The impact of high nitrogen content in carbon raisers

The impact of high nitrogen content in carbon raisers on castings is multifaceted, including the following points:

1. Formation of Nitrogen Pores: If the nitrogen content in the carbon raiser is high, these nitrogen elements may be released as gas during the solidification of molten iron, 

forming nitrogen pores within the casting. This not only affects the density of the casting but may also lead to defects such as cracks or reduced strength.

2. Impact on Mechanical Properties: High nitrogen content can cause fissure-type nitrogen pores in gray cast iron, affecting its mechanical properties. Although a certain 

amount of nitrogen can improve some mechanical properties of gray cast iron, such as curling graphite flakes and promoting pearlite refinement, excessively high nitrogen

 content (beyond 100ppm) will have adverse effects.

3. Increased Production Costs: To avoid quality issues in castings caused by high nitrogen content in carbon raisers, foundries may need to take additional measures to 

reduce the nitrogen content in molten iron, such as extending the holding time at equilibrium temperature. These measures will increase production costs and process 

complexity.

4. Limitations on Material Selection: Due to significant differences in nitrogen solubility among different carbon raisers, it is essential to pay attention to the nitrogen 

content when selecting coal-based and petroleum coke carbon raisers. Carbon raisers with high nitrogen content may limit the production of certain specific types of 

castings that have stricter requirements for nitrogen content.

In summary, the high nitrogen content in carbon raisers significantly impacts the quality of castings, including the formation of nitrogen pores, impact on mechanical 

properties, increased production costs, and limitations on material selection. Therefore, during the casting production process, it is crucial to strictly control the nitrogen

content in carbon raisers to ensure the quality of castings.