For a flat-shaped electric furnace cover, under the action of its own weight, the ribs in the middle of the electrode holes will crack, and without external support, it is prone to collapse or loosen, and even three electrode holes may form a large hole. However, for an arched-shaped furnace cover, even if there are cracks, under the action of the furnace cover's own weight, the cracks will be squeezed tight, and the service life of the furnace cover can be prolonged. Therefore, the arched-shaped furnace cover has a better service life than the flat-shaped one.
The requirements for refractory materials for the electric furnace cover include the resistance to slag of high-temperature slag. Due to the splashing of molten steel and slag and acidic substances, the furnace cover will suffer severe acidic erosion. Extremely cold and extremely hot temperatures also require excellent thermal shock resistance for the material of the electric furnace cover. Therefore, the base material of the electric furnace cover used cannot be ignored. The process ratio during production must consider slag resistance and thermal shock resistance.
Because the electric furnace cover has electrode holes and exhaust holes, the main furnace cover of the outer ring and the small furnace cover in the triangular area have very strict usage conditions due to the complex smelting process. The prefabricated pieces in the triangular area require very strict baking conditions. The prefabricated pieces produced must consider the temperature during the baking process, remove free water and crystalline water, so as to ensure the usage effect of the electric furnace cover. It is also necessary to consider the effects of electrode radiation, rapid cooling and heating, erosion by molten steel and slag, and the unreasonable factors formed by the impact of high-speed airflow during dust removal.
There are also furnace covers made of refractory bricks, and some small furnace covers are directly poured with refractory castable. This is relatively easier to construct and lay, but it is also necessary to consider the slow heating during the baking process and the initial setting and drying temperature.
In conclusion, the arched-shaped electric furnace cover is better than the flat-shaped one. Moreover, the castable furnace cover requires reasonable baking, and the usage effect will be doubled.