The specific requirements of different castings for synthetic graphite carburant

The specific requirements of different castings for synthetic graphite carburant can be elaborated from multiple aspects, including composition requirements, particle size and 

morphology requirements, absorption rate and effect requirements, etc. The following is a detailed analysis:

1. Composition Requirements:

   - The main component of synthetic graphite carburant is carbon, with a high fixed carbon content typically above 90%, ensuring sufficient carburization effects.

   - Sulfur content is one of the important indicators to measure the quality of carburant. For high-end castings such as ductile iron, low-sulfur synthetic graphite carburant 

   should be chosen, as sulfur elements hinder the graphitization process and affect casting quality.

   - Nitrogen content also needs to be considered. An appropriate amount of nitrogen can refine the grain structure, improving the tensile strength and hardness of the casting, 

   but an excess may lead to nitrogen gas hole defects.

2. Particle Size and Morphology Requirements:

   - The particle size of the carburant significantly affects its absorption rate. Generally, fine particles have greater contact area with the molten iron, dissolve quickly, and have a 

   high absorption rate, but excessively fine particles are easily oxidized, leading to high loss; while overly coarse particles dissolve slowly.

   - For different furnace types and casting types, it is necessary to choose an appropriate particle size range. For example, the particle size for induction furnaces might be  

   between 0.2-6mm, while for steel and other ferrous metals, the range might be broader.

3. Absorption Rate and Effect Requirements:

   - The absorption rate of the carburant refers to its ability to be absorbed by the molten iron and converted into carbon in the molten iron during the melting process. High 

   absorption rate carburants can improve casting efficiency and reduce production costs.

   - Different types of castings have varying requirements for the absorption rate of carburants. For instance, ductile iron castings may require higher absorption rates to ensure  

   sufficient carbon content to promote the graphitization process.

4. Other Special Requirements:

   - In certain specific cases, such as the production of brake pad additives or as abrasive materials, the carburant may need to meet additional performance requirements such 

   as wear resistance, thermal stability, etc.

   - For castings requiring strict control of chemical composition (such as certain alloy steels), the impurity content in the carburant also needs special attention to avoid 

   introducing unnecessary elements that affect casting quality.

In summary, the specific requirements of different castings for synthetic graphite carburant vary based on factors such as casting type, furnace type, production process, 

and product quality requirements. When selecting and using carburants, these factors must be comprehensively considered to ensure casting quality and production efficiency.