Effect of annealing temperature on microstructure and mechanical properties of TRIP590 steel

The effects of inter critical annealing temperature on microstructure and mechanical properties of a TRIP590 steel were investigated. The results show that the volume fraction of ferrite firstly decreases and then increases with annealing temperature increasing, but the average grain size of ferrite always decreases. The volume fraction of retained austenite and C concentration in austenite both reach a minimum value at 820°C as annealing temperature increases from 780°C to 860°C. The annealing temperature has little effect on tensile strength, while the yield strength increases slightly with increasing annealing temperature. The minimum value of elongation occurs for the steel annealed at 820°C, and the elongation reaches the maximum value at 860°C.