Alloy cov ntaub ntawv siv hauv kev tsim hluav taws xob cua sov ntsiab lus. Thaum cov hluav taws xob tam sim no dhau los ntawm cov khoom siv hlau, cov nyhuv Joule yog tsim, uas hloov hluav taws xob rau hauv thermal zog.
Cov khoom siv hluav taws xob tsis zoo yog feem ntau ua rau hauv cov tuav, cov xov hlau, cov hlua hlau hauv cov coils thiab cov strips, thiab tuaj yeem ua rau hauv cov kav dej thiab cov castings raws li cov kev cai tshwj xeeb.
Kev ua tau zoo ntawm cov hluav taws xob tiv thaiv alloy: ① Nws yuav tsum muaj qhov zoo oxidation tsis kam (los yog corrosion kuj ntawm nruab nrab cua) thiab txaus creep tsis kam ntawm qhov kub thiab txias. ② Nws yuav tsum muaj kev tiv thaiv siab, qhov kub thiab txias coefficient ntawm resistivity yuav tsum tsawg li sai tau, thiab nws tuaj yeem tiv taus tam sim no loj. ③ Nws yuav tsum muaj kev ua haujlwm zoo ntawm cov txheej txheem metallurgical thiab kev tsim khoom ua haujlwm.
Xyoo 1906, British Marsh (ALMarsh) tau tsim cov nickel-chromium hluav taws xob tiv thaiv alloy Cr20Ni80, Tebchaws Asmeskas FBLounsberry (FBLounsberry) xyoo 1929, Soviet Union Kornilov (И.И.корнилов) thiab lwm tus tau kawm hlau hauv 1934. Lub cev muaj zog Fe-Cr-Al alloys nrog Al2 ~ 6% thiab Cr7 ~ 13% ntxiv rau cov hlau. Rau lub hauv paus no, Fe-Cr-Al hom hluav taws xob tiv thaiv alloys yog tsim. Tuam Tshoj ua cov saum toj no ob hom hluav taws xob tiv thaiv alloys nyob rau hauv 1949. Nyob rau hauv lub 1970s, ntau tshaj 30 qib ntawm hluav taws xob kuj alloys tau tsim thiab siv nyob rau hauv ntau lub teb chaws, tab sis tsuas yog ob peb qib tau tsim nyob rau hauv ntau qhov ntau thiab dav siv.
Hom hluav taws xob tiv thaiv alloys Ni-Cr-(Fe) hom hluav taws xob tiv thaiv alloys yog ua los ntawm npib tsib xee lossis hlau, feem ntau muaj Cr15-31% thiab Ni29-80%, uas qhia cov qauv austenitic. Piv txwv li, Cr20Ni30, Cr20Ni80, Cr30Ni70, thiab lwm yam., qhov siab tshaj plaws kev khiav hauj lwm kub tuaj yeem ncav cuag 950, 1100, 1200 degree hauv ib ntus. Cov khoom tuaj yeem txhim kho tau los ntawm kev ntxiv cov kab ke xws li Ca, Ce, Zr, Ti thiab Si rau cov hlau. Cov yam ntxwv ntawm cov hlau no yog cov yeeb yaj kiab tiv thaiv saum npoo yog tsim los ntawm chromium oxide (Cr2O3), uas muaj zog corrosion kuj, kub siab zog, thiab zoo sib sau thiab vuam kev ua tau zoo. Qhov tsis zoo yog tias tus nqi siab, thiab nws tsis haum rau kev siv nyob rau hauv cov huab cua uas muaj leej faj.
Fe-Cr-Al hom hluav taws xob tiv thaiv alloys yog raws li cov hlau, muaj 12-30% Cr, 4-8% Al, tsim nyog piv ntawm Cr thiab Al thiab ntxiv cov kab lus xws li La, Ce, Y, thiab lwm yam. ., kom tau txais kev ua haujlwm siab ntawm hluav taws xob tsis kam alloys. Piv txwv li, Cr17Al5, Cr25Al5, Cr28Al8Ti, thiab lwm yam., lub siab tshaj plaws kev khiav hauj lwm kub yuav ncav cuag 1050, 1200, 1300 degree nyob rau hauv lem. Hom alloy no yog cov qauv ferrite, nrog thaj chaw embrittlement ntawm ib ncig ntawm 450 degree C thiab 700 degree C, feem. Thaum siv rau lub sijhawm ntev ntawm qhov kub thiab txias, cov nplej tau yooj yim coarsened, yog li qhov kub siab creep kuj thiab chav kub toughness yog tsawg, tab sis lub resistivity yog siab. , zoo oxidation kuj, thiab pheej yig, yog li nws yog dav siv.
Kev tsim cov txheej txheem hluav taws xob tiv thaiv alloy smelting yuav tsum ua raws li cov tshuaj muaj pes tsawg leeg ntawm cov hlau, tshwj xeeb tshaj yog cov pa roj carbon, phosphorus, sulfur thiab cov kab mob ntxiv los txhim kho cov kev ua tau zoo ntawm cov hlau thiab cov kev xav tau rau cov purity ntawm cov hlau, siv hluav taws xob arc rauv, lub tshuab nqus tsev. induction rauv thiab electro slag remelting, thiab lwm yam. Txhawm rau txhim kho kev ua haujlwm ntawm cov hlau, deoxidation yuav tsum muaj zog thaum lub sij hawm smelting txheej txheem los tiv thaiv oxidation theem nrab thaum lub sij hawm ingot casting, thiab kom txo tau segregation thiab coarse columnar siv lead ua qauv.
Kev ua cov yas kub ntawm Ni-Cr-(Fe) hom alloys yuav tsum tsis txhob cua sov hauv cov huab cua uas muaj leej faj los tiv thaiv kev tsim cov nickel sulfide tsawg thiab ua rau cov kab nrib pleb hauv qhov chaw ua haujlwm. Cov yas txias ua haujlwm ntawm cov hlau yog zoo. Tom qab txhua qhov annealing thiab softening kho, qhov txias ua hauj lwm deformation tus nqi tuaj yeem ncav cuag 60-80%.
Fe-Cr-Al hom alloys yuav tsum tiv thaiv cov cua kub kom tsis txhob siab dhau thiab lub sij hawm cua sov yog ntev heev thaum lub sij hawm ua hauj lwm kub kom tsis txhob grain coarsening. Qhov ntsuas kub ntawm kev ua haujlwm kub feem ntau tsis siab tshaj 850 degree. Cov khoom ua haujlwm txias ntawm hom alloy no tsis zoo, yog li kev kho recrystallization annealing yuav tsum tau nqa tawm hauv lub sijhawm thaum lub sijhawm ua haujlwm txias, thiab cov txheej txheem deformation yuav tsum tau saws thiab lubrication yuav tsum tau ntxiv dag zog.
