Effect of Magnetic Fields on Martensitic Transformations in Alloys with a Paramagnetic to Antiferromagnetic Transition in the Austenitic State

Tomoyuki Kakeshita, Hiroo Shirai, Ken'ichi Shimizu, Kiyohiro Sugiyama, Kimikazu Hazumi, Muneyuki Date
1988 Transactions of the Japan Institute of Metals  
which exhibit a paramagnetic to antiferromagnetic transition in the austenitic state, has been examined by means of differential scanning calorimetry, magnetic field susceptibility and magnetization measurements and optical microscopy, applying a pulsed ultra high magnetic field. As a result, it was found that the martensitic transformation was not thermally induced in all the alloys even at liquid helium temperature, but it occurred under magnetic fields higher than a critical one only in the
more » ... lloy with 4.5 at%C. The critical magnetic field vs temperature relation in the 4.5 at%C alloy showed a C-curve, being largely different from that for all the ferrous alloys previously examined. Irrespective of the formation temperature, the amount of magnetic field-induced martensites was dependent on the strength of magnetic field near the critical one, but was independent on a little higher magnetic fields. Morphology of the magnetic field-induced martensites was the same irrespective of the formation temperature. Thermodynamic analysis suggested that an antiferromagnetic short range order which exists in the paramagnetic austenite suppressed the martensitic transformation.
doi:10.2320/matertrans1960.29.553 fatcat:3nnrbjz2tzggniyd7vurqf76nu