Study of the Grain Growth Kinetics and Its Influence on Mechanical Behavior of Plain Carbon Steel

In the present study, the mechanical performances of plain carbon steel were explored based on the grain growth behavior. In the first step, the samples were normalized at different temperatures ranging from 900°C to 1100°C for 30, 60, 100, 150, and 200 min, respectively. In order to measure the grain size, the planimetric technique of Jeffries was used based on the optical micrographs taken for each sample. The mechanical properties of each grain such as hardness, elongation, yield, and tensile strength were studied, depending on the conventional methods. Experimental results showed that the increase in both heating temperature and holding time enhances grain growth, while the growth rate decreases with increasing time. The initial grain size and proportionality constant were calculated at 950°C, where K = 2.26 μm²/min and D ₀ = 25.09 μm. Moreover, a significant increase in strength and hardness was observed with a decrease in grain size. Conversely, a decrease in ductility was observed with grain size diminution.