingxenye yevolumu ye-austenite ku-duplex yensimbi engagqwali 28Cr–7Ni–O-0.34N kusixazululo se-NaCl esigcwele umoya ekuhlanganiseni okungu-3.5% wt.ngaphansi kwezimo ze-pH.futhi 27°C.Zombili izinsimbi ezingenasici eziyi-duplex ne-micro duplex zibonisa umphumela ofanayo we-nitrogen ekuziphatheni kokugqwala.I-nitrogen ayizange ithinte amandla okugqwala noma izinga ku-pH 7 no-10, nokho, amandla okugqwala ku-pH 10 ayephansi kune-pH 7. Ngakolunye uhlangothi, kuwo wonke amazinga e-pH ahlolisisiwe, amandla aqala ukwanda ngokwanda kokuqukethwe kwenitrogen. .Lacerda et al.I-20 ifunde umgodi wezinsimbi ezingenasici ze-duplex i-UNS S31803 kanye ne-UNS S32304 kusixazululo se-NaCl esingu-3.5% sisebenzisa i-cyclic potentiodynamic polarization.Kusixazululo se-NaCl esingu-3.5 wt.%, izimpawu zomgodi zitholwe kumapuleti ensimbi amabili aphenywayo.Insimbi ye-UNS S31803 inamandla okugqwala aphezulu (Ecorr), amandla omgodi (Epit) kanye nokumelana ne-polarization (Rp) kunensimbi ye-UNS S32304.Insimbi ye-UNS S31803 ine-repassivity ephezulu kune-UNS S32304 steel.Ngokocwaningo lukaJiang et al.[21], ukuphakama kokuvuselela okuhambisana nesigaba esikabili (i-austenite nesigaba se-ferrite) se-duplex yensimbi engagqwali ihlanganisa kufika ku-65% wokwakheka kwe-ferrite, futhi ukuminyana kwamanje kokuvuselela i-ferrite kuyanda ngokukhula kwesikhathi sokwelashwa kokushisa.Kuyaziwa ukuthi izigaba ze-austenitic ne-ferritic zibonisa ukusabela okuhlukile kwe-electrochemicals emandleni ahlukene we-electrochemical21,22,23,24.U-Abdo et al.25 basebenzise izilinganiso ze-potentiodynamic ze-polarization spectroscopy kanye ne-electrochemical impedance spectroscopy ukuze bahlole ukugqwala okwenziwe nge-electrochemically kwe-laser-welded 2205 DSS alloy emanzini olwandle okwenziwa (3.5% NaCl) ngaphansi kwezimo ze-acidity ehlukahlukene kanye ne-alkalinity.Ukugqwala kwe-pitting kwabonwa endaweni esobala yezibonelo ze-DSS ezihloliwe.Ngokusekelwe kulokhu okutholakele, kwasungulwa ukuthi kukhona ubudlelwano obulinganayo phakathi kwe-pH yendawo encibilikayo kanye nokumelana kwefilimu okwakhiwa ngenqubo yokudlulisa icala, okuthinta ngokuqondile ukwakheka kwe-pitting kanye nokucaciswa kwayo.Inhloso yalolu cwaningo kwakuwukuqonda ukuthi ukwakheka kwe-electrode yokushisela esanda kuthuthukiswa kuthinta kanjani ubuqotho bomshini nokungagugi kwe-DSS 2205 eshiselwe endaweni engu-3.5% ye-NaCl.
Amaminerali agelezayo (izithako) asetshenziswe ekwenziweni kokuhlanganisa i-electrode kwakuyi-Calcium Carbonate (CaCO3) evela esifundeni sase-Obajana, eSifundazweni sase-Kogi, eNigeria, i-Calcium Fluoride (CaF2) evela eSifundazweni SaseTaraba, eNigeria, i-Silicon Dioxide (SiO2), i-Talc Powder ( Mg3Si4O10(OH) ) )2) kanye ne-rutile (TiO2) zitholwe kwa-Jos, e-Nigeria, futhi i-kaolin (Al2(OH)4Si2O5) itholwe e-Kankara, e-Katsina State, e-Nigeria.I-Potassium silicate isetshenziswa njenge-binder, itholakala eNdiya.
Njengoba kuboniswe kuThebula 1, ama-oxide ahlanganisiwe akalwa ngokuzimela kubhalansi yedijithali.Yabe isixutshwa ne-potassium silicate binder (23% ngesisindo) kumxube kagesi (imodeli: 641-048) evela ku-Indian Steel and Wire Products Ltd. (ISWP) imizuzu engu-30 ukuze kutholwe ukunamathisela okulinganayo kwe-semi-solid.I-flux exubile emanzi icindezelwa ibe yisimo esiyicylindrical kusukela emshinini wokufaka ibriquetting futhi ifakwe ekamelweni lokuxhuma ngengcindezi engu-80 kuya ku-100 kg/cm2, futhi ukusuka ekamelweni lokuphakelayo kwezintambo kufakwa ku-3.15mm ububanzi be-stainless wire extruder.I-flux ifakwa ngohlelo lwe-nozzle/die futhi ijovelwe ku-extruder ukuze kukhishwe ama-electrode.Kutholwe isici sokumboza esingu-1.70 mm, lapho isici sokumboza sichazwa njengesilinganiso sobubanzi be-electrode kuya kububanzi bomucu.Khona-ke ama-electrode aboshwe omiswa emoyeni amahora angu-24 bese ebalwa esithandweni somlilo (imodeli PH-248-0571/5448) ku-150-250 ° C\(-\) amahora angu-2.Sebenzisa isibalo ukuze ubale i-alkalinity yokugeleza.(1) 26;
Ukuzinza okushisayo kwamasampula e-flux ezingoma ze-E1 ne-E2 kwanqunywa kusetshenziswa ukuhlaziywa kwe-thermogravimetric (TGA).Isampula cishe ye-25.33 mg ye-flux yalayishwa ku-TGA ukuze ihlaziywe.Ukuhlola kwenziwe ngendlela engasebenzi etholwe ukugeleza okuqhubekayo kwe-N2 ngenani elingu-60 ml/min.Isampula yashisisa ukusuka ku-30°C kuya ku-1000°C ngezinga lokushisa elingu-10°C/min.Ukulandela izindlela ezishiwo ngu-Wang et al.27, Xu et al.28 no-Dagwa et al.29, ukubola okushisayo nokulahlekelwa kwesisindo samasampuli emazingeni okushisa athile kwahlolwa kusukela ku-TGA iziza.
Hlanganisa amapuleti e-DSS amabili angu-300 x 60 x 6 mm ukuze ulungiselele ukusoda.I-V-groove yaklanywa yaba negebe lempande elingu-3mm, imbobo yempande engu-2mm kanye ne-engeli ye-60° groove.Ipuleti labe seligezwa nge-acetone ukuze kukhishwe ukungcola okungenzeka.Shisela amapuleti usebenzisa i-arc welder yensimbi evikelekile (SMAW) ene-electrode yamanje positive polarity (DCEP) esebenzisa ama-electrode ahlanganisiwe (E1 no-E2) kanye ne-electrode eyireferensi (C) enobubanzi obungu-3.15 mm.I-Electrical Discharge Machining (EDM) (Imodeli: I-Excetek-V400) yasetshenziselwa umshini izifanekiso zensimbi ezishiselwe ukuhlolwa komshini kanye nezinhlamvu zokugqwala.Ithebula lesi-2 libonisa ikhodi yesibonelo kanye nencazelo, futhi Ithebula 3 libonisa imingcele yokusebenza yokushisela esetshenziselwa ukushisela ibhodi le-DSS.Isibalo (2) sisetshenziselwa ukubala okokufaka okushisa okuhambisanayo.
Kusetshenziswa i-Bruker Q8 MAGELLAN optical emission spectrometer (OES) enobude begagasi obungu-110 kuya ku-800 nm kanye nesofthiwe yedathabheyisi ye-SQL, ukwakheka kwamakhemikhali okuhlanganisa ama-weld ama-electrode E1, E2 no-C, kanye namasampula ensimbi eyisisekelo, kwanqunywa.isebenzisa igebe phakathi kwe-electrode nesampula yensimbi ngaphansi kokuhlolwa Ikhiqiza amandla kagesi ngendlela yenhlansi.Isampula yezingxenye iyahwamuka futhi ifuthwe, ilandelwe ukuvuswa kwe-athomu, okuthi kamuva kukhiphe i-spectrum yomugqa othize31.Ukuze uthole ukuhlaziywa kwekhwalithi yesampula, ishubhu ye-photomultiplier ikala ubukhona be-spectrum ezinikele ye-elementi ngayinye, kanye nokuqina kwe-spectrum.Bese usebenzisa isibalo ukuze ubale inombolo elinganayo yokumelana ne-pitting (PREN).(3) Isilinganiso 32 kanye nomdwebo wesifunda we-WRC 1992 zisetshenziselwa ukubala okulinganayo kwe-chromium ne-nickel (Creq ne-Nieq) kusukela kuzibalo.(4) kanye no-(5) zinama-33 nama-34 ngokulandelana;
Qaphela ukuthi i-PREN icabangela kuphela umthelela omuhle wezinto ezintathu eziyinhloko u-Cr, Mo no-N, kuyilapho isici se-nitrogen x sisebangeni lika-16-30.Ngokuvamile, u-x ukhethwa ohlwini lwabangu-16, 20, noma abangu-30. Ocwaningweni lwama-duplex stainless steels, inani elimaphakathi elingu-20 lisetshenziswa kakhulu ukubala amanani angu-PREN35,36.
Amajoyinti ashiselwe enziwe kusetshenziswa ama-electrode ahlukene avivinywa ngokuqina emshinini wokuhlola wendawo yonke (Instron 8800 UTM) ngesilinganiso sobunzima esingu-0.5 mm/min ngokuhambisana ne-ASTM E8-21.Amandla e-Tensile (UTS), 0.2% amandla e-shear yield (YS), nobude kubalwe ngokuya nge-ASTM E8-2137.
Ama-weldments e-DSS 2205 aba phansi okokuqala futhi aphucuziwe kusetshenziswa osayizi abahlukene begrit (120, 220, 320, 400, 600, 800, 1000 kanye no-1200) ngaphambi kokuhlaziywa kokuqina.Izibonelo ezishiselwe zenziwe ngama-electrode E1, E2 kanye no-C. Ukuqina kukalwa ngamaphoyinti ayishumi (10) ukusuka enkabeni ye-weld kuya ensimbi eyisisekelo ngesikhawu esingu-1 mm.
I-X-ray diffractometer (i-D8 Discover, i-Bruker, eJalimane) icushwe ngesofthiwe ye-Bruker XRD Commander ukuze iqoqwe idatha kanye nemisebe ye-Fe-Filtered Cu-K-α enamandla angu-8.04 keV ehambisana nobude begagasi obungu-1.5406 Å kanye nesilinganiso sokuskena esingu-3 ° Ibanga lokuskena (2θ) min-1 lingu-38 ukuya ku-103° ukuze kuhlaziywe isigaba esinama-electrode e-E1, E2 no-C kanye ne-BM akhona kumashisela e-DSS.Indlela yokucwenga yase-Rietveld yasetshenziswa ukukhomba izigaba ezibambile kusetshenziswa isofthiwe ye-MAUD echazwe yi-Lutterotti39.Ngokusekelwe ku-ASTM E1245-03, ukuhlaziya okulinganiselwe kwe-metallographic kwezithombe ezincane ze-weld joints of electrode E1, E2 no-C kwenziwa kusetshenziswa isofthiwe ye-Image J40.Imiphumela yokubala ingxenye yevolumu yesigaba se-ferrite-austenitic, inani layo elimaphakathi nokuchezuka kunikezwa kuThebula.5. Njengoba kuboniswe ekucushweni kwesampula kufig.I-6d, ukuhlaziywa kwe-optical microscopy (OM) kwenziwa ku-PM kanye namajoyinti ashiselwe ngama-electrode E1 no-E2 ukuze kufundwe i-morphology yamasampuli.Amasampula apholishwa nge-sandpaper engu-120, 220, 320, 400, 600, 800, 1000, 1200, 1500, kanye ne-2000 grit silicon carbide (SiC).Amasampula abe eseqoshwa ngogesi kusisombululo se-aqueous oxalic acid engu-10% endaweni yokushisa kagesi ku-voltage engu-5 V amasekhondi ayi-10 futhi abekwa kusibonakhulu se-LEICA DM 2500 M sokubonwa kwe-morphological characterization.Ukupholishwa okwengeziwe kwesampula kwenziwa kusetshenziswa iphepha le-2500 grit silicon carbide (SiC) lokuhlaziya i-SEM-BSE.Ngaphezu kwalokho, amajoyinti ashiselwe ahlolelwa i-microstructure kusetshenziswa i-ultra-high resolution field emission scanning electron microscope (SEM) (FEI NOVA NANOSEM 430, USA) efakwe i-EMF.Isampula engu-20 × 10 × 6 mm yagaywa kusetshenziswa ama-sandpaper e-SiC ahlukahlukene anosayizi osuka ku-120 kuya ku-2500. Amasampula aqoshwe ngogesi ku-40 g we-NaOH kanye no-100 ml wamanzi acwengekile ku-voltage engu-5 V ngamasekhondi angu-15, bese emva kwalokho. kufakwe kusibambi wesampula , etholakala kugumbi le-SEM, ukuze kuhlaziywe amasampuli ngemva kokuhlanza igumbi nge-nitrogen.I-electron beam ekhiqizwa i-tungsten filament eshisayo yenza i-grating kusampula ukuze ikhiqize izithombe ngokukhuliswa okuhlukahlukene, futhi imiphumela ye-EMF itholwe kusetshenziswa izindlela zikaRoche et al.41 kanye neMokobi 42.
Indlela ye-electrochemical potentiodynamic polarization ngokusho kwe-ASTM G59-9743 kanye ne-ASTM G5-1444 yasetshenziswa ukuze kuhlolwe amandla okuwohloka kwamapuleti e-DSS 2205 ashiselwe nge-E1, E2 kanye ne-C electrode endaweni engu-3.5% ye-NaCl.Ukuhlolwa kwe-Electrochemical kwenziwa kusetshenziswa i-Potentiostat-Galvanostat/ZRA elawulwa ngekhompuyutha i-apparatus (imodeli: PC4/750, Gamry Instruments, USA).Ukuhlolwa kwe-electrochemical kwenziwa ekusethweni kokuhlolwa kwama-electrode amathathu: i-DSS 2205 njenge-electrode esebenzayo, i-saturated calomel electrode (SCE) njenge-reference electrode kanye ne-graphite rod njenge-counter electrode.Izilinganiso zenziwa kusetshenziswa iseli ye-electrochemical, lapho indawo yesenzo sesixazululo kwakuyindawo ye-electrode esebenzayo engu-0.78 cm2.Izilinganiso zenziwe phakathi -1.0 V kuya ku-+1.6 V okungenzeka ku-OCP ezinzile (okuhlobene ne-OCP) ngesilinganiso sokuskena esingu-1.0 mV/s.
Ukuhlolwa kokushisa okubalulekile kwe-electrochemical pitting kwenziwa ku-3.5% NaCl ukuze kuhlolwe ukumelana kwe-pitting kwama-welds enziwe nge-E1, E2, ne-C electrode.ngokucacile emandleni okugoba ku-PB (phakathi kwezifunda ze-passive ne-transpassive), kanye nezibonelo ezishiselwe nge-E1, E2, Electrodes C. Ngakho-ke, izilinganiso ze-CPT zenziwa ukuze kunqunywe ngokunembile amandla okugoba we-welding consumables.Ukuhlolwa kwe-CPT kwenziwa ngokuhambisana nemibiko ye-duplex yensimbi engagqwali ye-weld45 kanye ne-ASTM G150-1846.Kusukela kunsimbi ngayinye ezoshiselwa (S-110A, E1-110A, E2-90A), amasampula anendawo engu-1 cm2 asikwa, okuhlanganisa isisekelo, izindawo zokushisela, kanye ne-HAZ.Amasampuli apholishwa kusetshenziswa i-sandpaper kanye ne-alumina powder slurry engu-1 µm ngokuhambisana nezinqubo ezijwayelekile zokulungiselela isampula ye-metallographic.Ngemuva kokupholisha, amasampula ahlanzwa nge-ultrasonically ku-acetone imizuzu emi-2.Isixazululo sokuhlola esingu-3.5% se-NaCl sengezwe kuseli yokuhlola ye-CPT futhi izinga lokushisa lokuqala lalungiswa laba ngu-25°C kusetshenziswa i-thermostat (Neslab RTE-111).Ngemva kokufinyelela izinga lokushisa lokuhlola lokuqala lika-25 ° C, i-Ar gas yashaywa imizuzu engu-15, khona-ke amasampula afakwa esitokisini, futhi i-OCF yalinganiswa imizuzu engu-15.Isampula yabe ihlukaniswa ngokufaka i-voltage engu-0.3 V ekushiseni kokuqala okungu-25°C, futhi okwamanje kukalwa ku-10 min45.Qala ukushisisa isixazululo ngesilinganiso esingu-1 °C/min kuya ku-50 °C.Ngesikhathi sokushisa kwesisombululo sokuhlola, inzwa yokushisa isetshenziselwa ukuqapha ngokuqhubekayo izinga lokushisa lesixazululo nokugcina isikhathi nedatha yokushisa, futhi i-potentiostat/galvanostat isetshenziselwa ukukala okwamanje.I-electrode yegraphite yasetshenziswa njenge-electrode ekhawuntayo, futhi wonke amandla alinganiswa ngokuqhathaniswa ne-electrode eyireferensi ye-Ag/AgCl.I-Argon purge yenziwa kulo lonke ukuhlolwa.
Emkhiwaneni.I-1 ibonisa ukwakheka (ngephesenti lesisindo) sezingxenye ezishintshayo ze-F1 ne-F2 ezisetshenziselwa ukukhiqizwa kwama-electrode e-alkaline (E1) kanye ne-acidic (E2), ngokulandelana.I-flux basicity index isetshenziselwa ukubikezela izakhiwo zemishini nezensimbi zamalunga ashiselwe.I-F1 iyingxenye ye-flux esetshenziselwa ukumboza ama-electrodes e-E1, okubizwa ngokuthi i-alkaline flux ngoba inkomba yayo eyisisekelo ingu-> 1.2 (okungukuthi 2.40), futhi i-F2 iyi-flux esetshenziselwa ukumboza ama-electrodes e-E2, ebizwa ngokuthi i-asidi flux ngenxa yesisekelo sayo. inkomba <0.9 (okungukuthi 2.40).0.40).Kuyacaca ukuthi ama-electrode ambozwe ngama-fluxes ayisisekelo ezimweni eziningi anezakhiwo ezingcono zemishini kunama-electrode ahlanganiswe ne-acidic fluxes.Lesi sici siwumsebenzi wokubusa kwe-oxide eyisisekelo ohlelweni lokwakheka kwe-flux ye-electrode E1.Ngokuphambene nalokho, ukususwa kwe-slag (ukuhlukana) kanye ne-spatter ephansi ebonwa emalungeni ashiselwe ngama-electrode e-E2 kuyisici sama-electrode ane-acidic flux coating enokuqukethwe okuphezulu kwe-rutile.Lokhu kuqaphela kuhambisana nokutholwe kwe-Gill47 ukuthi umphumela wokuqukethwe kwe-rutile ekuhlukanisekeni kwe-slag kanye ne-spatter ephansi ye-acid flux coated electrode kunomthelela ekubandeni kwe-slag ngokushesha.I-Kaolin ohlelweni lwe-flux esetshenziselwa ukumboza ama-electrode E1 ne-E2 yasetshenziswa njengento yokugcoba, futhi i-talc powder yathuthukisa ukukhishwa kwama-electrode.Izibophezelo ze-potassium silicate ezinhlelweni ze-flux zifaka isandla ekushiseni okungcono kwe-arc nokuzinza kokusebenza, futhi, ngaphezu kwezakhiwo zabo zokunamathela, zithuthukisa ukuhlukaniswa kwe-slag emikhiqizweni eshiselwe.Njengoba i-CaCO3 iyi-net breaker (i-slag breaker) ekugelezeni kwegazi futhi ijwayele ukukhiqiza intuthu eningi ngesikhathi sokushisela ngenxa yokubola okushisayo ku-CaO futhi mayelana ne-44% CO2, i-TiO2 (njengomakhi wenetha / i-slag yangaphambili) isiza ukunciphisa inani yentuthu ngesikhathi sokushisela .ukushisela futhi ngaleyo ndlela kuthuthukiswe ukutholakala kwe-slag njengoba kuphakanyiswe uJing et al.48.I-Fluorine Flux (CaF2) iwukugeleza kwamakhemikhali okunolaka okuthuthukisa ukuhlanzeka kwe-solder.Jastrzębska et al.49 ibike umphumela wokwakheka kwe-fluoride yalokhu kwakheka kwe-flux ezimpahleni zokuhlanzeka kwe-weld.Ngokuvamile, i-flux yengezwa endaweni yokushisela ukuze kuthuthukiswe ukuzinza kwe-arc, ukwengeza izakhi ze-alloying, ukwakha i-slag, ukukhulisa ukukhiqiza, nokuthuthukisa ikhwalithi ye-weld pool 50.
Amajika e-TGA-DTG aboniswe ku-Fig.U-2a no-2b abonisa ukwehla kwesisindo okuzinyathelo ezintathu lapho kushisa ebangeni lokushisa elingu-30–1000°C endaweni enenitrogen.Imiphumela ku-Figure 2a kanye no-b ibonisa ukuthi kumasampuli ayisisekelo kanye ne-acidic flux, ijika le-TGA lehla liqonde phansi lize ligcine lihambisana ne-eksisi yezinga lokushisa, cishe ku-866.49°C no-849.10°C ngokulandelana.Ukulahlekelwa kwesisindo sika-1.30% no-0.81% ekuqaleni kwamajika e-TGA ku-Fig. 2a no-2b kungenxa yomswakama othathwe izingxenye ze-flux, kanye nokuhwamuka nokuphelelwa amandla kwamanzi omswakama ongaphezulu.Ukubola okuyinhloko kwamasampuli we-flux eyinhloko esigabeni sesibili nesesithathu emkhiwaneni.I-2a yenzeke kumazinga okushisa angu-619.45 ° C-766.36 ° C no-766.36 ° C-866.49 ° C, futhi iphesenti lokulahlekelwa kwesisindo sabo lalingu-2.84 no-9.48%., ngokulandelana.Ngenkathi amasampula e-acidic flux ku-Fig. 7b, ayesezingeni lokushisa lika-665.23 ° C-745.37 ° C no-745.37 ° C-849.10 ° C, ukulahlekelwa kwesisindo samaphesenti kwakungu-0.81 no-6.73%, ngokulandelana, okwakuthiwa ukubola okushisayo.Njengoba izingxenye ze-flux zingezona izinto eziphilayo, ama-volatiles anqunyelwe kungxube ye-flux.Ngakho-ke, ukunciphisa kanye ne-oxidation kubi.Lokhu kuhambisana nemiphumela ka-Balogun et al.51, Kamli et al.52 no-Adeleke et al.53.Isamba sokulahlekelwa okukhulu kwesampula ye-flux ebonwe kufig.2a kanye 2b 13.26% kanye 8.43%, ngokulandelana.Ukulahlekelwa okuncane kwesisindo samasampuli e-flux emkhiwaneni.I-2b ibangelwa amaphuzu aphezulu ancibilikayo e-TiO2 kanye ne-SiO2 (1843 kanye ne-1710 ° C ngokulandelanayo) njengama-oxides ayinhloko akha ingxube ye-flux54,55, kuyilapho i-TiO2 ne-SiO2 inamaphuzu aphansi okuncibilika.iphoyinti elincibilikayo I-oxide eyinhloko: i-CaCO3 (825 °C) kusampula lokugeleza kwefig.2a56.Lezi zinguquko endaweni yokuncibilika kwama-oxides ayinhloko ezixubeni ze-flux zibikwa kahle ngu-Shi et al.54, u-Ringdalen et al.55 no-Du et al.56.Ukubuka ukulahlekelwa kwesisindo okuqhubekayo ku-Fig. 2a no-2b, kungaphetha ngokuthi amasampula e-flux asetshenziswe ku-E1 kanye ne-E2 electrode coatings adlula isinyathelo esisodwa sokubola, njengoba kuphakanyiswe uBrown57.Ibanga lokushisa lenqubo lingabonakala kumajika aphuma kokunye (wt%) emkhiwaneni.2a kanye b.Njengoba ijika le-TGA lingakwazi ukuchaza ngokunembile izinga lokushisa elithile lapho isistimu ye-flux ishintsha khona isigaba kanye ne-crystallization, i-TGA derivative isetshenziselwa ukucacisa inani eliqondile lokushisa lesenzo ngasinye (ushintsho lwesigaba) njengesiqongo se-endothermic ukuze kulungiswe uhlelo lwe-flux.
Amajika e-TGA-DTG abonisa ukubola okushisayo (a) kwe-alkaline flux ye-E1 electrode coating kanye (b) ne-acidic flux ye-E2 electrode coating.
Ithebula lesi-4 libonisa imiphumela yokuhlaziywa kwe-spectrophotometric kanye nokuhlaziywa kwe-SEM-EDS kwe-DSS 2205 base base metal nama welds ezenziwe kusetshenziswa E1, E2 kanye C electrode.I-E1 ne-E2 ibonise ukuthi okuqukethwe kwe-chromium (Cr) kwehle kakhulu kwaya ku-18.94 no-17.04%, futhi okuqukethwe kwe-molybdenum (Mo) kwaba ngu-0.06 no-0.08%, ngokulandelana.amanani ama-welds ane-electrode E1 ne-E2 aphansi.Lokhu kuhambisana kancane nevelu ye-PREN ebaliwe yesigaba se-ferritic-austenitic kusukela ekuhlaziyweni kwe-SEM-EDS.Ngakho-ke, kungabonakala ukuthi umgodi uqala esiteji ngamavelu aphansi e-PREN (ama-welds avela ku-E1 no-E2), ngokuyisisekelo njengoba kuchazwe kuThebula 4. Lokhu kubonisa ukuncipha kanye nemvula engenzeka ye-alloy ekushiseleni.Kamuva, ukuncishiswa kokuqukethwe kwezakhi ze-Cr ne-Mo ze-alloying kuma-welds akhiqizwa kusetshenziswa ama-electrode E1 ne-E2 kanye namanani awo alingana ne-pitting ephansi (PREN) aboniswa kuThebula 4, okudala inkinga yokugcina ukumelana ezindaweni ezinolaka, ikakhulukazi. ezindaweni ezine-chloride.-indawo equkethe.Okuqukethwe kwe-nickel (Ni) okuphakeme kakhulu okungu-11.14% kanye nomkhawulo ovunyelwe wokuqukethwe kwe-manganese emalungeni ashiselwe ama-electrode e-E1 kanye ne-E2 kungenzeka kube nomthelela omuhle ezintweni eziwumshini zokushisela ezisetshenziswa ezimeni ezilingisa amanzi olwandle (Fig. 3) ).zenziwa kusetshenziswa umsebenzi we-Yuan ne-Oy58 kanye no-Jing et al.48 emthelela wokuqanjwa kwe-nickel ephezulu kanye ne-manganese ekuthuthukiseni izakhiwo zemishini zezakhiwo ezishiselwe i-DSS ngaphansi kwezimo ezinzima zokusebenza.
Imiphumela yokuhlolwa kwe-Tensile ye-(a) UTS no-0.2% sag YS kanye (b) neyunifomu nobude obugcwele kanye nokuchezuka kwazo okujwayelekile.
Amandla wezinto eziyisisekelo (BM) namajoyinti ashiselwe enziwe ngama-electrode athuthukisiwe (E1 kanye ne-E2) kanye ne-electrode etholakalayo kwezohwebo (C) kwahlolwa kuma-welding amabili ahlukene angu-90 A no-110 A. 3(a) futhi (b) bonisa i-UTS, YS eno-0.2% offset, kanye nobude bayo nedatha yokuchezuka evamile.Imiphumela ye-UTS ne-YS ye-offset ka-0.2% etholwe kuma-Fig.3a bonisa amanani alungile wesampula inombolo.1 (BM), inombolo yesampula.3 (weld E1), inombolo yesampula.5 (weld E2) kanye nenombolo yesampula.I-6 (ama-welds ano-C) angama-878 kanye nama-616 MPa, angu-732 nama-MPa angu-497, angu-687 nama-MPa angu-461 nama-769 nama-549 MPa, ngokulandelana, kanye nokuchezuka kwawo okujwayelekile.Kusukela emkhiwaneni.110 A) amasampula anombolo 1, 2, 3, 6 kanye no-7, ngokulandelana, anezindawo zokudonsa ezinconyiwe ezingaphezulu kwama-450 MPa ekuhlolweni kwe-tensile kanye nama-MPa angama-620 ekuhlolweni kwe-tensile okuhlongozwe i-Grocki32.Ukwelulwa kwezibonelo zokushisela ngama-electrode E1, E2 no-C, amelelwa amasampula No. 2, No. 3, No. 4, No. 5, No. 6 and No. ngokulandelana, libonisa plasticity nokwethembeka.maqondana nezinsimbi eziyisisekelo.Ukwelulwa okuphansi kwachazwa ngokukhubazeka okungenzeka kwe-welding noma ukwakheka kwe-electrode flux (Fig. 3b).Kungaphethwa ngokuthi i-BM duplex insimbi engagqwali namajoyinti ashiselwe anama-electrode e-E1, E2 kanye no-C ngokuvamile anezindawo eziqinile eziphakeme kakhulu ngenxa yokuqukethwe kwayo kwe-nickel ephezulu uma kuqhathaniswa (Ithebula 4), kodwa le ndawo yabonwa emajoyini ashiselwe.I-E2 engasebenzi kahle itholakala ekwakhiweni kwe-acidic ye-flux.I-Gunn59 ibonise umthelela we-nickel alloys ekuthuthukiseni izakhiwo zemishini zamajoyinti ashiselwe kanye nokulawula ukulingana kwesigaba nokusatshalaliswa kwezakhi.Lokhu futhi kuqinisekisa iqiniso lokuthi ama-electrode enziwe kusukela ekuqanjweni okuyisisekelo okuguquguqukayo anezakhiwo ezingcono zemishini kunama-electrode enziwe ngezingxube ze-acidic flux, njengoba kuphakanyiswe u-Bang et al.60.Ngakho-ke, kuye kwaba negalelo elibalulekile olwazini olukhona mayelana nezakhiwo zejoyinti elishiselwe le-electrode entsha ehlanganisiwe (E1) enezakhiwo ezinhle zokudonsa.
Emkhiwaneni.Izibalo 4a kanye ne-4b zibonisa izici ze-Vickers microhardness zamasampula okuhlola amalunga ashiselwe ama-electrode E1, E2 kanye no-C. 4a abonisa imiphumela yobulukhuni etholwe ohlangothini olulodwa lwesampula (kusuka ku-WZ kuya ku-BM), kanye nakumfanekiso.I-4b ibonisa imiphumela yokuqina etholwe nhlangothi zombili zesampula.Amanani okuqina atholwe ngesikhathi sokushiselwa kwamasampula Nos.Ukwanda okubukhali kokuqina kwabonwa kokubili ku-HAZ enohlamvu oluqinile kanye ne-HAZ ehlanjululwe kahle yawo wonke amasampula Nos. i-weld ngenxa yamasampula e-chromium-weld inothile ngokukhipha (Cr23C6) .Uma kuqhathaniswa namanye amasampula we-welding 2, 3, 4 kanye no-5, amanani obulukhuni bamalunga ashiselwe amasampula No. 6 no-7 ku-Fig.4a kanye no-4b ngenhla (Ithebula 2).Ngokuka-Mohammed et al.61 kanye noNowacki kanye no-Lukoje62, lokhu kungase kubangelwe yenani eliphezulu le-ferrite δ kanye nezingcindezi ezisalelayo ezibangelwa ukushisela, kanye nokuncipha kwezakhi ze-alloying ezifana no-Mo no-Cr ekushiseleni.Amanani okuqina awo wonke amasampula athathwa njengokuhlola endaweni ye-BM abonakala engaguquguquki.Umkhuba emiphumeleni yokuhlaziywa kokuqina kwezibonelo ezishiselwe uhambisana neziphetho zabanye abacwaningi61,63,64.
Amanani okuqina amajoyinti ashiselwe wezibonelo ze-DSS (a) ingxenye yengxenye yezifanekiso ezishiselwe kanye (b) nengxenye egcwele yamajoyinti ashiselwe.
Izigaba ezihlukahlukene ezikhona ku-DSS 2205 eshiselwe ene-electrode E1, E2 kanye no-C zatholwa kanye ne-spectra ye-XRD ye-engeli ye-diffraction 2\(\theta\) iboniswa ku-Fig. 5. Iziqongo ze-austenite (\(\gamma\) ) kanye nezigaba ze-ferrite (\(\alpha\)) zihlonzwe kuma-engeli e-diffraction angu-43° no-44°, okuqinisekisa ngokuphelele ukuthi ukwakheka kokushisela kuyinsimbi engagqwali yezigaba ezimbili ezingama-65.ukuthi i-DSS BM ikhombisa kuphela izigaba ze-austenitic (\(\gamma\)) ne-ferritic (\(\alpha\)), eqinisekisa imiphumela ye-microstructural eyethulwa kuMfanekiso 1 no-2. 6c, 7c kanye no-9c.Isigaba se-ferritic (\(\alpha\)) esibonwa nge-DSS BM kanye nenani eliphakeme ku-weld kuya ku-electrode C kukhombisa ukumelana nokugqwala, njengoba lesi sigaba sihlose ukukhulisa ukumelana nokugqwala kwensimbi, njengoba u-Davison no-Redmond66 benzile. kushiwo , ukuba khona kwezinto eziqinisa i-ferrite, njenge-Cr ne-Mo, kuzinzisa ngempumelelo ifilimu ye- passive ye-material ezindaweni ezine-chloride.Ithebula lesi-5 libonisa isigaba se-ferrite-austenitic nge-quantitative metallography.Isilinganiso sengxenye yevolumu yesigaba se-ferrite-austenitic emajoyini ashiselwe we-electrode C sifinyelelwa cishe (≈1:1).Ukubunjwa kwesigaba se-ferrite ephansi (\(\ alpha\)) sokushisela kusetshenziswa ama-electrode e-E1 ne-E2 emiphumeleni yengxenyana yevolumu (Ithebula 5) ibonisa ukuzwela okungenzeka endaweni eyonakalisayo, okuqinisekiswe ukuhlaziywa kwe-electrochemical.kuqinisekisiwe (Fig. 10a,b)), njengoba isigaba se-ferrite sinikeza amandla aphezulu nokuvikelwa ekuqhekekeni kokugqwala kokucindezeleka okubangelwa i-chloride.Lokhu kuqinisekiswa futhi amanani okuqina aphansi abonwa kuma-welds ama-electrode E1 no-E2 emkhiwaneni.4a,b, ezibangelwa ingxenye ephansi ye-ferrite esakhiweni sensimbi (Ithebula 5).Ukuba khona kwezigaba ze-austenitic ezingalingani (\(\gamma\)) kanye ne-ferritic (\(\alpha\)) emajoyini ashiselwe kusetshenziswa ama-electrode e-E2 kubonisa ukuba sengozini kwangempela kwensimbi ekuhlaselweni kokugqwala okufanayo.Ngokuphambene nalokho, i-XPA spectra yezinsimbi zezigaba ezimbili zamajoyinti ashiselwe anama-electrode e-E1 no-C, kanye nemiphumela ye-BM, imvamisa ikhombisa ubukhona bezakhi zokuzinzisa i-austenitic kanye ne-ferritic, okwenza izinto zibe wusizo ekwakheni nasembonini ye-petrochemical. , ngoba waphikisana noJimenez et al.65;Davidson & Redmond66;UShamant nabanye67.
Ama-micrographs abonakalayo wamajoyinti ashiselwe ama-electrodes e-E1 anamajiometri e-weld ahlukene: (a) I-HAZ ebonisa umugqa wokuhlanganisa, (b) i-HAZ ebonisa umugqa wokuhlanganisa ekukhulisweni okuphezulu, (c) I-BM yesigaba se-ferritic-austenitic, (d) i-weld geometry , (e) Ibonisa indawo yoshintsho eseduze, (f) I-HAZ ibonisa isigaba se-ferritic-austenitic ekukhuliseni okuphezulu, (g) Indawo yokushisela ibonisa isigaba se-ferritic-austenitic Tensile.
Ama-micrographs okubonayo we-E2 electrode welds kuma-weld geometries ahlukahlukene: (a) I-HAZ ebonisa umugqa wokuhlanganisa, (b) i-HAZ ebonisa umugqa wokuhlanganisa ekukhulisweni okuphezulu, (c) i-BM yesigaba se-ferritic-austenitic bulk, (d) i-weld geometry , (e) ) ebonisa indawo yoguquko endaweni, (f) I-HAZ ebonisa isigaba se-ferritic-austenitic ekukhuliseni okuphezulu, (g) indawo yokushisela ebonisa isigaba se-ferritic-austenitic.
Izibalo 6a–c futhi, isibonelo, zibonisa ukwakheka kwe-metallographic yamajoyinti e-DSS ashiselwe kusetshenziswa i-electrode ye-E1 kumajiyometri wokushisela ahlukahlukene (Umfanekiso 6d), okubonisa lapho ama-micrographs okukhanya athathwe khona ngokukhuliswa okuhlukene.Emkhiwaneni.I-6a, b, f - izindawo zokushintsha zamalunga ashiselwe, abonisa isakhiwo sokulingana kwesigaba se-ferrite-austenite.Izibalo 7a-c kanye nesibonelo ziphinde zibonise i-OM yejoyinti le-DSS elishiselwe kusetshenziswa i-electrode ye-E2 kumajiyometri wokushisela ahlukahlukene (Umfanekiso 7d), omele amaphuzu okuhlaziya we-OM ekukhulisweni okuhlukene.Emkhiwaneni.7a,b,f khombisa indawo yenguquko yejoyinti elishiselwe ekulinganisweni kwe-ferritic-austenitic.I-OM endaweni yokushisela (WZ) iboniswa kumfanekiso.1 kanye fig.2. Ama-welds ama-electrode E1 no-E2 6g no-7g, ngokulandelana.I-OM ku-BM iboniswa kuMfanekiso 1 no-2. Kumfanekiso.I-6c, i-e kanye ne-7c, i-e ibonisa icala lamajoyini ashiselwe ngama-electrode E1 no-E2, ngokulandelana.Indawo yokukhanya yisigaba se-austenite futhi indawo emnyama emnyama yisigaba se-ferrite.Ukulingana kwesigaba endaweni ethinteke ekushiseni (HAZ) eduze komugqa wokuhlanganisa kubonise ukwakheka kwezimvula ze-Cr2N, njengoba kuboniswe kuma-micrographs we-SEM-BSE kumaFig.8a,b futhi iqinisekiswa kumkhiwane.9a,b.Ukuba khona kwe-Cr2N okuphawulwe esigabeni se-ferrite samasampuli ku-Fig.I-8a,b futhi iqinisekiswe ukuhlaziya kwephuzu le-SEM-EMF kanye nemidwebo yemigqa ye-EMF yezingxenye ezishiselwe (Fig. 9a-b), kungenxa yokushisa okuphezulu kokushisela.Ukujikeleza kusheshisa ukwethulwa kwe-chromium ne-nitrogen, njengoba izinga lokushisa eliphezulu endaweni yokushisela linyusa i-coefficient yokusabalalisa i-nitrogen.Le miphumela isekela izifundo zika-Ramirez et al.68 kanye no-Herenyu et al.69 ezibonisa ukuthi, kungakhathaliseki okuqukethwe kwe-nitrogen, i-Cr2N ivamise ukufakwa kuzinhlamvu ze-ferrite, imingcele yokusanhlamvu, kanye nemingcele ye-α/\(\gamma\), njengoba kuphakanyiswe futhi abanye abacwaningi.70.71.
(a) indawo yokuhlaziywa kwe-SEM-EMF (1, 2 kanye no-3) yejoyinti elishiselwe nge-E2;
I-surface morphology yamasampula amele kanye nama-EMF awo ahambisanayo aboniswa ku-Fig.10a–c.Emkhiwaneni.Izibalo 10a kanye ne-10b zibonisa ama-micrographs e-SEM kanye ne-spectra yawo ye-EMF yamajoyinti ashiselwe kusetshenziswa ama-electrodes E1 no-E2 endaweni yokushisela, ngokulandelana, kanye nakufig.I-10c ibonisa ama-micrographs e-SEM kanye ne-EMF spectra ye-OM equkethe i-austenite (\(\gamma\)) nezigaba ze-ferrite (\(\alpha\)) ngaphandle kwanoma yiziphi izimvula.Njengoba kuboniswe ku-spectrum ye-EDS ku-Fig. 10a, iphesenti le-Cr (21.69 wt.%) ne-Mo (2.65 wt.%) uma kuqhathaniswa ne-6.25 wt.% I-Ni inikeza umuzwa webhalansi ehambisanayo yesigaba se-ferrite-austenitic.Isakhiwo esincane esinokwehliswa okuphezulu kokuqukethwe kwe-chromium (15.97 wt.%) ne-molybdenum (1.06 wt.%) uma kuqhathaniswa nokuqukethwe okuphezulu kwe-nickel (10.08 wt.%) esakhiweni esincane sejoyinti elishiselwe le-electrode E2, eboniswe ku- umkhiwane.1. Qhathanisa.I-spectrum ye-EMF 10b.Umumo oyi-acicular onesakhiwo se-austenitic esicwengekile esibonwa ku-WZ eboniswe kufig.I-10b iqinisekisa ukuncipha okungenzeka kwezinto zokufaka umanyolo (i-Cr ne-Mo) ekushiseleni kanye nemvula ye-chromium nitride (Cr2N) - isigaba se-austenitic.Ukusatshalaliswa kwezinhlayiya zemvula eduze kwemingcele yezigaba ze-austenitic (\(\gamma\)) kanye ne-ferritic (\(\alpha\)) yamajoyini ashiselwe e-DSS kuqinisekisa lesi sitatimende72,73,74.Lokhu kuphinde kubangele ukusebenza kwayo kabi kokugqwala, njengoba i-Cr ibhekwa njengento eyinhloko yokwenza ifilimu engenzi lutho ethuthukisa ukumelana nokugqwala kwendawo kwensimbi59,75 njengoba kuboniswe ku-Fig. 10b.Kungabonakala ukuthi i-BM ku-SEM micrograph ku-Fig. 10c ibonisa ukuthuthukiswa okuqinile okusanhlamvu njengoba imiphumela ye-spectrum ye-EDS ibonisa i-Cr (23.32 wt%), i-Mo (3.33 wt%) ne-Ni (6.32 wt).%) izakhiwo zamakhemikhali ezinhle.%) njengento ebalulekile ye-alloying yokuhlola ukulingana kwe-microstructure yesigaba se-ferrite-austenitic sesakhiwo se-DSS76.Imiphumela yokuhlaziywa kwe-spectroscopic ye-EMF ye-spectroscopic yamalunga ashiselwe e-electrode ye-E1 ifakazela ukusetshenziswa kwayo ekwakhiweni nasezindaweni ezinolaka, njengoba ama-austenite formers nama-ferrite stabilizers ku-microstructure ahambisana nezinga le-DSS AISI 220541.72 lamalunga ashiselwe, 77.
I-SEM micrographs yamajoyinti ashiselwe, lapho (a) i-electrode E1 yendawo yokushisela ine-spectrum ye-EMF, (b) i-electrode E2 yendawo yokushisela ine-spectrum ye-EMF, (c) i-OM ine-spectrum ye-EMF.
Empeleni, kuqashelwe ukuthi amashisela e-DSS aqina kumodi ye-ferritic (F-mode), ene-austenite nuclei nucleating ngaphansi kwezinga lokushisa le-ferritic solvus, elincike kakhulu esilinganisweni esilinganayo se-chromium kuya ku-nickel (Creq/Nieq) (> I-1.95 ihlanganisa imodi F) Abanye abacwaningi baqaphele lo mphumela wensimbi ngenxa yekhono eliqinile lokusabalalisa lika-Cr no-Mo njengama-elementi e-ferrite-forming esigabeni se-ferrite8078,79.Kuyacaca ukuthi i-DSS 2205 BM iqukethe inani eliphezulu le-Cr ne-Mo (ebonisa i-Creq ephakeme), kodwa inokuqukethwe kwe-Ni ephansi kune-weld ene-E1, E2 kanye ne-C electrode, efaka isandla esilinganisweni esiphezulu se-Creq/Nieq.Lokhu kubonakala futhi ocwaningweni lwamanje, njengoba kuboniswe kuThebula 4, lapho isilinganiso se-Creq/Nieq sanqunywa ku-DSS 2205 BM ngaphezu kuka-1.95.Kungabonakala ukuthi ama-welds ane-electrode E1, E2 no-C aqina kumodi ye-austenitic-ferritic (imodi ye-AF), imodi ye-austenitic (imodi ye-A) kanye nemodi ye-ferritic-austenitic, ngokulandelana, ngenxa yokuqukethwe okuphezulu kwemodi yobuningi (imodi ye-FA) .), njengoba kuboniswe kuThebula 4, okuqukethwe kuka-Ni, Cr no-Mo ekushiseleni kuncane, okubonisa ukuthi isilinganiso se-Creq/Nieq siphansi kunesika-BM.I-ferrite eyinhloko ekushiseleleni ama-electrode e-E2 yayine-vermicular ferrite morphology futhi isilinganiso esinqunyiwe se-Creq/Nieq sasingu-1.20 njengoba kuchazwe kuThebula 4.
Emkhiwaneni.I-11a ibonisa i-Open Circuit Potential (OCP) ngokumelene nesikhathi se-AISI DSS 2205 isakhiwo sensimbi kusixazululo se-3.5% se-NaCl.Kungabonakala ukuthi ijika le-ORP liyashintsha liye endaweni enhle kakhulu, ebonisa ukubukeka kwefilimu yokwenziwa ebusweni besampula yensimbi, ukwehla kwamandla kubonisa ukugqwala okujwayelekile, kanye namandla acishe abe njalo ngokuhamba kwesikhathi akhombisa ukwakheka kwe ifilimu yokwenziwa ngokuhamba kwesikhathi., Ingaphezulu lesampula lizinzile futhi line-Sticky 77. Amajika abonisa ama-substrates okuhlola ngaphansi kwezimo ezizinzile zawo wonke amasampuli ku-electrolyte equkethe isixazululo se-NaCl esingu-3.5%, ngaphandle kwesampula 7 (inhlanganisela ye-weld ene-C-electrode), okukhombisa ukungazinzi okuncane.Lokhu kungazinzi kungafaniswa nokuba khona kwe-chloride ion (Cl-) kusixazululo, okungasheshisa kakhulu ukusabela kokugqwala, ngaleyo ndlela kwandise izinga lokugqwala.Ukubuka ngesikhathi sokuskena kwe-OCP ngaphandle kwamandla asetshenzisiwe kubonise ukuthi i-Cl ekuphenduleni ingathinta ukumelana nokuzinza kwe-thermodynamic kwamasampuli ezindaweni ezinolaka.UMa et al.81 kanye noLotho et al.5 ukuqinisekisile isimangalo sokuthi u-Cl- udlala indima ekusheshiseni ukucekelwa phansi kwamafilimu angenzi lutho kuma-substrate, ngaleyo ndlela kube nesandla ekuguge nakakhulu.
Ukuhlaziywa kwe-Electrochemical kwamasampuli ahlolisisiwe: (a) ukuvela kwe-RSD kuye ngesikhathi kanye (b) ne-potentiodynamic polarization yamasampuli kusixazululo se-3.5% se-NaCl.
Emkhiwaneni.I-11b iveza ukuhlaziywa okuqhathanisayo kwe-potentiodynamic polarization curves (PPC) yamajoyini ashiselwe ama-electrode E1, E2 no-C ngaphansi kwethonya lesisombululo se-3.5% se-NaCl.Amasampula e-BM ashiselwe ku-PPC kanye nesixazululo se-NaCl esingu-3.5% abonise ukuziphatha kokungenzi lutho.Ithebula lesi-5 libonisa imingcele yokuhlaziywa kwe-electrochemical yamasampuli atholwe kumajika e-PPC, njenge-Ecorr (amandla okugqwala) kanye ne-Epit (amandla okugqwala kwe-pitting) kanye nokuchezuka okuhambisana nawo.Uma kuqhathaniswa namanye amasampula No. 2 kanye No. ).Izakhiwo eziphakeme ezidlulayo zangaphambili uma kuqhathaniswa nalokhu zakamuva zibangelwa ibhalansi yokwakheka kwe-microstructural yensimbi (izigaba ze-austenitic kanye ne-ferritic) kanye nokugxila kwezakhi ze-alloying.Ngenxa yobukhona bezigaba ze-ferrite ne-austenitic ku-microstructure, u-Resendea et al.82 isekele ukuziphatha kwe-DSS kwemidiya ehlukumezayo.Ukusebenza okuphansi kwamasampula ashiselwe ngama-electrode e-E1 kanye ne-E2 kungahlotshaniswa nokuncipha kwezakhi eziyinhloko ze-alloying, njenge-Cr ne-Mo, endaweni yokushisela (WZ), njengoba zinzisa isigaba se-ferrite (Cr no-Mo), zenza njenge ama-passivators Ama-alloys esigabeni se-austenitic sezinsimbi ezinama-oxidized.Umthelela walezi zakhi ekumelaneni komgodi mkhulu esigabeni se-austenitic kunesigaba se-ferritic.Ngenxa yalesi sizathu, isigaba se-ferritic sidlula ngokushesha kunesigaba se-austenitic esihlotshaniswa nesifunda sokuqala sokudlula se-polarization curve.Lezi zakhi zinomthelela omkhulu ekuphikisweni kwe-DSS pitting ngenxa yokumelana kwazo okuphezulu kwe-pitting esigabeni se-austenitic uma kuqhathaniswa nesigaba se-ferritic.Ngakho-ke, ukudlula okusheshayo kwesigaba se-ferrite kuphakeme ngama-81% kunesigaba se-austenite.Nakuba isixazululo se-Cl-in sinomthelela omubi onamandla ekhonweni lokudlula lefilimu yensimbi83.Ngenxa yalokho, ukuzinza kwefilimu edlulayo yesampula kuzoncipha kakhulu84.Kusukela kuThebula.I-6 iphinde ibonise ukuthi amandla okugqwala (Ecorr) amajoyinti ashiselwe nge-E1 electrode ayizinzile kancane esixazululweni uma kuqhathaniswa namajoyinti ashiselwe ane-E2 electrode.Lokhu kuqinisekiswa namanani aphansi wokuqina kwama-welds usebenzisa ama-electrode E1 no-E2 emkhiwaneni.4a,b, okubangelwa okuqukethwe okuphansi kwe-ferrite (Ithebula 5) kanye nokuqukethwe okuphansi kwe-chromium ne-molybdenum (Ithebula 4) esakhiweni sensimbi esenziwe.Kungaphethwa ngokuthi ukumelana nokugqwala kwezinsimbi endaweni elungisiwe yasolwandle kukhuphuka ngokuncipha kwamandla okushisela futhi kuncipha ngokuqukethwe okuphansi kwe-Cr ne-Mo nokuqukethwe kwe-ferrite ephansi.Lesi sitatimende sihambisana nocwaningo lukaSalim et al.85 ngomphumela wemingcele yokushisela efana ne-welding current ekuqineni kokugqwala kwezinsimbi ezishiselwe.Njengoba i-chloride ingena ensimbi ngezindlela ezihlukahlukene njengokumuncwa kwe-capillary nokusabalalisa, kwakheka imigodi (i-pitting corrosion) yokwakheka nokujula okungalingani.Umshini uhluke kakhulu ezixazululweni ze-pH eziphakeme lapho amaqembu azungezile (OH-) avele akhangwe endaweni yensimbi, azinzise ifilimu engenzi lutho futhi anikeze ukuvikeleka okwengeziwe endaweni yensimbi25,86.Ukumelana nokugqwala okungcono kakhulu kwamasampula No. 1 kanye No. 7 kubangelwa ikakhulukazi ukuba khona esakhiweni sensimbi senani elikhulu le-δ-ferrite (Ithebula 5) kanye nenani elikhulu le-Cr ne-Mo (Ithebula 4), kusukela izinga lokugqwala kwe-pitting likhona ikakhulukazi ensimbi, eshiselwe indlela ye-DSS, esakhiweni sesigaba se-austenitic sezingxenye.Ngakho-ke, ukwakheka kwamakhemikhali we-alloy kudlala indima ebalulekile ekusebenzeni kokugqwala kwe-joint eshiselwe87,88.Ngaphezu kwalokho, kwaqashelwa ukuthi ama-specimens ashiselwe kusetshenziswa ama-electrode e-E1 no-C kulolu cwaningo abonise amanani aphansi e-Ecorr asuka kumajika e-PPC kunalawo ashiselwe kusetshenziswa i-E2 electrode evela kumajika e-OCP (Ithebula 5).Ngakho-ke, isifunda se-anode siqala ngamandla aphansi.Lolu shintsho lubangelwa ikakhulukazi ukuzinza kwengxenye yongqimba lwe-passivation olwakhiwe phezu kwesampula kanye ne-cathodic polarization eyenzeka ngaphambi kokuba kuzuzwe ukuzinza okuphelele kwe-OCP89.Emkhiwaneni.I-12a kanye ne-b ibonisa izithombe zephrofayili ye-3D ye-optical profiler yezibonelo ezigqwalile ezivivinywa ngaphansi kwezimo ezihlukahlukene zokushisela.Kuyabonakala ukuthi usayizi we-pitting corrosion we-specimens ukhuphuka ngamandla aphansi okugqwala kwe-pitting adalwe amandla okushisela aphezulu angu-110 A (Fig. 12b), uma kuqhathaniswa nosayizi we-pitting corrosion otholakala kuma-welds anenani eliphansi le-welding yamanje 90 A. (Fig. 12a).Lokhu kuqinisekisa isimangalo sika-Mohammed90 sokuthi ama-slip bands akhiwa ebusweni besampula ukuze abhubhise ifilimu ye-surface passivation ngokuveza i-substrate kusixazululo se-NaCl esingu-3.5% ukuze i-chloride iqale ukuhlasela, ibangele ukuthi izinto zihlakazeke.
Ukuhlaziywa kwe-SEM-EDS kuThebula 4 kubonisa ukuthi amanani e-PREN esigaba ngasinye se-austenitic aphezulu kunalawo e-ferrite kuwo wonke ama-welds kanye ne-BM.Ukuqaliswa komgodi kusixhumi esibonakalayo se-ferrite/austenite kusheshisa ukucekelwa phansi kwesendlalelo sezinto ezingashintshi ngenxa yokungahlangani nokuhlukaniswa kwezinto ezenzeka kulezi zindawo91.Ngokungafani nesigaba se-austenitic, lapho inani lokumelana ne-pitting elilingana (PRE) liphakeme, ukuqaliswa komgodi esigabeni se-ferritic kungenxa yenani eliphansi le-PRE (Ithebula 4).Isigaba se-austenite sibonakala siqukethe inani elikhulu le-austenite stabilizer (i-nitrogen solubility), ehlinzeka ngokugxila okuphezulu kwalesi sakhi futhi, ngakho-ke, ukumelana okuphezulu kwe-pitting92.
Emkhiwaneni.Umfanekiso we-13 ubonisa amajika okushisa e-pitting abalulekile e-E1, E2, ne-C welds.Uma kubhekwa ukuthi ukuminyana kwamanje kukhuphuke kwaba ngu-100 µA/cm2 ngenxa yokugoba ngesikhathi sokuhlolwa kwe-ASTM, kuyacaca ukuthi i-@110A weld ene-E1 ibonise izinga lokushisa elincane lokubeka elibalulekile elingu-27.5°C elilandelwa yi-E2 @ 90A soldering libonisa i-CPT engu-40 °C, futhi esimweni se-C@110A i-CPT ephakeme kakhulu ingu-41°C.Imiphumela ebhekiwe ivumelana kahle nemiphumela ebhekiwe yokuhlolwa kwe-polarization.
Izakhiwo zemishini nokuziphatha kokugqwala kokushisela insimbi engagqwali eyi-duplex kwaphenywa kusetshenziswa ama-electrode e-E1 ne-E2 amasha.I-alkaline electrode (E1) kanye ne-acidic electrode (E2) esetshenziswe kunqubo ye-SMAW zimbozwe ngempumelelo ngokubunjwa kwe-flux enenani eliphelele lokumboza elingu-1.7 mm kanye nenkomba ye-alkaline engu-2.40 no-0.40, ngokulandelana.Ukuzinza okushisayo kokuguquguquka okulungiselelwe kusetshenziswa i-TGA endaweni engasebenzi kuhlolisisiwe.Ukuba khona kokuqukethwe okuphezulu kwe-TiO2 (%) ku-matrix ye-flux kuthuthukisa ukukhishwa kwe-slag kwama-weldments ama-electrode ahlanganiswe ne-acidic flux (E2) uma kuqhathaniswa nama-electrode ahlanganiswe ne-basic flux (E1).Nakuba ama-electrode amabili ahlanganisiwe (E1 no-E2) anekhono elihle lokuqalisa i-arc.Izimo zokushisela, ikakhulukazi okokufaka ukushisa, ukushisela okwamanje kanye nesivinini, zidlala indima ebalulekile ekuzuzeni ibhalansi yesigaba se-austenite/ferrite ye-DSS 2205 welds kanye nezakhiwo ezinhle kakhulu zemishini ye-weld.Amajoyinti ashiselwe nge-electrode ye-E1 abonise izinto ezinhle kakhulu eziqinile (shear 0.2% YS = 497 MPa kanye ne-UTS = 732 MPa), eqinisekisa ukuthi ama-electrode ayisisekelo ahlanganisiwe ane-basicity ephezulu uma kuqhathaniswa nama-electrode ane-acid flux camera.Ama-Electrode abonisa izakhiwo ezingcono zemishini ezine-alkalinity ephansi.Kusobala ukuthi emalungeni ashiselwe ama-electrodes ane-coating entsha (E1 ne-E2) akukho ukulingana kwesigaba se-ferrite-austenitic, esivezwe kusetshenziswa ukuhlaziya kwe-OES kanye ne-SEM-EDS ye-weld futhi kubalwe ngengxenye yevolumu i-weld.I-Metallography iqinisekise ucwaningo lwabo lwe-SEM.microstructures.Lokhu ikakhulukazi ngenxa yokuncipha kwezakhi ze-alloying ezifana ne-Cr ne-Mo kanye nokukhululwa okungenzeka kwe-Cr2N ngesikhathi sokushisela, okuqinisekiswa ukuskena komugqa we-EDS.Lokhu kusekelwa futhi amanani okuqina aphansi aqashelwa kuma-welds ane-E1 ne-E2 electrode ngenxa yengxenye yawo ephansi ye-ferrite kanye nezakhi ze-alloying esakhiweni sensimbi.I-Evidence Corrosion Potential (Ecorr) yamashisela asebenzisa i-electrode ye-E1 ibonakale ingamelani nokugqwala kwesixazululo uma iqhathaniswa namashisela kusetshenziswa i-E2 electrode.Lokhu kuqinisekisa ukusebenza kahle kwama-electrode asanda kuthuthukiswa kuma-welds ahlolwe endaweni engu-3.5% ye-NaCl ngaphandle kokwakheka kwengxube yengxube ye-flux.Kungaphethwa ngokuthi ukumelana nokugqwala endaweni efanisiwe yasolwandle kuyanda ngokuncipha kwamandla okushisela.Ngakho-ke, imvula yama-carbides nama-nitrides kanye nokwehla okwalandela ekumelaneni nokugqwala kwamalunga ashiselwe kusetshenziswa ama-electrode e-E1 ne-E2 kwachazwa ukwanda kwamandla okushisela, okuholele ekungalinganini kwebhalansi yesigaba samajoyinti ashiselwe kusukela ezinsimbi ezinezinjongo ezimbili.
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