The aim of this project is to study the potentials of dilatometry for the investigation of 9-12wt.% Cr steels. In particular, the project focuses on the α’γ transformation in normalized extra low carbon steels. The analyzed alloys had been set up by CSM in order to study the behavior of 9-12wt.% Cr steels during long term high temperature exposure. Commercial X20CrMoV 12-1 have been analyzed too. In order to investigate the potentials of the technique, dilatometry has been coupled with optical microscopy and hardness measurements. This study shows how optical microscopy and hardness measurements give useful information about the critical temperatures A1 and A3, why these techniques are limited, and how dilatometry has the possibility to overcome these limits. Furthermore, the potential of isochronal dilatometry to investigate the kinetic of transformations is shown.
Gli acciai 9-12wt.% Cr sono materiali importanti per applicazioni ad alta temperatura. Questo elaborato è inserito nel contesto delle ricerche volte allo studio delle trasformazioni micro-strutturali che determinano il comportamento di questa classe di materiali. In particolare si focalizza sulla trasformazione α’γ e sull’uso del dilatometro come strumento di caratterizzazione. Lo studio analizza le potenzialità della dilatometria accoppiata a misure di durezza ed all’analisi metallografica, e mostra come questa sia in grado di superare i limiti delle singole tecniche e fornire un panorama pressoché completo di informazioni riguardanti la trasformazione analizzata.
Investigation of 9-12wt.% Cr steels with the use of dilatometer
VILLA, MATTEO
2009/2010
Abstract
The aim of this project is to study the potentials of dilatometry for the investigation of 9-12wt.% Cr steels. In particular, the project focuses on the α’γ transformation in normalized extra low carbon steels. The analyzed alloys had been set up by CSM in order to study the behavior of 9-12wt.% Cr steels during long term high temperature exposure. Commercial X20CrMoV 12-1 have been analyzed too. In order to investigate the potentials of the technique, dilatometry has been coupled with optical microscopy and hardness measurements. This study shows how optical microscopy and hardness measurements give useful information about the critical temperatures A1 and A3, why these techniques are limited, and how dilatometry has the possibility to overcome these limits. Furthermore, the potential of isochronal dilatometry to investigate the kinetic of transformations is shown.File | Dimensione | Formato | |
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https://hdl.handle.net/10589/683