Journal article
Isothermal martensite formation at sub-zero temperatures
Sub-zero treatment of steels with an M1 below 0°C relies (partly) on a continuation of the martensite formation. The present work reports on the observation of isothermal martensite formation in the sub-zero temperature regime for two steels: AISI 1070 and AISI 52100. Samples were austenitized, quenched in oil, and thereafter investigated with vibrating sample magnetometry, which allows a quantitative assessment of the fraction of retained austenite as a function of the sub-zero temperature and time.
Isothermal martensite formation was observed on interrupting the continuous cooling (5 K/min) at temperatures in the range of 80-233 K. The kinetics of isothermal martensite formation depends strongly on the temperature and can be described by Johnson-Mehl-Avrami-Kolmogorov kinetics. Isothermal experiments with dilatometry indicated the occurrence of a volume increase on isothermal holding, consistent with a continuation of the martensitic transformation.
On prolonged isothermal holding, a volume reduction was observed for AISI 52100, but not for AISI 1070. Copyright © 2011.
Language: | English |
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Year: | 2011 |
Pages: | 103459 |
ISSN: | 1546962x |
Types: | Journal article |
DOI: | 10.1520/JAI103459 |
ORCIDs: | Hansen, Mikkel Fougt and Somers, Marcel A. J. |