|About this Abstract
|2022 TMS Annual Meeting & Exhibition
|Phase Transformations and Microstructural Evolution
|Cementite Decomposition in 100Cr6 Bearing Steel during High-pressure Torsion: Influence of Composition, Size, Morphology and Matrix Hardness
|Kiranbabu Srikakulapu, Lutz Morsdorf, Po-Yen Tung, Michael Herbig
|On-Site Speaker (Planned)
Premature failure of rail and bearing steels by White-Etching-Cracks leads to severe economic losses. This failure mechanism is associated with microstructure decomposition via local severe plastic deformation (SPD). The decomposition of cementite here plays a key role as this hard phase is the most critical obstacle to overcome in the process. Therefore, understanding principal factors effecting cementite decomposition helps in designing damage resistant steels.
In this study, the standard 100Cr6 bearing steel microstructure is tailored to create two types of precipitates - spherical and lamellar cementite, surrounded by ferrite matrix. These two types of precipitates differ in size, morphology, and composition (Cr, Mn partitioning). The difference in decomposition behavior upon high-pressure torsion (to model SPD) is examined using multi-scale characterization techniques. We conclude that the cementite size and morphology, as well as the matrix mechanical properties predominantly influence the decomposition behavior of cementite.
|Iron and Steel, Phase Transformations, Other