About this Abstract |
Meeting |
2020 AWS Professional Program
|
Symposium
|
2020 AWS Professional Program
|
Presentation Title |
Effect of Heating Rate on Austenite Formation in a Low Carbon Microalloyed Steel |
Author(s) |
Alejandro Hintze Cesaro, Patricio F. Mendez |
On-Site Speaker (Planned) |
Alejandro Hintze Cesaro |
Abstract Scope |
Austenite formation during continuous heating on a grade X80 pipeline steel with an initial ferritic microstructure was studied by dilatometric analysis coupled with electron microscopy. Experiments with heating rates varying from 1 to 500 K/s were carried out to obtain the continuous heating transformation diagram. For low heating rates, austenite start transformation temperature was found to be higher than the one dictated by the equilibrium. For high heating rates, start transformation temperature gradually approaches the temperature at which the ferrite can transform without long-range diffusion into austenite, possibly through a massive transformation.
Partial transformation experiments suggested that austenite formation from a complex ferrite and bainitic structure occurs in two stages: (a) First, the transformation of bainitic zones into austenite and later (b) the transformation of austenite into larger pro eutectoid ferritic grains.
Thermodynamic calculations coupled with initial microstructure considerations were used to estimate the start transformation temperatures successfully. |
Proceedings Inclusion? |
Definite: Other |