Ferro Niobium Properties thiab Siv

Niobium yog lub siab melting point hlau, steel grey, atomic hnyav 92.9064, sab nrauv hluav taws xob qauv 4d5s, melting point 2467 degree C, boiling point 4740 degree C, ceev (20 degree C) yog 8.6 g / cm3. Daim duab 1 qhia txog qhov sib npaug theem ntawm daim duab ntawm ferro-niobium binary system. Muaj ob lub ntsiab lus eutectic thiab MgZn2-hom Raschmannian theem εNbFe2. Ob lub ntsiab lus eutectic nyob hauv Nb11.6%, 1360 degree thiab Nb txog 55%, 1560 degree. Lub melting kub ntawm industrially tsim ferro-niobium (FeNb60) yog li ntawm 1520 mus rau 1600 degree, nrog ib tug ceev ntawm txog 8.0 g / cm3.

Ferro Niobium yog tsuas yog siv nyob rau hauv lub smelting ntawm high kub (heat resistant) alloys, stainless hlau thiab siab zog tsawg alloy hlau. Niobium nyob rau hauv stainless hlau thiab tshav kub-resistant steel, thiab cov pa roj carbon nyob rau hauv cov hlau los tsim niobium carbide ruaj khov. Uniformly faib nyob rau hauv grain ciam teb ntawm steel, tiv thaiv cov grain loj hlob ntawm hlau nyob rau hauv high kub, lub koom haum ntawm cov hlau ua si lub luag hauj lwm nyob rau hauv refining, yuav txhim kho lub zog, toughness thiab creep zog ntawm hlau. Cov tshuaj affinity ntawm niobium thiab carbon yog ntau dua li ntawm chromium thiab carbon, yog li ntawd, thaum niobium nyob rau hauv stainless hlau, nws muaj peev xwm tiv thaiv chromium carbide los ntawm precipitating ntawm grain ciam teb ntawm hlau, yog li txhim kho corrosion kuj ntawm hlau. Niobium thiab nitrogen hauv cov hlau los tsim cov niobium nitride ruaj khov, txhim kho corrosion kuj ntawm steel nto. Niobium thiab cov pa oxygen hauv cov hlau los tsim cov niobium oxide ruaj khov, yog li cov hlau saum npoo los tsim cov niobium oxide zaj duab xis, uas tuaj yeem tiv thaiv cov pa tawm mus rau hauv cov nyhuv antioxidant. Cov pa roj carbon steel ntxiv Nb0.015% ~ 0.05%, tuaj yeem ua lub luag haujlwm hauv kev txhim kho lub koom haum, kom cov hlau muaj kev tsim tau zoo thiab kev ua haujlwm vuam. Niobium ntawm cov hlau austenite recrystallization muaj kev tiv thaiv zoo, yog li cov hlau ntawm qhov kub siab dua, kev tswj tau zoo ntawm dov, thiab kev tswj ntawm dov toughening nyhuv yog qhov tseem ceeb heev. Yog li niobium ua ib qho microalloying keeb nyob rau hauv carbon steel nyob rau hauv tus nqi ntawm heev nce. Tebchaws Asmeskas hauv microalloying nrog niobium, xyoo 1959 tsuas yog 1.9% ntawm tag nrho cov khoom siv ntawm niobium, thaum xyoo 1988 tau nce mus rau 68%.
Niobium nyob rau hauv high-temperature alloys ua si ib qho kev daws teeb meem ntxiv dag zog rau lub luag hauj lwm ntawm carbide nag lossis daus, txhim kho cov yield zog thiab nto stability ntawm high-temperature alloys. Qhov hnyav ntawm niobium yog ib qho sib dua ntawm cov hlau refractory thiab yog ib qho ntawm cov khoom siv rau cov khoom siv kub kub ntau. Niobium-nickel alloys yog siv los ua cov khoom ntxiv rau cov nickel-based high-temperature alloys, feem ntau los tsim 718 alloy. Qhov sib ntxiv ntawm niobium rau cov hlau nplaum tas mus li txhim kho cov khoom coercivity ntawm cov hlau.
Qhov sib ntxiv ntawm niobium rau cam khwb cia hlau pab tsim cov spheroidal thiab pearlitic cov koom haum. Nws ua raws li lub cev xeeb tub thiab ua kom zoo nkauj casting lub koom haum. Niobium txhim kho lub zog, toughness, hardness thiab kev pab cuam lub neej ntawm castings ntawm kub kub. Electrodes siv ferro-niobium los ua cov khoom siv los txhim kho qhov zoo ntawm cov vuam.