Analysis of performance improvement of Changshuikou refracto

The long nozzle made of Al2O3-C quality refractory material can withstand the strong thermal shock of molten steel from room temperature to above 1500 ℃ in an instant. According to the structure and use characteristics of different refractory materials and the damage mechanism, numerical simulation was used to analyze the temperature field and stress field response, thermal stress and strain relationship of different materials composites of Changshuikou under high temperature use environment, and found that different porosity and microstructure, different thermal The refractory materials with conductivity and linear expansion coefficient are multilayered in different forms, and the temperature field response to the thermal shock is different with time. The inner cavity of the nozzle that is in contact with the high temperature molten steel has a high porosity of 3 to 5mm and a low thermal conductivity. The refractory material can significantly optimize the instantaneous temperature field distribution of the steel, and the maximum thermal stress is reduced by 47%.

Multi-layer composite changes the stress-strain relationship and the stress distribution in the refractory material, and improves its thermal shock resistance. Therefore, based on functional zoning, gradient multilayer refractory materials with different carbon contents are designed.

 

In order not to pollute the molten steel, the inner layer material in contact with the molten steel uses a high porosity (20% to 30%) and a low-carbon refractory material with a low thermal conductivity (mass fraction 1% to 3%) to reduce the instantaneous thermal shock. Temperature gradient and maximum thermal stress; the parts that are severely attacked by high temperature molten steel or slag, use low carbon porosity and fiber reinforced medium carbon materials (mass fraction 6% ～ 24%) to ensure corrosion resistance and reduce steel Liquid carbon increase, the material erosion rate can be reduced by more than 30%: the body uses high-carbon materials (mass fraction 26% to 32%), giving the refractory sufficient strength to ensure the structure and function of the long nozzle. The gradient multi-layer composite design realizes the simultaneous improvement of the thermal shock resistance, erosion resistance and other resistance of the refractory.