Application of Electromagnetic Field Theory in the Study of Iron-Rich Slag Resistance Mechanism of Low Carbon MgO-C Refractories

Electromagnetic field (EMF) can promote the reaction between the Fe/Mn ion in slag and MgO-C refractories to form Mn-doped MgFe2O4 spinel. In order to further study the morphology and characteristics of Mn-doped MgFe2O4 spinel, the experiments were respectively carried out in medium-frequency induction furnace and resistance furnace. MgO-C refractories containing 6 wt.% carbon and iron-rich slag containing 53.62 wt.% Fe2O3 were used. The results show that the penetration layer in the slag line under EMF is obvious and the reduced Fe from FexO is distributed homogeneously in this layer. However in the resistance furnace having no EMF, there is not MgFe2O4 spinel but MgAl2O4 spinel formed. The iron content in Mn-doped MgFe2O4 spinels decrease dramatically from the erosion layer to penetration layer, while the manganese content in the spinel remains unchangeable.

Effect of Graphite Content on Corrosion Resistance of Zirconia Graphite Materials

The effect of graphite content on formation of decarbonization layer and corrosion resistance of zirconia graphite materials were studied by the corrosion test in induction furnace, and the effect of decarbonization layer on corrosion of zirconia graphite materials was also analysed by the kinetic models for the corrosion of SEN in mold, the result show that Thickness of decarbonization layer of slag line is decreasing with the increase of graphite content. Corrosion of zirconia graphite materials in steel liquid / slag interface is characterized by the features of consecutive reaction:original layer→decarbonization layer→corrosion layer, and k1, and k2 are their reaction rate constant respectively.when we adjust graphite content, k1 and k2 will be change in opposite directions, so graphite content with well corrosion resistance depend on the condition of continuous casting

Phase Composition Analysis of Recycled MgO-C Ladle Lining Materials

With the iron and steel metallurgy, cement, ceramic and other industries making a rapid development, the refractory consumption in our country is quite large. So how to recycle the used refractory materials effectively is more and more important. In this experiment, the phase composition of ladle lining bricks at slag line, rampart and bottom were researched systematically, to determine the phase composition change between the unused and recycled materials. It turned out that the low melting point minerals CaMgSiO4 and Ca3Mg (SiO4)2 formed due to the reaction between MgO and the impurity compositions like SiO2 and CaO from the melted slag and liquid steel. On the one hand, the formation of these low melting point minerals was one of the main reason for the damage of the recycled MgO-C ladle lining bricks. On the other hand, the alkaline magnesium carbon bricks had purification effect for the liquid steel as a result of the content reduction of SiO2 and CaO.

Research on Refractory Material Corrosion in Steelmaking Engineering

Researched on the refractory material corrosion by experiments. Each refractory was measured to take four different parts, and the average corrosion thicknesses of silicon carbide, quartz and corundum were 0.52mm, 1.03mm and 1.40mm. The corrosion of corundum refractory was most serious, and quartz refractory had a certain degree of corrosion, but it was not very serious. The corrosion of silicon carbide refractory was the least. In the experiment in intermediate frequency furnace, only upper and lower parts of slag line were connected to the refractory and the degree of corrosion was little for silicon carbide crucible. Slag part of the wall thickness was about 16.6mm after the reaction. Amorphous master alloy parts of the wall thicknessis about 16.9mm. For quartz crucible, refractory corrosion was much bigger, which was 10 mm thick before reaction. The erosion thick was about 2~3mm. It was a little thicker than corrosion experiment in static crucible.

Formation of Decarbonization Layer and its Effect on Corrosion Resistance of Zirconia Graphite Materials

The effect of graphite content on formation of decarbonization layer and corrosion resistance of zirconia graphite materials were studied by the corrosion test in induction furnace, and the effect of decarbonization layer on corrosion of zirconia graphite materials was also analysed by the kinetic models for the corrosion of SEN in mold, the result show that: (1) Thickness of decarbonization layer of slag line is decreasing with the increase of graphite content. When the mold fluxes for high carbon steel is used, decarbonization layer is thin and graphite content has little effect on corrosion resistance of zirconia graphite materials, and 10wt%graphite is better. When the mold fluxes for low carbon steel is used, decarbonization layer is thick and 14wt% graphite is the best. (2) Corrosion of zirconia graphite materials in mold is characterized by the features of consecutive reaction:original layer (k1) decarbonization layer (k2) corrosion layer . If k1<<k2, there is no decarbonization layer forming and decarbonization is the key step for the corrosion; If k1>>k2, there is decarbonization layer on the hot surface of zirconia graphite materials and the corrosion of the layer is the key step. Graphite content is too high or too low is all harmful for the corrosion resistance of zirconia graphite materials.