The influence of carburization parameters on the mechanical behavior of mild steel: a review

Abstract The process parameters influencing carburization have drawn considerable interest from researchers due to their impact on the structural morphology and mechanical performance of mild steel. Mild steel has a low carbon content, resulting in poor mechanical properties such as high wear rate, low impact strength, and inadequate surface hardness. As a result, carburization is a heat treatment process adopted to ensure that components made from mild steel satisfy the necessary performance standards. This study provides an overview of the significance of carburization and the various techniques used, assessing their advantages, limitations, and cost-effectiveness. It also integrates the impact of carburization parameters, including temperature, time, carbon source, and the effect of cooling on the microstructure and mechanical characteristics of mild steel to establish a more comprehensive insight into process relationship by recognizing the hierarchy of the impact of these variables. The review indicates that carburization temperature has the most significant effect, as it governs both carbon solubility and diffusion rate, making it a dominant factor in achieving the desired case depth and hardness. Soaking time and carbon source follow in influence, while cooling media play a secondary role. Building on the scope of previous works, this paper provides a unique comparison of carburization methods based on efficiency, ease of application, and environmental sustainability, including the use of agricultural waste as an alternative carbon source, highlighting its environmental and economic benefits. Furthermore, the review emphasizes the application of modern optimization techniques, including statistical design of experiments and multi-response optimization methods, which are often underrepresented in conventional processes. Additionally, it outlines future research directions and identifies gaps in existing literature to suggest opportunities for enhancing materials for diverse applications in the automotive and manufacturing sectors.