Effect of carbonization on the mechanical properties of mild steel utilizing oak charcoal as a carbon source

Abstract

Carburizing is a process that improves the mechanical properties of low-carbon steel, particularly its surface hardness. Introducing carbon into the steel's surface enhances the creation of a durable and resistant outer layer.  The technique is especially useful for low-carbon steel because it cannot be hardened by quenching and tempering. This work investigates the effects of solid carburizing on the mechanical properties of mild steel. Oak charcoal was used as a carbon source due to its local availability and low cost. The study examined how solid carburization affects the microstructure and mechanical characteristics of mild steel. Mild steel samples were carburized at 830, 880, and 930 °C temperatures for 30, 50, and 75 minutes. These samples underwent Rockwell hardness, impact, and tensile strength testing. The research investigated the influence of the carburization process, carburization temperature, oak charcoal as a carbon source, and soaking period on the mechanical properties of mild steel. It compared the mechanical properties of mild steel before and after carburization. The treated and untreated samples had different ultimate stress values. The untreated specimens had a value of 629 MPa, whereas the hardened specimens had a value of 1030 MPa. The specimens carburized at 930 °C and submerged for 75 minutes displayed the best mechanical characteristics. Oak charcoal is suitable since the research found that it considerably increases mild steel component surface hardness. This technology is cost-effective and efficient, making it a good choice when other carbon sources are scarce or costly.

Keywords

• engineering strain
• martensite
• mild steel
• oak charcoal
• surface hardening