I-Kanthal AF alloy 837 resistohm alchrome Y fecral alloy

I-Kanthal AF yi-ferritic iron-chromium-aluminium alloy (i-FeCrAl alloy) esetyenziswa kumaqondo obushushu afikelela kwi-1300°C (2370°F). Le ngxube ibonakaliswa kukumelana okuhle kakhulu ne-oxidation kunye nozinzo oluhle kakhulu olubangela ukuba izinto zihlale ixesha elide.

I-Kan-thal AF idla ngokusetyenziswa kwizinto zokufudumeza ngombane kwii-oven zoshishino nakwizixhobo zasekhaya.

Umzekelo wezicelo kwishishini lezixhobo zikwizinto ezivulekileyo ze-mica kwiitoaster, ii-hair dryers, kwizinto ezimile okwe-meander kwii-fan heaters kwaye njengezinto ezivulekileyo ze-coil kwizinto zokukhusela i-fibre kwii-heaters zeglasi ze-ceramic kwii-ranges, kwii-ceramic heaters zeeplates zokubilisa, ii-coils kwi-molded ceramic fiber kwiiplates zokupheka ezinee-ceramic hobs, kwizinto ezixhonyiweyo ze-coil zee-fan heaters, kwizinto ezixhonyiweyo ze-straight wire ze-radiators, ii-convection heaters, kwizinto ze-porcupine ze-hot air guns, ii-radiators, ii-tumble dryers.

Isishwankathelo Kolu phononongo lwangoku, indlela yokugqwala kwe-FeCrAl alloy (Kanthal AF) yorhwebo ngexesha lokugqwala kwigesi ye-nitrogen (4.6) kwi-900 °C kunye ne-1200 °C ichaziwe. Uvavanyo lwe-Isothermal kunye ne-thermo-cyclic olunexesha lokuvezwa elihlukeneyo, amazinga okufudumeza, kunye namaqondo obushushu okugqwala lwenziwe. Uvavanyo lwe-oxidation emoyeni nakwigesi ye-nitrogen lwenziwe ngohlalutyo lwe-thermogravimetric. Isakhiwo se-microstructure sibonakala ngokuskena i-electron microscopy (SEM-EDX), i-Auger electron spectroscopy (AES), kunye nohlalutyo lwe-ion beam egxile kwi-FIB-EDX. Iziphumo zibonisa ukuba ukuqhubela phambili kokugqwala kwenzeka ngokwenziwa kweendawo ze-nitridation ezingaphantsi komhlaba, ezakhiwe ngamasuntswana e-AlN phase, okunciphisa umsebenzi we-aluminium kwaye kubangele ukubhitya kunye nokuqhekeka. Iinkqubo zokwakheka kwe-Al-nitride kunye nokukhula kwesikali se-Al-oxide zixhomekeke kubushushu bokugqwala kunye nesantya sokufudumeza. Kufunyenwe ukuba i-nitridation ye-FeCrAl alloy yinkqubo ekhawulezayo kune-oxidation ngexesha lokutsalwa kwegesi ye-nitrogen enoxinzelelo oluphantsi lwe-oxygen kwaye imele eyona nto iphambili yokuwohloka kwe-alloy.

Intshayelelo Ii-alloys ezisekelwe kwi-FeCrAl (i-Kanthal AF ®) zaziwa kakhulu ngokumelana kwazo okuphezulu kwe-oxidation kumaqondo obushushu aphezulu. Le propati ibalaseleyo inxulumene nokwakheka kwesikali se-alumina esizinzileyo kwi-thermodynamically kumphezulu, esikhusela izinto kwi-oxidation engaphezulu [1]. Nangona iipropati eziphezulu zokumelana nokugqwala, ubomi bezinto ezenziwe kwii-alloys ezisekelwe kwi-FeCrAl bunokulinganiselwa ukuba iindawo zihlala zichaphazeleka kukujikeleza kobushushu kumaqondo obushushu aphezulu [2]. Esinye sezizathu zoku kukuba into eyenza isikali, i-aluminium, ityiwa kwi-alloy matrix kwindawo engaphantsi komhlaba ngenxa yokuqhekeka okuphindaphindiweyo kwe-thermo-shock kunye nokuguqulwa kwesikali se-alumina. Ukuba umxholo we-aluminium oseleyo wehla phantsi koxinzelelo olubalulekileyo, i-alloy ayinakuphinda iguqule isikali sokukhusela, nto leyo ebangela i-oxidation eyingozi ngokwenziwa kwee-oxides ezikhula ngokukhawuleza ezisekelwe kwisinyithi kunye ne-chromium [3,4]. Ngokuxhomekeke kumoya ojikelezileyo kunye nokuvuleka kwee-oxides eziphezulu, oku kunokunceda i-oxidation yangaphakathi okanye i-nitridation kunye nokwenziwa kwezigaba ezingafunekiyo kummandla ongaphantsi komhlaba [5]. UHan noYoung babonise ukuba kwisikali se-alumina esenza ii-alloys ze-Ni Cr Al, ipateni eyinkimbinkimbi ye-oxidation yangaphakathi kunye ne-nitridation iyavela [6,7] ngexesha lokujikeleza kobushushu kumaqondo obushushu aphezulu emoyeni, ngakumbi kwii-alloys eziqulethe ii-nitride formers ezinamandla ezifana ne-Al kunye ne-Ti [4]. Izikali ze-chromium oxide zaziwa ngokuba zi-nitrogen permeable, kwaye i-Cr2 N idalwa njengomaleko ongaphantsi okanye njenge-internal precipitate [8,9]. Esi siphumo sinokulindelwa ukuba sibe qatha ngakumbi phantsi kweemeko zokujikeleza kobushushu ezikhokelela ekuqhekekeni kwesikali se-oxide kwaye zinciphise ukusebenza kwayo njengomqobo kwi-nitrogen [6]. Ukuziphatha kokubola kulawulwa lukhuphiswano phakathi kwe-oxidation, olukhokelela ekwakhiweni/ekugcinweni kwe-alumina ekhuselayo, kunye nokungena kwe-nitrogen okukhokelela kwi-nitridation yangaphakathi ye-alloy matrix ngokwenziwa kwesigaba se-AlN [6,10], okukhokelela ekuqhekekeni kwaloo mmandla ngenxa yokwanda kobushushu okuphezulu kwesigaba se-AlN xa kuthelekiswa ne-alloy matrix [9]. Xa kuvezwa ii-FeCrAl alloys kumaqondo obushushu aphezulu kwi-atmospheres ezine-oxygen okanye ezinye ii-oxygen donors ezifana ne-H2O okanye i-CO2, i-oxidation yimpendulo elawulayo, kwaye kwenziwa isikali se-alumina, esingenako ukungena kwi-oxygen okanye i-nitrogen kumaqondo obushushu aphezulu kwaye sibonelela ngokhuseleko ekungeneni kwazo kwi-alloy matrix. Kodwa, ukuba zivezwe kwi-reduction atmosphere (N2+H2), kunye ne-protective alumina scale crack, i-local breakaway oxidation iqala ngokwenziwa kwee-non-protective Cr kunye ne-Ferich oxides, ezibonelela ngendlela efanelekileyo yokusasazwa kwe-nitrogen kwi-ferritic matrix kunye nokwakheka kwe-AlN phase [9]. I-protective (4.6) nitrogen atmosphere isetyenziswa rhoqo kwi-industrial application yee-FeCrAl alloys. Umzekelo, ii-resistance heaters kwi-heat treatment furnace ezine-protective nitrogen atmosphere ngumzekelo wokusetyenziswa ngokubanzi kwee-FeCrAl alloys kwindawo enjalo. Ababhali baxela ukuba izinga le-oxidation yee-FeCrAlY alloys licotha kakhulu xa lifakwa kwi-atmosphere ene-oxygen pressures ephantsi [11]. Injongo yolu phononongo yayikukufumanisa ukuba ingaba ukutsalwa kwe-annealing kwi-(99.996%) ye-nitrogen (4.6) gas (inqanaba lokungcola le-Messer® spec. O2 + H2O < 10 ppm) kuyayichaphazela na i-corrosion resistance ye-FeCrAl alloy (Kanthal AF) kwaye ixhomekeke kangakanani kubushushu bokutsalwa kwe-annealing, utshintsho lwayo (ukujikeleza kobushushu), kunye nesantya sokufudumeza.