| About this Abstract |
| Meeting |
MS&T24: Materials Science & Technology
|
| Symposium
|
Austenite Formation and Decomposition V: A Symposium in Memory of Prof. Mats Hillert
|
| Presentation Title |
Decomposition of Retained Austenite during Tempering of High-Strength Tool Steels: Effect of Silicon and Tempering Parameters |
| Author(s) |
Myriam Dumont, Marine Lachal, David Quidort, Denis Delagnes, Moukrane Dehmas |
| On-Site Speaker (Planned) |
Myriam Dumont |
| Abstract Scope |
Decomposition of retained austenite (RA) during tempering in tool steels is of prime importance in the good balance between strength and toughness for plastic injection moulding applications. Two grades differing in their silicon content with initial mixed bainitic/martensitic microstructures were investigated using in-situ synchrotron high-energy X-ray diffraction (HEXRD) during tempering at temperatures between 550 °C and 600 °C for a dwell time of one hour. Results indicated first carbide formation during heating or holding time of the tempering stage; however, austenite remains untransformed up to the end of the tempering holding time in all investigated conditions for both grades. In-situ HEXRD brings direct evidence of the transformation of austenite into fresh martensite on cooling from the tempering stage. This behaviour was correlated to the evolution of the carbon enrichment of retained austenite and the effect of silicon is discussed. |