I-Kanthal AF alloy 837 resistohm alchrome Y fecral alloy

I-Kanthal AF iyi-ferritic iron-chromium-aluminium alloy (i-FeCrAl alloy) esetshenziswa emazingeni okushisa afinyelela ku-1300°C (2370°F). I-alloy ibonakala ngokumelana okuhle kakhulu kwe-oxidation kanye nokuqina okuhle kakhulu kwesimo okuholela ekuphileni isikhathi eside kwezakhi.

I-Kan-thal AF ivame ukusetshenziswa ezintweni zokushisa zikagesi ezitsheni zezimboni nasezintweni zikagesi zasekhaya.

Isibonelo sezicelo embonini yamadivayisi zisezakhini ze-mica ezivulekile zama-toaster, ama-hair dryer, ezintweni ezimile okwe-meander zama-fan heater kanye nezinto ze-coil ezivulekile ezintweni zokuvikela i-fibre kuma-heater engilazi ye-ceramic asezingeni, kuma-heater e-ceramic ama-plate abilayo, ama-coil ku-fibre ye-ceramic ebunjiwe yama-plate okupheka anama-ceramic hobs, ezintweni ze-coil ezilengisiwe zama-fan heater, ezintweni ze-wire eqondile ezilengisiwe zama-radiator, ama-heater e-convection, ezintweni ze-porcupine zezibhamu zomoya oshisayo, ama-radiator, ama-tumble dryer.

Isifinyezo Esifundweni samanje, indlela yokugqwala kwe-FeCrAl alloy (Kanthal AF) yokuhweba ngesikhathi sokugqwala kugesi ye-nitrogen (4.6) ku-900 °C kanye no-1200 °C ichaziwe. Ukuhlolwa kwe-isothermal kanye ne-thermo-cyclic okunezikhathi zokuvezwa ezihlukene, amazinga okushisa, kanye namazinga okushisa okugqwala kwenziwa. Ukuhlolwa kwe-oxidation emoyeni kanye negesi ye-nitrogen kwenziwa ngokuhlaziywa kwe-thermogravimetric. Isakhiwo se-microstructure sibonakala ngokuhlaziywa kwe-scanning electron microscopy (SEM-EDX), i-Auger electron spectroscopy (AES), kanye nokuhlaziywa kwe-ion beam egxile (FIB-EDX). Imiphumela ikhombisa ukuthi ukuqhubeka kokugqwala kwenzeka ngokwakhiwa kwezifunda ze-nitridation ezingaphansi komhlaba, ezakhiwe yizinhlayiya zesigaba se-AlN, okunciphisa umsebenzi we-aluminium futhi kubangele ukubhidlika kanye nokuqhekeka. Izinqubo zokwakheka kwe-Al-nitride kanye nokukhula kwesikali se-Al-oxide zincike ekushiseni okugqwala kanye nesilinganiso sokushisa. Kutholakale ukuthi i-nitridation ye-FeCrAl alloy iyinqubo esheshayo kune-oxidation ngesikhathi sokufakwa kwegesi ye-nitrogen enomfutho ophansi we-oxygen futhi imele imbangela eyinhloko yokuwohloka kwe-alloy.

Isingeniso Ama-alloy asekelwe ku-FeCrAl (i-Kanthal AF ®) aziwa kakhulu ngokumelana kwawo okuphezulu kwe-oxidation emazingeni okushisa aphezulu. Le mpahla enhle kakhulu ihlobene nokwakheka kwesikali se-alumina esizinzile nge-thermodynamically ebusweni, okuvikela izinto ekushiseni okwengeziwe [1]. Naphezu kwezakhiwo zokumelana nokugqwala eziphakeme, isikhathi sokuphila kwezingxenye ezikhiqizwe ngama-alloy asekelwe ku-FeCrAl singanqunyelwa uma izingxenye zivame ukuchayeka ekushiseni okushisa emazingeni okushisa aphezulu [2]. Esinye sezizathu zalokhu ukuthi isici esakha isikali, i-aluminium, sidliwa ku-matrix ye-alloy endaweni engaphansi komhlaba ngenxa yokuqhekeka okuphindaphindiwe kwe-thermo-shock kanye nokuguqulwa kwesikali se-alumina. Uma okuqukethwe kwe-aluminium esele kwehla ngaphansi kokuhlushwa okubucayi, i-alloy ayisakwazi ukuguqula isikali sokuvikela, okuholela ekushiseni okuyingozi ngokwakhiwa kwama-oxide asekelwe ku-iron akhula ngokushesha kanye ne-chromium [3,4]. Kuye ngesimo esizungezile kanye nokugeleza kwama-oxide angaphezulu komhlaba lokhu kungasiza ekushiseni okungaphezulu kwangaphakathi noma i-nitridation kanye nokwakheka kwezigaba ezingafuneki esifundeni esingaphansi komhlaba [5]. UHan noYoung bakhombisile ukuthi esikalini se-alumina esakha ama-alloy e-Ni Cr Al, iphethini eyinkimbinkimbi ye-oxidation yangaphakathi kanye ne-nitridation ikhula [6,7] ngesikhathi sokujikeleza kokushisa emazingeni okushisa aphezulu emoyeni, ikakhulukazi kuma-alloy aqukethe ama-nitride formers aqinile njenge-Al ne-Ti [4]. Ama-chromium oxide scales aziwa ngokuthi angangena kwi-nitrogen, kanti i-Cr2 N yakha njengengqimba ye-sub-scale noma njenge-internal precipitate [8,9]. Lo mphumela ungalindelwa ukuthi ube mkhulu kakhulu ngaphansi kwezimo zokujikeleza kokushisa okuholela ekuqhekekeni kwe-oxide scale kanye nokunciphisa ukusebenza kwawo njengesithiyo ku-nitrogen [6]. Ngakho-ke ukuziphatha kokugqwala kulawulwa ukuncintisana phakathi kwe-oxidation, okuholela ekwakhekeni/ekugcinweni kwe-alumina evikelayo, kanye nokungena kwe-nitrogen okuholela e-nitridation yangaphakathi ye-alloy matrix ngokwakhiwa kwesigaba se-AlN [6,10], okuholela ekwandeni kwaleso sifunda ngenxa yokwanda kokushisa okuphezulu kwesigaba se-AlN uma kuqhathaniswa ne-alloy matrix [9]. Uma kuvezwa ama-FeCrAl alloys emazingeni okushisa aphezulu ezindaweni ezinawo umoya-mpilo noma abanye abanikeli be-oxygen njenge-H2O noma i-CO2, i-oxidation iyindlela ebusayo, futhi kwakheka isikali se-alumina, esingangeni umoya-mpilo noma i-nitrogen emazingeni okushisa aphezulu futhi sihlinzeke ngokuvikelwa ekungeneni kwawo kwi-alloy matrix. Kodwa, uma kuvezwa emoyeni oncishisiwe (N2+H2), kanye nokuqhekeka kwesikali se-alumina esivikelayo, i-oxidation yendawo iqala ngokwakhiwa kwama-Cr nama-Ferich oxides angavikeli, ahlinzeka ngendlela enhle yokusabalala kwe-nitrogen kwi-ferritic matrix kanye nokwakheka kwesigaba se-AlN [9]. Isimo se-nitrogen esivikelayo (4.6) sivame ukusetshenziswa ekusetshenzisweni kwezimboni kwama-FeCrAl alloys. Isibonelo, ama-resistance heater ezitsheni zokwelapha ukushisa anomoya we-nitrogen ovikelayo ayisibonelo sokusetshenziswa kabanzi kwama-FeCrAl alloys endaweni enjalo. Abalobi babika ukuthi izinga le-oxidation lama-FeCrAlY alloys lihamba kancane kakhulu lapho lifakwa emoyeni onengcindezi ephansi ye-oxygen engaphelele [11]. Inhloso yalolu cwaningo kwakuwukuthola ukuthi ukunamathela kugesi (99.996%) we-nitrogen (4.6) (izinga lokungcola le-Messer® spec. O2 + H2O < 10 ppm) kuthinta ukumelana nokugqwala kwe-FeCrAl alloy (Kanthal AF) nokuthi kuncike kangakanani ekushiseni kwe-annealing, ukuhlukahluka kwayo (ukujikeleza kokushisa), kanye nesilinganiso sokushisa.