Kanthal AF alloy 837 resistohm alchrome Y fecral alloy

Kanthal AF yog ib hom ferritic iron-chromium-aluminium alloy (FeCrAl alloy) uas siv tau rau qhov kub txog li 1300°C (2370°F). Cov alloy no muaj cov yam ntxwv zoo xws li kev tiv taus oxidation zoo heev thiab ruaj khov zoo heev ua rau nws siv tau ntev.

Kan-thal AF feem ntau yog siv rau hauv cov khoom siv hluav taws xob hauv cov cub tawg thiab cov khoom siv hauv tsev.

Piv txwv ntawm cov ntawv thov hauv kev lag luam khoom siv yog nyob rau hauv qhib mica ntsiab lus rau cov toasters, cov plaub hau dryers, nyob rau hauv meander zoo li cov ntsiab lus rau kiv cua cua sov thiab ua qhib coil ntsiab lus ntawm fiber insulating khoom nyob rau hauv ceramic iav sab saum toj cua sov nyob rau hauv ntau yam, nyob rau hauv ceramic cua sov rau boiling phaj, coils ntawm molded ceramic fiber rau ua noj ua haus phaj nrog ceramic hobs, nyob rau hauv suspended coil ntsiab lus rau kiv cua cua sov, nyob rau hauv suspended ncaj hlau ntsiab lus rau radiators, convection cua sov, nyob rau hauv porcupine ntsiab lus rau phom cua kub, radiators, tumble dryers.

Abstract Hauv kev tshawb fawb tam sim no, cov txheej txheem xeb ntawm kev lag luam FeCrAl alloy (Kanthal AF) thaum lub sijhawm annealing hauv cov roj nitrogen (4.6) ntawm 900 ° C thiab 1200 ° C tau piav qhia. Isothermal thiab thermo-cyclic kev xeem nrog ntau lub sijhawm raug, cua sov, thiab kub annealing tau ua tiav. Kev xeem oxidation hauv huab cua thiab nitrogen roj tau ua los ntawm kev tshuaj xyuas thermogravimetric. Lub microstructure yog tus cwj pwm los ntawm scanning electron microscopy (SEM-EDX), Auger electron spectroscopy (AES), thiab tsom ion beam (FIB-EDX) kev tshuaj xyuas. Cov txiaj ntsig qhia tau hais tias kev nce qib ntawm xeb tshwm sim los ntawm kev tsim cov cheeb tsam nitridation hauv av, tsim los ntawm AlN theem particles, uas txo cov haujlwm txhuas thiab ua rau embrittlement thiab spallation. Cov txheej txheem ntawm Al-nitride tsim thiab Al-oxide nplai loj hlob nyob ntawm qhov kub thiab txias annealing thiab cua sov nqi. Nws tau pom tias nitridation ntawm FeCrAl alloy yog ib qho txheej txheem sai dua li oxidation thaum lub sijhawm annealing hauv cov roj nitrogen nrog cov pa oxygen qis thiab yog qhov ua rau muaj kev puas tsuaj loj tshaj plaws ntawm cov hlau.

Kev Taw Qhia FeCrAl - raws li cov hlau alloys (Kanthal AF ®) yog paub zoo rau lawv qhov kev tiv thaiv oxidation zoo tshaj plaws ntawm qhov kub siab. Cov khoom zoo heev no yog cuam tshuam nrog kev tsim cov nplai alumina thermodynamically ruaj khov ntawm qhov chaw, uas tiv thaiv cov khoom tiv thaiv kev oxidation ntxiv [1]. Txawm hais tias muaj cov khoom tiv thaiv corrosion zoo dua, lub neej ntawm cov khoom tsim los ntawm FeCrAl - raws li cov hlau alloys tuaj yeem txwv yog tias cov khoom raug rau kev kub ntxhov ntawm qhov kub siab [2]. Ib qho ntawm cov laj thawj rau qhov no yog tias cov nplai tsim cov khoom, txhuas, raug noj hauv cov hlau matrix hauv thaj chaw hauv qab vim yog qhov rov ua dua thermo-shock cracking thiab reforming ntawm alumina nplai. Yog tias cov ntsiab lus txhuas seem txo qis hauv qab qhov tseem ceeb concentration, cov hlau alloy tsis tuaj yeem hloov kho qhov nplai tiv thaiv, ua rau muaj kev puas tsuaj loj heev los ntawm kev tsim cov hlau-raws li thiab chromium-raws li oxides [3,4]. Nyob ntawm huab cua ib puag ncig thiab permeability ntawm cov oxides saum npoo av qhov no tuaj yeem pab txhawb kev oxidation sab hauv lossis nitridation thiab kev tsim cov theem tsis xav tau hauv thaj chaw hauv qab [5]. Han thiab Young tau qhia tias hauv alumina nplai tsim Ni Cr Al alloys, tus qauv nyuaj ntawm kev oxidation sab hauv thiab nitridation tsim [6,7] thaum lub sijhawm thermal cycling ntawm qhov kub siab hauv huab cua, tshwj xeeb tshaj yog hauv cov alloys uas muaj cov nitride formers muaj zog xws li Al thiab Ti [4]. Chromium oxide nplai paub tias yog nitrogen permeable, thiab Cr2 N tsim ua ib txheej sub-scale lossis ua sab hauv precipitate [8,9]. Cov nyhuv no tuaj yeem cia siab tias yuav hnyav dua nyob rau hauv cov xwm txheej thermal cycling uas ua rau oxide nplai tawg thiab txo nws cov txiaj ntsig ua ib qho thaiv rau nitrogen [6]. Yog li tus cwj pwm corrosion yog tswj hwm los ntawm kev sib tw ntawm oxidation, uas ua rau alumina tsim / txij nkawm tiv thaiv, thiab nitrogen ingress ua rau nitridation sab hauv ntawm cov alloy matrix los ntawm kev tsim ntawm AlN theem [6,10], uas ua rau spallation ntawm thaj chaw ntawd vim muaj kev nthuav dav thermal ntawm AlN theem piv rau cov alloy matrix [9]. Thaum FeCrAl alloys raug rau qhov kub siab hauv huab cua nrog oxygen lossis lwm yam oxygen pub xws li H2O lossis CO2, oxidation yog qhov tshuaj tiv thaiv tseem ceeb, thiab alumina scale tsim, uas tsis tuaj yeem nkag mus rau oxygen lossis nitrogen ntawm qhov kub siab thiab muab kev tiv thaiv tiv thaiv lawv nkag mus rau hauv lub matrix alloy. Tab sis, yog tias raug rau huab cua txo qis (N2 + H2), thiab tiv thaiv alumina scale tawg, qhov oxidation hauv zos pib los ntawm kev tsim cov Cr thiab Ferich oxides tsis tiv thaiv, uas muab txoj hauv kev zoo rau nitrogen diffusion rau hauv ferritic matrix thiab tsim AlN theem [9]. Lub chaw tiv thaiv nitrogen (4.6) feem ntau siv rau hauv kev siv lag luam ntawm FeCrAl alloys. Piv txwv li, cov cua sov tiv thaiv hauv cov cua sov kho cua sov nrog huab cua nitrogen tiv thaiv yog ib qho piv txwv ntawm kev siv dav dav ntawm FeCrAl alloys hauv ib puag ncig zoo li no. Cov kws sau ntawv tshaj tawm tias qhov nrawm oxidation ntawm FeCrAlY alloys qeeb dua thaum annealing hauv huab cua nrog cov pa oxygen tsawg [11]. Lub hom phiaj ntawm txoj kev tshawb no yog txhawm rau txiav txim siab seb qhov annealing hauv (99.996%) nitrogen (4.6) roj (Messer® spec. impurity level O2 + H2O < 10 ppm) puas cuam tshuam rau kev tiv thaiv corrosion ntawm FeCrAl alloy (Kanthal AF) thiab nws nyob ntawm qhov kub annealing, nws qhov sib txawv (thermal-cycling), thiab qhov kub thiab txias.