High-Alloy Iron Castings
According to the ISO 16112 standard for compacted graphite cast irons (CGIs), the graphite particles in CGIs shall be predominantly in the vermicular form when viewed on a two dimensional plane of polish. This article begins with a schematic illustration of compacted graphite microstructures with nodularity. It describes the tensile properties, hardness and compressive properties, and impact properties of CGI. The article concludes with a discussion on the fatigue strength and thermal conductivity of CGI.
The high-alloy irons can be categorized into two main groups: the high-alloy graphitic irons (covering both gray and ductile grades) and the high-alloy white irons. High-alloy irons are used in applications with demanding requirements, such as high resistance to wear, heat, and corrosion, or for combined properties. This article discusses the specification and selection of high-alloy irons. The common alloying elements and their effect on the stable and metastable eutectic temperatures are listed in a table. The article provides information on the compositions, properties and applications of high-alloy graphitic irons and high-alloy white irons.