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

摘要

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℃. This experimental steel shows a high compressive strength of 1280 MPa with the yield strength of 385 MPa as well as an outstanding strain hardening rate of about 14,000 MPa at the 25 ℃. In addition the results indicate that the plastic deformation in the range of 25-150℃ 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℃. 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.