Strain control during high speed tensile testing

Mechanical properties of transition-induced plasticity steels depend on the possible variations in the complex microstructures, such as the shape, volume fraction, stability, and chemical composition of retained austenite. The effect of retained austenite stability on martensitic transformation is important, and can be evaluated in low strain rate testing conditions by stopping the deformation during testing. However, it is much more difficult to stop the test during a high speed dynamic tensile test. Hence, it was necessary to develop a method to stop a test during high speed deformation. An instrument was designed to attach to the sample to limit the strain during high speed tensile test and the applicability of the system was evaluated over the strain rate range of 10(-2) to 10(2) s(-1). This instrument was found to be successful in allowing controlled amounts of tensile strain to be imparted to a specimen under dynamic test conditions.