With the progress of metallurgical technology, the performance of refractories also put forward higher requirements. Because aluminum-magnesium spinel refractory has the advantages of high melting point, low thermal expansion coefficient, thermal shock resistance and slag resistance, it is widely used in electric furnace, refined ladle and skateboard and other major parts. In high temperature conditions, the refractory reacts not only with slag and reacts with molten steel, but also has an important effect on the refractory process.
Production practice shows that the molten steel temperature and its carbon mass fraction are the main factors that affect the reaction between refractory and molten steel. Therefore, it is very important to study the effect of molten steel temperature and its mass fraction on the erosion of aluminum-magnesium spinel refractory.
In this paper, Mg-Al spinel refractories were prepared by fused magnesia and fused corundum as raw materials. The effects of molten steel temperature and carbon mass fraction on the erosion of refractory materials were studied by thermodynamic calculation and thermal experiment. The chemical analysis of carbon in molten steel before and after the experiment was carried out, and the microstructure of the refractory was observed by scanning electron microscope.
(1) Thermodynamics analysis shows that Mg (g) and A1 produced by the reaction of magnesium oxide and aluminum oxide components with carbon in the refractory material with the increase of temperature. o (g) of the equilibrium sub-pressure increases.
(2) The experimental study shows that the erosion index of refractory increases with the temperature of molten steel, especially when the temperature is higher than 1630 ℃, the erosion index of refractory is affected by temperature. The corrosion index of refractory material decreases with the increase of carbon in molten steel when the boron (C) 0.12% of molten steel decreases, thus alleviating the erosion degree of refractory material.
(3) The erosion mechanism of molten steel to spinel refractories can be summarized as follows: First, the carbon and refractory components of molten steel react chemically with eroded refractory materials: secondly. The penetration of molten steel into the refractory material and the analysis of the low melting point phase in the refractory particles reduce the binding force between the refractory particles and exacerbate the degree of damage to the refractory material.
