Investigation microstructure and mechanical properties of white cast iron using sand casting

摘要

This project is to investigate mechanical properties and microstructure of white cast iron using sand casting. There are three objectives for this project which are firstly to study the processing method of gray cast iron to produce white cast iron. Secondly, to investigate the microstructure and hardness of white cast iron compared to gray cast iron and lastly, to study the microstructure and hardness of white cast iron in differential type of quenching medium. The first part for this project is foundry laboratory which is involving the process of sand casting was performed by using furnace to melt the raw material. Then, the melted raw material produced is then poured into the desired mould and let it solidify by itself. After the casting process, the material will be through second part which involves heat treatment. The material is heated at 1020oC for two hours. Then, the material is quenched into the medium of water and oil before inspection parameter was performed to investigate the mechanical properties (hardness) and microstructure of material before and after heat treatment process. To validate the prediction result, experimental values compared. Result showed that the hardness of material after heat treatment is higher than hardness before heat treatment. The grain size formed on material after heat treatment is finer grain size and there are no flakes. Different with material before heat treatment, it shows that there are flakes and the grain size is thin inside it. The predicted result showed that heat treatment exerted on material is influencing the change of mechanical properties and microstructure.