A kind of non-reactive mold flux for high aluminum steel

Abstract

The invention discloses non-reactive casting powder for high-aluminum steel. The non-reactive casting powder is composed of, by weight percent, 26%-40% of CaO, 18%-28% of Al2O3, 14%-28% of BaO, 2%-10%of Li2O, 6%-14% of F-, not larger than 2% of MgO, 2%-8% of C and the balance inevitable impurities, and it is kept that (Na2O+K2O+SiO2) in the impurities is smaller than or equal to 2%. The casting powder basically includes no components of SiO2, Na2O, Fe2O3, B2O3 and the like capable of reacting with active elements of [Al], [Ti] and the like in molten steel; after use, the components and performance of the casting powder are still stable; and a series of problems of casting powder performance deterioration, slag entrapment, longitudinal division and the like brought by traditional high-aluminum steel casting powder steel slag reacting are fundamentally solved. According to the casting powder, lubrication and heat transfer of a cast blank can be effectively and coordinately controlled, the high capacity of absorbing Al2O3 inclusions is achieved, and it can be guaranteed that the continuous casting process of the high-aluminum steel is smooth.

Description

technical field [0001] The invention belongs to the field of metallurgy, and in particular relates to a non-reactive mold slag for high-alumina steel. Background technique [0002] Traditional mold flux is mainly composed of CaO and SiO 2 Composition, while adding Al 2 o 3 , MgO, Na 2 O, F - and Li 2 O and other fluxes adjust the viscosity, melting point and solidification temperature of the mold flux, and a certain amount of C is added to adjust the melting speed of the mold flux. [0003] In the casting process of high aluminum steel, due to the high content of aluminum in molten steel, it is easy to mix with SiO in mold flux 2 、Na 2 O, Fe 2 o 3 and B 2 o 3 isocomponent reaction, such as SiO 2 Reaction with [Al]: 3(SiO 2 )+4[Al]=3[Si]+2(Al 2 o 3 ), thus causing SiO in mold flux 2 The content of other components is greatly reduced, and the Al 2 o 3 A large increase will lead to a large change in the melting point and viscosity of the mold slag, which will ...

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Problems solved by technology

Chinese patents 200710042540.6 and 201210253311.X disclose "a continuous casting mold flux for high aluminum steel and its manufacturing method" and "a high Al 2 o 3 In the mold flux for continuous casting of high-alumina steel, SiO 2 The content is controlled at a low level, which can effectively reduce the SiO 2 Reaction with [Al], but Na 2 Higher O content increases the risk of slag entrainment, and it still reacts with [Al], and at the same time, Na-Al-O crystals will be precipitated unevenly, affecting the solidification temperature of the mold flux, which is not conducive to heat transfer between the slab and the mold, and 201210253311 B in .X patent 2 o 3 The content is 2 to 15%, although it can replace SiO 2 Improve the mold slag glass shape, but still intensify the reactivity between steel slag

Chinese patents CN102233414B, CN201110220295.X by adding SiO 2 content to reduce the alkalinity of the mold slag, to ensure that the alkalinity rises to the expected alkalinity after the steel slag reaction and realize high-alumina steel casting, but the performance of the mold slag changes greatly before and after the steel slag reaction, and it cannot be absorbed and floated to the steel slag interface in time and formed by the steel slag reaction Al 2 o 3 Inclusions can easily cause defects such as slag inclusions on the surface of the slab and subcutaneous slag, and this type of mold slag can only be applied to steels with relatively low [Al] content

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