Experimental and Theoretical Analysis for Hypoeutectic Cast Iron Oxidation Behaviors

The anodic dissolution of hypoeutectic cast iron consisting of pearlite and ledeburite was studied in the sulfuric acid solution by electrochemical methods. The oxidation activities of ferrite and cementite, which are two phases in cast iron, are evaluated by their structural and electronic properties according to the first-principles calculations. The results show that the anodic dissolution of ferrite occurs at the more negative potential compared with cementite. With comparison of ledeburite, the microstructure of pearlite is easier to be crumbled during the anodic dissolution because more amount of ferrite dissolves from the framework of pearlite. The first principle calculations demonstrate the Fe 3d-band center of iron is closer to Fermi level than that of cementite, indicating that Fe atoms in ferrite are more active and prone to suffering electrophilic attack. It is the intrinsic reason that cementite is more stable than ferrite under anodic polarization in the sulfuric acid solution.

Automated summary

The anodic dissolution of hypoeutectic cast iron consisting of pearlite and ledeburite in sulfuric acid solution was investigated using electrochemical methods. The oxidation activities of the two phases in cast iron, ferrite and cementite, were evaluated based on their structural and electronic properties using first-principles calculations. The results indicate that ferrite undergoes anodic dissolution at a more negative potential compared to cementite. The microstructure of pearlite is more prone to crumbling during anodic dissolution compared to ledeburite due to the higher amount of ferrite dissolution from the pearlite framework. First-principles calculations demonstrate that the Fe 3d-band center of iron is closer to the Fermi level than that of cementite, indicating higher activity of iron atoms in ferrite and their susceptibility to electrophilic attack. This intrinsic reason explains why cementite is more stable than ferrite under anodic polarization in sulfuric acid solution.