Biaxial tests on Sandvik Nanoflex

Sandvik Nanoflex (ASTM-A 564) is a metastable steel that undergoes strain induced martensitic transformation during a mechanical deformation process. The aim of the experiments is to observe the transformation by recording the amount of martensite via a magnetic sensor. The physics underlying the process suggests that although transformation proceeds with plastic straining, the stress-state should have a big influence on its rate. Additionally, the Magee theory on martensitic variants states that transformation proceeds as different variants become energetically favorable. Hence, it remains a question how the material will behave upon a sudden change in the imposed stress-state since the number of favoured variants is expected to change abruptly. Therefore, making use of the biaxial setup a series of stress states and strain paths are imposed on the material and the effects on transformation rate are observed.