Effects of Carburizing Processes on Nodular Cast Iron with Variations in Temperature, Time and Cooling System

Nodular Cast Iron have ductile properties when added with elements of magnesium or cerium and this will cause the ductility range of 10-20% increase, hardness and low tensile strength, easy to be formed compared to alloy steel (alloy steel) or high carbon steel (high carbon steel) and the price is relatively cheap, making this material widely used as a basic material (raw material) for the manufacture of a product. To get hard properties on the surface, this material can be carried out a surface hardness process, so that the product can be functioned according to its application. Way that can be done to increase surface hardness as well as low carbon steel strength is by adding carbon elements to the steel which is commonly known as carburizing. The carburizing process is carried out on a muffle furnace specifically heat treatment that is easy to operate in setting the heating temperature, heating speed and holding time. In this research, it is designed and carried out on low carbon steel using carburization media with a ratio of 70% activated carbon and 30%, calcium carbonate (CaCO3) at 900°C heating temperature, holding time variations of 2, 3 and 4 hours respectively, then proceed with the process cooling or double quenching. The results of this study are expected to obtain a product made with cast iron nodular material, so it can the economic value of the product.