Ultrahigh-alkalinity crystallizer mould flux special for high-pulling-rate peritectic steel

Abstract

The invention discloses an ultrahigh-alkalinity crystallizer mould flux special for high-pulling-rate peritectic steel. 38%-42% of CaO, 25%-29% of SiO2 and 7%-10% of F- are adopted to improve the crystallization capacity of the mould flux, reduce stress concentration and improve lubrication; 2%-5% of MgO and 2%-5% of Al2O3 are adopted to improve the fluidity of a flux film and reduce cracks; an excellent heat transfer coordination and heat transfer control effect is achieved by adopting the mould flux with the alkalinity ranging from 1.35 to 1.52, 25%-29% of SiO2, 2%-5% of Al2O3 and 2%-5% of MgO; the effects of effectively controlling the melting rate to guarantee melt flux feeding and preventing subsurface blowholes can be achieved with the carbon proportioning range of 4%-7%. Raw materials for preparing the ultrahigh-alkalinity crystallizer mould flux can be easily obtained, the flux consumption ranges from 0.32 kg per ton of steel to 0.38 kg per ton of steel, and cost of per ton of steel is low; on-spot practical application indicates that the mould flux can be well spread in a crystallizer and be evenly and stably melt and is high in casting percent of pass.

Description

Technical field [0001] The invention belongs to the technical field of the preparation of steelmaking auxiliary materials, and specifically relates to an ultra-high basicity crystallizer mold powder special for high-speed peritectic steel. Background technique [0002] Continuous casting mold mold powder is an important material in continuous casting production, which can improve the surface and subcutaneous quality of cast slabs and expand the steel grades for continuous casting. The alkalinity of continuous casting mold powder is an important indicator, which determines the position of the entire mold powder design system. The basicity of the mold fluxes mainly used by major steel mills is generally controlled between 0.9 and 1.5, so that the mold fluxes have good adsorption and good heat transfer effect. High-basicity mold powder is not the mainstream in the production process, but for some high-speed solidification processes that have peritectic reaction and are prone to lon...

AI Technical Summary

Problems solved by technology

However, when using the mold slag in the traditional peritectic steel formation area, it is often found that the lubrication of the slab shell has deteriorated to varying degrees. The reason is that the solid slag film becomes thicker after the mold slag crystallization ability is enhanced, and the liquid slag film becomes relatively thinner, thus deteriorating For the lubrication of the billet shell, this situation can be alleviated in some cases by reducing the viscosity of mold flux, but it is difficult to fundamentally solve this problem

Later, through theoretical calculation and practice, it was found that after the lance spar was precipitated, the alkalinity of the remaining liquid slag would decrease, and the trace amount of SiO 2 will increase, the first may complicate the slag network structure and increase the viscosity of liquid slag, and the second is excessive SiO 2 Possibly due to other components of slag such as Al 2 o 3 , MgO, etc. form high melting point compounds, which are easy to deteriorate, and these will easily weaken the lubricating effect of the mold flux, so that the mold flux has defects in coordinating heat transfer and controlling heat transfer