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Effects Of Mineral Composition Of Mold Powder About Hypo-peritectic Steel For Slabs On Ore Phase Structure Of Slag Film

Posted on:2016-06-20Degree:MasterType:Thesis
Country:ChinaCandidate:H ZhangFull Text:PDF
GTID:2191330476454223Subject:Geological Engineering
Abstract/Summary:PDF Full Text Request
The hypo-peritectic steel for slabs are easy to produce casting defects in continuous casting process, which has a strict requirement on lubrication and heat transfer. So the mould fluxes casting the hypo-peritectic need valuable physical and chemical performance parameters and ore phase structure of flux film.Because mould fluxes are made from industrial minerals, and the research about physicochemical properities of mould fluxes and characteristic of flux film is less. So the trial is the first way to use mineral raw to make mould fluxes and study the influence of different mineral on physicochemical properities of mould fluxes and characteristic of flux film.The mould fluxes and flux film of Q235 B and SS400 are token from industries and the physicochemical properities and ore phase structure of which are analysised. The minerals of mould fluxes about hypo-peritectic steel for slabs are mainly wollastonite quartz and fluorite and so on. The content of glass is very high to 40%~65%. The thickness of flux film is about 1mm and the minerals of which are cuspidine wollastonite and melilitite. The crystallization rate of flux film is up to 60% and which has two or three layers. The growth of crystals is not well and there are glass phase distribution on both sides about Q235 B crack accident of flux film. Whereas the flux film corresponding accident leakage generate excess cupidine and high degree of crystallization. In order to find out the effect of the mineral composition on the physicochemical properties and mineral phase, the mineral raw materials are used to make from mould flux in orthogonal experiment. The effect of mineral composition on the physicochemical properties and ore phase structure of the flux film are researched. The degree of effect of minerals on melting temperature is: wollastonite>borax>soda ash>fluorite>basicity; degree of effect on crystallization temperature is: basicity >fluorite > wollastonite>soda ash >borax; degree of effect on viscosity is: basicity>fluorite>wollastonitex>soda ash>bora; degree of effect on crystallization rate is: basicity>bora >soda ash > wollastonitex >fluorite.By contrasting the physicochemical properities and ore phase structure of experimental mould fluxes and which use for Q235 B and SS400, the optimum composition of experiment fluxes is confirmed which are No.3, No.5 and No.18. The results of the research has a good applicability to design industrial fluxes, to choose reasonable raw material and to develop high quality mold fluxes.
Keywords/Search Tags:hypo-peritectic steel for slabs, mould fluxes, structure of flux flim, physicochemical properties
PDF Full Text Request
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