In order to increase the service life of the electric furnace roof, most of the domestic ultra-high power electric furnace roof are using water cooling structure, but the central area around the electrode must use refractory materials, and its service life determines the service life of the electric furnace roof.The central prefabricated parts of the electric furnace roof, especially the large and medium-sized electric furnace steel mills, are favored because of their good integrity, convenient construction and installation, and long service life.
 
1：Research on the central prefabrication of electric furnace roof
According to the technical requirement of prefabrication parts, in the development of the central prefabrication of the electric furnace roof, the following methods are mainly taken. 1)：pick high pure corundum as the major raw material, improve the high temperature resistance performance of the products, and enhance the resistance to melting loss; 2) Added high quality or pure Cr2o3 powder (Cr2o3>99%) in the corundum prefabrication parts, increases slag resistance, reduces slag penetration.3): Added the heat resistant stainless steel fiber into the corundum prefabrication parts, to change the toughness of products, improve the thermal shock stability of products, so as to improve the stress distribution, avoid crack, improve the service life of products. 4): Added efficient composite water reducing agent can improve the volume density of products, thus improve the strength of products, avoid the crack expansion, and improve the service life of products.
 
2: Impact of environmental factors and improvement measures
2.1; Cold and heat of furnace cover
When loading, the furnace cover should be opened to cause a sharp drop in temperature, so that the furnace cover differential heat stress and thus cause damage.The effective way is to process the scrap steel to reduce the number of loading.
2.2: The high-speed air flow formed by the dust removal system causes impact and wear on the prefabricated working surface of the center of chromium corundum electric furnace roof; when the extraction force is insufficient, the smoke and flame generated by smelting overflow and cause damage to the electrode hole.The effective method is to reasonably allocate the fan according to the capacity of the electric furnace, and clean up the steel slag at the entrance of the dust removal system in time.
2.3 Electrode spray
Electrode spray is a cooling method that protects the electrode to reduce the electrode consumption.It can not only effectively reduce the electrode consumption of the electric furnace steel-making, but also absorb a lot of heat due to the evaporation of water, effectively reduce the heat load of the electric furnace center prefabrication, and cool the prefabricated parts of the electric furnace roof.