Uncoupling the Effects of High Strain Rate and Adiabatic Heating on Strain Induced Martensitic Phase Transformations in a Metastable Austenitic Steel

Abstract

Background

The adiabatic temperature increase at high strain rates can affect the martensitic phase transformation, but the strain rate itself may also play an important role in determining the rate of phase transformation. To date, no systematic work has been carried out to investigate and isolate the effects of strain rate and adiabatic heating on the deformation-induced α′-martensite transformation.

Objective

Uncoupling the effects of high strain rate and adiabatic heating on strain induced martensitic phase transformations in a metastable austenitic steel.

Methods

Strain incremental experiments were carried out with a designed strain control fixture to assess the effect of strain rate effects on phase transitions. The effect of adiabatic heating of the specimens on the phase transformation is assessed by comparing interrupted and incremental tests.

Results

The results of the strain increment experiments indicate that the increase in strain rate has an inhibitory effect on the phase transformation. Comparing the interrupted and incremental tests, the results show that the adiabatic temperature rise inhibits the phase transformation of martensite.

Conclusion

The decoupling of the strain rate and adiabatic temperature increase on α′-martensite transformation was successfully realized by effectively reducing the adiabatic temperature rise of the samples by adopting the strain increment test method during the high strain rate application process.