Effect of annealing time and cooling methods on the microstructure and mechanical properties of Fe-28Mn-2.8Si-2.2Al-TWIP steel

The effect of annealing time and cooling methods on the microstructure and mechanical properties of Fe-28Mn-2.8Si-2.2Al-TWIP steel was studied by optical microscopy and electron backscatter diffraction technology. It is found that when the annealing time is 5,10 and 20 min,the austenite grains grow quickly. At the same time,annealing twins in the austenite grains get long and thick,the tensile strength and yield strength decrease,but the change in elongation is little. Compared with air cooling,water cooling is more advantageous for the TWIP steel to obtain good mechanical properties,and the cooling rate has a certain effect on the grain orientation.