  The corrosion property of Nickel-titanium (NiTi) shape memory alloy is
investigated during forward martensitic transformation between 40C and 0C. The
Differential Scanning Calorimetry technique is used to find the forward and
reverse martensitic transformation temperatures. NiTi shows the present of
martensitic phase at near room temperature by cooling from 80C. The change in
corrosion behavior is monitored by electrochemical Open Circuit Potential (OCP)
during phase transformation. Cyclic potentiodynamic polarization method is used
to identify the corrosion compound of NiTi. Corrosion rate at each temperature
extracted from polarization data and activation energy for corrosion reaction
in martensite and austenite phase are calculated based on an Arrhenius relation
between corrosion current density and reciprocal temperature.
