An investigation into the mechanical behavior of a new transformation-twinning induced plasticity steel: Fid-Bau Portal

An investigation into the mechanical behavior of a new transformation-twinning induced plasticity steel

Eskandari, Mostafa / Zarei-Hanzaki, Abbas / Marandi, Ali

Highlights ► Effect of compression temperature on mechanical behavior of a new microalloyed TRIP/TWIP was clarified. ► TRIP and TWIP effects coexist in this 21Mn steel from 25 to 150°C and TWIP effect merely observed up to 1000°C. ► The occurrence of TWIP effect at high temperatures is a first-time observation in TWIP steels. ► The probable mechanisms of observed deformation twinning have been discussed.

Abstract In recent years, the transformation-induced plasticity (TRIP) and twinning-induced plasticity (TWIP) steels have been the focus of great attention thanks to their excellent tensile strength-ductility combination. Accordingly the mechanical behavior of an advanced microalloyed TRIP–TWIP steel, the compression tests were conducted from 25 to 1000°C. This experimental steel shows a high compressive strength of 1280MPa with the yield strength of 385MPa as well as an outstanding strain hardening rate of about 14,000MPa at the 25°C. In addition the results indicate that the plastic deformation in the range of 25–150°C is controlled by both the strain-induced martensite formation and mechanical twinning. However the mechanical twinning has been speculated as the only deformation mechanism in the temperature range of 150–1000°C. This as well has led to an outstanding grain refinement via grain partitioning. The occurrence of mechanical twinning at such high temperatures is a novel observation in this grade of TRIP–TWIP high manganese steels.