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 zitholakala kuma-mica avulekile ama-toaster, okomisa izinwele, ezintweni ezimise okwe-mender yezifudumezi zabalandeli nanjengezinto zekhoyili ezivulekile ku-fiber insulating material kuma-heaters aphezulu engilazini ye-ceramic ngobubanzi, kuma-heaters e-ceramic amapuleti abilayo, amakhoyili ku-ceramic fiber okupheka amapuleti anezinsimbi ze-ceramic, kuma-coil amisiwe ama-radiator alengayo, izakhi ze-coil ezilengayo kuma-radiator. izakhi ze-porcupine zezibhamu zomoya oshisayo, ama-radiator, ama-tumbled dryers.

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 phezulu, 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 no-Al no-Ti [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 kulawulwa ukuncintisana phakathi kwe-oxidation, okuholela ekwakhekeni kwe-alumina evikelayo / ukugcinwa, kanye nokungena kwe-nitrogen okuholela ku-nitridation yangaphakathi ye-alloy matrix ngokwakhiwa kwesigaba se-AlN [6,10], okuholela ekusakazweni kwaleso sifunda ngenxa yokwanda okushisayo kwesigaba se-AlN uma kuqhathaniswa ne-alloy matrix [9]. Lapho kuveza ama-alloys e-FeCrAl kumazinga okushisa aphezulu emkhathini anomoya-mpilo noma abanye abanikeli komoya-mpilo njenge-H2O noma i-CO2, i-oxidation iwukusabela okubusayo, namafomu esikali se-alumina, angangenwa umoya-mpilo noma i-nitrogen emazingeni okushisa aphakeme futhi anikeze ukuvikeleka ekungeneni kwawo ku-alloy matrix. Kodwa, uma echayeke emkhathini wokunciphisa (N2+H2), kanye nokuqhekeka kwesikali se-alumina esivikelayo, i-oxidation yendawo ehlukanayo iqala ngokwakhiwa kwama-oxide angavikeli e-Cr kanye ne-Ferich, ahlinzeka ngendlela evumayo yokusabalalisa i-nitrogen ku-matrix ye-ferritic kanye nokwakheka kwesigaba 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 bekuwukunquma ukuthi ukudonsa (99.996%) kugesi 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 ezingeni lokushisa le-annealing, ukuhluka kwayo), kanye nesilinganiso sokushisa kwe-thermal.