Silicon Nitride

Details:

Silicon nitride, a light grayish-white substance, is an inorganic non-metallic material composed of nitrogen and silicon elements. It finds extensive applications in steelmaking, refractories, and is widely used in fields such as wear-resistant rubber, plastics, ceramics, and abrasives for both ambient and high-temperature sealing.

Parameters 

Si	N	C	S	P	Al
56-61	35-38	≤0.3	≤0.03	≤0.03	≤0.5

Advantages of silicon nitride:
High Hardness: Silicon nitride exhibits excellent hardness and strength, surpassing many traditional materials such as steel and ceramics.
High Temperature Resistance: It maintains exceptional performance at high temperatures, typically up to 1700 degrees Celsius.
Corrosion Resistance: Silicon nitride shows strong resistance to most chemicals, including acids, alkalis, and solvents.
Excellent Insulating Properties: It is an excellent insulating material with high electrical and thermal insulation properties, suitable for high-pressure and high-temperature environments.
Good Thermal Conductivity: Despite being an insulating material, silicon nitride has high thermal conductivity, making it suitable for use as high-temperature heat dissipation material.
Methods of preparing silicon nitride:
Thermal Decomposition: Silicon material reacts with ammonia gas at high temperatures to produce silicon nitride.
Chemical Vapor Deposition (CVD) Method: Silicon and ammonia react in the gas phase, depositing silicon nitride thin films.
Reaction Sintering Method: Silicon powder and ammonia are mixed and reacted at high temperatures to produce bulk silicon nitride.
Applications of silicon nitride products:
In the non-ferrous metal industry, silicon nitride is widely used due to its excellent corrosion resistance and wetting properties.
In the steel industry:
Silicon nitride coatings effectively address oxidation issues during steel billet heat treatment. Experimental results show that nano-silicate anti-oxidation coatings can significantly reduce the oxide scale of ordinary hot-rolled plates from 3%-5% to 0.1%-0.8% and stainless steel hot-rolled plates from 1%-3% to below 0.2%.
Silicon nitride repair mixtures play an effective role in sintering activation, corrosion resistance, and crack resistance. When applied to furnaces, they help stabilize blast furnace tuyeres more effectively and are easy to cut.
Silicon nitride exhibits excellent application in HRB400 high-strength hot-rolled steel bars. Si3N4, as a nitrogen-bearing agent, combined with FeV, is used to produce V-microalloyed grade III steel bars. The performance of these bars is outstanding and stable, representing a new alloying process for producing HRB400 grade bars.
Silicon nitride has a nitrogen content per unit weight second only to boron nitride, making it cost-effective and competitive in nitrogen-bearing applications.