Deformation and fracture behaviour of high manganese austenitic steel

In this work, the deformation behaviour of high manganese austenitic Hadfield steel sheet samples was studied under uniaxial tensile test conditions. The tests were performed at various strain rates and temperatures to examine the effect of strain rate and microhardness on the strain hardening and formability of sheet samples for production of bullet-proof helmets. The effect of temperature on the tensile behaviour and fracture appearance was also studied using the scanning and transmission electron microscopes. It was found that deformation twinning and dynamic strain ageing phenomena are responsible for work hardening of the steel. The results also showed that steel sheet samples exhibited negative strain rate sensitivity and their hardening capacity decreased at 300–400 °C without the formation of strain induced transformation phases.