TY - JOUR
T1 - Characterisation of strain-induced precipitation behaviour in microalloyed steels during thermomechanical controlled processing
AU - Gong, Peng
AU - Palmiere, Eric J.
AU - Rainforth, W. M.
PY - 2017/2
Y1 - 2017/2
N2 - The temperature at which thermomechanical controlled processing is undertaken strongly influences strain-induced precipitation (SIP) in microalloyed steels. In this study, the recrystallisation-precipitation-time-temperature curve was simulated to determine the full recrystallisation temperature, recrystallisation-stop temperature and the temperature where precipitation would occur at the shortest time. The calculated temperatures were verified by experimental testing for rolling between 1100 °C and 850 °C. On the basis of this a finishing deformation of 850 °C was chosen in order to maximise the precipitate number density formed in a fully unrecrystallised austenite. The orientation relationship between the SIP in austenite, and subsequent transformation to ferrite was identified by calculation from the coordinate transformation matrix, and by electron diffraction in the transmission electron microscope. The NbC formed as coherent/semi-coherent precipitates in the austenite, and remained coherent/semi-coherent in the ferrite, indicating a Kurdjumov-Sachs orientation relationship between the austenite and ferrite on transformation.
AB - The temperature at which thermomechanical controlled processing is undertaken strongly influences strain-induced precipitation (SIP) in microalloyed steels. In this study, the recrystallisation-precipitation-time-temperature curve was simulated to determine the full recrystallisation temperature, recrystallisation-stop temperature and the temperature where precipitation would occur at the shortest time. The calculated temperatures were verified by experimental testing for rolling between 1100 °C and 850 °C. On the basis of this a finishing deformation of 850 °C was chosen in order to maximise the precipitate number density formed in a fully unrecrystallised austenite. The orientation relationship between the SIP in austenite, and subsequent transformation to ferrite was identified by calculation from the coordinate transformation matrix, and by electron diffraction in the transmission electron microscope. The NbC formed as coherent/semi-coherent precipitates in the austenite, and remained coherent/semi-coherent in the ferrite, indicating a Kurdjumov-Sachs orientation relationship between the austenite and ferrite on transformation.
KW - microalloyed steel
KW - recrystallisation-precipitation-time-temperature curve
KW - strain-induced precipitates
KW - orientation relationship
UR - http://dx.doi.org/10.1016/j.matchar.2016.12.009
UR - https://www.scopus.com/pages/publications/85006765790
U2 - 10.1016/j.matchar.2016.12.009
DO - 10.1016/j.matchar.2016.12.009
M3 - Article
SN - 1044-5803
VL - 124
SP - 83
EP - 89
JO - Materials Characterization
JF - Materials Characterization
ER -