Properties of TRIP/TWIP steel with different aluminium levels upon annealing

This paper deals with heat treatment of a manganese TRIP/TWIP steel containing various aluminium levels. Two heats were made with identical chemical compositions, apart from different aluminium levels: 0.4 and 1.4 wt. %. Cold-rolled sheets were made using a route in which the last forming operation involved 40 % reduction, and then annealed. The annealing times were 1, 2, and 3 hours. On the specimens taken from the annealed sheets, microstructures were examined and grain size, phase fractions and hardness were measured. These results were compared between the two heats to identity the impact of the aluminium level on properties of this steel. In addition, the results were compared with the data for the initial condition of the materials.