purpose of inoculantion for cast iron

The most important role of the Inoculating agent is to increase the crystalline core during the eutectic process of the molten iron. It is generally believed that the main content of gray iron cast eutectic crystal is graphite, and inculantion for cast iron is to increase the graphite core in cast iron.



The cast iron that has not been inoculated has such a large amount of free cementite and low-temperature graphite, and has low mechanical properties. Through inoculation for cast iron, free cementite can be eliminated, tensile strength, elongation, impact strength, wear resistance, etc. can be improved. When an efficient inoculation method is used, higher mechanical properties can still be obtained with the same carbon content. In modern inoculation technology, the corresponding Inoculant can be selected according to the performance requirements of different cast iron parts. For example, a graphitized inoculant with strong graphitization is used to make high toughness ductile iron; a stabilized inoculant with pearlite and alloying is used to improve the strength, hardness and wear resistance of castings. The most regular types are ferrosilicon inoculant, silicon barium inoculant, silicon carbon and other similar combined alloys, rare earth inoculant, ferro silicon magnesium alloy, etc.

Inoculants are mainly suitable for general or transient incubation in various situations. The mechanical properties of gray cast iron depend to a large extent on its microstructure. Uninoculated gray cast iron has unstable microstructure, low mechanical properties, and white mouth is easy to appear on the thin wall of the casting. In order to ensure the consistency of casting quality, inoculation treatment is essential. The inoculant used in the inoculation treatment of cast iron has a small amount of addition, has little effect on the chemical composition of cast iron, and has a great impact on its microstructure, so it can improve the mechanical properties of gray cast iron and also have a significant impact on its physical properties.