Development and application of argon blowing and venting bricks for smelting stainless steel in induction furnace

The presence of carbides, gas inclusions and oxide inclusions in the induction furnace smelting stainless steel castings is the main reason for the poor mechanical properties and corrosion resistance. The content of various inclusions in the stainless steel castings is consistent with the molten steel in the induction furnace smelting The purity is closely related. At present, most of the process of induction furnace smelting to produce stainless steel adopts the remelting method, which has no refining function. It cannot remove various inclusions brought in during the remelting process, and the quality of molten steel cannot be effectively guaranteed, resulting in low casting grades. How to reduce the content of various inclusions produced in the remelting process of stainless steel castings with high efficiency and low cost has become an urgent issue for manufacturers of stainless steel castings produced by induction furnace smelting.

The process of blowing argon into molten steel and stirring to remove various types of inclusions has become an essential part of the process for large-scale steel enterprises to produce high-quality and high-value-added steel. Through argon blowing refining, the molten steel can achieve the purpose of degassing, decarburizing and removing oxide inclusions. What is more meaningful is that when argon is blown into the chromium-containing molten steel, the chromium content of the molten steel is simultaneously decarburized. Will not change. According to the urgent needs of the market, we have developed argon blowing and breathable bricks suitable for induction furnace smelting stainless steel castings, which can reduce the content of various inclusions in the induction furnace smelting stainless steel process at low cost and high efficiency, improve the grade of castings, and make stainless steel casting manufacturers Obtain good economic benefits. Induction furnace smelting has three main requirements for breathable bricks:

①Good safety:

② Stable gas flow;

③Sufficient service life.

The products developed by the research and development of the material of the breathable brick are mainly used in the induction furnace for smelting stainless steel. The use temperature is relatively high, and the argon blowing time and the total argon blowing time of the furnace are relatively long. Therefore, the material of the breathable brick should have good resistance to molten steel and slag. Permeability and good high temperature strength. Due to the high temperature of smelting stainless steel in the intermediate frequency furnace, the low viscosity and strong permeability of stainless steel liquid steel, when ordinary gas-permeable brick materials are used, the alloy components in the liquid steel are likely to chemically react with the material of the gas-permeable brick working surface, blocking the gas-permeable channels and making the gas permeable The brick loses its ventilation function. Therefore, some of the raw materials of the breathable brick are optimized and adjusted to adapt to the smelting of stainless steel.