A study on the structure and composition of oxide inclusions in iron alloys

Non-metallic inclusions (such as oxide and sulphides) are common in all steels as a result of steelmaking and thermal treatment processes. Despite the small percentage that these inclusions represent in steel, they have a significant influence on several properties of steel, such as its formability, toughness, machinability and corrosion resistance. This influence is generally negative, even if at times, depending on their size, composition and distribution, some of these inclusions can also have a beneficial effect on steel properties.

The structure and composition of non-metallic inclusions in steels, which ultimately governs their mechanical behavior, is mainly determined by the deoxidation practice that was used in producing the steel (how and when deoxidizer elements such as Al, Si, Mn or Ca are added) and can also be affected by the chemical composition of the alloy and (eventual) thermal treatments to which it is subjected after being cast.

In this semester project, we will investigate how different thermo-chemical processes affect the composition and structure of oxides produced within iron alloys. The student will use metallographic characterization techniques, including optical microscopy and scanning electron microscopy (SEM) coupled with energy dispersive compositional analysis (EDS), to analyze the characteristics of inclusioms previously fabricated in the laboratory. In addition, Thermocalc software for thermodynamic calculations will be employed to understand the formation mechanism and the structure of the observed phases.

For more information please contact Alejandra Slagter at  [email protected]