Role of Inoculation in Spheroidal Graphite Cast Iron

• Published in: Chūzō kōgaku Vol. 74; no. 9; pp. 601 - 604
• Main Author: Kage, Hidehiko
• Format: Journal Article
• Language: Japanese
• Published: Japan Foundry Engineering Society 25.09.2002
• ISSN: 1342-0429; 2185-5374
• DOI: 10.11279/jfes.74.601

In conversation with various foundry plant engineers, the majority of them have emphasized on the importance of blow holes, reverse chill and chunky graphite etc mechanical properties and machining improvements measures. Inoculation method is one such technique and from the process point of view is divided into 4 types of: 1) simultaneous inoculation, 2) secondary, 3) at melt flow gate and 4) within cast, which last one is the subject of current paper. Along with presenting several microphotographs and drawings, the examples of microstructures are thoroughly explained. In the 4 ton, thick-wall casting for example, as seen the comparison with conventional melt kettle the inoculation cast is done with that of in-cast inoculation. Latter method shows 3.5 times more dispersed graphite particles and it is estimated that mean diameter of them is half the size. Similarly, low Mg (0.028 mass%) globular graphite cast iron improvement have shown no corrosion. The low Si inclusion cast iron improvement was observed in hardness of HB113 to HB139 along with other mechanical as shown with their respective microphotographs. A bar diagram displays graphite distribution based on their size which clearly in the new method the grain size distribution is more centered around 10-20 mu particles. simplicity of operation, reduced additives (by 1/3), no fading etc are among other improvements using this method.