Lightweight fluorine-free environmental protection continuous casting protective slag for enamel steel

Abstract

The invention discloses lightweight fluorine-free environmental protection continuous casting protective slag for enamel steel. The continuous casting protection slag comprises the following components including, by mass 22%-38% of CaO, 21%-37% of SiO2, 0.8%-3.0% of Al2O3, 1%-7% of MgO, 5%-20% of heating agent Si- Ca, 0.7%-2% of Li2O, 2%-8% of B2O3, 5%-10% of Na2O, 5%-17% of elemental C and unavoidable impurities; and the slag must meet: [CaO]/[Sio2] is greater than or equal to 0.8 and less than or equal to 1.0, namely, the alkalinity of the protective slag is 0.8- 1.0 The ratio of the heatingagent Si-Ca is 36-40 %: 64- 60%. The protective slag of the invention can reduce the occurrence of cold junction steel on a liquid surface by adding suitable heating elements without changing the alkalinity of the protective slag after the addition, and the steel leakage can be avoided; by adjusting a flux, another one or several substances are used for replacing fluoride, so the corrosion of thefluorine to a casting machine and the impact on human body are reduced.

Description

technical field [0001] The invention relates to a continuous casting mold flux, in particular to a light-weight, fluorine-free and environment-friendly special continuous casting mold flux for enamelled steel. Background technique [0002] Continuous casting mold slag is a synthetic auxiliary material added to the crystallizer to cover the surface of molten steel during the continuous casting of molten steel. Generally, the components of mold flux include base material, cosolvent, and melting rate regulator. The base material is CaO-SiO 2 -SiO 2 Mainly, it plays the role of heat insulation and absorption of non-metallic oxides. Cosolvent with Na 2 O and CaF 2 Mainly, LiO can also be used 2 , K 2 O, BaO, NaF, etc. are used as fluxes to adjust the melting temperature and viscosity. Due to SiO 2 Generally, as the content increases, the viscosity increases, and SiO 2 It plays the role of network former. CaO plays the role of basic alkalinity and can adsorb some non-me...

AI Technical Summary

Problems solved by technology

This patent has fundamentally changed the composition of mold slag. The basic composition of slag is CaO-SiO as mentioned above. 2 -Al 2 o 3 As the base material, the boron mud powder of this technology is more than 50%, the result is that the viscosity is too low, the network formation is small, and it cannot play the role of heat insulation and absorption of oxide inclusions

and too much K 2 O undoubtedly has an adverse effect on the composition of mold flux

The notification number CN102962420A discloses the use of 4-6 parts of manganese dioxide and 4-6 parts of barium carbonate, which is to use MnO and BaO to replace CaF 2 , in the conventional understanding, MnO, as an oxidant, can suppress the carbon-rich layer, avoid the situation of carburization in molten steel, and cannot improve the fluidity of mold slag