About this Abstract |
| Meeting |
MS&T25: Materials Science & Technology
|
| Symposium
|
Advances in Understanding of Martensite in Steels III
|
| Presentation Title |
Cooling rate effects on auto-tempered martensite: Insights from high-resolution microscopy |
| Author(s) |
Daniel Schrittwieser, Hannes Pahr, Oleksandr Glushko, Ronald Schnitzer |
| On-Site Speaker (Planned) |
Daniel Schrittwieser |
| Abstract Scope |
Low-carbon martensitic high-strength steels and weld metals typically contain auto-tempered martensite, which significantly influences their mechanical properties. Consequently, understanding the morphology of these phase is essential in low-carbon martensite research. To address this, the current study examines the impact of varying cooling rates on the microstructural properties of auto-tempered martensite in a high-strength weld metal. The quantity and morphology of the auto-tempered phase regions were analyzed using scanning and transmission electron microscopy. Atom probe tomography and high-energy X-ray diffraction were used to quantify the auto-tempered carbides and to reveal their type and chemical composition. The results show that the fraction of coarse, coalesced auto-tempered martensite increases with higher cooling rates, while the orientation and chemical composition of cementite precipitates within these regions remain unaffected. All plate-like cementite precipitates are oriented at 60° to each other and have virtually stoichiometric Fe3C composition without any additional carbide-stabilizing elements. |