Inoculation in Cast Iron
Poor base iron nucleation and inoculation can be a typical cause for the formation of poor graphite structures in both gray and ductile irons, which can ultimately lead to the desired mechanical and physical properties not being met. The morphology, chemistry and crystallinity of the recarburizer material can have a major impact on the overall metallurgical quality of the iron. Amorphous carbons, such as acetylene and petroleum coke, do not contribute to the nucleation of the melt, resulting in a lower metallurgical quality iron. To meet this challenge, Superior Graphite developed Desulco®, a high purity form of graphitic carbon with exceptional inoculating capability.
How can we help address your challenges?
Issue
Low nodule count due to poor nucleation can cause low hardness, yield, and tensile strength.
Solution
Desulco® used in conjunction with the appropriate proportion of charge materials will provide the necessary amount of nuclei in the melt to achieve the desired mechanical properties.
Issue
High base iron chill depth can occur due to super heating or excessive holding times.
Solution
Adding Desulco® to the melt, will replenish nuclei, reduce chill, and increase the carbon content to the specified level.
Fig. 01
Chill Depth Reduction
Fig. 02
Nucleating Effect
Over the past four decades, Desulco® has been successfully used as an inoculating carbon in cast iron. Based on University studies* where Desulco® was compared against various recarburizers with differing crystallinity, such as petroleum coke, or graphite electrode scrap, it was discovered that Desulco® showed the biggest nucleation improvement of the melt, resulting in optimum chill depth reduction in gray iron, and increased nodule count and nodule shape improvement in ductile iron.
*University of Wisconsin Madison, University of Wisconsin Platteville, Missouri University of Science and Technology
