Various grain sizes of Ferrosilicon Nitride

During the steelmaking process, different alloy materials can be added to produce steel with various performance characteristics. Silicon nitride iron is also a very common steelmaking additive on the market. However, when adding and using silicon nitride iron, in order to ensure the effectiveness, multiple factors need to be considered, such as process control and safety regulations, to ensure the quality and safety of the molten steel.

I. Key Points of Process Control

Addition timing: Add it after the steel water has undergone deoxidation and during the alloying stage to ensure that the nitrogen element is quickly incorporated. Adding too early may result in nitrogen loss due to oxidation.

Temperature and insulation system

Temperature control: It is recommended to set the temperature between 1400℃ and 1450℃. If the temperature is too low, nitriding will not be complete; if it is too high, energy consumption will increase.

Insulation time: It should be ≥ 3 hours to ensure that the nitrogen content meets the standard (national standard ≥ 30%). If the temperature drops to 1300℃, it is necessary to extend the time to 6 hours.

Mixing and homogeneity: Enhance the mixing process to ensure the uniform distribution of silicon nitride iron, avoiding excessive nitrogen content in certain areas or the aggregation of un-melted particles.

Nitrogen content regulation: Optimize the nitrogen content by adjusting the temperature and holding time. For instance, maintaining at 1400℃ for 4 hours can result in a nitrogen content of 30.28%.

II. Safety Operating Procedures

Personnel qualifications and protection: Operators must undergo training and obtain qualification certificates. They should wear heat protection suits, protective glasses, dust masks, etc.

Equipment inspection: Before operation, check whether the equipment and safety facilities (such as the furnace door and gas valves) are in good condition. Also, prepare emergency supplies such as fire extinguishers and cleaning tools.

Emergency measures: Develop an emergency response plan to deal with sudden situations such as slag overflow, nozzle blockage, and furnace door explosion. Take measures such as shutting down the furnace, isolating, and cooling down.

Environmental Management: Prevent the explosion of hot molten materials upon contact with water. Keep the front platform of the furnace dry. Strictly control the nitrogen pressure (e.g. 0.2 MPa is required for flash combustion synthesis), and prevent gas leakage.