Argon, an inert gas, does not dissolve in molten steel and does not react with any element. It is a very ideal stirring gas, so it is widely used. In terms of agitation, nitrogen is the same as argon, and nitrogen is cheap, but nitrogen can be dissolved in molten steel at high temperatures, and the amount of nitrogen increased with the temperature rising and the extension of nitrogen blowing time.
When the temperature is higher than 1575℃, the nitrogen content in steel can be increased by 0.003%, affecting the quality of steel, so the use of nitrogen as a stirring gas is limited. Only a small amount of nitrogen-containing steel can apply nitrogen as a stirring gas, and there is also a problem of unstable nitrogen increase.
