I-Kanthal AF alloy 837 resistohm alchrome Y fecral alloy

I-Kanthal AF iyingxube ye-ferritic iron-chromium-aluminium alloy (FeCrAl alloy) ukuze isetshenziswe emazingeni okushisa afika ku-1300°C (2370°F).Ingxubevange ibonakala ngokumelana ne-oxidation okuhle kakhulu kanye nokuzinza kwefomu okuhle kakhulu okuholela empilweni ende yezinto.

I-Kan-thal AF ivamise ukusetshenziswa ezintweni zokushisisa ugesi eziko ezimbonini nasezintweni zikagesi zasendlini.

Isibonelo sezinhlelo zokusebenza embonini yezinto zikagesi zisezicini ezivulekile ze-mica zama-toaster, okomisa izinwele, ezintweni ezimise okwe-mender yezifudumezi zabalandeli nanjengama-elementi ekhoyili avulekile ku-fiber insulating material kumahitha angaphezulu engilazi e-ceramic ngobubanzi, kuma-heaters e-ceramic amapuleti abilayo, amakhoyili. ku-ceramic fibre ebunjiwe yokupheka amapuleti anezinsimbi ze-ceramic, ezintweni zekhoyili ezimisiwe zezifudumezi zabalandeli, ezintweni zocingo eziqondile ezimisiwe zama-radiator, izifudumezi eziguquguqukayo, ezintweni ezinongungumbane zezibhamu zomoya oshisayo, ama-radiators, okomisa ama-tumble.

I-Abstract Ocwaningweni lwamanje, indlela yokugqwala ye-FeCrAl alloy yokuhweba (Kanthal AF) ngesikhathi sokudonsa kugesi ye-nitrogen (4.6) ku-900 °C kanye ne-1200 °C ichaziwe.Ukuhlolwa kwe-Isothermal kanye ne-thermo-cyclic enezikhathi zokuchayeka eziphelele, amazinga okushisa, namazinga okushisa okubamba amanzi kwenziwa.Ukuhlolwa kwe-oxidation emoyeni negesi ye-nitrogen kwenziwa ngokuhlaziywa kwe-thermogravimetric.I-microstructure ibonakala ngokuskena i-electron microscopy (SEM-EDX), i-Auger electron spectroscopy (AES), nokuhlaziywa kwe-ion beam (FIB-EDX) egxilile.Imiphumela ibonisa ukuthi ukuqhubeka kokugqwala kwenzeka ngokwakhiwa kwezifunda ze-nitridation zasendaweni ezingaphansi komhlaba, ezakhiwe yizinhlayiya zesigaba se-AlN, okunciphisa umsebenzi we-aluminium futhi kubangele i-embrittlement kanye ne-spallation.Izinqubo zokubunjwa kwe-Al-nitride kanye nokukhula kwesikali se-Al-oxide zincike ekushiseni kwe-anneal kanye nezinga lokushisa.Kutholakale ukuthi i-nitridation ye-FeCrAl alloy iyinqubo esheshayo kunokukhipha i-oxidation ngesikhathi sokudonsa kugesi ye-nitrogen enomfutho ophansi womoya-mpilo oyingxenye futhi imele imbangela eyinhloko yokuwohloka kwe-alloy.

Isingeniso I-FeCrAl – ama-alloys asekelwe (Kanthal AF ®) aziwa kakhulu ngokumelana kwawo ne-oxidation ephakeme emazingeni okushisa aphakeme.Lesi sakhiwo esihle kakhulu sihlobene nokwakhiwa kwesikali se-alumina esizinzile se-thermodynamically ngaphezulu, esivikela izinto ezisetshenziswayo ekuqhubekeleni phambili kwe-oxidation [1].Naphezu kwezakhiwo eziphakeme zokumelana nokugqwala, isikhathi sokuphila sezingxenye ezikhiqizwe kusuka ku-FeCrAl - ama-alloys asekelwe singakhawulwa uma izingxenye zivamise ukuchayeka ekubhayisikilini okushisayo emazingeni okushisa aphakeme [2].Esinye sezizathu zalokhu ukuthi i-elementi eyenza isikali, i-aluminium, isetshenziswa ku-matrix yealloy endaweni engaphansi komhlaba ngenxa yokuqhekeka okuphindaphindiwe kwe-thermo-shock kanye nokuguqulwa kwesikali se-alumina.Uma okuqukethwe kwe-aluminium okusele kuncipha ngaphansi kokugxiliswa okubucayi, ingxubevange ngeke isakwazi ukuguqula isikali sokuzivikela, okuholela ekuqhekekeni kwe-oxidation eyingozi ngokwakhiwa kwama-oxide asekelwe ensimbi akhula ngokushesha kanye ne-chromium [3,4].Ngokuya ngomkhathi ozungezile kanye nokungeneka kwama-oxide angaphezulu lokhu kungenza kube lula ukuqhubekela phambili kwe-oxidation yangaphakathi noma i-nitridation kanye nokwakheka kwezigaba ezingafuneki endaweni engaphansi komhlaba [5].U-Han no-Young babonise ukuthi esikalini se-alumina esakha ama-alloys e-Ni Cr Al, iphethini eyinkimbinkimbi ye-oxidation yangaphakathi kanye ne-nitridation iqala [6,7] ngesikhathi sokuhamba ngebhayisikili emazingeni okushisa aphakeme emkhathini womoya, ikakhulukazi kuma-alloys aqukethe ama-nitride aqinile afana ne-Al. kanye noTi [4].Izikali ze-Chromium oxide zaziwa njenge-nitrogen evunyelekayo, futhi i-Cr2 N yakha njengesendlalelo sesikali esingaphansi noma njengemvula yangaphakathi [8,9].Lo mphumela ungalindelwa ukuthi ube nzima kakhulu ngaphansi kwezimo zamabhayisikili ezishisayo okuholela ekuqhekekeni kwesikali se-oxide futhi kunciphise ukusebenza kwawo njengesithiyo ku-nitrogen [6].Ngakho-ke ukuziphatha kokugqwala kubuswa ukuncintisana phakathi kwe-oxidation, okuholela ekwakhekeni/ukugcinwa kwe-alumina evikelayo, kanye nokungena kwe-nitrogen okuholela ku-nitridation yangaphakathi ye-alloy matrix ngokwakhiwa kwesigaba se-AlN [6,10], okuholela ekusakazweni kwe-alumina. leso sifunda ngenxa yokwanda okushisayo kwesigaba se-AlN uma kuqhathaniswa ne-alloy matrix [9].Lapho kuvezwa ama-alloys e-FeCrAl emazingeni okushisa aphezulu emkhathini anomoya-mpilo noma abanye abanikeli komoya-mpilo njenge-H2O noma i-CO2, i-oxidation iwukusabela okubusayo, kanye namafomu esikali se-alumina, angangenwa umoya-mpilo noma i-nitrogen emazingeni okushisa aphakeme futhi anikeze isivikelo ekungeneni kwawo endaweni. ingxubevange matrix.Kodwa, uma kuvezwe emkhathini wokunciphisa (N2+H2), kanye nokuqhekeka kwesikali se-alumina esivikelayo, i-oxidation yendawo ehlukanayo iqala ngokwakheka kwama-oxide angavikeli e-Cr kanye ne-Ferich, ahlinzeka ngendlela evumayo yokusakazwa kwe-nitrogen ku-matrix ye-ferritic kanye nokwakheka. yesigaba se-AlN [9].Umkhathi we-nitrogen ovikelayo (4.6) uvame ukusetshenziswa ekusetshenzisweni kwezimboni zama-alloys e-FeCrAl.Isibonelo, izifudumezi ezingazweli ezithandweni zokushisa ezinomoya we-nitrogen ovikelayo ziyisibonelo sokusetshenziswa okusabalele kwama-alloys e-FeCrAl endaweni enjalo.Ababhali babika ukuthi izinga le-oxidation lama-alloys e-FeCrAlY lihamba kancane kakhulu lapho lidonsa emkhathini onezingcindezi zengxenye ye-oxygen ephansi [11].Inhloso yocwaningo bekuwukuthola ukuthi ukudonsa ku-(99.996%) yegesi ye-nitrogen (4.6) (i-Messer® spec. ileveli yokungcola i-O2 + H2O <10 ppm) kuthinta ukumelana nokugqwala kwe-FeCrAl alloy (Kanthal AF) nokuthi kuncike kangakanani. kumazinga okushisa e-annealing, ukuhluka kwawo (i-thermal-cycling), nezinga lokushisa.